Characterization, Antioxidant and Antibacterial Potentials of Tamarindus indica L. Fruit Pulp Extract Loaded O/W Nanoemulsions

Abstract The main purposes of the current study were to formulate o/w nanoemulsions as a carrier for Tamarindus indica (tamarind) fruit pulp extract and to study the antioxidant and antibacterial potentials of nanoemulsions containing tamarind extract, focusing on cosmetic/hygiene applications. The o/w nanoemulsions using a mixture of Tween 80 and Span 80 as an emulsifier (5%w/w) were prepared by a high pressure homogenization process. Two concentrations of sweet tamarind extract, 3.3 and 6.6%w/w, based on the bioactivity study, were incorporated into the blank nanoemulsions to produce loaded nanoemulsions, F1-3.3TE (3.3%) and F1- 6.6TE (6.6%). As compared with the unloaded nanoemulsion, both tamarind extract loaded nanoemulsions showed reduced pH and significantly increased viscosity. Overall, the loaded nanoemulsions had droplet sizes of approximately 130 nm, zeta potential around -38 mV and polydispersity index (PDI) values less than 0.2. The nanoemulsion F1-3.3TE had better stability (e.g. significantly greater % tartaric acid content and lesser PDI value) than the nanoemulsion F1-6.6TE did. The antioxidant activity using 2,2-diphenyl-1-picrylhydrazyl assay revealed that the nanoemulsions F1-3.3TE and F1-6.6TE had scavenging activities of 81.66 ± 0.77% and 63.80 ± 0.79%, respectively. However, antioxidant activity of these two formulations decreased under stress conditions (heating-cooling cycles). Such incidence did not occur for their antibacterial properties investigated by agar well diffusion technique. The two formulations exhibited inhibition zones of approximately 24.0-27.7 mm against Staphylococcus aureus and Staphylococcus epidermidis, responsible for malodor of underarms. The results suggest the potential of using sweet tamarind pulp extract loaded nanoemulsions as hygiene products.

Using Algebraic Geometry to Describe Boundaries of Microemulsion Regions in Nonionic Systems.

This study aimed to propose an empirical polynomial function based on algebraic geometry which could represent microemulsion regions in nonionic systems. The systems composed of olive oil (OO), water (W) and various ratios of sorbitan monooleate (SMO) and polyoxyethylene 20 sorbitan monooleate (PSMO) mixtures were investigated for their microemulsion regions obtained on the phase diagrams. Concept of algebraic geometry in this study was that description of close-boundary shape was cross-sectioning of a 3D-geometrical object with a plane which could be explained by an empirical polynomial function of the {oil, water, surfactant mixture}. In-house ad hoc software was created according to the proposed concept. It was found that this method could describe boundaries of microemulsion regions in the studied systems. Although this method could not reduce time consumption since it required intensive computational powers, the software could automatically run. Moreover, the developed program could provide acceptable level of accuracy.

Evaluation of Caffeine Gels on Physicochemical Characteristics and In Vivo Efficacy in Reducing Puffy Eyes.

The eyelids are the thinnest skin in the body, leading to be easy for the blood vessels to show through the skin caused a swollen and dark appearance called puffy eyes. Placing refrigerated damp tea bags on the eyelids has been believed for a long time that it can reduce the puffy eyes due to the vasoconstriction of caffeine. This study aimed to characterize physicochemical properties and to determine in vivo efficacy in reducing puffy eyes of the prepared caffeine gels. The formulation composed of 3% caffeine, 2% ethanol, 0.3% Uniphen® P-23, 7.5% propylene glycol, 0.5% Carbopol® Ultrez-21 and water to 100% was selected for eye irritation test and efficacy evaluation since it possessed good characteristics and provided sustained skin permeation. The 34 volunteers (18 women, 16 men) who easily developed puffy eyes after going to bed without sleep and with no irritation to caffeine gel as well as its gel base were treated with the gels in a randomized, double-blind, placebo-controlled trial. The skin permeation profiles showed that all caffeine gels allowed caffeine to permeate through the newborn pig skin. However, the overall efficacy of the selected caffeine gel in reducing puffy eyes was not significantly different from that of its gel base. It could be concluded that the cooling effect of the hydrophilic gels was the main parameter in reduction of eye puffiness rather than the vasoconstriction of caffeine.

Evaluation of Shampoos Containing Silicone Quaternary Microemulsion.

This study aimed to characterize properties and to evaluate conditioning performance providence of shampoos containing various concentrations, i.e., 0, 1, 2, 3 and 4 %w/w, of silicone quaternary microemulsion. The results indicated that all samples were clear yellowish liquids with good odor. Addition of silicone quaternary microemulsion in the investigated formulation did not markedly affect the characteristics of the obtained shampoos, except viscosity. Their averaged pH values were in the range of 6.59-7.17 which were acceptable according to TIS 162-2541. All samples provided stable foam, surface tension reduction and low viscosity with Newtonian flow. Under a light microscope, the cuticle arrangement of five tresses washed by the studied shampoos seemed to be better than their counterpart tresses before washing. However, no obvious difference on the cuticle arrangement of the tresses after washing by the identical manner with different shampoos was observed. Most of 50 referees rated and scored that the tress washed with shampoo containing 1%w/w silicone quaternary microemulsion provided the highest conditioning performance, i.e., smooth and softness, via contacting. It could be concluded that silicone quaternary microemulsion was able to be incorporated with the investigated shampoo formulation as an effective hair-conditioning agent.