[Analytical and stability studies carried out during the formulation development of Hevizos ointment].

BIOGAL Pharmaceutical Works Ltd. had started to develop an antiviral ointment named Hevizos in 1984, which was then registered as a drug in 1987. In this paper results of the developing work of the test analytical methods for both the raw material epervudine and the ointment itself are reported. To assay the active ingredient and to detect the impurities a high performance liquid chromatographic method elaborated by Central Chemical Research Institute (Budapest, Hungary) was adapted and validated by BIOGAL. The method was tested for applicability for studying the stability of the active ingredient and the preparation. It was established that epervudine decomposes in acidic medium the final product being isopropyl-uracil. Wide-ranging stability test were performed in order to form a suitable packaging, to establish the storage conditions and to determine expiration time of Hevizos ointment. Further stability studies are under progress on the preparation with modified tropic-resistant packaging.