Controlled release pharmaceuticals - have PVA partially acetalised with butyraldehyde as matrix former

摘要

A pharmaceutical prepn. with controllable delayed release of active ingredient contains, as the matrix former, a polyvinylalcohol which is partially acetalised with butyraldehyde and which has a stepped deg. of acetalisation of 0-21%. In the case of sparingly soluble low dose pharmaceuticals, the deg. of acetalisation is e.g. 0-4% or 15-21% and for readily soluble high dosed substances, the deg. of acetalisation is 5-10%. The active ingredient, the partially acetalised polyvinyl alcohol and conventional lubricants are mixed and pressed into tablets by direct tableting. USE/ADVANTAGE - The active ingredient can be uniformly and completely released over a period of at least 8 hrs. The retardation is achieved using readily available, easily worked, non-toxic auxiliaries. The matrix swells under physiological conditions and dissolves step-wise and gives controllable release of the active ingredient by working in hydrophilic auxiliaries.