Method development is the process of proving that an analytical method is acceptable for use in our laboratory to measure the concentration of an API in a specific compounded dosage form. Full method development procedures are complex, extended, and expensive endeavors. These studies usually are required when data from the analysis is going to be submitted to regulatory authorities for certification of a new or amended drug application. The analytical method is tested extensively for specificity, linearity, accuracy, precision, range, detection limit, quantitation limit, and robustness. For established pharmaceutical preparations, which are not new drug species, the analytical method process can be much simpler. Modern analytical instrumentations, like HPLC, UPLC, HPTLC and UV, allow simplified procedures to be employed to verify that an analysis procedure accurately and consistently will deliver a reliable measurement of an active ingredient in a compounded preparation and biological fluids. This book will provide basics for method development and validation for aspirants in analytical chemistry