The Construction of Sustained-Release Systems of Tanshinone IIA and Sodium Tanshinone IIA Sulfonate by SBA-15 Mesoporous Material

The basic problems of the low dissolution rate of Tanshinone IIA (TSN) and the instability and precipitation of sodium tanshinone IIA sulfonate (STS) injection limit their usage in clinical. For these facts, the study aims to improve the dissolution rate of TSN and to enhance the sustained release effects of TSN and STS by using SBA-15 mesoporous molecular sieve as a drug carrier. Furthermore, controlling the pore size of SBA-15 and using different loaded methods to achieve expectations and provide a novel scheme for existing Danshen formulations. The effect of loading methods on drug loading efficiency (DL%), as well as the influence of the pore size of SBA-15s, the drug polarities and release mediums on drug loading and release behaviors were analyzed. It was found that the DL% was enhanced with the enlargement of the pore size, and was higher of TSN than STS. The in vitro tests of drug-loaded SBA-15s confirmed that the dissolution rate of TSN was improved obviously as compared with pure TSN. Moreover, SBA-15s prolonged the release times up to 12 h of TSN and 60 h of STS and promoted the sustained-release behaviors by decreasing the pore size. To ascertain the kinetic mechanisms of these samples, the Korsmeyer-Peppas release model was employed and the fitted results indicated that TSN/SBA-15s followed Fickian diffusion and non-Fickian transport was the predominant kinetic release mechanisms for STS/SBA-15s.