A Rapid and Validated RP-HPLC Method for the Simultaneous Quantification of Benzoic Acid, Metronidazole and Miconazole Nitrate in Vaginal Formulations.

A rapid, specific, precise and accurate reversed-phase high-performance liquid chromatography method has been developed and validated for the determination of benzoic acid, metronidazole and miconazole nitrate in vaginal formulations of cream and tablet (excluding benzoic acid). The validation was carried out with reference to ICH guidelines. The chromatography was carried out on a Zorbax SB-CN column (250 × 4.6 mm, 5 µm) linear gradient elution with mixture of solvent A (phosphate buffer) and solvent B (acetonitrile) as a mobile phase at the flow rate of 1.0 mL/min and dual mode of detection that is 233 nm for benzoic acid and miconazole nitrate and 319 nm for metronidazole. The limit of detection and limit of quantification are 1.07, 0.79 and 0.62 μg/mL and 3.23, 2.40 and 1.88 μg/mL for benzoic acid, metronidazole and miconazole nitrate, respectively. The linearity of benzoic acid, metronidazole and miconazole nitrate showed a correlation coefficient of 0.9997, 0.9995 and 0.9993, respectively. The good results were achieved with respect to repeatability of relative standard deviation ≤2% and recovery within 98.0-102.0%. The selected column in this study performed well. The method is simple, accurate and precise, and may be recommended for routine quality control test for any dosage forms containing benzoic acid, metronidazole and miconazole nitrate.