Irbesartan

The purpose of the present study was to enhance the solubility and dissolution rate of a poorly water soluble drug by solid dispersion technique. Irbesartan was used as a model drug to evaluate its release characteristics from the formulations. Solid dispersions of Irbesartan with PEG 4000 and PEG 6000 were prepared by physical mixing, solvent evaporation and melting techniques in w/w ratios (drug: carrier). Characterization of the solid dispersions was carried out by Differential Scanning Calorimetry (DSC) and Fourier Transform Infra-Red spectroscopy (FTIR). The dissolution profiles of solid dispersions were compared with those of the pure drug. Solid dispersions of Irbesartan with PEG 4000 prepared by solvent evaporation technique at 1:1 ratio showed greater dissolution compared to other formulations. FTIR and DSC studies showed no significant interaction between Irbesartan and the hydrophilic carriers.

A simple, sensitive and specific HPLC method with UV detection was developed for the estimation of irbesartan in tablet dosage form. Separation was achieved by Lithosphere 100 RP-18e, 5µ column having 250x4.0 mm internal diameter with mobile phase containing phosphate buffer and acetonitrile in 50:50 (v/v) with an ambient temperature. The flow rate was 0.8mL min-1 and eluent was monitored at 220 nm. The proposed method was found to be rectilinear over theconcentration range of 20µg/ml to 60µg/ml. This method was validated for system suitability, Specificity, Linearity, Precision, Accuracy, Range, Stability studies, Ruggedness, Robustness and Filter validation.  The results of all the validation parameters were well within their acceptance values. Therefore the proposed method can be used for routine analysis of estimation of Irbesartan in its tablet formulation