The invention relates to controllably dissolving a composite.
Controlled release of medication in vivo is the subject of much research. Various methods and release agents have been suggested, tested and marketed. Calcium sulfate has been utilized as filler for bone cavities as it is capable of being spontaneously adsorbed and replaced by bone. Calcium sulfate, formed from the hemihydrate, has been used as a controlled release agent alone for the filling of bone cavities and in combination with additives such as medicaments and pesticides. As a carrier for medicaments, it has been useful in vivo because it is biocompatible and is progressively resorbed by the body, thereby eliminating the need for secondary surgical procedure.
One application for a calcium sulfate controlled release agent is the local delivery of medicaments in vivo. The ideal characteristics of a local medicament delivery system are (1) biodegradability, (2) biocompatibility, (3) prolonged pharmaceutical release (e.g., over a period of at least 4 to 6 weeks), (4) reproducibility, (5) predictable pharmacokinetics, and (6) controllability.
One of the disadvantages to the use of calcium sulfate as a carrier is that, for some medicaments, the medicament is eluted from the calcium sulfate matrix at too rapid of a rate.