Formulation of oil-in-water emulsions containing spray-dried tamarind pulp extract and whitening efficacy test in volunteers

Abstract

The aims of this study were to prepare spray-dried tamarind pulp extract and oil-in-water emulsions containing tamarind pulp extract. Physical and chemical properties were studied. Whitening and moisturizing efficacies of oil-in-water emulsion containing spray-dried tamarind pulp extract in volunteers were evaluated. Analytical method for determining tartaric acid in tamarind pulp, spray-dried tamarind pulp extract and oil-in-water emulsion containing spray-dried tamarind pulp extract were developed. In the preparation of spray-dried tamarind pulp extract, 10 %w/w acacia, inlet temperature 110 ºC, fan setting 50 were successful for spray drying tamarind pulp extract. Percent yield of spray-dried tamarind pulp extract was 55.73 ± 4.75 %, percent moisture content was 6.41 ± 0.64 %, spherical and smooth surface with slightly aggregated particles were obtained. The spray-dried tamarind pulp extract contained 7.83 ± 0.13 % w/w of tartaric acid. Stability of spray dried products were determined by keeping in tight, clear or light protected vials at accelerated temperature 40 ± 2ºC, relative humidity 75 ± 5% for 6 months. Amount of tartaric acid in spray-dried product was slightly decreased, finally, percent remaining of tartaric acid in both vials was as same as 93.16 % w/w. Eight percents by weight of spray-dried tamarind pulp extract was incorporated into oil-in-water emulsions. The prepared emulsions showed good physical and chemical stability at the ambient temperature for 6 weeks. Whitening and moisturizing efficacies of oil-in-water emulsion containing tamarind pulp extract using oil-in-water emulsion base as a control were tested in 35 healthy female volunteers which age in range 20 – 45 years. Tested and control sample of emulsions were applied on forehead twice per day for 6 weeks. Melanin value and moisture content were determined. After using emulsion containing spray-dried tamarind pulp extract, moisturizing value was increased in first week and significantly increased in three weeks more than using oil-in-water emulsion (p=0.000), melanin value at forehead was significantly decreased in four weeks more than using oil-in-water emulsion base (p=0.035).