Formulation and in vivo evaluation of niosome-encapsulated daunorubicin hydrochloride

The central aim of this present study was to modify the reverse evaporation process, such that an enhanced entrapment, with increased storage stability and prolonged release, could be achieved, and to translate these advantages to increased therapeutic efficacy of daunorubicin hydrochloride on Dalton's ascitic lymphoma. Niosomes prepared exhibited entrapment efficiency 20% higher than theoretically possible by the reverse evaporation process. The niosomes were found to be very stable at a storage temperature of 4 degrees C for a duration of three months. Even the drug leakage was restricted to just 10%. The in vivo studies suggested a prolonged release of 20 hr. Niosomal daunorubicin hydrochloride exhibited an enhanced anti-tumor efficacy when compared to free drug. The niosomal formulation was able to destroy the Dalton's ascitic lymphoma cells in the peritoneum within the third day of treatment, while free drug took around six days and the process was incomplete. The hematological studies also prove that the niosomal formulation was superior to free drug treatment. An enhanced mean survival time was achieved by the niosomal formulation that finally substantiates the overall efficacy of the niosomal formulation. This study suggests that the multilamellar vesicles obtained by the presently utilized reverse evaporation process resulted in vesicles that resisted the immediate lysis in the Kupffer cells, whereby a prolonged drug concentration was achieved which enhanced the cell lysis. But the major factor responsible for the quicker onset of action could be the increased permeability of the niosomes into the cell membrane and the cytoplasm of the Dalton's ascitic lymphoma cells.