Preparation, Characterization, and In Vitro Evaluation of Multiple Emulsion for Topical Application of Lawsone and Dihydroxyacetone

Dihydroxyacetone (DHA) is the primary ingredient in most sunless tanners. Lawsone is a primary component of red henna, used in henna tattooing and reversed tattooing. DHA initiates a reaction called the Maillard reaction which results in the browning of the skin. Application of lawsone results in the production of colored keratin-bound fluorescent polymers called melanoidins. DHA alone gives some protection in the UVA spectrum, with minimal UVB. When lawsone is applied after the application of DHA, a different set of melanoidins are produced, giving UVB and even greater UVA protection. |In this study, a multiple emulsion (W1/O/W2) containing 0.035% (w/w) lawsone and 1% (w/w) DHA were prepared using the two step process by Matsumoto et al. The first step was the production of the primary (W1/O) emulsion. The primary emulsion, making up 40% of the final volume of the emulsion, was then added to the secondary aqueous phase (W2). A combination emulsion was prepared by combining doubled concentrations of lawsone and DHA multiple emulsions (W1/O/W2) in a 1:1 ratio through trituration. The structure of the multiple emulsions was determined by light and fluorescent microscopy. The stability of the prepared emulsions was characterized after storage at 25˚C, 32˚C, and 40˚C and over a period of 28 days. DHA and DHA in combination showed a significant decrease in % entrapment efficiency to 37.41 ± 6.03% and 5.41 ± 3.82% after 28 at 40˚C, showing physical/ chemical instability of emulsions at increased temperature. Chemical instability of the emulsions was confirmed by varying decrease in pH at 32˚C and 40˚C of DHA emulsion and combination emulsion. Structural instability of emulsions at 40˚C was confirmed by increase of zeta potential and rheological tests using flow and oscillatory stress/time sweeps. No significant changes in particle size suggest no coalescence occurring. Spreadability remained within the range of ≈ 20 cm²/g to 35cm²/g respectively. Characterization testing suggest the stability of lawsone and DHA emulsions were best when kept separate at 25˚C. In vitro surface release and Franz diffusion studies verified and confirmed drug release were more effective when lawsone and DHA emulsions were kept separate.

Grantor dc:publisher

Creighton University

Year dc:date.issued

2015

Author dc:creator

• Grana, Anne

Advisor dc:contributor.advisor

• Dash, Alekha K.

Statement dc:rights

• Copyright is retained by the Author. A non-exclusive distribution right is granted to Creighton University and to ProQuest following the publishing model selected above.

Language dc:language.iso

en_US

Handle dc:identifier.uri

http://hdl.handle.net/10504/68742

OAI identifier oai:identifier

oai:cdr.creighton.edu:10504/68742