Validation.

A new reverse phase high performance liquid chromatography (RP-HPLC) method for the quantitative determination of Sitagliptin in human plasma was developed and validated as per US-FDA guidelines. The drug was spiked in the plasma and extracted with mobile phase by precipitation method. The extracted analyte was injected into an INTERSIL C18 column (150 mm × 4.6 mm, 5μm), maintained at ambient temperature and effluent was monitored at 267 nm. The mobile phase consisting of acetonitrile: methanol: buffer (2:3:5 v/v). The pH of the mobile phase was adjusted to 4.0 by using O-phosphoric acid. The flow rate was maintained at 1.0 mL/min. The developed method shows high specificity for sitagliptin. Calibration curve was plotted with a range from 25-125µg/mL (r2>0.9994). The lower limit of quantification (LLOQ) was found to be 25μg/mL. The method was validated for parameters like accuracy, precision, recovery, linearity, range, stability and sensitivity. This RP-HPLC method is suitable for determining the concentration of sitagliptin in human plasma and it was applied to routine analysis for determination of the Sitagliptin from dosage form during pharmacokinetic study.

The proposed method is a simple, accurate, precise, specific and rapid method for the simultaneous estimation of dextromethorphan hydrobromide (DXM) and chlorpheniramine maleate (CPM) in bulk and syrup formulation. Stationary phase consist of Eclipse-XDB C18 column(150×4.6mm, 5μm) and mobile phase with gradient mode consisting of phosphate buffer (adjusted to pH 3.0 with o-phosphoric acid): acetonitrile (80:20 v/v) was used. The flow rate was set at 1.0 ml/min and UV detection was carried out at 272 nm. The retention time of DXM and CPM were 9.05 min and 7.53 min respectively. The % recovery of DXM and CPM was found to be 99.58 ±1.33 and 98.24 ±1.97 respectively. DXM and CPM drugs were found to be linear over the concentration range of 2-50 µg/ml and 0.8 - 20 µg/ml respectively. The proposed method can be useful in the quality control of DXM and CPM in bulk drug and drug products. 

  An accurate, precise and reproducible Reverse Phase High Performance Liquid Chromatographic (RP-HPLC) method was developed and validated for the estimation of Metformin Hydrochloride, Glimepiride and Atorvastatin in Pharmaceutical dosage forms. In this method Qualisil gold C18 column (250mmx4.6mm I.D., 5µm particle size) with mobile phase containing 0.1% TFA in Water (pH adjusted to 2.92 with ammonia) and Methanol in the ratio of 28: 72v/v was used. The flow rate was 1ml/min. and the detection wavelength was 235nm1-2. The linearity was observed in the range of 50 - 225µg/ml, 0.2 - 0.9µg/ml and 1 – 4.5 µg/ml for Metformin Hydrochloride, Glimepiride and Atorvastatin with correlation coefficient of 0.9992, 0.9992, and 0.9997 respectively. Retention times were 3.1min, 7.8min, and 10.1min for Metformin Hydrochloride, Atorvastatin and Glimepiride respectively. The proposed method was validated for Linearity, accuracy, precision and Robustness. The proposed method was validated as per ICH guidelines and can be applied for routine quality control analysis of pharmaceutical dosage forms used for Multidrug therapy containing Metformin Hydrochloride, Glimepiride and Atorvastatin. Key words: RP-HPLC, OPA, Multidrug therapy, ICH, Validation.

An accurate, precise and economic reversed phase high performance liquid chromatographic (RP-HPLC) method was developed and validated for the estimation of lamivudine, zidovudine and nevirapine in pharmaceutical dosage forms. In this method Qualisil BDS C8 column (250mmx4.6mm i.d., 5µm particle size) with mobile phase containing water and acetonitrile in the ratio of 70: 30 v/v with pH adjusted to 5 with ortho phosphoric acid (OPA). The flow rate was 1mL/min and the detection wavelength was 250nm. The linearity was observed in the range of 1-15µg/mL for lamivudine, 3-24 µg/mL for zidovudine and 2.5-20 µg/mL for nevirapine. Retention times were 3.1min, 4.4min, and 7.0min for lamivudine, zidovudine and nevirapine respectively. The proposed method was validated as per ICH guidelines for linearity, accuracy, precision and robustness and can be applied for routine quality control analysis of pharmaceutical dosage forms used for multidrug therapy containing lamivudine, zidovudine and nevirapine.

  The present work describe simple, sensitive, rapid, accurate, precise and economic dual wavelength spectrophotometric method for the simultaneous estimation of Nebivolol hydrochloride and Hydrochlorothiazide in combined tablet dosage form. The principle for dual wavelength method is “the absorbance difference between two points on the mixture spectra is directly proportional to the concentration of component of interest”. The utility of this method is its ability to calculate unknown concentration of components of interest in a mixture containing an interfering component. The method was based on determination of Nebivolol hydrochloride at 246 nm and 292 nm and Hydrochlorothiazide at 264 nm and 295 nm. The two drugs follow Beer’s law over the concentration range of 5-30 µg/ml. The method was successfully applied to pharmaceutical dosage form. The results of analysis have been validated as per ICH guidelines.

  A new simple, accurate, precise, highly sensitive and reproducible difference spectrophotometric method for the determination of Fluvastatin in bulk and pharmaceutical dosage form is described. Difference spectroscopic method is based on the principle that Fluvastatin exhibit two different forms; in acidic and basic medium which differs in their absorption spectra. The difference spectra were obtained by reading the absorbance of Fluvastatin in 0.1N HCl in the reference cell and the absorbance of Fluvastatin in 0.1N NaOH in the sample cell and vice versa; in the difference spectrum maxima and minima were seen at 229nm and at 304nm respectively. The amplitude values were calculated, which was plotted against concentration. The method was found to be linear in the concentration range of 10-50 μg/ml. The percentage recovery was found to be between the ranges from 99.44 % to 100.45 %. The LOD & LOQ was found to be 0.215 μg/ml & 0.652 μg/ml respectively. The proposed method was statistically validated and successfully applied for analysis of Fluvastatin in capsule dosage forms. As per ICH guidelines the results of the analysis were validated statistically and were found to be satisfactory.

Development and validation of an analytical UV derivatives spectrophotometric method to quantify carbimazole as a single active principle in pharmaceutical formulation were done. Based on the spectrophotometric characteristics of carbimazole, a signal of first (314 nm), second (300 nm), third (289 nm), fourth (320 nm) order derivative spectrum was found to be adequate for quantification. The method obeyed Beer's law in the concentration range of (2-18 µg/ml) with square correlation coefficient (r2 = 0.999). The mean percentage recovery was found to be 99.56 ± 0.7179. As per ICH guidelines the results of the analysis were validated in terms of linearity, precision, accuracy, limit of detection and limit of quantification, and were found to be satisfactory. Key Words: Carbimazole, Derivative spectrophotometry, ICH, Validation.

The present manuscript describe simple, sensitive, rapid, accurate, precise and economical Q-absorbance ratio method for the simultaneous determination of Cefpodoxime proxetil and ofloxacin in combined tablet dosage form. Absorbance ratio method uses the ratio of absorbances at two selected wavelengths, one which is an isoabsorptive point and other being the λ-max of one of the two components. Cefpodoxime proxetil and ofloxacin show an isoabsorptive point at 272 nm in methanol. The second wavelength used is 236 nm, which is the λ-max of Cefpodoxime proxetil in methanol. The linearity was obtained in the concentration range of 5-17 μg/ml for both Cefpodoxime proxetil and Ofloxacin. The concentrations of the drugs were determined by using ratio of absorbances at isoabsorptive point and at the λ-max of ofloxacin. The method was successfully applied to pharmaceutical dosage form because no interference from the tablet excipients was found. The results of analysis have been validated statistically and by recovery studies. Key Words: Cefpodoxime proxetil, Ofloxacin, Absorption ratio method Tablets, Validation.