Inventory Valuation in R&D Comapnies

How do R&D Companies value their stocks as they do not use it for production of final products nor they use the same inventory for re sale? Can the inventory of the company be treated as raw material even though they are not for the purpose for producing a final product, but merely, the usage of chemicals for R&D, an intermediate process? Or is it that, if the outcome of the R&D process results in a cure for some specified disease, the chemicals (Inventory) be treated as "in process of production for sale" and be valued as AS 2 specifies. Ravi