title: Repaglinide-loaded solid lipid nanoparticles: effect of using different surfactants/stabilizers on physicochemical properties of nanoparticles.
abstract: BACKGROUND
  Repaglinide is an efficient anti-diabetic drug which is prescribed widely as multi-dosage oral daily regimens. Due to the low compliance inherent to each multi-dosage regimen, development of prolonged-release formulations could enhance the overall drug efficacy in patient populations.
  
  
  METHODS
  Repaglinide-loaded solid lipid nanoparticles (SLNs) were developed and characterized in vitro. Various surfactants were used in this study during the nanocarrier preparation procedure and their corresponding effects on some physicochemical properties of SLNs such as size, zeta potential; drug loading parameters and drug release profiles was investigated. Stearic acid and glyceryl mono stearate (GMS) were used as lipid phase and phosphatidylcholin, Tween80, Pluronic F127, poly vinyl alcohol (PVA) and polyvinyl pyrrolidone (PVP) were used as surfactant/stabilizer.
  
  
  RESULTS
  The results showed some variations between formulations; where the Tween80-based SLNs showed smallest size, the phosphatidylcholin-based SLNs indicated most prolonged drug release time and the highest loading capacity. SEM images of these formulations showed morphological variations and also confirmed the nanoscale size of these particles. The FTIR and DSC results demonstrated no interaction between drug and excipients. The invitro release profiles of different formulations were studied and observed slow release of drug from all formulations. However significant differences were found among them in terms of their initial burst release as well as the whole drug release profile. From fitting these data to various statistical models, the Peppas model was proposed as the best model to describe the statistical indices and, therefore, mechanism of drug release.
  
  
  CONCLUSIONS
  The results of this study confirmed the effect of surfactant type on SLNs physicochemical properties such as morphological features, loading parameters, particle sizes and drug release kinetic. With respect to the outcome data, the mixture of phosphatidylcholin/Pluronic F127 was selected as the best surfactant/stabilizer to coat the lipid core comprising stearic acid and GMS.
authors.affiliation: Biotechnology Research Center, Tabriz University of Medical Sciences, Tabriz, Iran. haliebrahimi@gmail.com.|Department of Pharmaceutics, Faculty of Pharmacy, Tabriz University of Medical Sciences, Tabriz, Iran. haliebrahimi@gmail.com.|Zanjan Pharmaceutical Nanotechnology Research Center (ZPNRC), Zanjan University of Medical Sciences, Zanjan, Iran. haliebrahimi@gmail.com.
authors.forename: Hossein Ali
authors.initials: HA
authors.lastname: Ebrahimi
authors.affiliation: Biotechnology Research Center, Tabriz University of Medical Sciences, Tabriz, Iran. javadzadehy@tbzmed.ac.ir.|Department of Pharmaceutics, Faculty of Pharmacy, Tabriz University of Medical Sciences, Tabriz, Iran. javadzadehy@tbzmed.ac.ir.
authors.forename: Yousef
authors.initials: Y
authors.lastname: Javadzadeh
authors.affiliation: Zanjan Pharmaceutical Nanotechnology Research Center (ZPNRC), Zanjan University of Medical Sciences, Zanjan, Iran. hamidim@zums.ac.ir.|Department of Pharmaceutics, School of Pharmacy, Zanjan University of Medical Sciences, Zanjan, Iran. hamidim@zums.ac.ir.
authors.forename: Mehrdad
authors.initials: M
authors.lastname: Hamidi
authors.affiliation: Department of Pharmaceutics, Faculty of Pharmacy, Tabriz University of Medical Sciences, Tabriz, Iran. Barzegar_jalali@yahoo.com.
authors.forename: Mohammad Barzegar
authors.initials: MB
authors.lastname: Jalali
mesh_terms: D002152:Calorimetry, Differential Scanning; D002219:Carbamates / Q000737:chemistry* / Q000493:pharmacokinetics*; D003692:Delayed-Action Preparations; D004339:Drug Compounding; D004355:Drug Stability; D006801:Humans; D007004:Hypoglycemic Agents / Q000737:chemistry*; D053758:Nanoparticles / Q000737:chemistry; D010316:Particle Size; D010880:Piperidines / Q000737:chemistry* / Q000493:pharmacokinetics*; D013501:Surface-Active Agents / Q000737:chemistry*
chemical_list: D002219:Carbamates; D003692:Delayed-Action Preparations; D007004:Hypoglycemic Agents; D010880:Piperidines; D013501:Surface-Active Agents; C072379:repaglinide