GB1414812A - Device for sustained release of drugs and like active agents - Google Patents

Abstract

1414812 Sustained release medicaments ALZA CORP 19 Sept 1972 [30 Sept 1971 17 Aug 1972] 43369/72 Addition to 1333576 Heading A5B A device which delivers a medicament at a substantially constant rate over a prolonged period of time comprises a sealed container containing a solid medicament and a liquid in which it is sparingly soluble, the container being composed, at least partially, of a material through which the medicament diffuses at a rate slower than that at which it can be dissolved by the liquid and transported to the inner face of the container wall (this being the sole mode of release of medicament). The container material may be one through which the medicament will diffuse or it may be a microporous material, the pores of which are filled with a liquid through which the medicament diffuses. A very wide range of medicaments. liquids and container materials are specified, the latter being chiefly various natural and synthetic polymers. Examples relate to contraceptive implants and intra-uterine devices comprising a hormone, e.g. progesterone, and a liquid e.g. asilicone oil, aqueous polyvinyl pyrrolidone or aqueous carboxymethylcellulose enclosed within a container composed essentially of polyethylene, ethylene/vinyl acetate copolymer or cured silicone; cortisone and aqueous methyl cellulose in an ethylene/vinyl acetate elastomer container; phenagocine HCL and water in a PVC, ethylene/vinyl acetate copolymer or radiation cross-linked poly(cis-1, 4-polyisoprene); pilocarpine and an unspecified liquid in ethylene/vinyl acetate copolymer (ocular insert) and various shaped devices (polyethylene "band", polyethylene heart valve and polyamide suture) containing unspecified medicaments.