Rajan V. Rele

Simple and precise UV- spectrophotometric methods, first order derivative and area under curve [AUC], have been developed and validated for the estimation of azelnidipine in bulk drug and its tablet formulation. The standard and sample solutions of azelnidipine were prepared in methanol. Azelnidipine was estimated at 242.6 nm for the first order derivative UV-spectrophotometric method (A) while in area under curve (AUC) method (B) the zero order spectrum of azelnidipine was measured in between 250.5 nm to 258.8 nm. Beer’s law was obeyed in the concentration range of 1 to 20 μg / ml with coefficient of correlation value 0.9993 for first order derivative method. Similarly in AUC method, Beer’s law was obeyed in the concentration range of 1 to 20 μg / ml with coefficient of correlation value 0.9991. These methods were tested and validated for various parameters according to ICH guidelines. The precision expressed as relative standard deviation, which was within the range of 0.1157 to 0.9995 % for the above two methods. The proposed methods were successfully applied for the determination of azelnidipine in pharmaceutical formulation. Results of the analysis were validated statistically and were found to be satisfactory. The proposed methods are simple, easy to apply, low-cost and require relatively inexpensive instruments.

A simple, rapid and accurate high performance liquid chromatography method is described for determination of rupatadine fumarate from its active pharmaceutical ingredients. The separation of drug was achieved on Inertsil ODS-3 C18 (250 X 4.6 mm) 5µ column. The mobile phase was a mixture of acetonitrile and methanol (80:20 v/v) : buffer of pH  4.5 [70:30 % v/v]. The buffer of pH 4.5 was prepared from 0.01 M ammonium acetate and pH was adjusted with dilute acetic acid. The detection was carried out at wavelength 250 nm. The mixture of water: acetonitrile (30:70 % v/v) was used as a diluent. The method was validated for system suitability, linearity, accuracy, precision, robustness, stability of sample solution. The method has been successfully used to analyze rupatadine fumarate from pharmaceutical formulation.

A simple precise, rapid, accurate and sensitive non-aqueous potentiometric titration method was developed for quantitative determination of oxolamine citrate from pharmaceutical dosage form. The titration was carried out using standardized 0.1 N perchloric acid. The proposed method was found to be precise with % RSD 0.99 ) between 20 % to 100 % of 100 mg of drug substance weight. The percentage recovery of oxolamine citrate in the optimized method was between 99.773 to 101.229 %. The method is also found to be rugged when checked by different analysts and using different lots of reagents and different makes of titrators.

  Rapid and accurate isocratic reverse phase high performance liquid chromatography method is described for simultaneous determination of aceclofenac and thiocolchicoside in the combination dosage form. The separation of two drugs was achieved on Thermo Hypersil BDS C18 (250 mm X 4.6 mm) column of 5 µm particle size. Mobile phase consisted of 42:58 of acetonitrile and buffer of pH 6 respectively. Detection was carried out at 261 nm. Thermo Hypersil BDS C18 column showed most favorable chromatographic parameters for analysis. The method was validated for system suitability, linearity, accuracy, precision, robustness and stability of sample solution. The linear range for aceclofenac and Thiocolchicoside was 25-125 μg/ml and 1-6 μg/ml respectively.

  Residual solvents in intermediates and active pharmaceutical ingredient were monitored by using gas chromatography. It is mandatory to control adequately the quality of active pharmaceutical ingredient by checking the levels of residual solvents. A systematic approach for the identification and quantification of residual solvents in citalopram hydrobromide was described in proposed analytical method. The analysis was carried  on DB624 (30 m x 0.32 mm id, 5 µm  coating thickness) capillary column by gas chromatography with flame ionization detector. It was validated as per ICH guidelines1. The method was validated for system suitability, specificity, LOD, LOQ, linearity, accuracy, precision and robustness. The method described was simple, sensitive, reliable and reproducible for the quantization of residual solvents at levels as per ICH guideline. Key words: Citalopram hydrobromide, Active pharmaceutical ingredient, Residual solvent, Gas chromatography