ABSTRACT
OBJECTIVE:To prepare Baicalin monolithic osmotic pump tablets and investigate its in vitro drug release behavior. METHODS:Using accumulative release rate as evaluation index,baicalin solid dispersion was prepared to improve solubility,sin-gle factor test and orthogonal test were used to optimize preparation technology(the amount of penetrating agent and pore-forming agent,weight gaining of coating film) of monolithic osmotic pump tablets using baicalin solid dispersion as intermediate. Release rate and mechanism of samples prepared by optimized technology were investigated in 3 kinds of release medium (water,0.1 mol/L HCl,simulated gastric fluid). RESULTS:The optimal preparation technology was that penetrating agent sodium chloride was 30 mg;pore-forming agent polyethylene glycol 400 was 20% amount of excipient cellulose acetate;weight gaining of coating film was 2%. RSD of 12 h accumulative release rate was 1.06%(n=3)for 3 batches of Baicalin monolithic osmotic pump tablets pre-pared by optimized technology. 12 h accumulative release rate of them in 3 kinds of medium were similar to each other,being all more than 80%. Release equation was in line with zero-order drug release model (r=0.9985). CONCLUSIONS:Prepared Ba-icalin monolithic osmotic pump tablets after optimization can release drug at controlled rate.