Content Uniformity / Homogeneity

Analytical testing is a critical part in every step of drug development and manufacturing. The qualitative and quantitative results generated from validated analytical testing provide first-hand information to control and ensure the quality and safety of raw materials, intermediates, and finished products. Like many other CMC (chemical, manufacturing and control) activities, analytical testing is also frequently outsourced. Many factors are attributed to this rapid market growth, including continuous outsourcing from pharmaceutical companies, growing pipelines for biological candidates, and increasing demand for more analytical details on drugs and process development by regulatory agencies. In response to the changing market dynamics, service providers are striving to provide analytical testing with quality, accuracy, and robustness all within tight timelines. As the contract research organizations (CROs) have become more integrated, small analytical labs need to establish their niche to succeed. Global contract analytical Laboratories provide QC laboratory analysis, method development, validation and expert advice for both finished products and raw materials for pharmaceutical and biopharmaceutical companies. Quality Compliance testing is done a wide variety of raw material and finished product forms including High Potent Active Pharmaceutical Ingredients (APIs), Raw Materials and Excipients, Powders - Capsules/Semi-solids, Oils - Oral Solutions and Syrups, Liquids, Vitamins, Minerals, and Nutritional, Natural Health Products (NHPs) – Powders, Herbals – Suspensions, Finished Pharmaceutical Products (Tablets, Capsules/Semi-solids, Oral Solutions and Syrups, Gels, Creams and Ointments, Powders, Suspensions, Transdermals etc. Blend uniformity is a function of both the formulation and mixing action. Once the formulation is optimized from a theoretical process standpoint, blend uniformity must be validated during piloting and scale-up. From a manufacturer’s perspective; poor uniformity generates unacceptable amounts of discarded products, resulting in significant loss of revenue. However, no method currently exists that detects uniformity during the blending process, and as a result the true optimum endpoint is realized rarely. CGMP (21 CFR.211.110) for testing homogeneity and uniformity requires an in-process testing of powder blends to demonstrate adequacy of mixing, but it does not state that the blend has to be directly assessed for uniformity. It was on this premise that the original draft stratified sampling guidance document allowed the use of in-process dosage unit data as a surrogate to demonstrate dosage unit uniformity during routine manufacture. Blend uniformity should be assessed during process design (Stage 1 Validation) and process qualification (Stage 2 Validation). Defaulting directly to the testing of in-process dosage units is discouraged, the exception being when blend sampling presents severe risks to the operators taking the samples (which should be discussed and accepted by regulators).