Under the USP <661> General Chapter, specific test methods are established for plastic components that are used as part of a drug product or medical device package system. These standards are designed to address the safety and impact of the interactions between the plastic and the pharmaceutical product that comes in contact with and each test required has assigned specifications that must be met. By definition, plastics are composed of a mixture of homologous polymers and may contain other substances such as residues from the polymerization process and additives such as plasticizers, stabilizers, antioxidants, pigments, and lubricants. Plastic is used to form a variety of container components to include the bottle, closure, inserts, closure liners, silica gel or desiccant canisters and other unique parts. The USP <661> Chapter identifies five specific plastic types that are commonly used in drug product container systems:
- High Density Polyethylene (HDPE)
- Low Density Polyethylene (LDPE)
- Polypropylene (PP)
- Polyethylene Terephthalate (PET)
- Polyethylene Terephthalate G (PETG)
The testing includes identification procedures to ensure the specific plastic meets the assigned USP standard. ID testing includes an Infrared scan (FT-IR) and Thermal Analysis test using a differential scanning calorimeter (DSC). In addition, there are a series of basic extractions tests – commonly referred to as physicochemical tests – that the plastic components will be subject to. The physicochemical testing will be defined based upon the drug product type (solid or liquid) and can vary for the different plastic types. Extraction medium used include purified water, hexane and alcohol. For PET and PETG materials, the physicochemical extraction testing requires colorant extraction, heavy metals, total terephthaloyl moieties and ethylene glycol.
Plastic components used in package systems that come into contact with drug product must also meet the requirements of USP <87> biological reactivity. For plastic container and closure systems, it is also common to concurrently perform USP <671> Performance Testing. Collectively USP <661>, USP <671> and USP <87> represent that usual and comprehensive plastic container system qualification process established by the USP and enforced by the FDA.
The CS Analytical Team are experts in these test methods and have experience with every variety of plastic component. We can define a test program to your specific and unique package system that meets all regulatory requirements.