Abstract: The present invention relates to a method for the preparation of polyamino acids, with controlled molecular weights, by polymerization of N-carboxyanhydrides (NCAs) of at least one amino acid, using at least one initiator of the strong base type and in liquid medium, characterized in that it consists in including, in the liquid reaction medium, given amounts of water and/or of alcohol. Application: synthesis of polyamino acids with mechanical and rheological characteristics adapted to applications as biomaterials.

Abstract: The invention relates to microcapsules containing at least one active ingredient, characterized in that they are constituted by:an hydrophilic and essentially non-aqueous liquid inner core, formed of a solution of at least one active ingredient which is water-soluble and amphiphilic in at least one non-aqueous hydrophilic solvent, andby a wall, enclosing said inner core and based on at least one polymer or copolymer, and to one of their preparation methods.The invention finds an application in systems of instant release of active ingredient, such as articles of hygiene, surgical gloves and materials.

Abstract: The present invention relates to a cellular cellulosic material containing a biocide agent and to a process for preparing same. Characteristically, matrix type microparticles, containing at least one biocide agent, are distributed in the network of cellulose of said material, ensuring therein, in the presence of moisture or water, a controlled release of the biocide agent or agents.

Abstract: Polyester/silicon co-crosslinked polymer substrates at least partially degradable by hydrolysis, well adopted as matrices for the controlled release of a wide variety of active agents therefrom, are prepared by controlledly co-crosslinking (a) at least one diorganopolysiloxane having at least two hydroxyl groups per molecule and (b) an oligomeric polylactic and/or polyglycolic polyester .alpha.,.omega.-diol, with an effective co-crosslinking amount of (c) an organic polyisocyanate.

Abstract: Non-agglomerating elastomeric organopolysiloxane particulates having a mean particle size ranging from 50 .mu.m to 3 mm, uniformly coated with silica powder on the face surfaces thereof and well adapted as a soft filler material for natural or synthetic polymers or as a controlled release dosage form, are produced by (a) forming an oil-in-water emulsion of .alpha.,.omega.-dihydroxydiorganopolysiloxane oils, silica powder, a platinum curing catalyst and, optionally, an active principle such as a medicament or an agrochemical, and then (b) breaking and polycondensation crosslinking such emulsion into the desired particles by heating it to a temperature ranging from 40.degree. to 100.degree. C.

Abstract: Non-agglomerating elastomeric organopolysiloxane particulates having a mean particle size ranging from 50 .mu.m to 3 mm, uniformly coated with silica powder on the face surfaces thereof and well adapted as a soft filler material for natural or synthetic polymers or as a controlled release dosage form, are produced by (a) forming an oil-in-water emulsion of silicone oils, silica powder, a platinum curing catalyst and, optionally, an active principle such as a medicament or an agrochemical, and then (b) breaking and polyaddition crosslinking such emulsion into the desired particles by heating it to a temperature ranging from 40.degree. to 100.degree. C.