Stability assay of allantoin in lotions and creams by high-pressure liquid chromatography.

A high-pressure liquid chromatographic method for indicating stability is described for the rapid quantitative analysis of allantoin in lotions and creams. Allantoin was extracted from the preparations using distilled water containing 70% (v/v) methanol and separated from interferences by reversed-phase chromatography. The separation was carried out using an amino column (250 X 4.5-mm i.d.) and a mobile phase of distilled water containing 70% (v/v) acetonitrile. Quantitation was accomplished using a UV detector at 220 nm. The assay has a relative standard deviation of approximately 1.7% (n = 10) and the average recovery from laboratory prepared samples was 100%.