Abstract: Compositions for the controlled delivery of active ingredients, for example, drugs, cosmetic materials, and agricultural materials. The compositions include a multiplicity of particles, each of the particles comprising (1) a microstructure comprising a semicrystalline polymer which has a peak melting temperature, Tp, of at least 20° C., and (2) the active ingredient. The microstructure comprises (i) crystalline domains of the semicrystalline polymer, the crystalline domains being separate from each other, and (ii) amorphous domains of the semicrystalline polymer, the amorphous domains providing a multiplicity of tortuous paths between the crystalline domains. At least part of the active ingredient is present in the amorphous domains. One of many valuable uses for the compositions is to provide a coating on a seed, for example a coating containing one or more of an insecticide, a fungicide, a nutrient, a biotic, a growth regulator and an herbicide.

Abstract: Compositions for delivering release materials, for example drugs, agricultural materials, other bioactive materials, cosmetic materials, organic or inorganic compounds which take part in or catalyse a chemical reaction, a fragrance-emitting material for a vaporizer, or a lubricating material. The release material is associated with a crystalline carrier. The carrier may be a crystalline polymer containing a plurality of crystalline groups or a crystalline monomer which contains a single crystalline group, the crystalline group preferably comprising a straight chain polymethylene radical containing at least 16 carbon atoms. Some of the carriers are obtained by modifying hyaluronic acid, collagen, gelatin, a polysaccharide, a carbohydrate or cyclodextran. The release material may contain a similar crystalline group, for example may be an active compound which has been modified to introduce a crystalline group.