The present invention concerns compositions for rinsing the nasal cavity and the sinus cavities for curative or prophylactic treatments of acute and/or chronic rhinitis, and acute and/or chronic sinusitis, comprising:
sodium chloride and/or potassium chloride; quercetin, and at least one active agent of the polyphenolic group chosen from the compounds: quercetin-4′-glycoside, 2-(3,4-dihydroxybenzoyl)-2,4,6-trihydroxy-3(2H)-benzofuranone, protocatechuic acid; and wherein the quercetin is in the anhydrous form with an approximate molecular mass of 302 g/mol, or in the form of quercetin hydrate with an approximate molecular mass of 320 g/mol, or in the form of quercetin dihydrate with an approximate molecular mass of 338 g/mol.
The present invention also relates to the methods for preparing these compositions and the method for treating acute and chronic rhinosinusitis using these compositions.