Sustained release formulations containing tacrolimus - Patent 6576259 Sustained release formulation containing tacrolimus or its hydrate is provided. The time (T63.2%) required for 63.2% of the maximum amount of tacrolimus or its hydrate to be dissolved is 0.7 to 15 hours. The time is measured in accordance to the Japanese Pharmacopoeia, the 13-th edition, Dissolution Test, No. 2 (Puddle method, 50 rpm) using an aqueous 0.005% hydroxypropyl cellulose solution. This aqueous test solution is adjusted to pH 4.5, accordingly. The formulation further comprise a solid base which is a water-soluble polymer and/or wax. The formulation is in the form of a powder, fine powder, granule, tablet or capsule. Furthermore, the formulation is administered to a patient once a day for preventing organ or tissue rejection by transplantation or autoimmune diseases. An oral formulation of one of macrolide compounds, namely tacrolimus with an useful immunosuppressive activity, has been prepared as a solid dispersion compositions, which possesses a rapid-release characterization by using polymers such as hydroxypropylmethyl cellulose and disintegrator (see for example EP 0 240 773). Owing to the presence of disintegrator therein, it is a rapid-release formulation. It has been appraised highly in clinical field owing to its high absorbability. In clinical practice, alternatively, the emergence of an oral tacrolimus formulation with a sufficient long action and excellent oral absorbability has been expected. However, it is the state of the art for a person skilled in the art that the absorbability of a pharmaceutically active agent given orally in a manner as sustained-release formulation is generally reduced and/or that a non-negligible variation of the absorbability is observed. The inventors of the invention have carried out a lot of investigations.
