A Reverse Phase Stability Indicating HPLC Method Development for Estimation Assay of Benzyl Alcohol and Glycopyrrolate in Glycopyrrolate Injection

Background: The present work is focused on developing a simple stability indicating method for the estimation of the assay of benzyl alcohol and glycopyrrolate in glycopyrrolate injection using reverse high performance liquid chromatography. Methods: A simple, selective, rapid, precise, and gradient reversed-phase high-pressure liquid chromatography procedure has been proposed to estimate the assay of benzyl alcohol and glycopyrrolate for glycopyrrolate injection. It was developed on a Kromasil 100-5, C8 250 mm x 4.6 mm, 5 µm column using mobile phase-A, containing pH 2.5 potassium dihydrogen phosphate buffer and methanol in a ratio of 80:20 v/v. and mobile phase-B, containing pH 2.5 potassium dihydrogen phosphate buffer and methanol in a ratio of 10:90 v/v at a flow rate of 1.5 mL/min. The detection of glycopyrrolate and benzyl alcohol was carried out at 222 nm and 254 nm. A sharp peak was obtained for glycopyrrolate and benzyl alcohol at a retention time of about 8.4 and 4.8 min. Results: The method was validated for specificity (blank, system suitability solution, standard, and sample and stress samples for any interference), precision (six replicate sample preparations), robustness (by slightly varying critical method parameters), and solution stability, and the results were found satisfactory. Conclusion: The method is specific, precise, accurate, and robust for estimation of the assay of benzyl alcohol of glycopyrrolate in glycopyrrolate injection.