Pinki Rajbhar, S. S. Gautam, Raj K. Prasad, Anil K. Patel and A. K. Sahu
Objective: Our main aim was to prepare co-crystals of Clarithromycin, which is having poor solubility but high permeability. Thus the main aim is used to enhance the solubility and dissolution rate. Methods: Co-crystal was prepared using the stoichiometric ratio of CLN: Urea in 1:1, 1:1.5, 1:2, and 1:2.5 respectively by using solvent evaporation technique. In this method co-crystal components or cocrystal formers are taken in stoichiometric ratio and solubilize in a common solvent. The resultant solution is allowed to evaporate slowly. This technique works on the principle that, when different molecules of complimentary functional groups afford hydrogen bonds that is more favorable than each of the individual molecular components. In this case, the co-crystal is likely to be thermodynamically favored. In-vitro dissolution studies were carried out in USP apparatus II (paddle) using 900mL phosphate buffer pH 7.4 as dissolution media at 75rpm for 30minutes. Results: In-vitro dissolution studies of co-crystals it was found that the Pure CLN shows only a release of 75% after 30min whereas, the co-crystals shows a few folds increase (80%) in the dissolution profile. Hence, it is clear that the CLN: Urea co-crystals shows better in-vitro drug release than pure drug. Conclusion: The prepared co-crystals showed improved solubility of CLN and in turn higher dissolution rate than the pure drug indicating co-crystal approach as a novel and valuable means to alter the physical characteristics of an API without chemical modification.
