INFLUENCE OF HEAT-TREATMENT ON DISSOLUTION AND MASKING DEGREE OF BITTER TASTE FOR A NOVEL FINE GRANULE SYSTEM

The influence of heat treatments on the dissolution and the masking de gree of the bitter taste for the coated fine granules with water-insol uble film composed of ethylcellulose, hydroxypropylmethylcellulose, ti tanium dioxide and sucrose fatty acid ester (SS) (4:2:1:1), containing sparfloxacin (SPFX) and low-substituted hydroxypropylcellulose in the cores was investigated. The dissolution rate of SPFX from the coated fine granules in water was increased by heat treatment of the granules . Dissolution percentage at 30 min in water after heat treatment at 70 degrees C for more than 4 h reached almost 100%, whereas it was about 90% before the heat treatment. The masking degree of the bitter taste for the coated fine granules was improved by the heat treatment. Diff erential scanning calorimetry (DSC) analysis of the coating him indica tes that the endothermic peak due to melting of SS in the film disappe ared with the heat treatment at 70 degrees C for 4 h, and also that th e tensile strength of the film was reduced to one-half of the initial value after the heat treatment. It is thought that heat treatment caus ed changes of film properties, i.e. that tensile strength and wettabil ity are attributable to the melting and diffusing of SS in the film, r esulting in the dissolution level being increased to about 100% and th e masking degree of the bitter taste being greatly improved.