| 摘要 |
Uric acid as the monovalent urate is a potent endogenous antioxidant protecting against free radical damage in man and other animals. Aging of human skin characterised by wrinkling results from free radical damage to vital tissues beneath the stratum corneum. Synthetic urate spheres formed in a cation rich aqueous solution at ambient temperature are extracted in ethanol and selectively filtered for 0.5žm or less; following air-drying being incorporated in a simple ointment base for skin application. Negatively charged particles of 0.5žm or less, as represented by these selected synthetic urate spheres, can permeate the barrier of the stratum corneum enabling free radical scavenging. These spheres show stability in various physiological media and added to the low solubility of urate, ensures prolonged local tissue activity; also precluding the risk of systemic absorption causing gout, although excessive application may cause local irritation.
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