ABSTRACT
A dissolution method with robust high performance liquid chromatographic (HPLC) analysis for im-mediate release tablet formulation was developed and validated to meet the requirement as per Inter-national Conference on Harmonization (ICH) and United States Food and Drug Administration (USFDA) guidelines. The method involved the use of Agilent ZORBAX Eclipse XDB C18 column, and temperature was maintained at 30 °C. After optimization, the mobile phase was selected as phosphate buffer (KH2PO4, 30 mM):ACN (60:40, v/v) with pH 3.0, and retention time Rt was found as 3.24, 4.16, and 2.55 min for paracetamol (PCM), chlorpheniramine maleate (CPM) and phenylephrine hydrochloride (PH) respec-tively at 265 nm and at a flow rate of 1 mL/min. The relative standard deviation (%RSD) for 6 replicate measurements was found to be less than 2%. Furthermore net analyte signal standard addition method (NASSAM) with spectrophotometer was performed for standard and liquid oral suspension. On the basis of selectivity, sensitivity and accuracy analysis, it was confirmed that this novel method could be useful for simultaneous estimation of the given drug combinations. Two-way analysis of variance (ANOVA) was applied for evaluating the statistical difference between the assay results obtained via both NASSAM and RP-HPLC methods and ultimately no significant difference was found between both the methods. All the methods and results were acceptable and confirmed that the method was suitable for intended use.
ABSTRACT
A RP HPLC method for estimation of sildenafil citrate (SC) in tablet dosage form and seminal fluid was developed and validated. Best resolution was obtained with column Waters Spherisorb® C18 bonded silica, (5 μm, 4.6 x 250 mm) at 230 nm with retention time of 5.01 min. The mobile phase used was TEA (0.2%) pH adjusted at 3 with OPA and ACN (60:40) with flow rate of 1.0 mL/min. The method for estimation of sildenafil citrate in tablet dosage form was found to be linear, accurate, precise, sensitive and selective. Whereas the bioanalytical estimation of SC in seminal fluid was found to be in the range of 100 ng/mL to 10μg/mL. Method was found to be highly sensitive as LOD and LOQ were found to 0.3 μg/ml and 0.9μg/ml. The repeatability and reproducibility were within the range i.e. less than 2%.The accuracy of the method was 99.3%. The percentage purity was calculated for market formulation was 102.8%. The internal standard used for bioanalytical methods was Diclofenac sodium. The drug was extracted from seminal fluid by protein precipitation using ACN as precipitating agent. The linearity range was from 100.0ng/mL to 2.0μg/mL. The LOD and LOQ were found to 0.03μg/mL and 0.1μg/mL. The repeatability and reproducibility were within the range i.e. % RSD less than 15%. The accuracy of the method was 90.36%.and the extraction efficiency was found to be 98.25%. The stability of drug was found to be within the range i.e. less the 15%.