Process for coating active principles using a pH-sensitive polymer
AssigneeRhone-Poulenc Nutrition Animale
InventorsPierre Ardaillon, Christian Prud'Homme
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Abstract
A process for coating at least one medicinal and/or foodstuff active principle useful for ruminants. At least one monomer is polymerized in an oil-in-water emulsion in the presence of a surfactant to synthesize a pH-sensitive-polymer composition, the composition being obtained in an oil-in-water emulsion. Without isolation of the pH-sensitive polymer, the oil-in-water emulsion is used to coat the active principle, preferably methionine or lysine or a derivative thereof. The pH-sensitive polymer is not dissolved in an organic solvent(s) in either the polymerization or coating steps. The pH-sensitive polymer is stable at pH 6 but at pH 2, the coated active principle is released.
Claims17
A process for coating at least one medicinal and/or foodstuff active principle useful for ruminants consisting essentially of the steps of:
- (a) polymerizing at least one monomer in an oil-in-water emulsion in the presence of a surfactant, to synthesize a pH-sensitive-polymer, said synthesized polymer being contained in said oil-in-water emulsion, and
- (b) without isolation of the pH-sensitive polymer, coating said active principle with said oil-in-water emulsion containing said pH-sensitive polymer, wherein said pH-sensitive polymer is not dissolved in an organic solvent or mixture of organic solvents in either step (a) or in step (b), and further wherein said pH-sensitive polymer is stable at pH 6 but wherein at pH 2 said coated active principle is released.
A process for coating a methionine or lysine active principle consisting essentially of the steps of:
- (a) polymerizing a mixture of vinylpyridine and styrene in an oil-in-water emulsion in the presence of sodium oleate, to synthesize a vinylpyridine-styrene polymer said synthesized vinylpyridine-styrene polymer being contained in an oil-in-water emulsion,
- (b) adding stearic acid and an aqueous sodium hydroxide solution to said oil-in-water emulsion resulting from step (a) to form an oil-in-water coating emulsion, and
- (c) without isolation of the vinylpyridine-styrene polymer, coating said active principle with said oil-in-water coating emulsion resulting from step (b), wherein said vinylpyridine-styrene polymer is not dissolved in an organic solvent or mixture of organic solvents in any of steps (a)-(c).
Dependencies are inferred from the claim text.