title: PLGA nanoparticles simultaneously loaded with vincristine sulfate and verapamil hydrochloride: systematic study of particle size and drug entrapment efficiency.
abstract: PLGA nanoparticles simultaneously loaded with vincristine sulfate (VCR) and verapamil hydrochloride (VRP) were prepared via combining O/W emulsion solvent evaporation and salting-out method. Ten independent processing parameters and two materials characteristics were assessed systematically to enhance the incorporation of the two hydrophilic low molecular weight drugs into PLGA nanoparticles and minimize nanoparticles size. Approaches investigated for the enhancement of drug entrapment efficiencies and the minimization of particle size included the influence of the molecular weight (MW) of PLGA and the lactide to glycolide (L:G) ratio of PLGA, PLGA concentration, the degrees of hydrolyzation and polymerization of PVA, PVA concentration, initial VCR and VRP content, acetone to dichloromethane volume ratio, aqueous phase pH, salt concentration of aqueous phase, aqueous to organic phase volume ratio, sonication time, sonication energy and removal rate of organic solvents. The nanoparticles produced by optimal formulation were submicron size (111.4+/-2.35nm, n=3) and of low polydispersity (0.062+/-0.023, n=3). Nanoparticles observed by transmission electron microscopy (TEM) showed extremely spherical shape. The entrapment efficiencies determined with high performance liquid chromatogram (HPLC) by ultracentrifuge method were 55.35+/-4.22% for VCR and 69.47+/-5.34% for VRP, respectively (n=3).
authors.affiliation: West China School of Pharmacy, Sichuan University, Chengdu, Sichuan 610041, People's Republic of China.
authors.forename: Xiangrong
authors.initials: X
authors.lastname: Song
authors.forename: Yu
authors.initials: Y
authors.lastname: Zhao
authors.forename: Wenbin
authors.initials: W
authors.lastname: Wu
authors.forename: Yueqi
authors.initials: Y
authors.lastname: Bi
authors.forename: Zheng
authors.initials: Z
authors.lastname: Cai
authors.forename: Qiuhong
authors.initials: Q
authors.lastname: Chen
authors.forename: Yuanbo
authors.initials: Y
authors.lastname: Li
authors.forename: Shixiang
authors.initials: S
authors.lastname: Hou
mesh_terms: D002626:Chemistry, Pharmaceutical; D019344:Lactic Acid / Q000008:administration & dosage*; D053758:Nanoparticles; D010316:Particle Size; D011100:Polyglycolic Acid / Q000008:administration & dosage*; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D011108:Polymers / Q000008:administration & dosage*; D012965:Sodium Chloride / Q000737:chemistry; D014700:Verapamil / Q000008:administration & dosage* / Q000737:chemistry; D014750:Vincristine / Q000008:administration & dosage* / Q000737:chemistry
chemical_list: D011108:Polymers; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D011100:Polyglycolic Acid; D019344:Lactic Acid; D012965:Sodium Chloride; D014750:Vincristine; D014700:Verapamil