Screening of Silk Fibroin as a Stabilizer for Freeze Drying of Thermolabile Drug

Aim: In the present research work an attempt is made to investigate use of silk fibroin as a stabilizer for model thermolabile drug Tenofovir Alafinamide Fumarate (TAF). Materials and Methods: On the basis of literature reviewed various lyophilized formulations of TAF using silk fibroin as a stabilizer were prepared. Lyophilized formulations were optimized by analyzing for % drug content, % moisture retention and appearance of lyophilizate and further investigated by using modern techniques such FT-IR, XRD and DSC. Formulations were tested to confirm suitability of silk fibroin to stabilize TAF during lyophilization. Initially for achieving desirable product features the fibroin concentration was optimized. The optimized concentration of fibroin was compared with commonly used cryoprotectants such as mannitol and sucrose. The process efficiency of fibroin as cryoprotectant was compared using product features. Results: Product features and stabilization efficiency of fibroin was lower than mannitol where as it was better than sucrose. The short term stability study retained drug to desired strength indicating lyophilized products stability over the period of a month. Thus it can be concluded that silk fibroin could be successfully used to stabilize theromosensitive therapeutics. In comparison fibroin seems to stabilize labile drugs efficiently reducing production cost and at lower toxicity risk. Thus, natural silk fibroin is a promising excipient to be used as a stabilizer due of its cryopreserving properties.