Acta Pharm. 60 (2010) 427-443
Original research paper
Silymarin-solid dispersions: Characterization
and influence of preparation methods on dissolution
DALWADI SONALI, SONI TEJAL, THAKKAR VAISHALI and GANDHI
TEJAL
sonali.dalwadi@yahoo.com
1 Ramanbhai Patel College of Pharmacy, Charotar
University of Science and Technology, Changa-388421, India
2 Anand Pharmacy College, Anand-388001, India
Accepted October 25, 2010
The influence of preparation methodology of silymarin solid dispersions using a hydrophilic polymer on the dissolution performance of silymarin was investigated. Silymarin solid dispersions were prepared using HPMC E 15LV by kneading, spray drying and co-precipitation methods and characterized by FTIR, DSC, XRPD and SEM. Dissolution profiles were compared by statistical and model independent methods. The FTIR and DSC studies revealed weak hydrogen bond formation between the drug and polymer, while XRPD and SEM confirmed the amorphous nature of the drug in co-precipitated solid dispersion. Enhanced dissolution compared to pure drug was found in the following order: co-precipitation > spray drying > kneading methodology (p < 0.05). All preparation methods enhanced silymarin dissolution from solid dispersions of different characteristics. The co-precipitation method proved to be best and provided a stable amorphous solid dispersion with 2.5 fold improved dissolution compared to the pure drug.
Keywords: silymarin, HPMC, solid dispersions, kneading, spray drying,
co-precipitation, dissolution parameters