Measurement Of Sun Protection Factor (SPF) Of Cream Containing Mangrove Xylocarpus Extract Using A Modified Solar Simulator (IFSCC Poster Presentation by Wong Lip Wih, PhD)
Mangrove xylocarpus plants have been very useful plant in preventing floods nearby the coastal areas in many parts of Indonesian islands. The objective of this investigation is to assess the Sun Protection Factor of the cream containing Mangrove xylocarpus extract using a modified solar simulator which is portable in size, unlike the big, conventional solar simulator.
Methods Used: The sunscreen cream containing 10% of the Mangrove xylocarpus extract was made as test cream. The SPF of the resulting cream was tested in vitro using spectrocolorimeter method This result will be used as comparison with the SPF number obtained clinically using the modified Solar Simulator with Minimal Erythema Dose (MED) as the visual end point. A specially made adaptor was made with 5 different segments of the adaptor body containing different numbers of hexagonal holes giving a customized dose output ratio (hole 1 to hole 5 decreasing) : 100%. 80%, 60%, 40%, 20%. A total of 32 subjects with skin type IV were recruited for the study. On one side of each panelist’s forearm was radiated with the UV light and the adaptor installed thus giving 5 dose output simultaneously. On the other side of the forearm, 0.5 gram of the test cream was applied and then the SPF test was then carried out with the UV source and modified adaptor. About 24 hours after the irradiation, the forearm of each panelist was examined for erythema. The site with smallest perceptible erythema (faint redness with distinct edge) was selected as the MED. There should be one test site which shows no reaction, and the other should show progressively more erythema with increasing dose of UV exposure.
Results Obtained: The SPF for the test cream was calculated as follows: SPF = MED Test Material/MED Unprotected skin The SPF number obtained using the spectrocolorimeter method was found to be 16. The average SPF number of the test cream containing 10% of the Mangrove xylocarpus extract was found to be 14.72.
Discussion and Conclusion: The test cream was formulated containing only the Mangrove xylocarpus extract as the sunscreen active ingredient. The SPF number is expected to increase with increasing percentage of Mangrove xylocarpus used, however, more experiment must be conducted to confirm if any correlation exists between the SPF number obtained using the in vitro (spectocolorimeter method) and the in vivo (clinical method).The other important aspect of this investigation is the fact that a much more convenient method can now be used to measure the Minimal Erythema Dose (MED) and hence the SPF number using a portable UV simulator. This will eliminate the troubles of placing the panelist under the big UV source in the conventional way.