Influence on analgesic activity and serum levels after meloxicam complexation with beta-cyclodextrin in mice and rats

The aim of the present study was to evaluate and compare the analgesic activity and serum levels of meloxicam (CAS 71125-38-7) after administration of meloxicam associated with beta-cyclodextrin (BCD, CAS 7585-39-9) and unmodified meloxicam. The analgesic activity was measured using the plantar test (rats) and the writhing test (mice). In the plantar test, BCD-meloxicam (3 mg/kg and 10 mg/kg orally) showed higher analgesic activity than corresponding doses of meloxicam alone; in the writhing test BCD-meloxicam (7 mg/kg and 15 mg/kg orally) showed stronger analgesic activity than unmodified meloxicam. Serum levels of meloxicam were significantly higher, at 0.5 h and 1 h after administration of BCD-meloxicam orally than those of unmodified meloxicam (both dosed at 10 mg/kg). The present results suggest that association with beta-cyclodextrin increases the analgesic activity of meloxicam. This may be due to an icreased systemic bioavailability of meloxicam after oral administration of its complex with beta-cyclodextrin.