COMPOSITION CONTAINING SILVER METAL NANOPARTICLES AND A HYALURONATE SALT AS INTERMEDIATE IN THE PREPARATION OF TOPICAL PHARMACEUTICAL FORMULATIONS

摘要

A process for preparing a composition (A) is disclosed containing an aqueous dispersion of a pharmaceutically acceptable hyaluronic acid salt, having a weight average molecular weight ranging from 1,000,000 and 1,400,000 in an amount of from 0.4 to 2% by weight based on the total composition weight and metal silver particles, having an average size of from 4 to 10 nm in a concentration of from 0.004 to 0.02% comprising the following steps: a) Preparing an aqueous solution of said pharmaceutically acceptable hyaluronic acid salt having the above molecular weight with a concentration comprised in the aforementioned range, b) Adding an aqueous solution of a silver salt, to the aqueous solution and an alkaline metal hydroxide until reaching a pH ranging from 9.8 to 12.5, and an Ag ion concentration of from 0.004 to 0.02% c) Letting react the mixture of step b) at temperature ranging from 20 to 65°C d) Neutralizing the reacted mixture of step c) with an organic acid. This composition A) s used as intermediate for preparing pellets (B), wherein said metal silver nanoparticles are dispersed within said pharmaceutically acceptable hyaluronate salt or film (C) or gel (C) obtained by addition of a filming or gelling polymer to said composition (A) previously neutralized with an organic acid. Topical compositions are also disclosed containing: • The pellets (B) • The film (C) or the gel (C) in combination with suitable excipients and/or diluents, to be used in particular in the treatment of wound and lesions in particular of skin, and vaginal mucosa.