title: Liquid chromatographic method for the simultaneous determination of captopril, piroxicam, and amlodipine in bulk drug, pharmaceutical formulation, and human serum by programming the detector.
abstract: A highly sensitive LC method with UV detection has been developed for the simultaneous determination of coadministered drugs captopril, piroxicam, and amlodipine in bulk drug, pharmaceutical formulations, and human serum at the isosbestic point (235 nm) and at individual λmax (220, 255, and 238 nm, respectively) by programming the detector with time to match the individual analyte's chromophore, which enhanced the sensitivity with linear range. The assay involved an isocratic elution of analytes on a Bondapak C18 (10 μm, 25 × 0.46 cm) column at ambient temperature using a mobile phase of methanol/water 80:20 at pH 2.9 and a flow rate of 1.0 mL/min. Linearity was found to be 0.25-25, 0.10-6.0, and 0.20-13.0 μg/mL with correlation coefficient >0.998 and detection limits of 7.39, 3.90, and 9.38 ng/mL, respectively, whereas calibration curves for wavelength-programmed analysis were 0.10-6.0, 0.04-2.56, and 0.10-10.0 μg/mL with correlation coefficient >0.998 and detection limits of 5.79, 2.68, and 3.87 ng/mL, respectively. All the validated parameters were in the acceptable range. The recovery of drugs was 99.32-100.39 and 98.65-101.96% in pharmaceutical formulation and human serum, respectively, at the isosbestic point and at individual λmax . This method is applicable for the analysis of drugs in bulk drug, tablets, serum, and in clinical samples without interference of excipients or endogenous serum components.
authors.affiliation: Research institute of Pharmaceutical Sciences, Faculty of Pharmacy, University of Karachi, Karachi, Pakistan.
authors.forename: Najma
authors.initials: N
authors.lastname: Sultana
authors.forename: M Saeed
authors.initials: MS
authors.lastname: Arayne
authors.forename: Saeeda Nadir
authors.initials: SN
authors.lastname: Ali
mesh_terms: D017311:Amlodipine / Q000032:analysis*; D002216:Captopril / Q000032:analysis*; D002626:Chemistry, Pharmaceutical; D002853:Chromatography, Liquid / Q000295:instrumentation / Q000379:methods*; D064368:Healthy Volunteers; D006801:Humans; D015394:Molecular Structure; D004364:Pharmaceutical Preparations / Q000737:chemistry*; D010894:Piroxicam / Q000032:analysis*; D013056:Spectrophotometry, Ultraviolet / Q000295:instrumentation
chemical_list: D004364:Pharmaceutical Preparations; D010894:Piroxicam; D017311:Amlodipine; D002216:Captopril
keywords: Amlodipine; Captopril; Piroxicam; Time program