Patent ID: 7247423

Claim:
A method for determining the effect on skin of topically applied materials comprising: i. maintaining a piece of skin of area greater than 1 cm 2 at the air/liquid interface of a suitable culture medium under conditions that maintain the viability and substantially normal structure of the skin for a period of time between 2 and 28 days at a temperature at or below 30° C., said skin comprising the majority of the epidermal layer plus an appropriate amount of supporting dermis and wherein the surface of said skin is partitioned by the application of a surface barrier film into a pattern of isolated regions to which different test materials can be topically applied; ii. applying test materials to the surface of the skin in such a way that they do not significantly migrate around the edges of the skin into the culture medium; and iii. measuring the effect of the topically applied material on the skin after an appropriate time using an appropriate method.