Acta Pharm. 62 (2012) 31-44
Original research paper
Optimization of self-assembling properties of fatty acids
grafted to methoxy poly(ethylene glycol) as nanocarriers for etoposide
JALEH VARSHOSAZ, FARSHID HASANZADEH and MOJTABA ESLAMDOOST
1 Department
of Pharmaceutics, Faculty of Pharmacy and Isfahan Pharmaceutical Sciences
Research Center, Isfahan University of Medical Sciences, Isfahan, Iran
2 Department
of Medicinal Chemistry, Faculty of Pharmacy and Isfahan Pharmaceutical Sciences
Research Center, Isfahan University of Medical Sciences, Isfahan, Iran
Accepted January 16, 2012
The objective of this work was to study the effect of fatty acid chain length grafted to methoxy poly(ethylene glycol) (mPEG) on self assembling properties of micelles for etoposide delivery. Three amphiphilic copolymers were synthesized using mPEG, myristic acid, stearic acid and behenic acid through an esteric linkage. The particle size and zeta potential of the micelles were determined by the dynamic light scattering method. Etoposide was loaded into micelles by film casting using various drug/polymer ratios. Drug release was studied by the dialysis method. The structure of copolymers was confirmed by 1H NMR and FTIR. Critical micellar concentration (CMC) measurements showed that the longer hydrophobic chains formed more thermodynamically stable micelles. Among the prepared copolymers, etoposide showed the highest solubility in the mPEG-behenic copolymer. Drug loading efficiency depended on the hydrophobic chain length and drug/polymer ratio. The highest drug loading efficiency was found in mPEG-myristic micelles with 1:20 drug/polymer ratio. Micelles released 80 % of loaded drug within about 5 h.
Keywords: methoxy poly(ethylene glycol), fatty acid, micelles, etoposide