IN-VITRO RELEASE EVALUATION OF HYDROCORTISONE LIQUISOLID TABLETS

The potential of liquisolid systems to improve the dissolution propert ies of water-insoluble agents was investigated using hydrocortisone as the model medication. The in vitro release patterns of this very slig htly water-soluble corticosteroid, formulated in directly compressed t ablets and liquisolid compacts, were studied at different dissolution conditions. The new formulation technique of liquisolid compacts was u sed to convert liquid medications such as solutions or suspensions of hydrocortisone in propylene glycol, a nonvolatile liquid vehicle, into acceptably flowing and compressible powders by blending with selectiv e powder excipients. Several liquisolid tablet formulations were prepa red using a new mathematical model to calculate the appropriate quanti ties of powder and liquid ingredients required to produce acceptably f lowing and compressible admixtures. Due to their increased wetting pro perties and surface of drug available for dissolution, liquisolid comp acts demonstrated significantly higher drug release rates than those o f conventionally made, directly compressed tablets containing microniz ed hydrocortisone. The in vitro drug dissolution rates of liquisolid t ablets were found to be consistent and independent of the volume of di ssolution medium used, in contrast to the plain tablets which exhibite d declining drug release patterns with decreasing dissolution volumes. It has been also shown that the fraction of molecularly dispersed dru g in the liquid medication of liquisolid systems is directly proportio nal to their hydrocortisone dissolution rates.