An Ultra-sensitive LC Method for the Simultaneous Determination of Paracetamol, Carbamazepine, Losartan and Ciprofloxacin in Bulk Drug, Pharmaceutical Formulation and Human Serum by Programming the Detector

Abstract

An ultra-sensitive LC method for the simultaneous quantitation of paracetamol, carbamazepine, losartan and ciproflox-acin have been developed and validated following the ICH guidelines at isobestic point and by programming the detector at individual wavelength of each component. The components were eluted by 50:50 v/v acetonitrile-water (pH 3.0) using a Bondapak, C 18 (10 µm, 25 × 0.46 cm) column at flow rate of 1.0 mL·min −1 with detection wavelength 240 nm at isobestic point and 245, 230, 206 and 272 nm for paracetamol, carbamazepine, losartan potassium and ciprofloxacin respectively by programming the detector. Linearity was found to be 0.5-24, 0.25-8.0, 0.4-12 and 0.75-10 µg·mL −1 (R 2 > 0.999) with detection limits 99, 20, 30 and 6.0 ng·mL −1 respectively. Comparison study with time program method showed more sensitivity with calibration range of 0.4-12, 0.2-6.0, 0.1-3.0 and 0.25-8.0 µg·mL −1 (R 2 > 0.999) and LOD values 29, 11, 2.0 and 5.0 ng·mL −1 respectively. Percent recoveries > 98.37% from pharmaceutical formulation and human serum samples and RSD < 2% for inter-day and intra-day assay were obtained. The method was found to be robust and can be successfully applied for the determination of studied drugs in, pharmaceutical formulations and human serum without interference of excipients or endogenous components of serum.