Stability Indicating RP-HPLC Method for Simultaneous Estimation Bimatoprost and Timolol Maleate in Bulk & Pharmaceutical Dosage Form

Narsu Kumari K*, Tarun S¹, Divakar M², Bhuvana Chandra³, Ramana Kumar A⁴
*¹²³⁴A.M. Reddy Memorial College of Pharmacy, Narasaraopet, 522412, A.P, India

A B S T R A C T
In the method development for RP-HPLC method for Bimatoprost & Timolol Maleate in bulk drug dosage form with water: methanol as Diluents 10mints run time. Method was optimized by varying chromatographic parameters like column, mobile phase composition, mobile phase PH and flow rate to satisfy system suitability testing. Various columns and mobile phase combinations were tried. A satisfactory separation and good peak symmetry was obtained by using Intersil ODS (150×4.6mm, 5µ) column, Acetonitrile: 0.02M Potassium dihydrogen orthophosphate as mobile phase with gradient technique. Quantification was achieved with PDA detection at 213nm based on peak area. The assay results obtained by using the proposed method for the analysis of marketed ophthalmic solution containing Bimatoprost 4mg and Timolol maleate 5mg were in good agreement with the labelled amounts of Bimatoprost and Timolol maleate. The average contents of Bimatoprost and Timolol maleate were 3.8964 mg/ml (97.41 %) and 4.834 mg/ml (96.68%) respectively.
Keywords: Bimatoprost, Acetonitrile, Potassium dihydrogen orthophosphate