<b>Development and application of Liquid Chromatographic method for determination of Caspofungin Acetate in sterile, lyophilized powder for Injection</b> Caspofungin is an antifungal agent of the novel echinocandin class. Caspofungin, the first inhibitor of fungal b 1,3 glucan synthesis to receive approval by the United States Food and Drug Administration, is effective for the treatment of mucosal and invasive candidiasis and invasive aspergillosis. It is also active in vitro and in animal models against a number of other filamentous and dimorphic endemic fungi and in animal models of Pneumocystis carinii infection. Caspofungin is a water soluble amphipathic lipopeptide is a semisynthetic derivative of pneumocandin B0, a fermentation product of Glarea lozoyensis. Developing a accurate and precise alytical method for the estimation of cagpsofungin in a sterile, lyophilized product for intravenous IV infusion a is very challenging, due to the formation of drug drug and drug excipient interactions. The present study demonstrates the applicability of chromatographic method to develop a new, sensitive, single HPLC method for the quantitative determination of antifungal agents in freeze dried powder for injection pharmaceutical dosage form. Chromatographic separation active pharmaceutical ingredient was achieved by using a isocratic elution at a flow rate of 1.0 mL min on X Terra RP 18 column 250mm×4.6 mm, 5µm particle size, 100Å pore size at ambient temperature. The contents of the mobile phase were 3.48 gms of Di Potassium hydrogen ortho phosphate 0.03M in 1000 ml of water and by adjusting the pH to 3.2 with dilute ortho phosphoric acid mobile phase solvent A and acetonitrile mobile phase solvent B in a isocratic mode in the ratio of 30 70 v v of separation was used to resolute the Caspofungin. UV detection at 278 nm was employed to monitor the analytes. A linear response was observed for caspofungin over the concentration range 0.5–6 µg mL. Limit of detection LOD and Limit of quantification LOQ for Capsofungin were found to be 0.001µg mL, and 0.003µg mL respectively. Caspofungin, Isocratic HPLC, Casporan®, Lyophilized powder for injection 455-464 Issue-3 Volume-2 Dr. L. Satyanarayana | Dr. Sumalatha Reddi