Study of the absorption of myo-inositol hexakisphosphate (InsP6) through the skin.

Recently, some properties of myo-inositol hexakisphosphate (InsP(6)) are related to its dermatological use as discolouring agent, on preventing calcinosis cutis or due to its important role on premature aging. Some studies also seem to demonstrate a capacity of InsP(6) to inhibit skin cancer. In this paper, a first study of the absorption of InsP(6) through the skin is developed. Due to the correlation between InsP(6) absorption and its urinary excretion, these last values were used to evaluate this process. It was found that using a moisturizing cream as vehicle, the InsP(6) sodium salt was absorbed at significantly higher amounts than the InsP(6) calcium-magnesium salt. Maximum InsP(6) urinary concentrations were observed approximately at 14 d of 2% InsP(6) topical cream application, and gave 66.35+/-5.49 mg/l urinary InsP(6) when the sodium salt was used and 16.02+/-2.61 mg/l urinary InsP(6) when the calcium-magnesium salt was applied. When the InsP(6) topical cream administration ceased, the InsP(6) urinary excretion fell dramatically approximately during a period of 10 d. From these results, it can be deduced that by topical administration InsP(6) can achieve important concentrations in tissues and biological fluids, this demonstrating that it is possible to propose the topic use as a new InsP(6) administration route.