Preparation, characterization and pharmacodynamic evaluation of fused dispersions of simvastatin using PEO-PPO block copolymer

The solubility enhancement of poorly soluble compounds is an important task in pharmaceutical technology as it leads to better bioavailability and a more efficient application. Fused dispersions [FDs] of simvastatin [SIM] using PEO-PPO block copolymer were prepared which paved the way for the formation of an amorphous product with enhanced dissolution and bioavailability. The accumulative solubility of simvastatin [SIM] from PEO-PPO block copolymer [Lutrol NF 127 prill surfactant] was found to be superior to the drug alone which may be due to the increased oxyethylene content that played the major role in solubility enhancement. A 3[2] full factorial approach was used for optimization wherein the temperature to which the melt-drug mixture cooled [X[1]] and the drug-to-polymer ratio [X[2]] were selected as the independent variables and the time required for 90% drug dissolution [t[90%]] was selected as the dependent variable. A low level of X[1] and a high level of X[2] were suitable for obtaining higher dissolution of SIM from SIM FDs. On increasing melt to cool drug temperature, t[90%] increased thus improving dissolution rate of FD[2] batch with the maximum drug release [99.63%] in 120 min. The optimized FDs were characterized by saturation solubility study, drug content, in-vitro dissolution, fourier transform infrared spectroscopy, scanning electron microscopy, differential scanning calorimetry, x-ray diffraction, [1]HNMR spectroscopy and pharmacodynamic evaluation. Capsules containing optimized FDs were prepared and compared with marketed brand [SIMVOTIN[registered]]. Finally, it can be concluded that the optimized FDs of SIM ameliorate the solubility and dissolution of drug with improved pharmacodynamic activity

Colon targeted drug delivery systems: a review on primary and novel approaches

The colon is a site where both local and systemic delivery of drugs can take place. Local delivery allows topical treatment of inflammatory bowel disease. However, treatment can be made effective if the drugs can be targeted directly into the colon, thereby reducing the systemic side effects. This review, mainly compares the primary approaches for CDDS [Colon Specific Drug Delivery] namely prodrugs, pH and time dependent systems, and microbially triggered systems, which achieved limited success and had limitations as compared with newer CDDS namely pressure controlled colonic delivery capsules, CODESTM, and osmotic controlled drug delivery which are unique in terms of achieving in vivo site specificity, and feasibility of manufacturing process