Paliperidone

The main objective of the study is to enhance the dissolution rate and solubility of paliperidone by using the solid dispersion technique which were wildly used in pharmaceutical company because of its less cost. Paliperidone is antipsychotic classes of drug that can be used for the treatment of schizophrenia. Initially preformulation studies were conducted to check the incompatibilities of drug substance. Initially phase solubility studies were performed with respect to different molar ratio. Drug polymer interactions were investigated using differential scanning calorimetry (DSC), X-ray diffraction (XRD), and Fourier transform infrared spectroscopy (FTIR). As indicated from XRD and DSC data, paliperidone was in the amorphous form, which explains the better dissolution rate of then drug from its solid dispersion. Solid dispersion of paliperidone were prepared to check the solubility of paliperidone because of its poor solubility issue by using the different polymer and to find out the effect of various solubilizer on its solubility and dissolution rate.

A novel, precise and selective high performance liquid chromatographic method was developed for the estimation of paliperidone using paracetamol as the internal standard. Separation was achieved on a LiChrospher® RP-18 HPLC column (5 μ particle size and 25 cm × 4.6 mm internal diameter) using 10 mM ammonium acetate: methanol in the ratio of 10:90 (v/v) as the mobile phase, at flow rate of 0.7 ml/min and the eluate was monitored at 277 nm. The method was validated in compliance with ICH guidelines. The correlation coefficient of the calibration graph was 0.99946±0.00037 over the concentration range 1 to 5 µg mL-1. The limit of detection and limit of quantification were 0.569 µg mL-1 and 1 µg mL-1, respectively. Overall percentage recovery of paliperidone ranged between 98.92±0.595 to 100.30±0.693. Relative standard deviations for intra- and inter-day precision studies were