Drug delivery system based on polyethylene vinylacetate copolymers

Abstract

A drug delivery system consisting of one or more compartments and comprising a progestogenic compound dissolved in a thermoplastic polyethylene vinylacetate copolymer whereby, if the delivery system consists of one compartment, the compartment comprises (i) a core of a thermoplastic polyethylene vinylacetate copolymer comprising the progestogenic compound, such progestogenic compound being dissolved in the polyethylene vinylacetate copolymer up to a concentration below the saturation level at 25° C., and an estrogenic compound; and (ii) a skin of a thermoplastic polyethylene vinylacetate copolymer covering the core, said skin being permeable for both compounds; if the delivery system consists of more than one compartment, only one compartment comprises (iii) the progestogenic compound, such progestogenic compound being dissolved in a core of a thermoplastic polyethylene vinylacetate copolymer up to a concentration below the saturation level at 25° C., and an estrogenic compound; and (iv) a skin of a thermoplastic polyethylene vinylacetate copolymer covering the core, said skin being permeable for both compounds.

1 - 16 . (canceled) 
     
     
         17 . A drug delivery system consisting of:
 (i) a core that is comprised of:
 a thermoplastic polyethylene vinylacetate copolymer containing 30 to 50 wt % vinylacetate; 
 a progestogenic compound, that is dissolved in the polyethylene vinylacetate copolymer at a concentration below the saturation level at 25° C., based on the weight of the core; and 
 an estrogenic compound; and 
   (ii) a skin that is comprised of a thermoplastic polyethylene vinylacetate copolymer and that covers the core, said skin being permeable to the progestogenic and estrogenic compounds; and   wherein the drug delivery system is physically stable when stored at a temperature ranging from about room temperature to about 40° C.   
     
     
         18 . A drug delivery system according to  claim 17 , wherein the progestogenic compound is a steroidal progestogenic compound and the estrogenic compound is a steroidal estrogenic compound. 
     
     
         19 . A drug delivery system according to  claim 17 , wherein the progestogenic compound is etonogestrel. 
     
     
         20 . A drug delivery system according to  claim 19 , wherein the release on day 21 of etonogestrel of the drug delivery system is 80 μg/day or more. 
     
     
         21 . A drug delivery system according to  claim 17 , wherein the estrogenic compound is ethinyl estradiol. 
     
     
         22 . A drug delivery system according to  claim 17 , wherein the system is ring-shaped. 
     
     
         23 . A drug delivery system according to  claim 17 , wherein the drug delivery system is a drug delivery system for intravaginal use. 
     
     
         24 . A drug delivery system according to  claim 17 , wherein the polyethylene vinylacetate copolymer of the skin is a copolymer containing 1-15 wt % of vinylacetate. 
     
     
         25 . A drug delivery system according to  claim 24 , wherein the skin has a thickness in the range of 10 to 110 μm. 
     
     
         26 . A drug delivery system according to  claim 24 , wherein the skin has a thickness in the range of 20 to 100 μm. 
     
     
         27 . A drug delivery system according to  claim 24 , wherein the skin has a thickness in the range of 30 to 70 μm. 
     
     
         28 . A drug delivery system according to  claim 17 , wherein the polyethylene vinylacetate copolymer of the skin is a copolymer containing 14 to 28 wt % vinylacetate. 
     
     
         29 . A drug delivery system according to  claim 28 , wherein the skin has a thickness in the range of 70 to 250 μm. 
     
     
         30 . A drug delivery system according to  claim 28 , wherein the skin has a thickness in the range of 110 to 250 μm. 
     
     
         31 . A contraceptive kit comprising the drug delivery system according to  claim 17 .