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

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.