Drug products factors affecting stability

Factors Affecting Drug Substance and Product Stability... 

Microbial stability is one of the factors affecting drug product reliability. Under design and interpretation of stability studies, the Center for Drugs and Biologies... 

Other factors, such as lack of experience at the new site in a particular dosage form or difference in the environmental conditions between the sites, can potentially affect the quality or stability of a drug product. Therefore, one site-specific batch may not be sufficient in these cases. More than one site-specific batch may be needed for a drug substance or product that is intrinsically unstable. 

Landersjo L, Stjernstrom G, Lundgren P (1977) Studies on the stability and compatibility of drugs in infusion fluids. IV. Factors affecting the stability of benzylpenicillin in carbohydrate solutions. Acta Pharm Suec 14 293-308 Larsen C, Bundgaard H (1977) Polymerization of penicillins. VI. Time-course of formation of antigenic di- and polymerization products in aqueous ampicillin sodium solutions. Arch Pharm Chem Sci 5 201-209... 

As the stability data can be affected by many factors like formulation, manufacturing, storage conditions, in-process and GMP controls, analytical methods, and process validation, the biggest challenge is to figure out the source of the variability in the stability results. At least three batches of the drug substance or product are required to establish the acceptance criteria for future production batches as a measurement... 

There are many factors that can affect the stability of a pharmaceutical product. These include the stability of the active drug(s), interactions between active and inactive ingredients, the dosage form, manufacturing process, the container system, and environment for shipping, handling, and storage. 

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