High Performance Liquid Chromatographic Method for Simultaneous Determination of Alprazolam with Antihistamines in Bulk Drug, Pharmaceutical Formulation and Human Serum

A high performance liquid chromatographic method with UV detection for simultaneous quantification of alprazolam with antihistamine was developed and validated following the ICH guidelines. Separation was achieved on Shimadzu Shim-pack CLC-ODS (M) 25 M column employing mobile phase 80:20methanol-water with pH 3.5 at 230 nm adjusting flow rate 1.0 mL min-1. The linear concentration ranges were 0.2-12.5 μg mL-1 for alprazolam and 0.4-25 μg mL-1 for antihistamines with correlation coefficient greater than 0.998 and detection limits 2.85, 6.92, 10.56, 4.9 ng mL-1 for promethazine, levocetirizine, alprazolam, and loratadine respectively. Validation showed RSD < 2% and 98.05-101.89% recovery. Proposed method was successfully applied for quantification of studied drugs in pharmaceutical formulations without excipients interference and also in human serum.