Assessment of performance of manufacturing procedures in a unit for production of investigational anticancer agents, using a mixed effects analysis

Purpose. To identify the magnitude and sources of variability of a generic, aseptic manufacturing process for experimental anticancer agents employed at our facility, and to estimate the effects on product quality. Materials and Methods. In-process and quality control data of all products manufactured according to this generic process (composed of weighing, dissolution, filtration, filling, semi-stoppering and lyophilization) over a 3-year period were retrospectively analyzed using mixed-effects analysis. Results. Variability in the filling process was shown to be marginal and of minor importance for product quality in terms of content and content uniformity. An overall content of 101% was found with batch-to-batch and vial-to-vial variability up to 4.21% and 2.57%, respectively. Estimation of the overall batch failure revealed that structural bias in content and a high batch-to-batch variability in content were the most prominent factors determining batch failure. Furthermore, content and not content uniformity was shown to be most important parameter influencing batch failure. Calculated Process Capability Indices (CpKs) calculated for each product showed that the process is capable of manufacturing products which will routinely comply with the specification of 90-110% for content. However, the CpK values decreased dramatically using the specification of 95-105% as required for approved drug products. Conclusion. These results indicate that at the early stage of product development less tight specification limits must be applied to prevent unnecessary batch rejection of investigational agents.