title: Bioadhesion and oral absorption of enoxaparin nanocomplexes.
abstract: Polyelectrolyte complexes (PEC) formed between chitosan derivatives and enoxaparin were prepared by a self-assembly process and were characterized in terms of particle size and surface charge. The morphology was observed by atomic force microscopy (AFM). The colloidal stability and bioadhesion of the PEC were characterized by dynamic light scattering (DLS). The absorption of enoxaparin in rats was evaluated by activated partial thromboplastin time (APTT) assay. It was shown that the prepared PEC had a spherical shape with positive charge and a mean diameter in the range of 200-600 nm. An increase in temperature led to a decrease in particle size (ca. 10%) with an increased kcps value (ca. 10-20%) for the PEC studied, depending on the polymer structure. Thiolation and methylation of chitosan could significantly improve the corresponding PEC's bioadhesion and hence the oral absorption of enoxaparin. A good relationship between bioadhesion and in vivo absorption was established. However, PEC of PEGylated chitosan did not display a significantly enhanced permeation of enoxaparin compared with unmodified chitosan. In conclusion, the oral bioavailability of enoxaparin can be enhanced by improving the bioadhesive properties of PEC via the chemical modification of chitosan employed.
authors: School of Pharmacy, Shenyang Pharmaceutical University, 103 Wenhua Road, Shenyang 110016, China.
authors: Wei
authors: W
authors: Sun
authors: Shirui
authors: S
authors: Mao
authors: Yanjun
authors: Y
authors: Wang
authors: Varaporn B
authors: VB
authors: Junyaprasert
authors: Tingting
authors: T
authors: Zhang
authors: Lidong
authors: L
authors: Na
authors: Juan
authors: J
authors: Wang
mesh_terms: D000268:Adhesiveness; D000284:Administration, Oral; D000818:Animals; D000925:Anticoagulants / Q000008:administration & dosage* / Q000737:chemistry / Q000493:pharmacokinetics; D001682:Biological Availability; D001777:Blood Coagulation / Q000187:drug effects; D002626:Chemistry, Pharmaceutical; D048271:Chitosan / Q000031:analogs & derivatives / Q000737:chemistry* / Q000378:metabolism; D004337:Drug Carriers; D004355:Drug Stability; D017984:Enoxaparin / Q000008:administration & dosage* / Q000737:chemistry / Q000493:pharmacokinetics; D006863:Hydrogen-Ion Concentration; D007408:Intestinal Absorption; D007413:Intestinal Mucosa / Q000378:metabolism; D008297:Male; D008745:Methylation; D018625:Microscopy, Atomic Force; D053758:Nanoparticles; D036103:Nanotechnology; D010314:Partial Thromboplastin Time; D010316:Particle Size; D011092:Polyethylene Glycols / Q000737:chemistry; D051381:Rats; D017208:Rats, Wistar; D012995:Solubility; D013438:Sulfhydryl Compounds / Q000737:chemistry; D013499:Surface Properties; D013678:Technology, Pharmaceutical / Q000379:methods; D013696:Temperature
chemical_list: D000925:Anticoagulants; D004337:Drug Carriers; D017984:Enoxaparin; D013438:Sulfhydryl Compounds; D011092:Polyethylene Glycols; D048271:Chitosan