Purpose: To prepare orally disintegrating tablets (ODT) of montelukast sodium using Design-Expert for improved patient compliance. Methods: Central composite design was selected to delineate and optimize the formulations. Concentrations of crospovidone (X1) and sodium bicarbonate (X2) were selected as the variables, and responses were based on friability (Y1) and disintegration time (Y2). Varying amounts of super disintegrating agents and effervescent bases were used with microcrystalline cellulose to prepare montelukast sodium ODT. Results: Carr's index of montelukast sodium was 4.76±0.075, indicating the good compressibility of powder. Whereas the Carr's value for microcrystalline cellulose and mannitol were 30.14±0.021 and 22.41±0.053 respectively. The FTIR spectra indicated that there were no major shifting and loss of functional groups in drug and excipients blends. Formulations were evaluated, check point batch (CPB, F2) was selected using Design-Expert. The friability of CPB tablets was found to be 0.27 ± 0.085;

The major goal of this study was to modify and validate a HPLC analytical method to quantify the pregabalin in its solid dosage form. The separation and quantification were done on waters 3.9 x 300 mm column with 10 μm internal diameter. Mobile phase consisted of acetonitrile: phosphate buffer (KH2PO4) in the ratio of 50:950. Flow rate was 1.5 ml/min whereas the detection was done at 210 nm. The retention time for pregabalin was 6.5 min with average USP tangent of 5730.195± 0.376. There was a good correlation between concentration of pregabalin and their dilutions with r2 =0.9993. The capacity of method for percent recoveries at three levels over a range of 70-130% were 97.68 - 102.48% with % CV value of 0.73 - 1.95 %. The % CV of intra and inter-day variation was between 0.46 -0.79 and 1.37-0.072 for the concentration of 50, 100 and 150 μg/ml respectively. The results indicated the repeatability, reproducibility and robustness of the method with limit of detection 0.25 μg/ml and 1.0 μg/ml as limit of quantification. The stability study of 160 μg/ml of pregabalin solution (mobile phase) was done to assess the possible decomposition. It was concluded that the proposed method is suitable for routine analysis of pregabalin in its dosage forms. It could be beneficial for the estimation of stability of pregabalin in in-vitro pharmacokinetic studies.