SUBSTANTIALLY WATER-INSOLUBLE MATRIX CONTAINING BIOACTIVE SUBSTANCES FOR SLOW RELEASE

摘要

The invention provides a matrix which is substantially water-insoluble and is capable of effecting a slow release of an encapsulated bioactive substance. The matrix comprises a protein or protein-containing material cross-linked by a cross-linking agent to urea to form a 3-dimensional structure throughout which the bioactive substance is substantially uniformly dispersed. In preferred embodiments, the protein or protein-containing material is acid casein, and the bioactive substance is a trace element such as selenium or cobalt. Also provided is a process of preparing a matrix according to the invention.