Abstract

Simultaneous Liquid Chromatographic Determination of Two Co- Prescribed Anti-Cancer Drugs in Bulk Drug, Dosage Formulations and in Human Serum Using Multivariate Technique: Application to in vitro Drug Interaction

Najma Sultana, Saeed Arayne M, Saeeda Nadir Ali and Arman Tabassum

Present study describes the development and validation of a high-performance liquid chromatographic (HPLC) assay for the simultaneous quantification of atorvastatin and celecoxib in human serum and pharmaceutical formulations. The separation was carried out on Bondapak, C18 (10 ?m, 25×0.46 cm) column using mobile phase 80:20 methanol-water of pH 3.5, maintained with o-phosphoric acid. The method was optimized using multivariate technique and detector response was recorded at five different wavelengths. Chromatography was performed at ambient temperature by pumping the mobile phase at a flow rate of 1.0 mL min-1. Calibration curves were found to be linear with correlation coefficient greater than 0.998 over the concentration range 2-60 and 2-70 ng mL-1 with detection limits 0.024 and 0.019 ng mL-1 in bulk drug and 0.04 and 0.01 ng mL-1 in serum at isobestic point. The method was validated for specificity, selectivity, and linearity, accuracy, precision and intermediate precision. The proposed method is valid for the determination of drugs in pharmaceutical formulations without interference of excipients. Recovery values of both drugs were 99.33 to 101.65%. Moreover the in vitro interaction studies of atorvastatin in presence of celecoxib were carried out at physiological temperature (37°C), simulating stomach environment and the reactions were studied by RP-HPLC.