Novel Tanshinone II A ternary solid dispersion pellets prepared by a single-step technique: In vitro and in vivo evaluation

Novel Tanshinone II A (TA) ternary solid dispersion (tSD) pellets with the combination of polyvinylpyrrolidone and poloxamer 188 as dispersing carriers were prepared by a single-step technique. A formulation screening study showed that the addition of poloxamer 188 to binary TA-PVP system could remarkably promote the dissolution rate of TA from 60% to 100% after 60 min. Scanning electron microscopy study revealed a smooth surface and a tightly packed coating structure. Differential scanning calorimetry analysis confirmed the formation of solid dispersions. In vivo test showed that TA tSD pellets presented significantly larger AUC(O-t), which was 0.76 times more than that of binary solid dispersion (bSD) pellets, 2.87 times more than that of physical mixtures (PMs) and 5.40 times more than that of TA. C-max of TA tSD pellets also increased by 1.82-8.97-fold as that of bSD pellets. PMs and TA. TA tSD pellets generated obviously shortened T-max of (3.80 +/- 0.398) h, compared to bSD pellets with (4.15 +/- 0.456) h, PMs with (4.65 +/- 0.226) h and TA with (5.52 +/- 0.738) h. In conclusion, the addition of poloxamer 188 to pellets containing PVP-based solid dispersions could achieve complete dissolution, accelerated absorption rate and superior oral bioavailability. The fluid-bed technique becomes an alternative approach to obtain solid dispersion-coated pellets. (C) 2011 Elsevier B.V. All rights reserved.