Influence of Heat Treatment on Dissolution and Masking Degree of Bitter Taste for a Novel Fine Granule System.

Abstract

The influence of heat treatments on the dissolution and the masking degree of the bitter taste for the coated fine granules with water-insoluble film composed of ethylcellulose, hydroxypropylmethylcellulose, titanium 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°C for more than 4h 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. Differential scanning calorimetry (DSC) analysis of the coating film indicates that the endothermic peak due to melting of SS in the film disappeared with the heat treatment at 70°C for 4h, and also that the tensile strength of the film was reduced to one-half of the inital value after the heat treatment.It is thought that heat treatment caused changes of film properites, i.e. that tensile strength and wettability are attributable to the melting and diffusing of SS in the film, resulting in the dissolution level being increased to about 100% and the masking degree of the bitter taste being greatly improved.