Validation.

The emerging new fixed dose combination of Glipizide (GLZ) as sustained release and Telmisartan (TEL) as immediate release were formulated as a bilayer matrix tablet using guggul. Guggul used as a binding agent with three different concentrations (70%, 80%, and 90%; F1-F6) was used for the preparation of first layer of tablet containing glipizide. The conventional tablet of telmisartan was prepared as a second layer. Prepared bilayer tablets were studied for the in vitro release study carried out at pH 1.2 for first two hours and then at pH 6.8 for 6 hours using USP dissolution apparatus II (Basket). All the evaluation tests were found to be within the acceptance limits specified in Indian Pharmacopeia. The assay and dissolution study of tablets were done by HPLC which was developed and validated according to the ICH Q2 (B) guidelines. The contents of assay of the tablets were found to be 90.92% - 103.84% for F2-F5. The release of glipizide from the tablet was extended up to 8 h. Tablet containing 2.5 mg of glipizide with 80% of guggul release of drug after 8 h was found to be 82.36% and tablet containing 5 mg of glipizide with 90% guggul release of glipizide after 8 h was found to be 74.67%. The release pattern of each formulation (F2-F5) was fitted into the dissolution kinetics models and all the formulations were best fitted in the Higuchi model kinetic. From the results, we have concluded that the guggul act as a binding agent as well as rate retarding agent.

A simple, sensitive, rapid, precise, and accurate Spectrofluorimetric method has been developed for estimation of Hydroquinone (HYQ) its pharmaceutical dosage forms.HYQ showed good fluoroscence intensity in double distilled water and so Double distilled water was selected as a solvent for estimation of HYQ. The optimized excitation and emission wavelength were 290 nm and 337 nm respectively with 2.5nm slit width for HYQ determination. The linear regression data for the calibration curves shows a good linear relationship over the concentration range of 50 to 900 ng/mL for HYQ with respect to fluorescence intensity. The LOD and LOQ values were found to be 6.88 ng/mL and 20.85 ng/mL respectively. The developed method was validated in terms of linearity, precision, accuracy, limit of detection and quantification, robustness as per International Conference on Harmonization Q2 (R1) guidelines. The utility of the developed method has been demonstrated by assay of commercially available cream formulations. The developed spectrofluorimetric method can be successfully applied for routine quality control of HYQ from its formulations.

The present manuscript describes simple, sensitive, rapid, accurate, precise and economical Q-absorbance ratio method for the simultaneous determination of diclofenac sodium and eperisone hydrochloride in bulk and synthetic mixture. 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. Eperisone hydrochloride and diclofenac sodium show an isoabsorptive point at 270 nm in methanol. The second wavelength used is 255 nm, which is the λ-max of eperisone hydrochloride in methanol. The linearity was obtained in the concentration range of 2-20 μg/ml for both eperisone hydrochloride and diclofenac sodium. The concentrations of the drugs were determined by using ratio of absorbances at isoabsorptive point and at the λ-max of eperisone hydrochloride. The method was successfully applied to pharmaceutical dosage form because no interference from the synthetic mixture excipients was found. The suitability of this method for the quantitative determination of eperisone hydrochloride and diclofenac sodium was proved by validation. The proposed method was found to be simple and sensitive for the routine quality control application of eperisone hydrochloride and diclofenac sodium in synthetic mixture or pharmaceutical dosage form. The results of analysis have been validated statistically and by recovery studies. 

The present manuscript describes simple, sensitive, rapid, accurate, precise and economical spectrophotometric method for the simultaneous determination of Eperisone hydrochloride and Aceclofenac sodium in mixture. The method is based on the simultaneous equations for analysis of both the drugs using methanol as solvent. Eperisone hydrochloride has absorbance maxima at 255 nm and Aceclofenac sodium has absorbance maxima at 275 nm in methanol. The linearity was obtained in the concentration range of 4-20 μg/ml and 4-20 μg/ml for Eperisone hydrochloride and Aceclofenac sodium, respectively. The concentrations of both drugs in synthetic mixture were determined by using simultaneous equations. The mean recovery was 100.34 ± 0.27 and 100.64 ± 0.71 for Eperisone hydrochloride and Aceclofenac sodium, respectively. The method was applied for the determination of these drugs in mixture. The suitability of this method for the quantitative determination of Eperisone hydrochloride and Aceclofenac sodium was proved by evaluating different validation parameters. The proposed method was found to be simple and sensitive for the routine estimation of these drugs in combination. The results of analysis have been validated statistically and by recovery studies.  

A simple, rapid, and precise RP-HPLC method for simultaneous analysis of Losartan potassium and Atorvastatin calcium in bulk and its pharmaceutical formulations has been developed and validated. Atorvastatin was separated from losartan by using Grace Smart Altima C-18 column (25 cm × 4.6 mm, 5-μm) with a mobile phase consisting of acetonitrile: 10mM phosphate buffer (55:45 %v/v, pH 3.0) a flow rate of 1mL/min and detection wavelength at 240 nm. Aceclofenac was used as an internal standard in this method. Losartan, atorvastatin and aceclofenac were eluted with retention times of 4.85 min, 8.31min and 9.51 min respectively. The method was validated for accuracy, precision, linearity and sensitivity in accordance with ICH (Q2B) guidelines and the results of all the validation parameters were found to be within the acceptable limits. The calibration plots were linear over the concentration ranges from 200-30000ng/mL (r2 = 0.999) for both the drugs. Accuracy and precision were determined by QC sample covering low, medium, and high concentration levels. Intra and inert-day accuracy were found to be 97.16-102.57% for losartan and 97.01-103.05% for atorvastatin. The limit of quantification was found to be166ng/mL and 179ng/mL for losartan and atorvastain respectively. The method was successfully applied for the assay of the dosage form, recovery of the individual drugs from the combined tablet dosage was found to be >97% for both the drugs. From the results it is suggested that the proposed method is simple, reproducible, accurate and precise.

The present manuscript describes simple, sensitive, rapid, accurate, precise and economical Q-absorbance ratio method for the simultaneous determination of ibuprofen and chlorzoxazone in bulk and synthetic mixture. 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. Ibuprofen and Chlorzoxazone show an isoabsorptive point at 227 nm in methanol. The second wavelength used is 221 nm, which is the λ-max of Ibuprofen in methanol. The linearity was obtained in the concentration range of 2-20 μg/ml for both Ibuprofen and Chlorzoxazone. The concentrations of the drugs were determined by using ratio of absorbances at isoabsorptive point and at the λ-max of Ibuprofen. The method was successfully applied for the determination of these two drugs in synthetic mixture. No interference was observed from excipients present in the synthetic mixture. The suitability of this method for the quantitative determination of Ibuprofen and Chlorzoxazone was proved by validation. The proposed method was found to be simple and sensitive for the routine analysis of these two drugs in synthetic mixture. The results of analysis have been validated statistically and by recovery studies. 

A New simple, precise, accurate and rapid RP-HPLC method was proposed for determination of Dorzolamide hydrochloride from pure and its dosage form. A Symmetry Hypersil C18   (250 × 4.6mm, 5µ) column in isocratic mode with mobile phase phosphate buffer (pH 6.2): Acetonitrile (60:40) at a flow rate of 1ml/min. The effluent was monitored at 254nm. The retention time was 3.337min for Dorzolamide hydrochloride. The linearity range was found to be 20 – 120 µg/ml. The developed method was validated for parameters like specificity, accuracy, ruggedness and robustness and ascertained values were found to be within limits. The method has significant advantages in terms of shorter analysis time, selectivity and accuracy then previously reported method and indicates that the method can be considered suitable for carrying out quality control &routine determination of Dorzolamide hydrochloride in bulk and pharmaceutical dosage form.

The present manuscript describes simple, sensitive, rapid, accurate, precise and economical spectrophotometric method for the simultaneous determination of Gatifloxacin sesquihydrate and Prednisolone Acetate in  mixture. The method is based on the simultaneous equations for analysis of both the drugs using methanol as solvent.Gatifloxacin sesquihydrate has absorbance maxima at 293 nm and Prednisolone Acetate has absorbance maxima at 243 nm in methanol. The linearity was obtained in the concentration range of 2-12 μg/ml and 2-24 μg/ml for Gatifloxacin sesquihydrate and Prednisolone Acetate, respectively. The concentrations of the drugs were determined by using simultaneous equations at both the wavelengths. The mean recovery was 99.19 ± 0.22 and 99.64 ± 0.37 for Gatifloxacin sesquihydrate and Prednisolone Acetate, respectively. The method was successfully applied to laboratory prepared synthetic mixture because no interference from the mixture excipients was found. The suitability of this method for the quantitative determination of Gatifloxacin sesquihydrate and Prednisolone Acetate was proved by validation. The proposed method was found to be simple and sensitive for the routine quality control application of  Gatifloxacin sesquihydrate and Prednisolone Acetate in combination. The results of analysis have been validated statistically and by recovery studies. 

A simple, specific, accurate and precise reverse phase high performance liquid chromatographic method has been developed for determination (drug release) of Citicoline in controlled release tablet dosage form by reverse phase separation was carried out on a columns containing different stationary phases, the final choice giving satisfactory theoretical plates and tailing with good reproducibility and run time, with dimension 250 mm × 4.6 mm internal diameter, 5-μm particle; Zorbax C18 reversed-phase column. The mobile phase consisting of buffer: methanol (95:5, pH 6.0) at a flow rate of 0.8mL/min. The UV detection wavelength was set at 270nm. The retention time for Citicoline was found to be 6.4 min. and recoveries from controlled release tablet dosage form were between 99.7% and 104.4%. The method was validated for specificity, linearity, accuracy, precision and robustness. The proposed method was optimized and validated as per the ICH guidelines. Key words: Citicoline monosodium, Reverse Phase -High performance liquid chromatography, Dissolution, Validation.

A new reverse phase high performance liquid chromatography (RP-HPLC) method for the quantitative determination of Nimorazole was developed and validated as per ICH guidelines. The analyte was injected into an HIBER C18 column (150 mm × 4.6 mm, 5μm), maintained at ambient temperature and effluent was monitored at 297 nm. The mobile phase consisting of acetonitrile: methanol: buffer (2:3:5 v/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. and retention time was observed 1.76 min. The developed method shows high specificity for Nimorazole. Calibration curve was plotted with a range from 1-5µg/ml (r2>0.999). The lower limit of quantification (LLOQ) was found to be 0.5μg/ml. The method was validated for parameters like accuracy, precision, recovery, linearity, robustness. This RP-HPLC method is suitable for determining the concentration of Nimorazole and it was applied to routine analysis for determination of the Nimorazole from its formulation during pharmacokinetic study.