OBJECTIVE:To prepare Zuojin gastric-mucoadhesive tablets and evaluate their drug release properties in vitro. METHODS:Zuojin gastric-mucoadhesive tablets were prepared with hydroxypropyl methyl cellulose K15M(HPMC-K15M),car-bomer 934P and HPMC-E50 as the bioadhesive and matrix materials,and basic magnesium carbonate(foaming material),95% al-cohol solution(adhesive)and aerosil(glidant and lubricant)as the adjuvants. With the accumulative release of total alkaloids from Coptis chinensis Franch. at 2,6 and 10 h(Q2 h,Q6 h and Q10 h)as the indexes,orthogonal design test was conducted to optimize the amounts of HPMC-K15M,carbomer 934P,HPMC-E50 and basic magnesium carbonate,and verification was carried out. Drug re-lease properties in vitro of the preparation and Zuojin conventional tablets were observed and in vitro adhesion thereof determined. RESULTS:The optimal formulation was as follows as that for 50 tablets,HPMC-K15M of 0.7 g,carbomer 934P of 0.2 g, HPMC-E50 of 3.5 g and basic magnesium carbonate of 0.4 g. The Q2 h,Q6 h and Q10 h of three batches of prepared samples were 24.32%,56.10% and 77.04% respectively. 1-12 h drug release in vitro of prepared samples was in conformity with Ritger-Peppas equation. The Q2 h of Zuojin conventional tablets and Zuojin gastric-mucoadhesive tablets were 80.46% and 24.04%,Q12 h thereof 92.15% and 95.83% and gastric adhesion thereof 24.2 and 74.0 g/cm2,respectively. CONCLUSIONS:Zuojin gastric-mucoadhesive tablets which have sustained-release effect and adhesive property have been prepared successfully.