Investigation of the synergistic effect and the morphology of the binary compound systems with potassium N-lauroyl glycinate

Potassium N-lauroyl glycinate (PLG) is an amino acid surfactant widely used in detergents and has excellent chemical properties. In the present work, PLG was mixed in different molar ratios (α1) with the commonly used amphoteric surfactant lauryl amidopropyl betaine (LAB) or the non-ionic surfactant alkyl glycoside (APG). Subsequently, the surface tension, average hydrodynamic radius and number of micellar aggregates of the individual surfactants and the compound systems were measured using the hanging plate method, dynamic light scattering and fluorescence probe method, respectively, and the corresponding surface activity parameters were calculated. The results show that the binary PLG/LAB and PLG/APG systems exhibit non-ideal behaviour and that there was mutual attraction in the systems. The broad distribution of the micelle radius of the PLG/LAB compound system indicates that there are two types of micelles, namely spherical and rod-shaped in the systems. The distribution of the micelle radius of the PLG/APG compound system decreases to the minimum value at α 1 = 0.5. At α 1 = 0.7 and 0.9, double peaks and a broad distribution were also observed. The number of micelle aggregates in the PLG/LAB and PLG/APG compound systems is less than that of the individual surfactants at the respective mole fractions.

Zooceuticals and Cosmetic Ingredients Derived from Animals

Many substances derived from animals are used as ingredients in the cosmetic industry and constitute a particular type of product: zooceuticals. The main ingredients used can come from insects, such as snail slime; land animals, such as lanolin; and marine animals, such as marine collagen. Today, they are used less than in the past for hygienic–sanitary, ethical, and ecological reasons. Moreover, some can give rise to irritative or allergic dermatitis. However, they still represent a fraction of the common ingredients in certain types of cosmetic products today.

Análisis del rótulo y características de los jabones utilizados en la piel del recién nacido

Objetivo:

Analizar la información del rótulo, y las características físicas y fisicoquímicas de los jabones usados en recién nacidos (RN).

Método:

Estudio cuantitativo y descriptivo de 17 jabones comercializados en San Pablo, Brasil. Se analizó la información del rótulo (tensioactivos, pruebas de seguridad y descripción del valor de pH), y las características físicas (color y fragancia) y fisicoquímicas (valor de pH) del producto; las dos últimas, en laboratorio.

Resultados:

Se identificaron 27 tipos de tensioactivos: 70,3% (n=19) aniónicos, 18,5% (n=5) anfóteros y 11,1% (n=3) no iónicos. El 37% (n=10) tuvo un potencial moderado de irritación. En cuanto a las pruebas de seguridad, la mayoría de las formulaciones (94,1%) citó “dermatológicamente probado”. Sólo 42% citó “oftalmológicamente probado”. La translucidez estuvo presente en 23,5% (n=4) de los jabones. Todas las formulaciones presentaron fragancia. El promedio más alto de valor de pH fue de jabones en barra tradicionales (9,94 DE 0,81).

Conclusión:

Las formulaciones analizadas indicaron un potencial de irritación bajo o moderado. Cuatro jabones líquidos y uno en barra combinados tuvieron valores cercanos a los del pH de la piel del RN, y mostraron ser adecuados para la homeostasis de la barrera cutánea. Aunque las formulaciones citaron “dermatológicamente probado”, no todas citaron “oftalmológicamente probado”. Este estudio proporciona elementos para seleccionar un jabón adecuado para el RN.

Synthetic and Bio-Derived Surfactants Versus Microbial Biosurfactants in the Cosmetic Industry: An Overview

This article includes an updated review of the classification, uses and side effects of surfactants for their application in the cosmetic, personal care and pharmaceutical industries. Based on their origin and composition, surfactants can be divided into three different categories: (i) synthetic surfactants; (ii) bio-based surfactants; and (iii) microbial biosurfactants. The first group is the most widespread and cost-effective. It is composed of surfactants, which are synthetically produced, using non-renewable sources, with a final structure that is different from the natural components of living cells. The second category comprises surfactants of intermediate biocompatibility, usually produced by chemical synthesis but integrating fats, sugars or amino acids obtained from renewable sources into their structure. Finally, the third group of surfactants, designated as microbial biosurfactants, are considered the most biocompatible and eco-friendly, as they are produced by living cells, mostly bacteria and yeasts, without the intermediation of organic synthesis. Based on the information included in this review it would be interesting for cosmetic, personal care and pharmaceutical industries to consider microbial biosurfactants as a group apart from surfactants, needing specific regulations, as they are less toxic and more biocompatible than chemical surfactants having formulations that are more biocompatible and greener.

Release studies of undecylenoyl phenylalanine from topical formulations

The aim of this study was to characterize the stability of new vehicles for the undecylenoyl phenylalanine that is used as skin-lightening agent in the melasma treatment. The purpose of this research was also to analyse the release kinetics of phenylalanine derivative from topical preparations through different synthetic membranes. Topical formulations such as two different macroemulsions, hydrogels (based on carbomer and hydroxyethylcellulose) and microemulsions were characterized in terms of stability by laser diffraction method. Additionally, multiple light scattering assessed the stability of macroemulsions. The release rates of active substance through different membranes (such as Cuprophan, nitrocellulose, cellulose acetate and Strat-M) were determined using enhancer cell. In order to explain the mechanism of release process the results were fitted with different kinetic models. New stable vehicles for Ude-Phe were successfully obtained. The results proved that the membrane structure had the influence on the release rate of undecylenoyl phenylalanine. The slowest release rate of Ude-Phe was observed when Strat-M membrane was applied. The highest amount of active substance was released from the hydrogel based on carbomer. The release of undecylenoyl phenylalanine from both macroemulsions and hydrogel based on hydroxyethylcellulose followed the Higuchi model. Whereas the release results of Ude-Phe from both microemulsion-based hydrogels and carbomer hydrogel can be described by using Korsmeyer-Peppas model. Hydrogels and microemulsion-based hydrogels could be recommended as proper vehicles for the derivative of phenylalanine.