Study of a myo-inositol hexaphosphate-based cream to prevent dystrophic calcinosis cutis

Summary Background Calcinosis cutis is a disorder caused by abnormal deposits of calcium phosphate in the skin and is observed in diverse disorders. Myo‐inositol hexaphosphate (InsP6) is a diet‐dependent molecule found in all mammalian fluids and tissues, which exhibits an extraordinary capacity as a crystallization inhibitor of calcium salts. Objectives To establish the effects of topically administered InsP6 cream on artificially provoked dystrophic calcifications in soft tissues. Methods Fourteen male Wistar rats were randomly assigned into two groups: control and treated groups. Rats were fed with an InsP6‐free or phytate diet. Plaque formation was induced by subcutaneous injection of 0·1% KMnO4 solution. From 4 days before plaque induction to the end of the experiment, control rats were treated topically with a standard cream, whereas treated rats were treated with the same cream with 2% InsP6 or phytate (as sodium salt). Calcification of plaques was allowed to proceed for 10 days. InsP6 in urine was determined. The plaques were excised and weighed. Results It was found that when InsP6 was administered topically through a moisturizing cream (2% InsP6‐rich), the plaque size and weight were notably and significantly reduced compared with the control group (1·6 ± 1·1 mg InsP6‐treated, 26·7 ± 3·0 mg control). The InsP6 urinary levels for animals treated with the InsP6‐enriched cream were considerably and significantly higher than those found in animals treated topically with the cream without InsP6 (16·96 ± 4·32 mg L−1 InsP6‐treated, 0·06 ± 0·03 mg L−1 control). Conclusions This demonstrates the important capacity of InsP6 as a crystallization inhibitor and also demonstrates that it is possible to propose topical use as a new InsP6 administration route.