| 摘要 |
PURPOSE:To obtain the title pharmaceutical preparation capable of passing with intactness through the stomach or small intestine, when orally administered, but of degrading, when reached the large intestine, resulting in releasing the medicinal substances there from into the large intestine by coating a solid pharmaceutical preparation with a chitosan layer followed by an enteric film. CONSTITUTION:A pharmaceutical preparation is coated with (A) a layer of chitosan having >=85% in deacetylation degree and >=30cSt in the viscosity at 20 deg.C in the form of its 0.5% aqueous acetic acid solution at a concentration of 0.5wt.% followed with (B) an enteric film consisting mainly of an enteric base (e.g. hydroxypropylmethyl cellulose acetate succinate) which is intact in the test with the Japanese Pharmacopoeia solution I and insoluble for >=120min in the following Clark-Lubs' buffer solution test at a pH of <=6.5, thus obtaining the objective pharmaceutical preparation. In case the medicinal substances to be used are readily soluble in water, it is preferable that a coating with the enteric base be made prior to the chitosan coating to form an enteric base film layer in advance.
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