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. Stability assay methods should be specific enough to differentiate between analytes and possible degradation products. The overall quality of drug-substance and drug-product batches placed on formal stability studies should represent the quality of materials used in clinical studies and of the quality of materials to be made at manufacturing scale. Supporting stability data can be provided using stability data generated from batches of drug substances and drug products made on a laboratory scale. Stability studies also should be conducted on material stored in a container–closure system that is the same as (or simulates) packaging proposed for real storage and distribution. Stability Studies are performed to understand the compounds/formulation in development: Physical & Chemical properties of API and drug product, Drug and excipient compatibility, Impact of manufacturing process steps, Interactions with packaging materials, Assignment of shelf life etc. Analytical stability programs for a drug substance or drug product also can be used for the characterization of impurities and related substances in line with dissolution studies, and to residual solvents, disintegration, and friability. Testing can be performed at ambient temperature, accelerated conditions, intermediate conditions, and other storage conditions. cGMP stability analyses include ICH Stability Services, Real-Time & Long Term Stability, Accelerated Stability, Forced Degradation Studies, Stress Stability Testing, R&D Stability Testing, In-Use Studies, Photostability, Comparative/Comparator Stability, Follow Up Stability Testing (FUST), Formulation Evaluation Stability, Finished Product Release, Cycling Chamber Stability Studies etc.