Evaluation of entities with low absorption in the ultra violet region in pharmaceutical drug substances and drug products

Abstract

Present work reveals the importance of ?Evaluation of entities with low absorption in the ultra-violet region in pharmaceutical drug substances and drug products?. In general, the HPLC system is equipped with UV ?Visible detector for evaluation of impurities in the pharmaceutical drug substances and a limited application in GC for ionizable impurities in pharmaceutical drug substances. The UV inactive compound can be evaluated by various techniques or using different detectors. In this work the instruments employed are Ion chromatography using conductivity detector and zone electrophoresis with UV indirect photo detection technique and chapters 2 and 3 describe the Ion chromatography method and 4-6 chapters describe the capillary electrophoresis method for evaluating the UV-inactive substances in the pharmaceutical drug substances. Chapter 1 describes a general description of impurity profiles, classification of the impurities. This chapter also elaborates the method validation parameter, principle and instrumentation of Ion chromatography and capillary electrophoresis techniques along with literature reference. Chapter 2 describes the formation of monoethylsulfate during synthesis as well as stability of indinavir sulfate as its ethanol solvate. Synthesis of Indinavir sulfate was carried out in presence of sulfuric acid and Indinavir base in ethanol medium. At ambient temperatureitself sulfuric acid reacts with ethanol to form monoethylsulfate. Indinavir sulfate contains about 6% of ethanol, which can readily react with traces of free sulfuric acid that may be in equilibrium with drug substance and form monoethylsulfate during stability.This chapter describes determination of monoethylsulfate in very low levels in Indinavir sulfate drug substance by simple Ion chromatography method. It is clearly demonstrated that monoethylsulfate is a potential impurity of Indinavir sulfate, which forms during the synthesis as well as the storage.