Hydrophilic/hydrophobic wound care preparation based on the nanoscale silica: physicochemical and technological aspects

Неaling of infected ulcers and wounds, particularly in older people, is a serious problem in modern surgery. As a result of many years efforts, we have created an innovative wound care composition that has high absorptive, anti-inflammatory and wound-healing capabilities and are starting the clinical study of it. The composition, which got a trade mark Pathelen®, contains nanoscale hydrophilic silica (A-300), hydrophobic silica (Aerosil® R972 Pharma) and benzalkonium chloride. This work aimed to develop an optimal pathway of industrial production, as well as methods of quality control of the drug. The examination of manufacture intermediates and the final product includes bulk density measurement, thermal analysis, IR spectroscopy, chemical methods of identification, adsorption capacity and microbial contamination control. The pathway of manufacture which consists of mechanochemical immobilization of benzalkonium chloride on hydrophobic silica surface and mixing of obtained semi-product with hydrophilic nanoscale silica is developed. Thus, a technological method is proposed for combining hydrophilic and hydrophobic nanomaterials in one preparation. The final product complies to the elaborated quality parameters. In particular, the bulk density is distributed in a range 50–60 g/L, the adsorption capacity is not less than 140 mg of protein per gram. The absence of pathogenic microorganisms and fungi was demonstrated; the quantity of non-pathogenic microorganisms meets the requirements of the European Pharmacopoeia for products in this category. The results obtained can be useful for the organization a large-scale production of the proposed drug in future.