In this study methods of analysis of mediborol in rectal suppositories for this drug standardization are presented. We used the method chromatography in a thin layer of sorbent for establishment of the parameter « Identification » of mediborol in suppositories. Alkaline solution of potassium hexacyanoferrate (III) was chosen as the detector, because this reagent is specific in relation to the drug. A threshold of detectability of mediborol was established with an alkaline solution of potassium hexacyanoferrate (III) on different plates, and the lowest threshold of detectability was observed when using plates «Sorbfil», which amounted to 0.06 mg. We proposed the spectrophotometric method for the assay and uniformity of content of mediborol in suppositories. The validation data showed that this technique is specific, because it allows us to determine mediborol among other components of the dosage form at the analytical wavelength. The accuracy of the method ranged from 99.34 to 101.25%. The relative error in the determination of the drug was 0.62%. The method showed linear response in the range of the mediborol content in suppositories from 0.035 to 0.065 g (r = 0,99930).