Avoiding Excipient Variability

Excipients are essential components in drug products. Although sometimes defined as “functional” or “inert,” each has a specific role within the formulation that is necessary for the overall function of the medicine. Variability in the properties and performance of excipients may, depending on the nature of the variability and the role and quantity of the excipient, have a significant impact on the safety and/or efficacy of the final drug product. Managing��minimizing—excipient variability is, therefore, an essential part of drug product development and manufacture. Excipient variability depends on many factors. One important determiner relates to whether the excipients are prepared from natural materials or via chemical synthesis, according to Liam Cullen, an engineering specialist with Servier. For example, he points to cellulose-based materials, which are derived from wood pulp that is then chemically treated. “Natural materials, particularly those that are grown, can be subject to environmental conditions such as soil type, weather, and the use of fertilizers. Secondary processing steps can also provide further material variability,” he explains.