A New Crystal Engineering Technique for Dissolution Enhancement of Poorly Soluble Drugs Combining Quasi-emulsion and Crystallo-co Agglomeration Methods

A target of best dissolution improvement of poorly soluble drugs is a necessity for the success of formulation in industry. The present work describes the preparation, optimization, and evaluation of a new spherical agglomeration technique for glimepiride as a model of poorly soluble drugs. It involved the emulsification of a drug solution containing a dispersed carrier that tailors the crystal habit of the drug to a perfect spherical geometry, in a poor solvent containing a hydrophilic polymer which imparts sphericity and strength to the formed agglomerates. The FTIR peaks of optimized product did not show any sign of chemical interaction between the drug and adsorbed carrier. The DSC and X ray diffractogram showed a peak characteristic of spherical agglomerates with much less intensity than that of glimepiride. The dissolution t1/2 of the drug slightly decreasedfrom 381 min to 334 min in plain agglomerates. Introducing polymers in the aqueous phase of emulsion led to an improvement in the dissolution, reflected in t1/2 ranging from 118 to 231 min. Agglomerates prepared with Starlac/PVP demonstrated the most optimum physicochemical characteristics being spherical, with the best flowability and packability parameters. The t1/2 was as short as 19 min. The new carrier/polymer system offered a synergistic combination that highly contributed in dissolution enhancement of glimepiride. The spheronization and amorphisation offered by the new technique could account for such improvement.