Compatibility and efficiency of preservatives in emulsive cosmetics containing high surfactant content

Abstract The objective of this study was to determine the influence of nonionic surfactants on the effectiveness of preservatives used in emulsions containing high surfactant content. Mixtures of different concentrations were prepared between polyethoxylated (40) hydrogenated castor oil (PHCO) and polyoxyethylene sorbitan monooleate (PSO), with methylparaben, phenoxyethanol, methylparaben, ethylparaben, propylparaben, and isobutylparaben (PMEPBI) blend, phenoxyethanol and benzoic acid (BP) blend, and phenoxyethanol and caprylyl glycol (PC) blend. Subsequently, the compatibility of the formulation ingredients and the effectiveness of the preservatives were evaluated by the challenge test. It was found that PHCO and PSO inactivated the antimicrobial action of methylparaben and PMEPBI. Paraben-free preservatives BP and PC had less influence on surfactants than systems containing parabens. When incorporated into microemulsions and nanoemulsions containing 40% and 20% surfactants, methylparaben and BP 0.2% and 0.5% were only effective against Aspergillus niger. The PMEPBI 0.2% was effective as a preservative in nanoemulsified formulations against A. niger, Escherichia coli, Pseudomonas aeruginosa, and Staphylococcus aureus. The results demonstrate that the efficacy of the preservative system in formulations containing nonionic surfactant excipients depends on the type of excipient, the components of the formulation, the preservative systems composition, the excipient to preservative ratio, and the availability in the formulation.

Programa de ensino de facoemulsificação CBO/ALCON: resultados do Hospital de Olhos do Paraná / CBO/ALCON teaching method of phacoemulsification: results of Hospital de Olhos do Paraná

Objetivo: Analisar os resultados obtidos com a aplicação do programa de ensino de facoemulsificação CBO/ALCON no curso de especialização em oftalmologia do Hospital de Olhos do Paraná. Métodos: Realizou-se um estudo retrospectivo analítico dos resultados das cirurgias de catarata realizadas pelo programa de ensino de facoemulsificação CBO/ALCON que utiliza o método "reverso" em pacientes provenientes do ambulatório do SUS do Hospital de Olhos do Paraná. O programa consta da progressão dos alunos por cinco etapas chamadas de "check points", sendo analisadas as intercorrências per-operatórias em cada um deles, bem como as pós-operatórias. Resultados: Do total de 84 olhos operados, 77 (91,67 por cento) apresentaram acuidade visual (AV) final de 20/40 ou melhor. Entre as intercorrências, a principal delas foi a rotura de cápsula posterior (RCP) e ocorreu em 11 (13,09 por cento) dos 13 (15,48 por cento) olhos que apresentaram algum tipo de complicação. Conclusão: O método "reverso" proposto para o ensino de facoemulsificação pelo programa CBO/ALCON se mostra uma forma de ensino adequada, para o médico residente e seu instrutor, e principalmente para o paciente, devido ao baixo índice de complicações.

Purpose: To analyze the results obtained with a new phacoemulsification teaching method in the specialization course of Hospital de Olhos do Paraná. Methods: A retrospective study evaluated the results of a "reversal" method used in the CBO/ALCON teaching program at the Hospital de Olhos do Paraná. The method is based on the student progression through five checkpoints starting from the end of the surgery towards the beginning and analysis of intra- and postoperative complications at each one of the checkpoints. Results: Of 84 operated eyes, 77 (91.67 percent) presented final visual acuity of 20/40 or better. Among the complications, the main one was the posterior capsular rupture and occurred in 11 (13.09 percent) of 13 (15.48 percent) eyes with complications. Conclusion: The "reversal" teatching method used in the CBO/ALCON teaching program is appropriate to the student, his instructor, as well as to the patient.