title: Stability study and lyophilization of vitamin E-loaded nanocapsules prepared by membrane contactor.
abstract: In this research, we studied the accelerated stability of vitamin E-loaded nanocapsules (NCs) prepared by the nanoprecipitation method. Vitamin E-loaded NCs were optimized firstly at the laboratory scale and then scaled up using the membrane contactor technique. The optimum conditions of the membrane contactor preparation (pilot scale) produced vitamin E-loaded NCs with an average size of 253 nm, polydispersity index 0.19 and a zeta potential -16 mV. The average size, polydispersity index and zeta potential values were 185 nm, 0.12 and -15 mV, respectively for the NCs prepared at laboratory scale. No significant changes were noticed in these values after 3 and 6 months of storage at high temperature (40±2 °C) and relative humidity (75±5%) in spite of vitamin E sensitivity to light, heat and oxygen. The entrapment efficiency of NCs prepared at pilot scale was 97% at the beginning of the stability study, and became (95%, 59%) after 3 and 6 months of storage, respectively. These values at lab-scale were (98%, 96%, and 89%) at time zero and after 3 and 6 months of storage, respectively. This confirms the ability of vitamin E encapsulation to preserve its stability, which is one major goal of our work. Lyophilization of the optimized formula at lab-scale was also performed. Four types of cryoprotectants were tested (poly(vinyl pyrrolidone), sucrose, mannitol, and glucose). Freeze-dried NCs prepared with sucrose were found acceptable. The other lyophilized NCs obtained at different conditions presented large aggregates.
authors.affiliation: Laboratory of Pharmaceutical Research, Department of Quality Control, Faculty of Pharmacy, University of Aleppo, Syria.
authors.forename: N
authors.initials: N
authors.lastname: Khayata
authors.forename: W
authors.initials: W
authors.lastname: Abdelwahed
authors.forename: M F
authors.initials: MF
authors.lastname: Chehna
authors.forename: C
authors.initials: C
authors.lastname: Charcosset
authors.forename: H
authors.initials: H
authors.lastname: Fessi
mesh_terms: D004339:Drug Compounding / Q000379:methods; D004355:Drug Stability; D005079:Excipients / Q000737:chemistry; D005612:Freeze Drying; D005947:Glucose / Q000737:chemistry; D008353:Mannitol / Q000737:chemistry; D008567:Membranes, Artificial; D053769:Nanocapsules / Q000737:chemistry*; D036103:Nanotechnology; D011205:Povidone / Q000737:chemistry; D013395:Sucrose / Q000737:chemistry; D014810:Vitamin E / Q000737:chemistry*
chemical_list: D005079:Excipients; D008567:Membranes, Artificial; D053769:Nanocapsules; D014810:Vitamin E; D008353:Mannitol; D013395:Sucrose; D011205:Povidone; D005947:Glucose