Stability studies of isohydrafural and fluocinolone acetonide combined ointment

Background: The isohydrafural and fluocinolone acetonide combined ointment contributes to the diversification of the treatment of dermatitis and psoriasis associated with bacterial infections. Complex stability studies were performed to ensure the quality of it during the shelf life. The objective of this study was to determine the stability and shelf life of the combined ointment containing isohydrafural and fluocinolone acetonide. Material and methods: Three series of ointment were tested by the real-time method (temperature 25± 2°C; relative humidity 60 ± 5%) over a period of 30 months, periodically determining the appearance, homogeneity, pH, viscosity, identity, purity and assay. OHAUS DV215 CD electronic balance, Shimadzu LC-20 A HPLC, Consort C861 pH meter and Fungilab rheometer were used to fulfil the study. Results: At 24 months after storage, the three series of the ointment proved to be homogeneous, with a pH between 5.76 and 5.53. The rheograms showed a pseudoplastic behavior, with a slight thixotropy, with a viscosity close to 70 cP. The active substances were detected at the characteristic retention times: isohydrafural – 3 minutes, fluocinolone acetonide – 5.9 minutes and also no additional peaks occurred. The content of active substances was within the permitted limits: 0.098-0.11% (m/m) for isohydrafural and 0.0248-0.025% (m/m) for fluocinolone acetonide. Conclusions: The combined ointment containing isohydrafural and fluocinolone acetonide was found to be stable under the storage conditions stipulated in the quality specification. The established shelf life is 24 month