Incorporation of METHOCEL E6 PLV by a Novel Foam Granulation Technique for Dissolution Augmentation of the Poor Soluble Silymarin

Objective: In the present study Foam Granulation Technique (FGT) TM was employed in the development of IR tablets of high dose of silymarin dried plant extract which is a very fine, poorly compressible material with poor water solubility and these characteristic features poses extensive technological challenge in its manufacturing. Methods: In FGT, the Methocel E6 PLV was used as foam binder in varying concentrations of 1%, 5%, 7% and 10%. The evaluation of potentially important foam properties, foam penetration mechanism assessment and tablet evaluation was carried out in details and compared with direct compression tablet of silymarin. Results and Discussion: The foam penetration followed foam drainage controlled mechanism and was found to be less dependent on the powder hydrophobicity compared to water drop which followed drop controlled mechanism. The foam induced nucleation successfully created nuclei with relatively uniform structure, size and sphericity as compared to water. The dissolution profile of silymarin foam bonded tablets with 5% Methocel E6 exhibited better dissolution profiles with T20%, T50%, T75% at 6, 30 and 120 min, when compared with direct compression control tablets with T20% at 120 min. The drug release from optimized 5% foam tablets followed Higuchi model with R2 = 0.8831 and were found to be stable in accelerated stability studies for a period of 3 months. Conclusion: Thus silymarin with high dose-low solubility characteristics can be easily formulated into IR tablet for clinical and commercial use using this helpful technique.