Closure Options Expand

The closure market continues to expand. Worldwide demand for caps and closures is expected to grow at a 5.6% compound annual growth rate between 2022 and 2026, according to a report from Future Market Insights. Pharmaceutical applications will help spur that growth, particularly with the development of innovative child-resistant designs and more sustainable, often lighter weight, options (1).

When considering caps and closures for pharmaceutical products, manufacturers and contract packagers express concerns about container/closure integrity; product, patient, and caregiver safety; tamper evidence; child resistance; precise dispensing; and ease-of-use by consumers who lack dexterity and strength. In addition, any changes in cap/closure design or application equipment must integrate seamlessly on filling lines.

To provide tamper evidence and an indication of first-opening on syringes and vials at point-of-use, Schreiner MediPharm has developed label-based security concepts. For example, its Cap-Lock security label/cap adapter combination for luer-lock syringes features a plastic cap adapter placed on the primary closure of the syringe and interlinked with it to equalize the diameter differences of the syringe body and closure. Subsequently, a label is applied on conventional labeling equipment and wraps around the syringe body and cap adapter. “When a user opens the syringe cap, the label is partially destroyed, thus clearly and irreversibly indicating that the cap has been opened,” reports Gene Dul, president of Schreiner MediPharm US. “The utilization of Cap-Lock in daily healthcare settings is particularly easy and safe; the syringe can be opened as usual and, due to the larger diameter, the adapter is easier to twist off, even when wearing gloves,” he explains.

For vials, Schreiner MediPharm has developed a similar tamper-evident concept to help prevent illegal reuse of original containers. This security label wraps around the vial up to the level of the cap. Opening the vial requires the removal of an integrated tear strip. Any attempt to reseal the label leaves visible evidence. In addition, once the tear strip is removed, a warning message emerges and clearly indicates the vial has been opened. Optionally, a void effect can be added, featuring previously invisible lettering or symbols that separate from an indicator field. “Thus, it is obvious at first glance whether the product is an originally sealed medication,” says Dul. Unlike shrink-wrap solutions, no heat is applied, so the tamper-evident labels are compatible with heat-sensitive drugs. The highly customizable labels can be adapted to specific
applications and integrated with additional functionalities such as counterfeit protection, light (ultraviolet) barrier, or radio frequency identification chip for digital applications.

Tamper-evident protection extends to dropper bottles with a product line from Tekni-Plex Healthcare. The bottles range in capacity from 5 to 30 mL fitted with 0.03-, 0.04-, or 0.05-mL droppers and tamper-evident or child-resistant caps (2).

Selig Group combines tamper evidence with hermeticity in its TamperSeal induction seal liner. The two-piece Top Tab 2 TamperSeal induction seal eliminates the need to break through the liner with a potentially unclean tool or unwashed finger. This prevents contaminants from entering the package or transferring to residual lining material (3).

Selig also is working on a custom
dispensing liner, which combines an initial hermetic seal with dispensing control for solid dosage forms. “Currently consumers can get many doses when pouring from a 38- or 43-mm orifice, and then are challenged with getting these (now touched by hands) doses back into the container,” explains John Brown, vice-president, Marketing and Business Development at Selig Group. He explains, “If the FDA issues any advice for controlled dosage, similar to blister pack dispensing, we believe we have a solution that is easy to
commercialize with existing bottles, caps, and equipment.”

On the filling line

Cap/closure application equipment also must keep pace with new designs and other industry trends. Container/closure integrity depends on consistent torques within the correct tolerances. “This is especially important for induction-sealed products,” says Omar Azam, Eng., applications engineering manager at NJM, a ProMach product brand.

To ensure product quality, pharmaceutical manufacturers and contract packagers want feedback on every cap application. “They want to know how tightly each cap is closed,” reports Deborah Smook, vice-president of Marketing & Business Development at TurboFil Packaging Machines. “This is especially true for containers that could potentially leak, which could impact product efficacy as well as total delivered dosage,” she explains. To meet that need, TurboFil has developed the servo-driven Acrobat chuck capper, which records how tightly each cap is applied.

In addition to precision torque and torque data reporting, the servo-driven chuck capper provides gentle handling and minimizes the need for change parts. Servo motor operation controls torque accurately and repeatably regardless of container size.

The module’s two-chuck system features a “chasing chuck” that automatically locates the next bottle along the belt. The mobile, adjustable chasing chuck allows the belt itself to serve as a spacing tool. This proprietary technology and parallel belts eliminate the expense of making and storing change parts for all but the smallest bottles, which need only minor inexpensive parts.

For caps with difficult threads, the system can perform counterclockwise thread seating. Gentle handling is assured through positive placement and cap-specific stainless steel serrated pneumatic chucks. This differentiating combination eliminates erosion between the chuck and the cap ridges, mitigating the risk of generating particulates that can contaminate machine surfaces as well as bottle contents. “By contrast, simple spindle cappers drop caps onto bottles, frequently resulting in misfeeds, cross-threading, and rejects,” says Smook.

The Acrobat chuck capper can handle most cap styles and sizes up to three inches in diameter, including flat, port, hinged, child-resistant, continuous-thread, twist-top, metal-lug, tilt-top, and tamper-evident designs and accommodate bottle heights ranging from 1–12 inches and nearly any bottle shape—round, square, rectangular, oblong, and F-style. Ideal for lines running multiple bottle and cap sizes, the machine is available in single- and dual-head formats capable of processing up to 90 units per minute.

Other machines that are capable of consistent torques within required tolerances along with real-time torque adjustment, applied torque monitoring, and tracking capability, include NJM’s beltorque in-line capper family. Patented cap-to-container alignment incorporates precision-machined cap delivery change parts to eliminate cross-threads and rejects.The systems also offer patented non-slip and synchronized cap pre-tightening and final torquing belts that eliminate container damage or cap scuffing even under the most demanding torque applications.

Future forecast

As cap/closure designs continue to evolve, Azam expects closures will offer easier opening and dispensing along with improved child-resistant and tamper-evident performance. Dul agrees, predicting, “Sophisticated label-based security concepts combining analog and digital tamper evidence will contribute to enhanced container integrity. The ultimate goal is supporting product and patient safety while ensuring smooth processability in pharma production.”

“We also believe that ‘controlled dosage’ will again be considered by the federal government as a way to discourage overdosing either accidentally or purposefully, including accidental child ingestion,” says Brown. In addition, there will be growing awareness of environmental impact. “Sustainability has not been completely adopted by brand owners yet as these [pharma] packages are not typically used outside of the home and are not becoming an eyesore on beaches, parks, ocean plastics, etc.,” he concludes.

References

1. Future Market Insights, “Caps and Closures Market Is Set to Expand at a CAGR of 5.6% & to Reach US$ 141 Bn During 2021 to 2031,” Press Release, July 26, 2022.
2. Tekni-Plex Healthcare, “At Pharmapack Paris, TekniPlex Healthcare to Showcase Robust Range of Drug Delivery Solutions,” Press Release, June 28, 2022.
3. SeligGroup, “TamperSeal,” TamperSeal - Selig Liners (seligsealing.com), accessed Aug. 1, 2022.

About the author

Hallie Forcinio is manufacturing editor for Pharmaceutical Technology.