Formulation and Evaluation of a Vitamin C Multiple Emulsion

Abstract

Multiple phase emulsions are increasingly used as alternatives to simple emulsions in personal care products. One of the major advantages of these emulsions over simple emulsions is slow and controlled release of their ingredients. Other favorite cosmetic characteristics of multiple emulsions include occlusivity (in O/W/O emulsions), esthetics and consumer acceptance. Vitamin C (ascorbic acid) has been widely used in formulations of skin care products. Due to its effects on collagen biosynthesis, it is considered as moisturizing and anti-aging active ingredient. Instability problems such as oxidation susceptibility have made incorporating vitamin C in topical formulations a challenging issue. The O/W/O emulsions have been formulated using two-step procedure, to investigate vitamin C stability and its release profile. By using different surfactant types and ratios, volume ratio of phases, multiple emulsions containing vitamin C were prepared. Different parameters and formulation factors such as temperature of phases, duration and speed of mixing were evaluated. Based on our results, more stable emulsions were prepared from non-ionic siliconized surfactants, sorbitan derivatives and co-surfactants such as polyglyceryl derivatives. Physical stability was determined by microscopic examination, centrifugation and incubating emulsions in different temperatures. Vitamin C in vitro release studies from O/W and O/W/O emulsions were conducted using Franz diffusion cell (at room temperature) and UV spectrophotometry. The results showed that in the first four-hour period, about 14% of vitamin C released from O/W/O emulsions. It appears that in multiple emulsions the profile of release follows zero-order kinetics. Our data indicate that incorporating vitamin C in multiple emulsions significantly increased its stability possibly attributed to the formation of reverse micelles of surfactants (and/or co-surfactants), which entrapped vitamin C inside the micelles surrounded by hydrophilic heads of surfactant. Moreover, vitamin C was released from multiple emulsions in a zero order slow and controlled release manner.

A novel L-ascorbic acid and peptide conjugate with increased stability and collagen biosynthesis

“…In addition, because of its low stability against oxygen, light and heat, it has been difficult to develop and maintain the effective activity of L-ascorbic acid for commercial use in the cosmetics field (8). As ascorbic acid is highly labile to environmental conditions, it requires modification to reduce rapid degradation.…”

“…The stability of ascorbic acid is so low, however, that it is difficult to deliver and does not remain in skin tissue for extended periods of time. According to previous reports, ascorbic acid is rapidly oxidized by air in aqueous solutions (8). Historically, retinoic acid, also known as a potent inducer of the collagen biosynthesis, has been used as a key cosmetic material commercially (9).…”

Preparation and Characterization of Water-in-Oil-in-Water Emulsions Containing a High Concentration ofL-Ascorbic Acid

“…Several research groups have encapsulated L-ascorbic acid at low concentrations (up to 5%) in aqueous droplets using the W/O/W and O/W/O techniques. [22][23][24][25][26] Nevertheless, in order to formulate food-based products such as high energy drinks, high concentrations of active components are required.…”

“…The release pattern of L-ascorbic acid follows zero-order kinetics in W/O and O/W/O emulsions. 23) In most food matrices (juices and fruits) and in water, L-ascorbic acid oxidation and decomposition follow first-order kinetics. 39) In conclusion, food-grade W/O/W emulsions containing a high concentration of L-ascorbic acid were successfully prepared using suitably selected compositions, including gelatin in the inner aqueous phase and glucose in both aqueous phases.…”

Evaluating the Aging of Multiple Emulsions Using Resonance- Enhanced Multiphoton Ionization Time-of-Flight Mass Spectrometry

“…For use in drug-delivery systems (DDS), which is one of the applications of multiple emulsions in the pharmaceutical field, active ingredients are expected to be encapsulated in an individual phase. 9,10 However, aging as well as several collapse processes including migration, which is specific for multiple emulsions, make it difficult to manage multiple emulsions in an expected form. The conditions and properties of multiple emulsions depend on factors such as constituents, concentrations, and preparation schemes.…”