Our oral pharmaceutical product is packaged by a range of contract packaging companies. Adverse properties of the final packaged product from one particular company indicate that the product shelf life is shorter than it should be. It has been suggested that this could be related to gas filling issues. Is this anything that surface analysis could clarify?

This could certainly be the case — gas contamination and compositional errors are an increasingly common issue, particularly in the pharmaceutical industry where gas-filled packaging is frequently used. However, 'could' is no good when your product and, ultimately, your profits are suffering. Clarification is required. 

The particular value of surface analysis in this scenario is in identifying the correct course of further investigation to avoid costly and unnecessary testing procedures.  

Pharmaceutical packaging can be for powder, liquids, tablets, capsules, creams and gels, and is generally more sophisticated than packaging for other industry sectors. 

High-barrier packaging, such as gas-filled packaging,

maintains the atmosphere within the packaging, but this atmosphere must be modified to provide a long product shelf life. This is achieved in one of two ways: vacuum packing or gas flush packaging. It is the second method that concerns us.  

Gas flush packaging reduces the amount of oxygen surrounding the drug to slow or eliminate the growth of aerobic life forms, which increase the rate of oxidation reactions. Often, the displaced oxygen is replaced with nitrogen, carbon dioxide or sometimes argon. The gas composition of an average blister-packed pharmaceutical product, for example, would contain less than 1% oxygen compared with the 21% typically found in air. 

Pharmaceutical products that show signs of oxygen or moisture attack often indicate atmospheric issues in the packaging itself. Unfortunately, spotting these symptoms is not always straightforward, and without definitively identifying the root cause as being atmospherically related, the resolution remains unclear.  

This is where surface analysis techniques can be invaluable. While some harmful effects caused by atmospheric issues can be observed visually, such as discolouration, most are much less obvious and can only be confirmed using extremely sensitive analytical equipment. As an example, one of the most common side-effects of atmospheric interference is a change in surface morphology. Differences in the surface contact area can interfere with engineered dissolution rates and affect the speed of absorption 

. Topographical changes at the surface of the pharmaceutical, or simply a change in roughness, can easily be demonstrated using noncontact surface profiling (3DP), where changes at the submicron level can be monitored.  

Sometimes chemical changes at the drug surface occur because an unprotected pharmaceutical product undergoes surface chemistry oxidation or hydration. Once again, surface analysis techniques are the ideal identification tools; for example, x-ray photoelectron spectroscopy (XPS) offers quantified data on elemental and oxidation state changes within the top 5–8 nm of a surface. The technique not only enables the overall level of oxygen (as combined in oxygen-containing groups) at the surface to be measured, but can also differentiate between the form of the oxygen — such as whether it is present as an acid, carbonyl, ester or alcohol. Figure 1 shows XPS technology in action. 

Whereas XPS provides quantified data, time-of-flight secondary ion mass spectrometry (ToFSIMS) provides detailed molecular information from the outer 1–2 nm, enabling unequivocal fingerprinting of drug molecular ions, excipients and any modified contaminants or modified species. One demonstrable example of the technique in practice is 'blooming'. Oxygen attack, caused by atmospheric issues in packaging, often results in 'blooms' occurring at the drug surface. By taking repeated measurements from the drug surface to the sample subsurface, ToFSIMS can differentiate between blooming caused by oxidation and a straightforward contamination of the external surface. 

Additionally, scanning electron microscopy can be used to analyse the physical form of the 'bloom' crystals to identify how they formed. In the case of atmospheric problems, material at the drug surface is likely to have been dissolved and then slowly recrystalized because of water vapour ingress. 

Using the techniques outlined previously provides a clear picture of the form of attack the drug surface has suffered. The amount of tests available to troubleshoot potential product lifespan problems is immense, but with our data a likely candidate can be identified and the correct form of further analysis can be selected. In the case of atmospheric related symptoms, this further analysis usually takes the form of residual gas analysis (RGA). This technique has recently been refined for pharmaceutical packaging gas analysis (PPGA) to allow intact pouches or blister packs to be studied. Similarly, modified RGA analysis can also be used to study entrained bubbles of contaminated gas to identify a likely contamination source.  

Taking its routes from secondary ion mass spectrometry, PPGA enables the residual gas from sealed packaging or glass bubbles to be leaked in a controlled manner into the residual gas analyser (Figure 2). 

Figure 2: Detail of fracture chamber and pumping arrangement.

 fracturing of samples is based on a modified ultra high vacuum (UHV)

valve assembly where the central sealing spindle is replaced by a diamond-tipped shaft. This shaft is mechanically driven by rotation of the valve assembly, bringing the diamond tip into contact with the surface of the sample (Figure 3). Increasing the pressure on the tip causes rupturing of the sample with resultant release of the internal atmosphere into the evacuated chamber. An UHV leak valve is then used to bleed the gas into the main instrument chamber for mass spectral gas analysis. 

Figure 3: Glass bubble trial sample mounted for fracturing. 

Returning to the specific query outlined at the beginning, the benefits of combining analytical techniques are two fold. By using the initial surface analysis techniques to identify the specific symptoms demonstrated by the drug, the field of potential causes is significantly narrowed.  

In turn, appropriate further action can be taken more quickly and with less risk of wasted effort. From a business perspective, this means that lifespan issues are likely to be resolved faster, without the expenses of unnecessary extensive testing. 

Figure 4: Mass spectrum from gas-filled packaging. 

In effect, surface analysis provides the key to unlocking the correct door to a solution, and can make a big difference to profit lines and continued production. 

 joined CSMA in 2005 as a Technical Sales Consultant. She promotes the features and benefits of surface analysis techniques to a range of sectors and disciplines, providing valuable advice on troubleshooting and on delivering analytical solutions for commercial applications, including successful product development and reverse engineering. 

If you have any questions for the experts at Surface Surgery then please send an email to 

Articles

Surface Surgery

Gas-filled packaging problems

When drugs are encapsulated, electrification (the electrostatic charge of the capsule) may sometimes cause problems, such as capsule adhesion during transportation or dispersion of the capsule content in the filling process. In this article, the electrification of gelatin and nongelatin capsules is examined. 

Polyvinyl alcohol (PVA) copolymer capsules are a form of nongelatin capsule under development. PVA, acrylic acid (AA) and methyl methacrylate (MMA) are used as raw materials. As previously reported, these capsules have advantages, such as low gas permeability, and can be particularly suitable for encapsulation of hydrophilic solvents, such as polyethylene glycol (PEG) 400, and surfactants.

  Using such capsules facilitates the formulation of insoluble drugs and is expected to enhance bioavailability. 

The electrostatic characteristics of PVA copolymer capsules were determined using gelatin and nongelatin (hypromellose (HPMC)) capsules as controls. After, the stability of a PVA copolymer capsule preparation of indomethacin (IND) solution was examined as a model of an insoluble drug preparation. In addition, the bioavailability of a sparingly water-soluble drug, acetaminophen, and a practically water-insoluble drug, nifedipin (NF), in both gelatin and nongelatin capsules was evaluated by administering the preparations to Beagle dogs. 

It is well known that electrification of capsules has different characteristics depending on the raw material of the polymer compound used. Low electrification is desirable and there have been many cases where an antistatic agent was used to reduce capsule electrification. The electrostatic characteristics of three types of capsules were determined. 

Measurement of electrification using the Faraday cage method. 

Approximately 2–3 g of each capsule type was measured out and placed in a Faraday cage (Advantest; Tokyo, Japan). The amount of triboelectricity generated by the capsules was measured with a digital multimeter (Advantest) and the specific charge electrification (nC/g) was calculated (Table 1). Of the three capsule types, the gelatin and HPMC capsules showed high electrification values with positive electricity. In contrast, the PVA copolymer capsule had the lowest electrification value with negative electricity. 

Table 1: Specific charges for the three capsule types per 1 g. 

Measurement of surface potential charges after generation of triboelectricity. 

Approximately 10 g of each capsule type was measured out, placed in a tablet friability tester. (Tsutsui Rikagaku Kikai; Tokyo, Japan). Triboelectricity was generated for 1 min and the surface potential charges of 20 randomly selected capsules were then measured using a surface charge electrometer (Model 1279, Monroe Electronics; NY, NY, USA) 5 and 10 min after the start of the test (Figure 1). 

Figure 1: Surface potential charge for the three capsule types. 

The gelatin capsules gained the most charge and were characterized by positive electrification. Additionally, their surface potential did not decrease easily. HPMC capsules are known to have less water content (~3%) than gelatin capsules (~15%) and their electrification tends to be lower. This tendency was confirmed in these experiments. However, the HPMC capsules showed a high level of surface potential, even after 10 min, and the charge tended not to attenuate easily. This phenomenon is considered to be a result of the low moisture content of the capsules. 

The PVA copolymer capsules displayed the lowest level of electrification, as well as a negative charge. After displaying a surface potential charge of ~ –500 V immediately after electrification, the capsules attenuated toward 0 V, proving that these capsules are characterized by easy attenuation of the surface potential charge.  

The attenuation of the surface potential charge of the capsules was affected by the functional groups of the raw materials and their polymeric structure. The PVA copolymer capsules are not easily electrified and show easy attenuation of any electricity that is generated. 

In contrast with gelatin and HPMC capsules, it has been proven that PVA copolymer capsules are compatible with PEG 400, Tween 80 and LABRASOL.

  In a further experiment, the stability of a liquid preparation of insoluble PEG 400 encapsulated in PVA copolymer capsules was evaluated. 

 A PVA capsule of size 0 was filled with 625 mg of PEG 400 solution containing 25 mg of IND and band-sealed. 

 The encapsulated sample was placed in an airtight Lamizip AL (Seisannipponsha Ltd; Japan), a heat-shielded PET/AL/PE multilayer film bag, and an accelerated stability test was performed at 40 °C and 75% relative humidity. No appearance changes, leaks or softening were observed after 1, 2 and 3 months of storage. The encapsulated solution was collected from the capsule and its water content was measured according to the Karl Fischer's method. It increased only slightly on storage, but this did not influence the drug dissolution rate (Figure 2). 

Figure 2: Change in water content of the encapsulated solution. 

The dissolution testing of the capsule preparation was conducted using Japanese Pharmacopoeia (JP) Apparatus 2 (Toyama Sangyo Co., Ltd; Osaka, Japan [paddles]) at 50 rpm in water and two test solutions (first and second fluids for the dissolution test of JP). IND concentration was assayed using ultraviolet (UV) absorbance at 320 nm. Figure 3 shows that IND dissolved quickly in water and in the second fluid. The dissolution rate for all of the capsule preparations at 15 min was ~100%. However, in the first fluid only 90% of the drug was released. This is considered to be a result of decreased solubility of IND in acid. No effect of storage on drug dissolution was found in any of the fluids. 

Figure 3: IND release rate from a solution filled into a PVA copolymer capsule. 

Administration of an encapsulated powder form of a water-soluble drug

 Size 1 gelatin, HPMC and PVA copolymer capsules were filled with 250 mg of a mixture containing 150 mg of lactose powder mixed with 100 mg of AA. 

 The drug dissolution testing of each capsule was evaluated according to the 

Guideline for Bioequivalence Studies of Generic Products

 using the JP Apparatus 2 (paddles) at 50 rpm in water, 25% McIlvaine buffer solution (pH 5.5, 6.5) and two test solutions (the first and second fluids for the dissolution test of JP). The AA concentration in the fluids for the dissolution test of JP was assayed using UV absorbance at 245 nm. 

Figure 4: AA release rate from a capsule preparation in various test solutions. 

AA encapsulated in the gelatin, HPMC and PVA copolymer capsules dissolved quickly in the dissolution test solutions. In addition, as the difference in the dissolution rates after 15 min was within ±10% among all the capsules, they were deemed to be equivalent (Figure 4 and Table 2). 

Table 2: AA release rate* from a capsule preparation in various test solutions (%). 

 Animal studies were performed using Beagle dogs (6 dogs; all male; aged 1–2 years; weight 10–11 kg; the same individual used in all tests) with a drug-free period of <1 week between tests. 

The capsules were administered orally under fasting and nonfasting conditions, and AA concentration in plasma was assayed by HPLC — as reported previously — before and after 0.25, 0.5, 1.0, 1.5, 2, 3, 4 and 6 h after administration.

  The AA plasma concentration profile is shown in Figure 5. 

Figure 5: AA blood concentration curve upon administration of the three capsule types filled with 100 mg AA to Beagle dogs (n=56). 

 (time to the maximum drug concentration) were measured from AA plasma concentration data and the area under the curve (AUC) was calculated according to the trapezoid method. The difference among the preparations on each parameter was evaluated by the paired t-test (Table 3). There was no significant difference (p>0.05) between the capsules in each pharmacokinetic (PK) parameter, and the gelatin and nongelatin capsules filled with AA, which was used as a model of a water-soluble drug, were deemed to be biologically equivalent. 

Table 3: PK parameters upon administration of the three capsule types filled with 100 mg AA to Beagle dogs (n=56). 

Administration of an encapsulated insoluble drug formulation

 100 mg of a 150 mg mixture containing 140 mg of lactose mixed with 10 mg of NF was placed in a size 1 gelatin capsule and used for the dissolution test. In animal studies, a capsule filled with 150 mg of mixture containing 120 mg of lactose mixed with 30 mg of NF was used to ensure adequate absorption. In addition, 0.5 mL of a PEG 400 solution containing 10 mg NF was encapsulated in a PVA copolymer capsule to form a band-sealed liquid formulation. 

 Drug dissolubility from the three capsule preparations was evaluated using JP Apparatus 2 (paddles) at 50 rpm in water and the first fluid for the dissolution test of JP. The NF concentration in the fluid for the dissolution test of JP was assayed using UV absorbance at 238 nm. 

The dissolution profile is shown in Figure 6. Dissolution of NF from the PVA copolymer capsule filled with NF/PEG solution in the first fluid and in water was ~100% after 15 min, similar to the drug dissolution rate without a capsule. Conversely, the dissolution of NF from the gelatin capsule filled with powder was significantly delayed (<40% in 45 min). 

Figure 6: Drug release from preparations containing NF 10 mg. 

 A solution containing 10 mg of NF, a PVA copolymer capsule preparation of the solution containing of 10 mg of NF, and a gelatin capsule preparation of the powder containing 30 mg of NF were administered orally to fasting Beagle dogs. The NF concentration in plasma, as reported previously, was determined before and after 0.5, 1.0, 2.0, 3.0, 4.0, 6.0 and 8.0 h after administration and was assayed using HPLC-ECD.

  The solution was administered directly to the stomach 

The NF plasma concentration profile is shown in Figure 7 and the PK parameters are shown in Table 4. There were no significant differences in PK parameters between the encapsulated and non-encapsulated solutions (p>0.05). In addition, when the solution preparation and the powder preparation were compared taking the difference in NF doses into consideration, the former was found to be improved approximately 6-fold in terms of C

 and approximately 3-fold regarding AUC. 

In terms of bioavailability, PVA copolymer and HPMC capsules should be treated as equivalent to the widely used gelatin capsules (Figure 5 and Table 3). In addition, PVA copolymer capsules enable encapsulation of hydrophilic solvent, which makes insoluble drugs dissolve, formulations (Figure 7 and Table 4). These solution preparations were confirmed to enhance bioavailability when administered to Beagle dogs. 

Figure 7: NF blood concentration curve after administration of the NF preparations to Beagle  dogs (n=56). 

PVA copolymer, which is a new pharmaceutical agent, completed safety studies based on the relevant guidelines and was registered in the FDA Drug Master File in 2006. 

Table 4: PK parameters upon administration of the NF preparations to Beagle dogs (n=56). 

These PVA copolymer capsules have various advantages compared with traditional gelatin capsules, such as low water content, low electrification level and the capability of filling with hydrophilic solvent, and are expected to facilitate the development of new drug formulations in the future. 

 was Manager of Technological Research at the Research & Development Group, Nisshin Kasei Co., Ltd (Japan).

 is a reseacher at the Research & Development Group, Nisshin Kasei Co., Ltd (Japan).

 is Head of Oral Solid Formulation at CMC Development Laboratories, Shionogi & Co., Ltd (Japan).

 is Scientist, Oral Solid Formulation at CMC Development Laboratories, Shionogi & Co., Ltd (Japan).

Dosage Forms

When drugs are encapsulated, electrification (the electrostatic charge of the capsule) may sometimes cause problems, such as capsule adhesion during transportation or dispersion of the capsule content in the filling process.

Creating PVA copolymer capsules

On 7–9 May I attended ERBI's Biopartnering Exchange in Cambridge (UK), an event that brought together national and international entrepreneurs, senior executives and industry experts of the biotechnology sector. 

As 2008 was ERBI's 10th anniversary they really pushed the boat out: we enjoyed talks by Nobel Prize winners, Professors and one or two Sirs, and were treated to a fabulous firework display.  

From where I was sitting, the meeting was hugely successful: the sessions were interesting, informative and entertaining, and the hectic biopartnering schedule saw many delegates trying to fulfil their extremely busy timetables yet maximize the quality of the time spent meeting potential clients and investors. 

A very insightful session was chaired by Andy Richards, who invited four key players in the industry to discuss their experiences and reminisce about the good, the bad and the sometimes ugly days that have helped shape their careers. It was also very refreshing to hear Clive Cookson, Science Editor of the 

, encouraging researchers and scientists to engage with the press and talk to journalists. Simultaneously, he called for the media to focus on the relevance of the information provided and not its entertainment value when reporting scientific developments.  

And there was debate too! There seemed to be strong disagreement among the different experts with regard to funding availability (i.e., venture capitalists or VCs) and the future of the biotechnology sector. While some asserted that there are no funds and many small companies, unviable in their view, should disappear, others maintained that although a proportion of VCs appear to have vanished into thin air, there is still money, room for investment and will to aid start-up private companies. However controversial this may be, it is a sign that all parties (industry, academics, investors) are still passionately trying to steer any developments in the biotechnology sector in the right direction. 

But my favourite moment of the event has to be Professor Sir Christopher Evan's presentation. Among many incisive comments, whacky slides and clever quotes, the concluding statement "I'd rather be a tiger for one day than a sheep for 100" was the icing on the cake. It is a very romantic notion indeed, but one that, I fear, remains quite invalid as a business model. It makes, however, for wonderful life ethics... 

On 7–9 May I attended ERBI's Biopartnering Exchange in Cambridge (UK), an event that brought together national and international entrepreneurs, senior executives and industry experts of the biotechnology sector.

A tiger for a day!

Drug products subjected to degradation because of environmental stresses can be salvaged if proper packaging and protection is provided by sorbents. By the time the drug product is handed from the formulation chemists to the packaging engineers, mechanisms of degradation, such as hydrolysis, oxidation, dehydration, isomerization, racemization, elimination and photodegradation, are usually known. It is then up to the packaging engineers to plan a 'defence' against these degradation pathways.  

In accordance with various regulatory guidelines, stability studies are required to prove that a drug will maintain its physical and chemical characteristics during a given time frame (expiration dating) to ensure the safety, identity, strength, quality and purity of the medicines. The International Conference on Harmonisation (ICH) has published a widely known guidance document regarding the outline of such stability studies.

Whether dealing with a new drug application for innovators or an abbreviated new drug application (ANDA) for generics, time is money and quickly bringing a quality product to market is key. This is particularly true for generic companies filing ANDAs for reference listed drugs, as they are in competition for the 180-day exclusivity provisions set forth by the Hatch-Waxman Amendments to the Federal Food, Drug and Cosmetics Act.

Many modern drug substances and products are susceptible to environmental humidity, and may physically or chemically degrade, or lose potency and efficacy when exposed to atmospheric moisture. Although higher barrier packaging can combat this issue, it is often cost-prohibitive compared with less expensive packaging solutions, such as high-density polyethylene (HDPE) bottles and incorporating sorbents. 

Historically, basic calculations were made for products requiring a sorbent regarding sorbent selection for registration stability lots. A sorbent-ranging study was performed prior to this to determine whether or not the desiccant recommended and its quantity were correct. Performing these additional characterization tests, such as dissolution, assay and degradant monitoring, takes time and money. 

Our goal was to eliminate sorbent-ranging studies or 'guesswork' by creating a predictive model of moisture permeation and adsorption to determine the appropriate sorbent and its amount to achieve shelf-life targets for given pharmaceutical formulations and dosage forms. 

A pseudo-empirical modelling programme has been developed by Multisorb Technologies to mathematically predict the stability outcomes of testing. No model can truly replace empirical testing, but the programme decreases excessive testing, and demonstrates and predicts the effects of the selected packaging and its incorporated sorbents. The model predicts the internal conditions of a drug product package based on a given set of external conditions and selected input criteria. This modelling is based on the integration of internal and external equilibrium relative humidity (ERH) conditions with time, and the adsorption profiles/isotherms of the desiccant and drug product. 

One of the assumptions necessary regarding the dynamics of permeation and adsorption was that, at any given time, the system inside a package is in a state of equilibrium: Φin=ERH

Each component, i (i=D, 1, 2, 3,...) inside the bottle has its own sorption isotherm, Si(Φ) (Figure 1). 

Figure 1: A typical bottle container system. 

The water vapour transmission rate (WVTR) of the bottle is measured at some known humidity difference (ΔRH) between internal and external environments: ΔRH=Φ

A simplified picture of permeation and adsorption is considered:  

The RH outside the bottle is constant, as is the case with stability testing.

Moisture permeation through container/package surface area is relatively slow, allowing for fairly rapid equilibration and an uniform ERH of all components.

Quasi steady-state pattern of permeation through the bottle wall is present.

Package WVTR is linearly scalable with ΔRH between separated environments, which is the case with many polymers including polyolefins.

The methodology follows a mass balance of moisture inside the bottle, including the moisture in the headspace air (typically minimal as can be calculated using psychrometric equations) and in each solid component such as drug product and sorbent. The model is isothermal with T(t)=constant. The sorption isotherms, Si(Φ), and density of saturated water vapour in air are obtained at a specific environmental temperature, T. The initial ERH of the package system is determined from the initial RH of all packaged components and atmospheric air at the time of package sealing. Through a series of mathematical operations and integrations, the time, t, to reach a given ERH, Φ, within the package is found. Consequently, the rate of water vapour ingress is controlled by the WVTR of the package material and the sorption capacity of the components within the packaging system. As the internal ERH of the bottle increases, the ΔRH between the inside of the package and the external conditions decreases, and the rate of moisture permeation through the package surface area decreases. 

Moisture can play a critical role in solid-state degradation. There are two kinds of water potentially present in a given drug product: bound water and 'free' or 'available' water.

  Bound water (i.e., water of crystallization) is an integral part of a molecule and may not be available for chemical activity. The energy of activation required to release this moisture is not usually achieved by solely lowering the RH or adding a desiccant. Unbound or 'free' water is loosely held by powder particles and available for chemical activity. The energy of activation required to release this moisture can be achieved by lowering the RH or adding a desiccant. 

Water content is an extensive property of a given material. The quantitative measurement of water is typically performed by Karl Fischer titration, near-infrared spectroscopy or loss on drying (LOD). Karl Fischer titrations have dominated the measurement of water in pharmaceutical products for many years.

  "The Karl Fischer method measures surface moisture (unbound moisture) and most types of bound moisture. For some products, this means that the Karl Fischer method will measure more moisture than the gravimetric method."

×100 and expressed as a percentage) is derived from the fundamental principles of thermodynamics and physical chemistry. a

 is an intensive property of a material and a qualitative measurement of the energy status of water in a system determined by equilibrating the liquid phase water in the sample with the vapour phase water in the headspace and measuring the RH of the headspace.

can be correlated by analysing the adsorption/desorption isotherm of a material. Sorption isotherms delineate a substance's affinity for moisture at varying RH and temperature. 

By determining the water content and water activity of a product and generating temperature-dependent sorption isotherms for all components in a package system, it is possible to model the internal conditions of the package system with time given constant external temperature and RH conditions. The entire package, including drug product and desiccant, acts as a complete system and will reach equilibrium with time. For packaging configurations that exclude desiccants, the moisture that ingresses through the bottle with time is adsorbed only by the drug product and evidenced by a higher ERH within the bottle during the stability testing time. For packaging configurations that include a desiccant, the desiccant will first adsorb moisture within the headspace (minimal). Because of the adsorption characteristics of the drug product 

 the desiccant, the desiccant will adsorb moisture from the drug product. The drug product in proximity to the desiccant will desorb or transfer moisture in a shorter period of time than the drug product located further away from the desiccant. The moisture that ingresses through the bottle with time will be adsorbed by the drug product and desiccant according to their respective sorption isotherms. 

A pharmaceutical company asked for recommendations for a specific drug product that was experiencing degradation with time. In total, 30 tablets were examined. The drug product samples were representative of the physical and chemical characteristics as would be at the time of commercial packaging. 

The company achieved acceptable stability results in one package configuration, but an undesired negative trend in another. Therefore, the goal of this evaluation was to provide supporting data for a desiccant recommendation for the one bottle that would most closely mirror that of the other bottle. 

The tablets were weighed on a Model AG245 analytical balance (Mettler-Toledo, OH, USA) and an average weight of 260 mg was obtained with a relative standard deviation of 0.86%. Samples of the product were crushed in a mortar and pestle to obtain a

 of the product at 25 °C and 40 °C using a Series 3TE Water Activity Meter (Decagon Devices Inc., WA, USA). The samples were allowed to equilibrate in the instrument for 15–17 min while continuous readings were taken and a constant value was obtained. Prior to testing, the instrument was calibrated using a LiCl 13.41 molal solution in water. The resultant values are listed in Table 1. 

Accelerated stability testing and real time stability testing are generally performed per ICH-prescribed conditions of 40 °C /75% RH for 6 months and 25 °C/60% RH for the duration of the expiration date label claim (typically 2 years),

  respectively. Recognizing this, water vapour sorption testing of the drug product was performed at 25 °C and 40 °C. Using a symmetrical gravimetric analyser, the water vapour adsorption of the product was characterized from 10% to 90% RH in 10% increments. The water vapour desorption of the product was characterized from 90% to 10% RH in 10% increments. The equilibrium criteria were established such that the weight percent change of the tablet was <0.005% in 10 min or after a period of 300 min as maximum. These parameters defined the conditions necessary to progress from one RH step to the next. The data logging interval was every 2 min or a 0.200% change in weight. 

For each experiment, one tablet was crushed with a mortar and pestle and the entire contents placed onto the weighing pan in the instrument. The samples were preconditioned within the instrument at their respective testing temperatures (40 °C or 25 °C) and <2% RH for a period of time to remove residual moisture and obtain a baseline of water vapour adsorption. The baseline is used to compare the drug product ERH with respect to residual moisture content. The moisture removed from the tablet during the preconditioning process is usually a good indication of how much moisture a desiccant could potentially remove. 

Adsorption/desorption isotherms/profiles were generated at 40 °C and 25 °C. The sorption isotherms for the drug product are illustrated in Figure 2. 

Figure 2: Drug product sorption isotherms at 25 and 40 Â°C. 

The company provided drawings for the bottles utilized for commercial packaging: a 75-cc Blake bottle and a 160-cc wide-mouth Blake bottle. The HDPE resin used to produce the bottles is Marlex HHM 5502-BN, as manufactured by Chevron Phillips Chemical Company (TX, USA). 

The quantity of tablets intended for commercial packaging was 350 in the 160-cc bottle and 30 in the 75-cc bottle. For the stability simulation models of the drug product, the following assumptions and principles applied:  

The water vapour permeability for the Marlex resin is 0.381 g×mL/(100 in

 ×day; nominal value at test conditions of 38 °C/90% RH), and 0.085 g×mL/(10 in

 ×day; nominal value at test conditions of 23 °C/60% RH).

The bottle dimensions and thickness obtained from the drawings were utilized to calculate the approximate surface areas of the bottle and corresponding moisture ingression, excluding the foil induction seal. The inside diameter of the mouth of the bottle and the base-to-shoulder height was utilized for ergonomics of the desiccant (i.e., ability to fit within the bottle).

The reported bottle wall thickness is the minimum wall thickness at midpoint of the bottle. As there was no tolerance for thickness provided on the 160-cc bottle drawing, the worst case minimum value plus 0.25 mm was used in all calculations and simulations. For the 75-cc bottle, it was previously calculated and reported by the company that the average wall thickness was ;0.84 mm. It is noted that variations in the bottle wall thickness are inherent because of the molding process. Thicker portions of the bottle wall will have a lower WVTR than thinner portions and 

. WVTR of the whole sealed bottle can also be measured directly using Illinois Instruments' (IL, USA) series 7000 water vapour permeation analyser.

The actual volume of space within the container that the drug product consumed was unknown. Because the moisture contribution to the system from the headspace of the container is minimal, the total volume in the container was estimated and utilized as void volume.

The bottles maintain a foil-induction seal, and the simulations provided herein account for a steady-state moisture transmission through the bottle and do not account for poor seals, pinholes or thickness variations that could possibly occur in the molding or induction sealing process of the bottle.

There are time constraints and limitations when performing isotherms on drug products in the finished tablet form. To compensate for the relatively short period of time a tablet will be subjected to given conditions within the gravimetric symmetrical analyser, as compared with extended periods of time in a container, the tablet was crushed prior to testing. This method increases surface area and accelerates the adsorption/desorption of the tablet. The reasoning behind this test is that, with extended periods of time (days/months), the moisture available to the tablet will eventually migrate and equilibrate throughout the entire tablet. The isotherms for the crushed tablets were used in all simulations.

Fundamentally, as the adsorption isotherms did not display significant desorption moving from 0% to 10% RH, it was assumed that the drug product was sufficiently dried and a good baseline was established. Therefore, variations in moisture content of the drug product, assuming no chemical changes occurred, would only vary the initial equilibrium RH of the drug product, which was determined by evaluating the isotherm's X and Y axes. Slight variations in moisture content during formulation and/or processing of the drug product will alter the initial ERH slightly, but should not significantly affect the simulations as presented.

The simulations account for steady-state conditions and equilibrium capacity of the drug product and desiccant. The 'initial RH of packaging system' is considered instantaneous. In actuality and not shown in the simulations, the ERH will gradually decrease and then increase with time to the reported 'initial RH of packaging system', similar to a cosine curve. For this reason, the simulations are less accurate during early stages of the testing, and do not account for the lag time in desorption/adsorption of the drug product and adsorption by the desiccant. This is especially true with real-time simulations as the kinetics of the system are slower than those at accelerated conditions. As time progresses and the system becomes more stable and change is more gradual, the predictions become more accurate.

The moisture removal that occurred during preconditioning/drying of the drug products within the instrument during the testing was ~1.15 and ~1.05% at 40 °C and 25 °C, respectively. This corresponded fairly well with the moisture content reported by the company (1.21% and 1.18%). Analysing the respective isotherms in Figure 2, moisture contents of 1.15% and 1.05% approximately equate to an ERH of 29–33%. The ERH is determined by first locating the initial moisture content of the product on the Y-axis of a graphical isotherm and then following the line perpendicular to the Y-axis until the said point crosses the isotherm line. The X-coordinate of this point is determined to be the ERH. Referring to the a

 test results reported for crushed tablets in Table 1 of this report (0.298–0.337), the correlation is reasonable and within acceptable variation. 

The company forwarded actual moisture content results from real-time stability testing of the drug product in 75-cc and 160-cc bottles. The water content measurements determined by LOD at given time points are presented in Table 2 (time in months). 

Table 2: Actual drug product moisture content (real time stability testing). 

As confirmed by the company, the time-point, t=0, was the 'initial' moisture content of the product at the start of stability testing and is not truly the 'release' moisture content of the drug product, as there was a delay between packaging and production of tablets. Also of importance is the fact that the t=0 data was that of the 75-cc bottle for both package configurations; a t=0 was not measured for the product in the 160-cc bottle. 

Considering the aforementioned, the initial moisture content (i.e., the moisture content measured at initiation of stability testing) for the simulations of the 75-cc bottle was considered to be 0.80%. Analysing the actual moisture results on the previous page and considering the moisture content of the product, it follows reason that the 'initial' moisture content of the drug product packaged in the 160-cc bottle would be >0.80%. An average value of 1.13% was utilized for simulations pertaining to the 160-cc bottle configuration. 

The 25 °C isotherm was used for real-time simulations and the 40 °C isotherm was utilized for accelerated simulations. Figure 3 displays the predicted ERH and corresponding drug product moisture content of the 350-count/160-cc bottle and 30-count/75-cc bottle, respectively, packaged with 2 g of silica gel (730 days real-time stability at 25 °C/60% RH). The actual moisture content data relayed by the company (Table 3) was converted to drug product ERH per the 25 °C isotherm and plotted on the graphs. A polynomial trend line was fitted to the data. As can be seen, the simulation's endpoint is very similar to the endpoint of the polynomial trend of the actual data. 

Figure 3: 160-cc versus 75-cc comparison, simulated versus actual data real time  -25 Â°C/60% RH. 

Packaging and Labelling

Drug products subjected to degradation because of environmental stresses can be salvaged if proper packaging and protection is provided by sorbents.

The science behind sorbent selection

Q: You have many years of experience in marketing and business development. What are the most significant changes you have observed in this time?

The old tactics no longer work. There is too much competition vying for attention, and companies need to find new and different ways to rise above the din. For example, partnerships need to be based on substance, action and meaningful mutual commitments. Puff press releases and logo swaps are no longer sufficient, and that sort of superficiality is transparent in every way. Effective marketing depends on a deep understanding of who you're selling to — almost an internalization of their needs and a channelling of their role. High-level, generic messaging is tuned out and dismissed as a generic platitude — it is either ignored or seen as disingenuous. This is forcing us to be better and smarter about the campaigns we run, and how we run them. 

Q: Do you believe this will have a positive effect on the sector?

Absolutely. In many ways, it has made it harder, but it has also forced organizations to think carefully about the message they deliver and how they go to market. From my perspective, it has made marketing and business development more of a chess match — it requires a strategic bias, the ability to adapt to change and a focus on the end game. It has made both the best and the worst examples more conspicuous and it's impressive to see when it's done well.  

Q: Although originally established in Japan, JustSystems has recently expanded to North America and Europe. How do the North American, European and Asian markets compare?

As you would expect, they're quite different. In North America and Europe, there is more competition and a different way of doing things down to the most fundamental level. We've recruited a seasoned group of people who understand these markets very well, and that has really helped to bridge these differences and make market entry successful.  

What are the challenges that the pharmaceutical industry and in particular your sector currently faces?

Pharmaceutical companies face three primary challenges:   

Filling the pipeline with new drug candidates by better identifying viable compounds — largely, a discovery problem of finding needles in haystacks and pattern matching within a massive amount of information. 

Improving process efficiency and technology transfer across phases and between organizations to accelerate time-to-market, pre-empt competitors and take advantage of patent protection that is quickly eroded by commercialization delays. 

Compliance issues, which are the ongoing backdrop of all pharmaceutical functions, from early discovery to clinical trials, manufacturing, labelling and distribution. 

There are systems and partners that can help pharmaceutical companies address each of these challenges.  

Q: How do you see the future of the sector?

I think it will become more challenging. With the growth of global competition and the emergence of generics, pharmaceutical companies need to accelerate the process from discovery to commercialization, and find better ways to grow the pipeline through improved lead generation and unique risk-sharing partnerships and collaborations at various steps in the life cycle. All this is dependent on how information is created, shared, published and maintained, which is why software solutions are so important.  

Q: Do you have any developments in the pipeline?

We're working on solutions to help pharmaceutical, biotech and process manufacturers in general to standardize the creation, transfer and maintenance of batch process definitions. Today, this is done in a very 

 and manual way, which creates the risk of using out-of-date design specifications and parameters. It also slows time-to-market by complicating technology transfer between phases and forcing organizations to rekey vast amounts of information. We have a solution that allows organizations to create reusable and authoritative recipe building blocks that are visually assembled, connected together and expressed as XML, allowing them to be seamlessly imported by plant floor systems and published as dynamic documents for human consumption. This improves the quality and consistency of the batch process definitions that drive manufacturing processes. In turn, this increases the speed and accuracy of technology transfer across life cycle phases.

Inside Out

Jake Sorofman Q&A

Once famous for coal and steel, Wales now aims to make its mark in the life sciences sector. The recent BioWales 2008 (UK) conference demonstrated how much the region has progressed, thanks to the support of the Welsh Assembly government, the EU and the enthusiasm of the Welsh biotech community. The country's bioscience sector, which comprises approximately 200 companies, grew by 18% last year and is now worth £1.3 billion (€1.6 billion) in annual turnover, employing 15–20000 people. 

Addressing more than 400 delegates at the conference, Dr John Patterson, Executive Director for the development of AstraZeneca's new medicines, spoke of the patents that are expected to expire on many of the world's best-selling drugs by 2011, the increasing frequency of patent challenges and the limits of data exclusivity. "Generic erosion is steeper and faster each year," he said. Added to this, the public is increasingly critical of the pharmaceutical industry, while having ever higher expectations. People seem to have bought into an instant gratification mentality; as soon as a gene is discovered, a cancer cure is expected to swiftly follow.  

"So why do we bother?" Patterson asked. The answer is that there are so many unmet medical needs — some of them clearly related to aspects of modern life, such as stress, pollution and obesity. Then there is the problem of antibiotic resistance and the demands of an ageing population. Pharma must try to grab these opportunities, but how can the industry boost its flagging success rate? 

Patterson noted that academia and small companies are very good at discovering new therapeutic molecules, but they are unable to turn them into medicines. Biotech companies are flexible and innovative but, unlike big pharma, they cannot fund failure or scale-up. Pharma has the global reach, the manufacturing standards, the track record and the ability to withstand failure, but it is just too big?  

"You are now seeing the whole of the pharmaceutical industry undergoing a revolution," Patterson said. In the future, he believes the winners will be the companies who access both big and small molecules — a blend of biotech and traditional pharma, although where the balance between the two will lie is debatable. The winners will be those who use translational medicine, meaning closer collaboration between the research and clinical sides, and those who leverage emerging markets. 

Many of these lessons are being put into practice in one of Wales's leading biopharmaceutical companies, Ipsen BioPharma, which is headquartered in France, but has a manufacturing facility in Wrexham that opened in 2000. Ipsen has five products in oncology, endocrinology and neuromuscular disorders, including Dysport, which competes with Botox, and Decapeptyl, a GnRH analogue. The Wrexham facility is dedicated to the manufacture of these therapeutic proteins and others that are moving through Ipsen's pipeline.  

According to Mike Harvey, VP of Manufacturing Supply Operations for Ipsen, design is the key to pharma success. "We so often hear of a discovery being stillborn because of a factor like dosage or distribution," he says. "Design must be thought through right at the beginning if you are to be successful in this industry." Although neither easy nor cheap, earlier commitment and decision making are needed to assure product quality in its broadest sense. "Product form and presentation must be thought of early, and early analytical development is vital for biologics," he adds. "Quality by design is here to stay and it is important for proteins too. It must be used." 

Design is what keeps a company competitive as 85% of the cost of goods is set by how a product or process is designed. Harvey believes that the key to Ipsen's manufacturing success in Wales is "a constant drive, a burning desire to improve, with focused teams in manufacturing with a mixture of skills, including those with commercial awareness." This is particularly important when products are manufactured far from the site where they were developed; for example, by a contract manufacturer. 

Wales is famous for its sheep — so maybe it is suitable that it is also home to two companies that make therapeutic antibodies raised in sheep (even if one of them uses Australian sheep). Protherics, a leading biopharmaceutical company, has its main manufacturing operations in Llandysul, where it produces three commercial products: CroFab, ViperaT and DigiFab, as well as a new product in

clinical development. These are all polyclonal antibody fragments (also known as Fab fragments) for the critical care market, based on antibodies raised in sheep sourced from Australia. CroFab and ViperaT are for treating poisonous bites from North American rattlesnakes and European vipers, respectively, while DigiFab treats overdoses of digoxin, a heart drug with a narrow therapeutic index. CytoFab, also a Fab fragment for severe sepsis is being groomed for blockbuster status with AstraZeneca.  

Meanwhile MicroPharm, which is located in Newcastle-Emyln in West Wales, uses local sheep to raise a range of antisera and antivenoms for contract manufacture, and offers Wales's only contract sterile filling service. The company has a deal with the Nigerian government to supply antivenom against the Carpet Viper, which is responsible for approximately 2000 bites a year, meaning that the MicroPharm product has likely saved hundreds of lives. The company also helps Nigeria save money because it has a liquid rather than freeze-dried formulation contained in cheaper vials. They also reduce cleaning costs by using disposables in their manufacturing plant. 

Meanwhile, Wrexham is the location of one of India's leading generic companies, Wockhardt UK, which is the second largest producer of hospital generics in the UK. "The Welsh experience encouraged us to grow our business in Europe," says Sirjiwan Singh, Managing Director of the company. "When we located here, people thought we were fools for not going East."  

But Wockhardt has earned $450 million (€284 million) in Europe, mainly through mergers and acquisitions, since moving. Currently, Europe accounts for 60% of revenues of the companies, while those from India have declined. In Wales, Singh says he likes: the good infrastructure, a supportive business environment and a good support structure. "We are now moving to value-added niche products. We want to build an entrepreneurial and risk-taking ability in our managers."  

It seems to work, for Wockhardt is now growing at a rate of 14%, which is twice the rate of UK pharma. "I've learned that we must improve at a rate greater than the competition," he concludes. "What has happened in the computer industry in the last 15 years will happen to pharma in the next 15." There is going to be a lot of change and evolution, and only those companies that can keep up will survive. 

Meanwhile, Ortho-Diagnostics, which is part of Johnson & Johnson, will open a facility for the manufacture of diagnostic kits for heart disease, HIV and hepatitis B virus in the new Pencoed Industrial Park in July. In the UK, locations outside of London, Cambridge and Oxford struggle to get the attention they deserve from the rest of the world, but Wales is developing connections with Israel. For instance, MaimoniDex RA of Tel Aviv, which develops monoclonal antibodies for rheumatoid arthritis, is intending to establish a facility in Swansea. Addressing BioWales, Gil Erez, Minister for Commercial Affairs at the Embassy of Israel in London, commented that Israel and Wales are actually the same size. His country is a fast growing, high-tech economy, which scored high on the Global Competitiveness Report. It is an EU partner in Framework Programme 7 and has 50 ongoing projects with the UK. Israel has 466 life science start-ups and is fourth in the world for molecular patents and second for medical device patents. The UK is seen as an expensive place to locate a biopharma facility, and Israeli companies still do not know enough about life beyond London. However, Erez believes Wales is going in the right direction, by sending delegates to BioIsrael, for example, and encouraging companies to come here.

Feature article

Once famous for coal and steel, Wales now aims to make its mark in the life sciences sector. The recent BioWales 2008 (UK) conference demonstrated how much the region has progressed, thanks to the support of the Welsh Assembly government, the EU and the enthusiasm of the Welsh biotech community. The country's bioscience sector, which comprises approximately 200 companies, grew by 18% last year and is now worth Â£1.3 billion (â‚¬1.6 billion) in annual turnover, employing 15–20000 people.

Building bioscience in Wales?

There is no doubt that the shift of pharmaceutical business is tilting towards Asia. With the industry growing at high speed, Asia is being hailed as 'the pharmaceutical hub', and most multinational and domestic companies in the region believe it is inevitable that Asia will soon be leading the pharma market.

Two decades ago, the industry was strongly affected by intellectual property rights issues, insufficient infrastructure and a lack of a 'think big' approach and proactiveness. Additionally, Asian industry leaders mainly focused on domestic business; a factor that, combined with a poor talent pool, affected industry growth. Only multinational companies (MNCs) were able to succeed in the market and more than 70% of the country's business was in their hands.

Many changes have helped the the Asian pharmaceutical industry become a global leader such as improved business acumen; a thirst for merger and acquisitions, and in-licensing/out-licensing deals; the establishment of partnerships; a focus on R&D innovations; greater financial support; new marketing strategies; and support from regulators to improve consistency in manufacturing. These changes altered the volume of business from a few hundred million Euro to billions.

India, China and Singapore are expected to become leaders in the pharmaceutical sector. India and China have become major suppliers of APIs, with India also exporting high volumes of pharmaceutical dosage products. South Korea, Malaysia, Thailand, Taiwan and Hong Kong are also creating strong pharmaceutical bases, although these markets are mainly dominated by MNCs. More clinical trials are also being conducted in Asia and India has taken the lead in clinical trial outsourcing. Asia is now returning to GDP levels of the 19th century when it was at its highest (12%). According to Goldman Sachs, India is expected to become the world's third largest economy by 2050. Many MNCs are investing and building their businesses in China and India, and it is expected that total pharmaceutical sales in China (at current levels of approximately $14 billion [9 billion]) will double to $28 billion (18 billion) by 2010.(1)

In late 2006, Novartis (Switzerland) announced a $100 million (64.2 million) investment in Shanghai for a new R&D centre. AstraZeneca (UK) also has plans to invest approximately $100 million (64.3 million) in China by 2009 for R&D operations. Other MNCs, including Pfizer (NY, USA), Roche (France) and Bayer (Germany) are investing in existing or new facilities in China. DSM (The Netherlands) has joint venture with North China Pharma Group with more than $100 million (64.3 million) investment. As far as domestic companies are concerned, the Chinese government is taking the necessary steps to boost their business, such as strengthening regulatory compliances.

And China is not the only one experiencing new growth; in India, sales increased by approximately 18% to $8 billion (5.1 billion) in 2006, according to a survey by IMS Health,(1) and by 2010 the Indian clinical trials market is expected to be worth $1 billion (642 million) from a current level of approximately $150 million (96 million). Also by 2010, contract manufacturing is expected to rise to $1 billion (642 million) from a current level of approximately $350 million (225 million).

One of the key reasons for this development is Asia's large population, combined with the increasing percentage of the aged, better infrastructure in terms of facilities, hospitals and skills, as well as government support for healthcare R&D. Other major changes in the Asian market are the increased medical insurance coverage of the population, the growing popularity of the internet and the option of home delivery of medicines, intensifying local competition and an increasing number of research centres in Asia.

Consumer confidence is also on the rise with China's entry into the World Trade Organization, as well as a reform of both the financing and the delivery of the healthcare system.(2) Continued price declines are expected, but this will be outweighed by strong volume growth. China is considered to be ahead of other major countries, such as India, Singapore, South Korea and Thailand, with the establishment of the Gene Valley in Shanghai, which is expected to become the second Silicon Valley in biotechnology research. However, the problem of counterfeit drugs in China continues at epidemic proportions.The Indian pharmaceutical industry is one of the world's largest; ranking fourth in volume and thirteenth in value in the global pharmaceutical market. 

In 2005, domestic pharmaceutical sales were $4.5 billion (2.9 billion) and growing at a compound annual rate of 8.59%. The leading Indian pharmaceutical companies have become some of the most efficient manufacturing units in the world as they are approved by international regulatory agencies, such as FDA and the UK's Medicines and Healthcare Regulatory Agency, and India now has the highest number of US FDA-certified manufacturing facilities outside the US. There is an increasing number of opportunities with large Indian manufacturers and CMOs for the increasingly cost-conscious MNCs.

One major factor that has increased the confidence of foreign MNCs searching for opportunities in India is the adoption of a new product patent regime in January 2005. This facilitates concurrent global Phase II and III clinical trials and has changed the dynamics of the Indian pharmaceuticals industry. Several leading domestic producers have begun to conduct research into new chemical entities and novel drug delivery systems as they can patent the innovation and get protected from copying.

The Indian government is also giving the biotechnology sector a big push by establishing a comprehensive national biotechnology policy. Biotechnology in India is developing in cluster zones that have reputable and established public life science research institutes at their centres. Various state governments are individually establishing their own biotechnology policies and are actively setting up biotechnology parks to facilitate research in new therapeutic options using cutting-edge technology. Biocon, Shanta Biotech, Serum Institute, Reliance Bio-Pharma/Life Sciences and others are taking big steps in biotech areas by forming their own biotechnology parks, bringing back the Indian talent pool from overseas and providing better facilities.

India is fast becoming a desirable clinical trial destination because of:

Ranjit Barshikar, GMP/Quality Consultant and former Vice President of Global Quality for Ranbaxy Laboratories analyses the past, present and future of Asia's pharmaceutical industry. Read more...