Intravaginal ring

Claim 1

A shell design intravaginal ring comprising in combination a core made of an inert elastomer, a medicated layer encircling the core, and an outer inert elastomer layer having a thickness of about 0.1 to 0.6 mm, the medicated layer comprising an inert elastomer and a combination of estradiol with a progestogen selected from the group consisting of levonorgestrel, d,l-norgestrel and norethindrone and the medicated layer having a thickness of not more than twice the thickness of the outer layer.

Claim 9

A method of manufacturing a shell design intravaginal ring which consists of: (a) forming a core ring of a suitable inert elastomer; (b) dipping the core ring in a mixture of an inert volatile solvent containing an inert unvulcanized elastomer and a mixture of estradiol and a progestogen to form a medicated layer; (c) removing the ring from the mixture and allowing the solvent to evaporate; (d) repeating steps b and c until a medicated layer of the desired thickness is obtained; (e) dipping the ring from step d into a mixture of an inert unvulcanized elastomer in an inert volatile solvent removing the ring and allowing the solvent to evaporate to form an outer layer; and (f) repeating step e until an outer layer of desired thickness is obtained.

Claim 10

A method of manufacturing a shell design intravaginal ring which consists of: (a) forming a core ring of a suitable inert elastomer; (b) dipping the core ring in a mixture of an inert volatile solvent containing an inert unvulcanized elastomer and a mixture of estradiol and a progestogen to form a medicated layer; (c) removing the ring from the mixture and allowing the solvent to evaporate; (d) repeating steps b and c until a medicated layer of the desired thickness is obtained; (e) dipping the ring from step d into a mixture of an inert unvulcanized elastomer in an inert volatile solvent removing the ring and allowing the solvent to evaporate to form an outer layer; and (f) repeating step e until an outer layer of desired thickness is obtained.

Claim 12

A method of manufacturing a shell design intravaginal ring which consists of: (a) forming an annular core ring of a suitable inert elastomer by injecting the unvulcanized elastomer into a mold and allowing the ring to cure in the mold; (b) removing the core ring from the mold and cutting the ring open; (c) bringing the open ring to a constant weight; (d) pulling the open ring through a coating solution containing an unvulcanized elastomer and a mixture of estradiol and a progestogen; (e) dipping the coated open ring in a catalyst solution and allowing the coating to polymerize; (f) swelling a piece of tubing in volatile organic solvent and fitting it over the open ring from step e and allowing the solvent to evaporate; (g) trimming the excess tubing from the ends of the open ring and applying a medical grade adhesive to the ends of the open ring and on the surface of the ring close to the open end; (h) placing a piece of swollen tubing over both ends of the open ring to reform the ring and holding the ends of the open ring together for a few minutes and curing the ring for about 24 hours.

Claim 13

A method of manufacturing a shell design intravaginal ring which consists of: (a) forming an annular core ring of a suitable inert elastomer by injecting the unvulcanized elastomer into a mold and allowing the ring to cure in the mold; (b) removing the core ring from the mold and cutting the ring open; (c) bringing the open ring to a constant weight; (d) pulling the open ring through a coating solution containing an unvulcanized elastomer and a mixture of estradiol and a progestogen; (e) dipping the coated open ring in a catalyst solution and allowing the coating to polymerize; (f) swelling a piece of tubing in volatile organic solvent and fitting it over the open ring from step e and allowing the solvent to evaporate; (g) trimming the excess tubing from the ends of the open ring and applying a medical grade adhesive to the ends of the open ring and on the surface of the ring close to the open end; (h) placing a piece of swollen tubing over both ends of the open ring to reform the ring and holding the ends of the open ring together for a few minutes and curing the ring for about 24 hours.

Claim 15

A method of manufacturing a shell design intravaginal ring which consists of: (a) forming a core rod of suitable inert elastomer by injecting the unvulcanized elastomer into a mold and allowing it to cure: (b) removing the resulting core rod and cutting it into lengths about 15.5 cm; (c) bringing the rod to a constant weight; (d) pulling the rod through a coating solution containing a mixture of an unvulcanized elastomer and a mixture of estradiol and a progestogen; (e) dipping the coated rod in a catalyst solution and allowing the coating to polymerize; (f) swelling a piece of tubing in a volatile organic solvent, and sliding it over the coated rod from step e and allowing the solvent to evaporate; (g) trimming the excess tubing from the ends of the rod and applying a medical grade adhesive to the ends of the rod and to the surface of the rod close to the end; (h) placing a second piece of swollen tubing over both ends of the rod to form a ring and holding the ends of the rod together for 24 hours until the adhesive has cured.

Claim 16

A method of manufacturing a shell design intravaginal ring which consists of: (a) forming a core rod of suitable inert elastomer by injecting the unvulcanized elastomer into a mold and allowing it to cure: (b) removing the resulting core rod and cutting it into lengths about 15.5 cm; (c) bringing the rod to a constant weight; (d) pulling the rod through a coating solution containing a mixture of an unvulcanized elastomer and a mixture of estradiol and a progestogen; (e) dipping the coated rod in a catalyst solution and allowing the coating to polymerize; (f) swelling a piece of tubing in a volatile organic solvent, and sliding it over the coated rod from step e and allowing the solvent to evaporate; (g) trimming the excess tubing from the ends of the rod and applying a medical grade adhesive to the ends of the rod and to the surface of the rod close to the end; (h) placing a second piece of swollen tubing over both ends of the rod to form a ring and holding the ends of the rod together for 24 hours until the adhesive has cured.