High percutaneous bioavailability of granisetron by dissolving microneedles

High percutaneous absorption efficiency of granisetron (GST) was sought by formulating GST into two-layered dissolving microneedles containing 10.0 +/- 0.12 g GST (low dosage) and 37.6 +/- 2.31 g GST (high dosage). The GST-loaded microneedles were administered percutaneously to rat skin. Plasma GST concentrations were measured using LC/MS/MS. The GST bioavailabilities (BAs) were, respectively, 97.6 +/- 9.7% (low dosage) and 93.1 +/- 14.9% (high dosage). No skin irritation or damage to the skin was observed where it was administered. GST was stable with 100.6-101.4% in microneedles in within three months at 4-40 degrees C. Results show that dissolving microneedles are a good percutaneous delivery system for GST.