Combating Glass Delamination and Other Issues: Lessons from the 2012 PDA Glass Quality Conference
Diane Paskiet, Director, Scientific Affairs, attended the 2012 PDA Glass Quality Conference in June in Washington, D.C. The conference included sessions on development considerations, pharmaceutical packaging, equipment, quality control, distribution and transportation. The final session focused on what the industry could do to combat the growing problems associated with glass, including breakage and delamination.
The following recap of the conference offers insight into the issues associated with delamination and how the Glass Quality Conference addressed industry challenges.
Glass containers can and do meet the requirements of most parenteral applications as long as the container closure system, process and equipment requirements are well defined and controls are linked to patient safety. However, the potential exists for millions of patients to be exposed to risks associated with glass, including glass delamination (flaking) or breakage.
Selection of a container closure system that is fit for use with the dosage form should include consideration of delivery to the patient. Integration of patient safety with the science of glass, parenteral product development, the drug manufacturing process and distribution is vital to demonstrating glass suitability.
When considering the overall supply chain, manufacturers must explore the possible opportunities for improvement from the point of glass manufacturing to delivery to the patient. Considerations such as understanding formulations and the strength of glass, as well as the potential for interaction of glass with drug products, manufacturing processes and filling equipment, should be explored for problems and potential solutions. Areas prime for reducing the risks associated with glass include:
- Filling and sterilization
- Secondary packaging, handling and transport
- Storage and shipping
- Wholesale distribution
- Patient administration
Glass delamination, the formation and separation of glass flakes from a glass surface, is a combination of chemical alteration and failure of the interior surface. Typically glass flakes are nearly invisible to the naked eye (< 50 micron). While many different chemical and processing parameters can lead to glass delamination, it is a time-dependent process.
Since any change in a container closure system can affect drug product quality, when reviewing the entire drug lifecycle from development to commercial stages, glass issues can be combated through lifecycle management. Such management would require that suppliers define, measure, analyze and control quality through programs developed in conjunction with manufacturers.
For the glass industry, this means implementing tighter control over temperature and time during the glass manufacturing process, and the development of production control test methods. For pharmaceutical manufacturers, risk-factor assessment plans and thorough testing of container closure systems should aid in reducing rejection rates due to breakage and delamination.
Glass breakage is recognized as an issue for all parties in the supply chain. Multiple stakeholders must work together to determine solutions and optimize glass manufacturing and equipment. Washing, sterilization and finish processes have been identified as problematic for glass-to-glass contact. In addition, misalignment during filling can contribute to glass breakage. Since friction problems arising from glass-to-glass contact contribute to breakage throughout the manufacturing processes, reduction of breakage and complications associated with broken glass can be minimized by use of individual transport systems. These systems support supply chain logistics, enable a more automated system, and can track and trace problems during production. Glass breakage can be mitigated on several fronts, such as by optimizing belt and conveyer systems, by implementing ready-to-use components, and considering robotic feeding from transport trays at the beginning and the end of the filling line. Solutions can be very sophisticated, and a big investment may be needed depending on types of product, speed of filling line and complexity.
Use of case studies was shown to be a critical step in the process after secondary packaging and beyond. There are distinct opportunities for suppliers, pharmaceutical, distribution and transportation companies to work together for the benefit of all. What are glass suppliers doing to prevent breakage during shipping? What should pharmaceutical companies be evaluating to ensure they are performing correct distribution testing during qualification? Dynamic and environmental conditions that occur during shipping and handling are potentially harmful to drug products. These include shock, vibration, compression, temperature, humidity and pressure. Measurement and continuous monitoring of the distribution and handling environment can provide data to understand the product and packaging system environment. Attaching data recorders directly to the transport vehicle will allow the dynamic conditions generated by a vehicles movements to be recorded during shipment.
Preventative measures can be instituted to allow identification of weaknesses for potential defects associated with breakage and other issues of glass suitability. Root cause investigations of particulates are another aspect of glass quality. Sources of particles in drug products can be a result of glass chips, delamination, interaction products or foreign contaminates. Appropriate identification of particles is necessary to diagnose problems and implement corrective actions.
Pharmaceutical companies and glass container manufacturers should work together to establish a final product quality specification that is based on patient safety and product requirements. The many presentations at the PDA Glass Quality Conference illustrated that lessons have been learned based on the mechanical and chemical aspects of manufacturing that have the potential to damage or create weaknesses in glass, but there is still guidance needed to qualify glass containers for intended use.