Compositions and methods to affect skin irritation
Compositions are described that contain treated chitosan, modified chitosan and/or modified and treated chitosan for use in formulations for skin, hair and nails, and in compositions and methods of reducing topical agent-induced skin irritation and inflammation.
1. A sunscreen composition comprising: (a) at least one sunscreen agent that causes skin irritation and/or skin inflammation and/or IL-1α secretion, and (b) at least one chitosan covalently modified with an octane sulfonic acid via a sulfonamide linkage, wherein the composition provides a reduction in skin irritation and/or a reduction in skin inflammation and/or a reduction in irritant-induced IL-1α secretion after contact with the composition compared with a control composition comprising the sunscreen agent but not the chitosan.
2. The composition of claim 1 , wherein the at least one covalently modified chitosan comprises about 0.0001-5% W/V of the total weight of the composition.
3. The composition of claim 1 , which is in the form of a solution, suspension, emulsion, lotion, cream, gel, or spray.