Supercritical Assisted Atomization for Preparation of Solid Lipid Nanoparticles

OBJECTIVE To prepare the solid lipid nanoparticles(SLN) via supercritical assisted atomization(SAA) and investigate the effect of formulation and process on physicochemical characteristics of nanoparticles(NPs).METHODS With self-made SAA particle-producing equipment,stearic acid(SA) based SLN was produced,and the effect of SA concentration,flow ratio of supercritical CO2 and material solution,pore size of nozzle,on particle size of SLN were investigated to discover the appropriate process conditions.SLN loading insulin,a hydrophilic macromolecule drug,was produced and their physicochemical characteristics was observed,such as size,zeta-potential,entrapment efficiency(EE) and drug-loading ratio(DL).RESULTS Particle size of NPs was depended on material concentration,flow ratio of supercritical CO2 and material solution,pore size of nozzle.SLN with mean size 300 nm were obtained through formulation and process adjustment during preparation.Insulin-loaded SLN with mean size of about 300 nm,EE 72.2% and DL 3.44% was obtained,which released drug slowly during 12 h in vitro.Poloxamer-modified formulation made SLN with reduced size and distribution range,meanwhile the drug EE was decreased and burst-release was significant.CONCLUSION SAA is successfully applied to produce SLN and hydrophilic-drug-loaded SLN with modified releasing profile.