Statistical Process Control in Quality Management of Pharmaceutical Manufacturing in Ogun State

Quality assurance in pharmaceutical manufacturing is governed by stringent regulatory standards enforced by the National Agency for Food and Drug Administration and Control, yet non-conformance rates in Nigerian domestic production remain elevated due to inconsistent process control practices. This study applies comprehensive statistical process control methodologies to the tablet compression and coating processes at a licensed pharmaceutical plant in Sagamu, Ogun State, South West Nigeria. Control chart analysis is conducted for critical quality attributes including tablet weight, hardness, friability, and coating uniformity, with data collected from 20-unit samples drawn at 30-minute intervals over 16 production weeks. X-bar, R, CUSUM, and EWMA control charts are constructed and compared for sensitivity to mean-shift detection. Process capability analysis computes Cp and Cpk indices for each quality attribute relative to regulatory specification limits. Results reveal that coating uniformity exhibits a Cpk of 0.87, indicating systemic incapability requiring process re-engineering. CUSUM charts detect mean shifts an average of 3.2 samples earlier than Shewhart X-bar charts for small shifts below 1.5 standard deviations. Root cause analysis using designed experiments identifies coating pan speed and ambient humidity as the primary assignable causes of coating non-uniformity. The study recommends adoption of EWMA and CUSUM charts as the primary monitoring tools and environmental control investment for the coating process. Keywords: statistical process control, pharmaceutical manufacturing, Ogun State, process capability, CUSUM chart.