No abstract

No abstract

Sildenafil citrate (SIL) is used in the treatment of erectile dysfunction and other chronic disorders. For the pharmacokinetic investigation of SIL we developed a simple and sensitive method for the estimation of SIL in rat plasma by reverse phase high-performance liquid chromatography (RP-HPLC). The drug samples were extracted by liquid-liquid extraction with 300 μl of acetonitrile and 5 ml of diethyl ether. Chromatographic separation was achieved on C18 column using methanol:water (85:15 v/v) as mobile phase at a flow rate of 1 ml/min and UV detection at 230 nm. The retention time of SIL was found to be 4.0 min having a separation time less than 5 min. The developed method was validated for accuracy, precision, linearity and recovery. Linearity studies were found to be acceptable over the range of 0.1-6 μg/ml. The method was successfully applied for the analysis of rat plasma sample for the application in pharmacokinetic study, drug interaction, bioavailability and bioequivalence.

A simple and sensitive method was developed for simultaneous estimation of Glimepiride (GLIM) and Sildenafil citrate (SIL) in rat Plasma by reverse phase high performance liquid chromatography (RP-HPLC). The drug samples were extracted by liquid-liquid extraction with 300 µl of acetonitrile and 5 ml of diethyl ether. Chromatographic separation was achieved on C18 column using methanol: water (85:15 v/v) as mobile phase at a flow rate of 1 ml/min and UV detection at 230 nm. The retention time of GLIM and SIL was found to be 2.5 and 4.0 min respectively with total run time of 7 min. The developed method was validated for accuracy, precision, linearity and recovery. The method was linear and found to be acceptable over the range of 100-12 000 ng/ml. The method was successfully applied for the analysis of rat plasma sample for application to pharmacokinetic.

A new, simple, specific, accurate and precise reversed phase-high performance liquid chromatography (RP-HPLC) method was developed for the determination of levofloxacin in rat plasma and saliva was developed. An HPLC system based on a Phenomenex Luna C 18 Column (250 × 4.6 mm) and a UV detector ( = 296 nm) were used. A mixture of Acetonitrile: water (80:20 v/v) adjusted to pH 3.5 by orthophosphoric acid at a flow rate of 1.4 ml/min was used as mobile phase. The proteins were precipitated with methanol. The average recovery was 94.79 and 92.66%, respectively in plasma and saliva. The detection limit for levofloxacin in plasma and saliva was 1 µg/ml. The calibration curve was linear over the concentration range 1 to 16 µ µ µ µg/ml for plasma and saliva. The inter-day and intra-day assay coefficients of variation were found to be less than 5%. The present validated method was successfully used for pharmacokinetic studies of levofloxacin in plasma and saliva.

Present work describes development and validation of HPLC-DAD method for the analysis of a complex mixture consisting phenylephrine hydrochloride (PHE), paracetamol (PAR), caffeine (CAF) and levocetirizine (LEV). Chromatographic separation was achieved using a Kinetex-C18 column involving gradient elution, the mobile phase composed of 10mM phosphate buffer (pH 3.3) and methanol. The three step gradient program started with step-1 initially with 2% (by volume) methanol and 98 % phosphate buffer (pH 3.3) for first 5 minutes. In step-2 methanol concentration changed linearly to 80% in next 12 minutes the analysis was concluded by step-3 changing methanol to 2% in next 8 minutes. The method was linear in concentration ranges of 50 to 200 % of labeled claims with r 2 near to 1. Developed method proved to be precise for inter and intra-day studies the %RSD values were < 2 , accuracy studies by standard addition at 80, 100 and 120% levels resulted in recoveries of standard near to 100%. The method was selective with no interferences from placebo; robustness of method was proved by no significant alteration in system suitability parameters. The LOD values for PHE, PAR, CAF and LEV were 0.13, 0.51, 0.05 and 0.05 and LOQ were 0.39, 1.53, 0.15 and 0.15 respectively. The study concluded a validated HPLC method for analysis of complex mixture consisting PHE, PAR, CAF and LEV in bulk, tablet and dissolution samples in simulated gastric fluid (SGF).

Present work describes the development and validation of a simple and reliable high-performance liquid chromatography-diode array detection (HPLC-DAD) procedure for the analysis of phenylephrine hydrochloride (PHE), paracetamol (PAR) and cetirizine dihydrochloride (CET), in pharmaceutical mixture. The method was applied successfully on tablet dosage form. Effective chromatographic separation of PHE, PAR and CET was achieved using a Kinetex-C18 (4.6, 150 mm, 5 mm) column with gradient elution of the mobile phase composed of 10 mM phosphate buffer (pH 3.3) and acetonitrile. The elution was a 3 step gradient elution program step-1 started initially with 2% (by volume) acetonitrile and 98% phosphate buffer (pH 3.3) for first 2 min. In step-2 acetonitrile concentration changed linearly to 20% upto 12 min the analysis was concluded by step-3 changing acetonitrile to 2% upto 20 min. The reliability and analytical performance of the proposed HPLC procedure were statistically validated with respect to linearity, ranges, precision, accuracy, selectivity and robustness. Calibration curves were linear in the ranges 5-15, 250-750 and 2.5-7.5 μg/ml for PHE, PAR and CET, with correlation coefficients >0.9996. The validated HPLC method was applied to a pharmaceutical mixture of a marketed preparation tablet in which the analytes were successfully quantified with good recovery values with no interfering peaks from the excipents.

A rapid and simple high Reverse-phase performance liquid chromatography method was developed and validated for simultaneous determination of Cefpodoxime Proxetil and Ofloxacin from pharmaceutical preparation. The separation was achieved on A kromosil (technokroma) 100 C-8 (3.5μm ,15x0.46) performed using Acetonitrile and phosphate buffer as mobile phase the of pH of buffer was adjusted to 4.8 using Ortho-phosphoric acid, the ratio was 58:42 (v/v) eluents were monitored at 275 nm. The detector response was linear in the range of 100 to 300 μg, for both Cefpodoxime Proxetil and Ofloxacin. The percentage assay Cefpodoxime Proxetil and Ofloxacin was found between 99.76 and 99.31% respectively. The described method has the advantage of being rapid and easy hence it can be applied for routine quality control analysis.