Abstract: The invention relates to a method for the preparation of a siloxane-based elastomer composition comprising at least one elastomer, said elastomer composition comprising poly(alkylene oxide) groups present in the elastomer as alkoxy-terminated grafts of polysiloxane units and linked to the polysiloxane units by silicon-carbon bonds wherein at least one vinyl functional polymer component is crosslinked in the presence of a peroxide catalyst.

Abstract: A membrane or matrix for controlling the permeation rate of a drug, where the membrane or matrix includes a siloxane-based elastomer composition which contains at least one elastomer and optionally a non-crosslinked polymer. The elastomer composition includes poly(alkylene oxide) groups, and the poly(alkylene oxide) groups are present as blocks in a chain of the elastomer or the polymer, or as blocks and alkoxy-terminated grafts of polysiloxane units, the blocks or blocks and grafts being linked to the polysiloxane units by silicon-carbon bonds, with at least three blocks being present in the elastomer or polymer chain. Methods for the preparation of the elastomer composition are also disclosed.

Abstract: The invention relates to a method for the preparation of a siloxane-based elastomer composition comprising at least one elastomer, said elastomer composition comprising poly(alkylene oxide) groups present in the elastomer as alkoxy-terminated grafts of polysiloxane units and linked to the polysiloxane units by silicon-carbon bonds wherein at least one vinyl functional polymer component is crosslinked in the presence of a peroxide catalyst.

Abstract: A membrane or matrix for controlling the permeation rate of a drug, where the membrane or matrix includes a siloxane-based elastomer composition which contains at least one elastomer and optionally a non-crosslinked polymer. The elastomer composition includes poly(alkylene oxide) groups, and the poly(alkylene oxide) groups are present as blocks in a chain of the elastomer or the polymer, or as blocks and alkoxy-terminated grafts of polysiloxane units, the blocks or blocks and grafts being linked to the polysiloxane units by silicon-carbon bonds, with at least three blocks being present in the elastomer or polymer chain. Methods for the preparation of the elastomer composition are also disclosed.

Abstract: A device for the controlled release over a prolonged period of time of a drug having antiprogestinic properties, the device including a core containing the drug, optionally a membrane encasing the core, where at least one of the core and membrane, when present, is made of a siloxane-based elastomer composition including at least one elastomer and optionally a non-crosslinked polymer. The device is characterized in that the elastomer composition includes poly(alkylene oxide) groups and that the poly(alkylene oxide) groups are present in the elastomer or polymer as alkoxy-terminated grafts of polysiloxane units, or as blocks, the grafts or blocks being linked to the polysiloxane units by silicon-carbon bonds, or as a mixture of these forms.

Abstract: The invention relates to a delivery device for the controlled release of the therapeutically active agent gestodene, over a prolonged period of time, at a release rate of 0,1-300 &mgr;g/day, said device comprising a core comprising at least said therapeutically active agent, and a membrane encasing said core wherein said membrane is made of an elastomer. According to the invention, the elastomer is a siloxane-based elastomer comprising 3,3,3-trifluoropropyl groups attached to the Si-atoms of the siloxane units, and the release rate of said therapeutically active agent of said delivery device is regulated by the amount of said 3,3,3-trifluoropropyl groups.

Abstract: The invention relates to a new polysiloxane-based block copolymer having a formula T(AB)xAT  (I) wherein A=—(SiR′R″O)nSiR′R″—, wherein R′ and R″ are the the same or different and represent a lower alkyl group or a phenyl group, wherein said alkyl or phenyl group may be substituted or unsubstituted; B is polyalkylene oxide of formula wherein R is hydrogen, lower alkyl, or phenyl; R1 is hydrogen or lower alkyl; y is 2-6; m is 1-30; n is 1-3000; and x is 0-100.

Abstract: The invention relates to a delivery device for the controlled release of a therapeutically active agent, especially an androgen, over a prolonged period of time, said device including a core containing the therapeutically active agent, and a membrane encasing the core wherein the membrane is made of an elastomer. According to the invention, the elastomer is a siloxane-based elastomer which includes 3,3,3-trifluoropropyl groups attached to the Si-atoms of the siloxane units.

Abstract: The invention relates to a delivery device for the controlled release of a therapeutically active agent, especially a progestin or an estrogen, over a prolonged period of time, said device including a core which contains the therapeutically active agent, and a membrane encasing the core wherein said membrane is made of an elastomer. According to the invention, the elastomer is a siloxane-based elastomer which includes 3,3,3-trifluoropropyl groups attached to the Si-atoms of the siloxane units.

Abstract: A process is provided for the preparation of pure cyclosporin which is purified chromatographically from a mixture of different cyclosporin forms and other substances prepared by fermentation. The process comprises feeding a mixture containing a desired form of cyclosporin with an eluent consisting of high pressure carbon dioxide and an adjuvant, into a chromatography column being packed with particles prepared of silica, and recovering from the eluent flow coming out of the chromatography column a fraction which contains the desired cyclosporin form in adequately pure form.

Abstract: The present invention concerns a novel process for the preparation of methylenebisphosphonic acids of the formula I ##STR1## wherein Q.sup.1 and Q.sup.2 are independently hydrogen or halogen, by hydrolyzing the corresponding methylenebisphosphonic acid tetraester of the formula ##STR2## wherein R has the meaning of a straight or branched alkyl group containing 1 to 4 carbon atoms, and Q.sup.1 and Q.sup.2 have the same meaning as above.