Preparation And Characterization Of Propranolol-loaded Novel Transfersomes Composed Of Both DPPC And SPC

The exact and impressive curative effect of propranolol oral application in treating infantile hemangiomas has been extensively confirmed by lots of clinical reports.However,the oral administration route of propranolol has many limitations such as the poor medication compliance,the low bioavailability,and the risk of inducing adverse reactions including bradycardia,hypotension,hypoglycemia and so on.In order to overcome the above shortcomings,a novel propranolol loaded transfersomes composed of both DPPC and SPC were successfully developed in the present investigation,certain pharmaceutical properties and pharmacokinetic performances after transdermal delivery were determined.The experimental results indicated that these propranolol loaded novel transfersomes,especially NT-64,provide higher encapsulation efficiency,better deformability,enhanced stability,and significantly improved bioavailability after administrated with the transdermal route.Based on the above experimental results,a speculation was proposed,that is,a new and special phase state formed in the lipid bilayer of these novel transfersomes,which is completely different from those of transfersomes prepared with just single phospholipids.Furthermore,when DPPC and SPC with the molar ratio of 6:4 are used for preparing the novel transfersomes,exactly the NT-64,the Tm of the resulting new phase is very likely close to 37?,which is close to body temperature.In other words,when been exposed to 37? temperature nearby,a critical phase transition state will present in the lipid bilayer of NT-64.And just because of the existence of this extremely special phase transition state,NT-64 exhibits the very unique pharmaceutic and pharmacokinetic properties.For verifying the above speculation,the mecular simulation technology was introduced for better understanding the interaction mode between DPPC and SPC.Results showed that DPPC and SPC can be interconnected together due to the electrostatic attraction under certain conditions,which results to the produce of a new phase.Meanwhile,the differential scanning calorimetry technology was applied to explore the phase transition behavior of NT-64,the results validated the formation of the new phase with Tm 37.03?,which effectively confirmed the above conjecture,and indicating that the novel transfersomes NT-64,with Tm closed to body temperature,has its unique advantages as transdermal drug delivery system.In addition,this investigation illustrated the probability of flexibly adjusting the Tm of the novel transfersomes by change the kinds and the ratios of phospholipids,and which will play a important role in the enhancement of drug percutaneous absorption mediated by transfersomes.