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

Abstract

This study sought to encapsulate a high concentration of L-ascorbic acid, up to 30% (w/v), in the inner aqueous phase of water-in-oil-water (W/O/W) emulsions with soybean oil as the oil phase. Two-step homogenization was conducted to prepare W/O/W emulsions stabilized by a hydrophobic emulsifier and 30% (v/v) of W/O droplets stabilized by a hydrophilic emulsifier. First-step homogenization prepared W/O emulsions with an average aqueous droplet diameter of 2.0 to 3.0 m. Second-step homogenization prepared W/O/W emulsions with an average W/O droplet diameter of 14 to 18 m and coefficients of variation (CVs) of 18% to 25%. The results indicated that stable W/O/W emulsions containing a high concentration of L-ascorbic acid were obtained by adding gelatin and magnesium sulfate in the inner aqueous phase and glucose in both aqueous phases. L-Ascorbic acid retention in the W/O/W emulsions was 40% on day 30 and followed first-order kinetics.

Factors affecting formulation characteristics and stability of ascorbic acid in water‐in‐oil creams

“…Various studies have earlier reported a similar order of reaction for the degradation of AA in o/w and w/o emulsions, multiple emulsions, etc. . It appears that the pH and formulation characteristics of creams greatly affect the rate of reaction, and hence these factors are discussed in the following sections.…”

“…The retention rate ( r ) can be defined as the ratio of measured AA concentration (AA found ) to its initial concentration (AA initial ). The r of AA in cream formulations was calculated by using the following formula : …”

“…In the recent past, interest in the topical use of AA has gained considerable importance due to its scavenging activity against reactive oxygen species (ROS) produced on exposure to sunlight and thus delaying the effect of ageing [16]. Various workers have formulated different AA topical preparations [1][2][3][4][16][17][18][19][20][21][22][23][24][25][26][27][28][29][30][31][32] but still the stability of AA remains a major concern. Derivatives of AA like sodium ascorbate, ascorbyl palmitate, etc.…”

Preparation of monodisperse aqueous microspheres containing high concentration ofl-ascorbic acid by microchannel emulsification

“…The d av ranged from 14.4 to 15.5 mm, and the CV ranged from 6 to 10%. In our previous studies using a rotor-stator homogenizer, L-ascorbic acid of a high concentration (up to 30% (w/w)) was encapsulated in W/O and W/O/W emulsions with similar compositions in the absence of Na-ALG (Khalid et al, 2013a(Khalid et al, ,b, 2014. The encapsulation efficiency of freshly prepared microspheres encapsulating 20% (w/w) L-ascorbic acid was determined using straightthrough MCE.…”

Physicochemical properties and encapsulation of silicon in double emulsions for healthier food applications

“…by thermal processing) are present, the inner emulsion droplets are converted into soft solid-like particles (Dickinson 2011). For instance, thickening or gelling biopolymers have been added to the dispersed aqueous phase of W/O emulsions such as gelatin (Sapei et al 2012;Khalid et al 2013;Oppermann et al 2015;Tepsongkroh et al 2015), locust bean gum and l-carrageenan (Patel et al 2015), alginate (Tepsongkroh et al 2015) etc., to improve their stability, and hence their encapsulation efficiency (EE).…”