Microencapsulação de peróxido de cálcio para liberação lenta de oxigênio

Abstract

This study proposes the microencapsulation of calcium peroxide, based on a polyanhydride for the controlled release of oxygen gas. The release aims to enhance healing in chronic wounds and present a process that is more economically viable than hyperbaric oxygen therapy (HBOT). This ability to release the active ingredient (O2) is due to the fact that polyanhydride is a polymer that can be degraded by the process of surface erosion, due to chemical hydrolysis, thus allowing contact with water as peroxide, which decomposes into oxygen. Releasing oxygen slowly over a certain period of time can promote more efficient healing, avoiding necrosis of the reconstituted tissue. To this end, the formulation was prepared in two stages: the first with condensation polymerization to synthesize the polyanhydride; the second with microencapsulation of the polymer and calcium peroxide. This study shows, through cyclic voltammetry release tests, that the calcium peroxide microspheres are capable of slowly releasing oxygen for 1 week. The solvent removal method was able to encapsulate 90% of the calcium peroxide in the polymer base. The products were characterized by IR to confirm the presence of the anhydride carbonyl and by NMR analysis to determine the degree of polymerization of the polymer. This resulted in a molecular mass of the repeating unit (Mn) of 33,000 Da for poly sebacic acid. TGA and DSC analyses were also carried out and it was found that the microencapsulated material has similar thermal properties to the pure polymer. In addition, the degradation time was analyzed and, using SEM, it was possible to observe the behavior of the microsphere surface during this process. From the data obtained, it was concluded that the release of oxygen occurs over a period of 7 days and it was observed that the release of the active ingredient occurs at approximately 60% on the first day and is slower thereafter.