The crescent number of skin cancer worldwide gives Impulse to the development of sunscreen that can both prevent skin cancer and also permit gradual tanning In this work the synthesis of hydroxyapatite and tricalcium phosphate nanocrystalline powders was investigated in order to obtain materials with optical properties and appropriate size for sunscreen Pure Zn2+-doped and Mn2+-doped hydroxyapatite (HAP) and tricalcium phosphate (beta-TCP) were produced by the wet precipitation process using diammonium phosphate calcium nitrate ammonium hydroxide zinc nitrate and manganese nitrate as reagents The pure and doped HAP precipitates were calcined at 500 C for 1 h while the beta-TCP (pure and doped) were calcined at 800 C for 2 h The powder samples were characterized by X-ray diffraction (XRD) energy dispersive X-ray fluorescence (EDX) atomic force microscopy (AFM) and ultraviolet (UV)-vis spectroscopy XRD and EDX showed the formation of the expected materials (HAP and beta-TCP) without toxic components AFM micrographs showed aggregated ellipsoidal particles with dimensions smaller than 120 nm Optical absorption spectra showed that the calcium phosphate produced in this work absorbs in the UV region The obtained materials presented structural morphological and optical properties that allow their use as the active centers in sunscreens (C) 2010 Elsevier B V All rights reserved