Microbiological Skip Test: Fundamentals and Evaluation of Water Activity in Pharmaceutical Ingredients

Abstract

Quality control is essential for Good Manufacturing Practices in the pharmaceutical industry. The time and costs associated with microbiological quality control are well known. It is proposed the reduction of traditional microbiological methods of counting the total number of microorganisms and research of specific pathogens using the water activity (Aw) method, a practice known as the skip test. The raw material selected as a prototype for this study met the criteria for the feasibility of reductions in analyses having synthetic origins, solid physical state, low or high pH in aqueous solution, and Aw results below 0.75 at a temperature of 25°C, and absence of nonconformity records. The risk management process was implemented using risk analysis with the mode, effect, criticality, failure analysis tool, and opening change control with the replacement of microbiological standard by Aw in 20 sequential batches after complete analysis of the first batch received in the year. It was possible to certify the microbiological quality of the selected pharmaceutical ingredients using the AW results, thereby confirming the feasibility of the skip test.