title: Solid lipid nanoparticles loaded with insulin by sodium cholate-phosphatidylcholine-based mixed micelles: preparation and characterization.
abstract: Solid lipid nanoparticles (SLNs) loaded with insulin-mixed micelles (Ins-MMs) were prepared by a novel reverse micelle-double emulsion method, in which sodium cholate (SC) and soybean phosphatidylcholine (SPC) were employed to improve the liposolubility of insulin, and the mixture of stearic acid and palmitic acid were employed to prepare insulin loaded solid lipid nanoparticles (Ins-MM-SLNs). Some of the formulation parameters were optimized to obtain high quality nanoparticles. The particle size and zeta potential measured by photon correlation spectroscopy (PCS) were 114.7+/-4.68 nm and -51.36+/-2.04 mV, respectively. Nanospheres observed by transmission electron microscopy (TEM) and scanning electron microscopy (SEM) showed extremely spherical shape. The entrapment efficiency (EE%) and drug loading capacity (DL%) determined with high performance liquid chromatogram (HPLC) by modified ultracentrifuge method were 97.78+/-0.37% and 18.92+/-0.07%, respectively. Differential scanning calorimetry (DSC) of Ins-MM-SLNs indicated no tendency of recrystallisation. The core-shell drug loading pattern of the SLNs was confirmed by fluorescence spectra and polyacrylamide gel electrophoresis (PAGE) which also proved the integrity of insulin after being incorporated into lipid carrier. The drug release behavior was studied by in situ and externally sink method and the release pattern of drug was found to follow Weibull and Higuchi equations. Results of stability evaluation showed a relatively long-term stability after storage at 4 degrees C for 6 months. In conclusion, SLNs with small particle size, excellent physical stability, high entrapment efficiency, good loading capacity for protein drug can be produced by this novel reverse micelle-double emulsion method in present study.
authors.affiliation: Key Laboratory of Drug Targeting, Ministry of Education, Sichuan University, No. 17, Section 3, Southern Renmin Road, Chengdu, Sichuan 610041, PR China.
authors.forename: Jie
authors.initials: J
authors.lastname: Liu
authors.forename: Tao
authors.initials: T
authors.lastname: Gong
authors.forename: Changguang
authors.initials: C
authors.lastname: Wang
authors.forename: Zhirong
authors.initials: Z
authors.lastname: Zhong
authors.forename: Zhirong
authors.initials: Z
authors.lastname: Zhang
mesh_terms: D002152:Calorimetry, Differential Scanning; D002626:Chemistry, Pharmaceutical; D004337:Drug Carriers; D004339:Drug Compounding; D004355:Drug Stability; D004591:Electrophoresis, Polyacrylamide Gel; D006863:Hydrogen-Ion Concentration; D007004:Hypoglycemic Agents / Q000737:chemistry*; D007328:Insulin / Q000737:chemistry*; D007700:Kinetics; D008823:Micelles; D008855:Microscopy, Electron, Scanning; D046529:Microscopy, Electron, Transmission; D008956:Models, Chemical; D053758:Nanoparticles; D019308:Palmitic Acid / Q000737:chemistry; D010316:Particle Size; D010713:Phosphatidylcholines / Q000737:chemistry*; D020358:Sodium Cholate / Q000737:chemistry*; D012995:Solubility; D013050:Spectrometry, Fluorescence; D013229:Stearic Acids / Q000737:chemistry; D013499:Surface Properties; D013678:Technology, Pharmaceutical / Q000379:methods; D013696:Temperature
chemical_list: D004337:Drug Carriers; D007004:Hypoglycemic Agents; D007328:Insulin; D008823:Micelles; D010713:Phosphatidylcholines; D013229:Stearic Acids; D019308:Palmitic Acid; C031183:stearic acid; D020358:Sodium Cholate