To establish A RP-HPLC method for determination of diazepam and his decomposition products present in pharmaceutical dosage form. Various parameters that can potentially affect the analytical process were investigated and optimised. LC operating conditions were also optimised, and the chromatographic separation was performed on a Lichrospher 100 RP column at 25 degrees C using methanol, acetonitrile and (KH₂PO₄) (pH 3.0; 0.05M). Diazepam showed good linear at the range of 42–78 μg/ml (0.9995)with short run time. The recovery was found to be in the range of 98.1–100.8%. The LOD and LOQ for estimation of DZP were found to be 1.49μg/ml and 4.80μg/ml, respectively. The intra- and inter-day coefficients of variation were less than 1.4% (R.S.D.). The proposed method is simple, economic and accurate. It can provide reliable evidence for development and quality control.

Spectrophotometric method for degradation study of Levofloxacin was described. The ultra violet spectrum of acidic, basic and oxidative degraded product was found to substantial difference from pure drug. The extent of degradation can be calculated by comparing the decrease in absorbance at selective wavelength. The UV spectrum of Levofloxacin showed maximum absorbance at 287nm. The solution in alkaline, acidic and oxidative condition showed a decrease in absorbance at 287nm. So the decrease in absorbance at 287nm was used as measure of extent of degradation in all the degradation conditions. The degradation in acidic condition was found to be more when compared to alkaline and oxidative conditions.

A simple, sensitive, rapid and precise RP-HPLC method has been developed for the estimation of Amiodarone in pharmaceutical formulations. Hypersil BDS column packed with C₁₈ chemically bonded porous silica. (Particle size 5μm) length 4.6mm x 150mm was used for separation. The mobile phase consisting of Acetonitrile: 0.5%Triethylamine Buffer pH to 6.5 with orthophosphoric acid (75:25). The mobile phase was pumped at a flow rate of 2.0 ml/min and the detection was carried out at 240.0 nm. The retention time was found to be 10.92min. This method is validated for Linearity, Specificity, Accuracy, System suitability, Precision, Ruggedness, and Robustness. The proposed method is a good approach for obtaining reliable results and found to be suitable for the routine analysis in Amiodarone in pharmaceutical formulations.

Three simple spectrophotometric methods A, B, C as here described for the assay of nimesulide in bulk and pharmaceutical dosage formulations. Method A based on reduction of nimesulide with zinc and hydrochloride and reacting the reduced nimesulide with sodium nitrate to give diazonium compound with resorcinol to give yellow coloured chromogen at 402 λmax. Method B is based on dissolving nimesulide in 0.1N Sodium hydroxide which gave a yellow coloured chromogen with λmax 392nm. Method C based on reaction of ferric alum with MBTH and reduced ferrous ions forms a complex with reduced drug which gives a light blue coloured chromogen with λmax 432nm.

A validated reverse phase HPLC method has been developed for the estimation of Adapalene in Topical Cream. The Chromatographic separation was carried out on Phenomenex C18 (250 X 4.6 mm, 5 µm) column and Tetra Hydrofuran: Acetonitrile: 0.1% Acetic acid in water in the ratio of 20:40:40% v/v was used as mobile phase at the flow rate of 1.2 ml/min with PDA detection at 270 nm. The retention time of Adapalene were found to be 10.44 minutes. Linearity dynamic range was of 10- 30 µg/ml for Adapalene. The developed HPLC method was validated by determining its sensitivity, selectivity, linearity, accuracy and precision. The accuracy of the method was assessed by percentage recovery studies at three different levels at 50%, 100% and 150% of its working concentration. The percentage recovery of the drugs in the developed method was found to be in the ranges of from 98.2% - 101.7%, that indicates the good accuracy of the method. This developed method can be used for the routine analysis for the estimation of Adapalene in bulk and Pharmaceutical formulations.