The aim of this study was to enhance the transdermal delivery of Sildenafil Citrate by encapsulation in nano sized ultra deformable vesicles, transfersomes. The thin film hydration and sonication technique was utilized in the preparation of Sildenafil Citrate loaded Transfersomes and both non ionic and ionic edge activators (anionic and cationic) were used in varying ratios to study their effects on the physicochemical characteristics and the release properties of the prepared formulations. Results revealed that the mean size of the prepared Sildenafil Citrate loaded nano vesicles ranged from 69.08nm to 265.80nm, the encapsulation efficiencies ranged from 59.90% to 92.49% and the in vitro drug release through synthetic membranes ranged from 40.21% to 99.99%. All formulations were subjected to rank order based on their physicochemical characteristics and in vitro release profiles. Transmission Electron Microscope imaging of the chosen formulations revealed the general images of transfersomes formulations and the predicted differences between the formulations. Results for the ex vivo release of the chosen formulations through isolated skin of rats ranged from 76.29% to 99.90% of the applied dose. Stability studies for the chosen formulations showed that formulations were generally stable. Rotary evaporation and sonication method was found to give more stable Transfersomes. Keywords10 Hence this technique was chosen for formulation development and batch processing. Table 1 shows the composition of the Transfersomal formulae containing SC prepared by thin film hydration technique. Formulations of SC-TS from 1 to 8 were prepared by weight ratios while formulae SC-aTS from 1 to 3 and formulae SC-cTS from 1 to 3 were prepared by molar ratios. The amounts of SLS in formulae SC-aTS were written in mgs which were equivalent to 0.27, 0.29 and 0.31mM of SLS (7.7, 8.0 and 8.9mgs). Also, the amounts of Cet in formulae SC-cTS were written in mgs which were equivalent to 0.27, 0.29 and 0.31mM of Cet (9.8, 10.5 and 11. mgs). The thin film hydration and sonication method was employed as described by El Zaafarany GM et al., 11Jain S.12 The amount of PL, the edge activators (T 80, S 80, SLS and Cet) and SC as a drug were accurately weighed and dissolved in 1:1 mixture of chloroform and methanol. The mixture was sonicated for one minute with probe sonicator (Qsonica, model Q125, Qsonica LLC., USA) to ensure complete dissolution of all components. The resultant ivory yellow clear solution was transferred to the egg plant shaped round bottom flask of the rotary evaporator (Heidolph, model WB2000, Heidolph co., Germany) which was previously cleaned and oven dried. The temperature of the water bath was adjusted to 45°C which is about 10 degrees above the transition temperature of the phospholipids component (32 °C). The rotor speed was adjusted to 60rpm. Complete removal of the organic solvent was accomplished after 45 minutes resulting in a homogenously distributed thin film on the wall of the flask. The flask was kept under va...

The purpose of this study is to evaluate the improvement in physical stability of Chitosan (CS) coated liposomes. Small unilamellar classic liposomes (RIV-CLs) and flexible liposomes (RIV-FLs) loaded with rivaroxaban (RIV) were coated with low molecular weight chitosan (LMW CS) by simply mixing the liposomal suspension with the acidic polymer solutions of varying strengths. Changes in particle size and zeta potential for CS coated liposomes confirmed the existence of a thick polymer layer on the surface of liposomes which was also manifested from the TEM images. The physical stability of CS coated liposomes was evaluated by measuring the change in particle size, zeta potential, in vitro drug release and the retention of entrapped contents after periods of storage.