Drug delivery system comprising a tetrahydroxylated estrogen for use in hormonal contraception
A method of contraception in mammalian females, which method comprises the parenteral or rectal administration of an estrogenic component and a progestogenic component to a female of childbearing capability in an amount effective to inhibit ovulation, wherein the estrogenic component is selected from the group consisting of substances represented by the following formula (1) in which R 1 , R 2 , R 3 , R 4 independently are a hydrogen atom, a hydroxyl group or an alkoxy group with 1-5 carbon atoms; each of R 5 , R 6 , R 7 is a hydroxyl group; and no more than 3 of R 1 , R 2 , R 3 , R 4 are hydrogen atoms; precursors capable of liberating a substance according to the aforementioned formula when used in the present method; and mixtures of one or more of the aforementioned substances and/or precursors. Another aspect of the invention concerns a drug delivery system for parenteral or rectal administration that contains the aforementioned estrogenic component and a progestogenic component, said drug delivery system being selected from the group consisting of suppositories, systems for intravaginal delivery, inhalers, nasal sprays and transdermal delivery systems.
1. A drug delivery system for parenteral, or rectal administration, comprising an estrogenic component and a progestogenic component, said drug delivery system being selected from the group consisting of suppositories, systems for intravaginal delivery, injectable or implantable depot preparations, inhalers, nasal sprays and transdermal delivery systems, wherein the system contains at least 0.01 mg of the estrogenic component, wherein said estrogenic component is selected from the group consisting of substances represented by the following formula:
in which formula R 1 , R 2 , R 3 , R 4 , independently are a hydrogen atom, a hydroxyl group or an alkoxy group with 1-5 carbon atoms; each of R 5 , R 6 , R 7 is a hydroxyl group; and no more than 3 of R 1 , R 2 , R 3 , R 4 are hydrogen atoms;
precursors capable of liberating a substance according to the aforementioned formula when used in the present method, which precursors are derivatives of the substances represented by the formula, wherein the hydrogen atom of at least one of the hydroxyl groups in said formula has been substituted by an acyl radical of a hydrocarbon carboxylic, sulfonic or sulfamic acid of 1-25 carbon atoms; tetrahydrofuranyl; tetrahydropyranal; or a straight or branched chain glycosidic residue containing 1-20 glycosidic units per residue; and
mixtures of one or more of the aforementioned substances and/or precursors, and
wherein the system does not contain a luteinizing hormone releasing hormone (LHRH) composition or a gonadotropin hormone releasing hormone (GnRH) composition.
2. The drug delivery system according to claim 1 , wherein the device contains at least 10 μg of the progestogenic component.