Method for providing enteric coating on solid dosage forms and aqueous compositions therefor

Abstract

A novel aqueous coating composition is proposed for providing enteric coating on solid dosage forms such as tablets. The aqueous coating composition of the invention comprises a fine powder of an enterosoluble cellulose derivative such as hydroxypropylmethylcellulose phthalate and hydroxypropylmethylcellulose acetate succinate, which is insoluble in water but can be plasticized and solubilized with certain plasticizing agents, as dispersed in an aqueous dispersing medium and a plasticizing agent having compatibility with the enterosoluble cellulose derivative and dissolved in the aqueous dispersing medium. The particle size of the enterosoluble cellulose derivative and the boiling point of the plasticizing agent is the key parameters and should be finer than 100 .mu.m in an average particle diameter and not lower than 100.degree. C., respectively. Upon application of the aqueous coating composition to the solid dosage forms, water as the dispersing medium is first evaporated leaving the cellulose derivative and the plasticizing agent, which latter solubilizes the former to form a continuous coating layer on the solid dosage forms imparting good and satisfactory enterosolubility thereto.

Dependencies are inferred from the claim text.