In vitro determination of Sun Protection Factor on Clays Used for Cosmetic Purposes in Kenya

Abstract

Ultraviolet radiation is a real problem to human health and it’s said to cause skin cancer and related skin ailments. These diseases are of economic burden in terms of diagnosis, treatment and prevention in low and middle level countries. Commercial sunscreens are considered as the most effective way of preventing the incidences of skin cancer, however they are costly, unavailable and they contain toxic ingredients, which can in the end be cancerous. Sunscreens from natural sources like plants and clay are currently being explored as cheap, reliable, and available and may offer simple alternative health benefits. The purpose of this study was to evaluate the amount of sun protection factor (SPF) offered by cosmetic clays used in Kenya by different communities. The SPF was determined in vitro using 3 M transpore adhesive tapes on twelve clay samples collected randomly from sites used in three counties namely Narok, Bomet and Bungoma. Using a spreading protocol of 2 µg/cm2 transmittances between 280 to 400 nm were measured using a UV 1800 Shimadzu, Japan spectrophotometer. A commercial sunscreen with known SPF was incorporated in the study as a positive control. The SPF values of the clays were found to be between 1.46 and 40.98. The SPF value obtained for the commercial sunscreen differed from the SPF cited by the manufacturer. A second method was used on the commercial sunscreen and values obtained were in close agreement with those used in the first method. This study revealed that clays used for cosmetic purposes offer some form of sun protection to its users. Determination of SPF using Transpore tape is cheap, easy to handle, readily available and rapid. Keywords: Sun Protection factor, Clay