This work is an application of the results obtained by classical Raman spectroscopy for fluocortolone and its trimethylacetate and caproate esters. These drugs are used together in a pharmaceutical preparation. To avoid fluorescence problems with excipients a solvent extraction was first applied, followed by an HPLC separation. The aim was to identify two corticosteroids through their molecular structure by applying Raman spectroscopy to HPLC eluates. Tests with the drugs in aqueous methanol solution proved unsatisfactory so recourse was made to use of the crystalline state and a Raman multichannel microprobe. This allowed the identification, with accuracy, of Delta(1,4)-3-one structure with sample quantities as small as 10(-12) g.