TACROLIMUS STABILITY

Solid Dispersion Comprising Tacrolimus and Entericcoated Macromolecule - Patent Application 20080132533 This invention relates to a solid dispersion formulation comprising tacrolimus and enteric polymer. The solid dispersion formulation may contribute to better stability of tacrolimus preparation under high temperature and humidity condition through reduced recrystallization rate of tacrolimus. In addition, the solid dispersion formulation releases tacrolimus immediately in aqueous media and elevated solubility level maintains for certain period of time and that way the formulation may also enhance the bioavailability and oral absorption rate of tacrolimus. The enteric polymer of this invention is not limited and the examples include Shellac, cellulose acetate phthalate, hydroxypropylmethylcellulose phthalate, acrylate copolymer (methacrylic acid/methyl methacrylate copolymer or methacrylic acid/ethyl methacrylate copolymer, brandname: Eudragit L), polyvinyl acetate phthalate, hydroxypropylmethylcellulose acetate succinate, carboxymethylethylcellulose, and other enteric polymers. It is preferred to employ hydroxypropylmethylcellulose phthalate, acrylate copolymer, hydroxypropylmethylcellulose acetate succinate, and carboxymethylethylcellulose, and among them, hydroxypropylmethylcellulose phthalate is the most preferred enteric polymer.