Hydroformed Microspheres as New Injectable Drug Vehicle

We have developed a new hydroforming process for making sustained release injectablebiodegradable microsphere and microcapsule well suited for delivery of water soluble drugs such aspeptides and proteins. The process incorporates drug into hydroformed microspheres made of sparinglysoluble calcium minerals, such s calcium sulfate, which can then be overcoated with a polymer, mineralor lipid shell. The technique can produce microsphere from calcium compounds involving sulfate,phosphate or silicate anions. Calcium sulfate cement, better known as plaster of Paris, is used as atemporary bone filler, and calcium phosphate cements based on a natural bone mineral, hydroxyapatite,are under investigation for tooth an drone repairs. Unlike thermoformed ceramics, which may persistindefinitely in the body, hydroformed calcium minerals have been found to bioresorb harmlessly.Although they offer many advantages as injectable microsphere, they have not previously beeninvestigated for that purpose. Using an opiate antagonist, methadone HCL, as a prototype water-solubledrug. Phase I will prepare and characterize hydroformed microcapsule and examine their erosion anddelivery in vitro. Phase II will then conduct in vivo animal tests, submit an IND to the FDA,and initiatehuman clinical studies on the use of such injectable microcapsule as part of opiate abuse therapy.