Study on the preparation of indomethacin sustained-release tablets and its bioavailability

AIM: Indomethacin sustained-release tablets(ISRT) were prepared. The drug release rate and drug content of the tablets were tested. The pharmacokinetic parameters and relative biovailability of ISRT were investigated. METHODS: UV method was used for assaying release degree of ISRT in vitro. The HPLC method was used to monitor plasma drug concentration in vivo. The pharmacokinetics and relative bioavailability (F) of ISRT and conventional capsules (CC) were investigated in 10 healthy male subjects in random 2-way crossover design. RESULTS: Single dose test showed that F of ISRT was 98.9%±10.9%; AUC of ISRT and CC were 14.100±2.817h. μg/ml and 14.254±2.347 h. μg/ml; C_max were 2.17±0.71 μg/ml and 3.95±0.78 μg/ml; T_max were 4.1±0.7h and 1.85±0.53h; MRT were 7.27±0.75 and 5.20±0.74, respectively. The C_maxinverted commas T_max and MRT for the ISRT and CC were significantly different, while the AUC for the two preparations was equal. After multiple doses, C_min^ss of ISRT and CC were 0.257±0.094 μg/ml and 0.302±0.104 μg/ml; C_max^ss were 1.945±0.340 μg/ml and 1.538±0.384 μg/ml respectively; FI of ISRT and CC were 1.537±0.145 and 1.334±1.86. CONCLUSION: The two preparations were bioequivalent.