title: Self-assembled carbohydrate hydrogels for prolonged pain management.
abstract: BACKGROUND
  Nanoparticulate systems are new tools that promise a revolution in the field of drug delivery. Among their numerous benefits, polyelectrolyte complexes (PECs) have shown to provide a barrier to drug release.
  
  
  OBJECTIVE
  In this study, PECs, in the form of self-assembled polymeric nanogels, have been studied as potential drug carriers of the freely soluble drug tramadol HCL trying to achieve a prolonged percutaneous permeation.
  
  
  METHODS
  The hydrogels were subjected to swelling, rheology, release and permeation studies and were characterized by FTIR spectroscopy and scanning electron microscopy.
  
  
  RESULTS
  P2 hydrogel composed of chitosan-carrageenan (1-1) PEC attained the most compromised rheological shear-thinning thixotropic behavior, good bioadhesive properties, the most retarded release and permeation with an f2 value <50 compared to chitosan hydrogel, altogether with non-irritancy to the skin. SEM photographs showed that P2 has spherical nanosized particles structure.
  
  
  CONCLUSIONS
  This approach can provide us promising results for an around-the-clock analgesia with better safety and tolerability profile.
authors.affiliation: Pharmaceutical Technology Department, National Research Center, Cairo, Egypt. drrababk@hotmail.com
authors.forename: R
authors.initials: R
authors.lastname: Kamel
authors.forename: H A
authors.initials: HA
authors.lastname: Abbas
mesh_terms: D000818:Animals; D002241:Carbohydrates / Q000008:administration & dosage* / Q000737:chemistry* / Q000493:pharmacokinetics; D002351:Carrageenan / Q000008:administration & dosage / Q000737:chemistry / Q000493:pharmacokinetics; D048271:Chitosan / Q000008:administration & dosage / Q000737:chemistry / Q000493:pharmacokinetics; D004337:Drug Carriers / Q000008:administration & dosage / Q000737:chemistry / Q000493:pharmacokinetics; D016503:Drug Delivery Systems / Q000379:methods; D020100:Hydrogels / Q000008:administration & dosage* / Q000737:chemistry* / Q000493:pharmacokinetics; D008297:Male; D051379:Mice; D000080385:Nanogels; D010146:Pain / Q000188:drug therapy*; D059408:Pain Management / Q000379:methods; D010539:Permeability; D011092:Polyethylene Glycols / Q000008:administration & dosage / Q000737:chemistry / Q000493:pharmacokinetics; D011094:Polyethyleneimine / Q000008:administration & dosage / Q000737:chemistry / Q000493:pharmacokinetics; D011108:Polymers / Q000008:administration & dosage / Q000737:chemistry / Q000493:pharmacokinetics; D051381:Rats; D017208:Rats, Wistar; D012867:Skin / Q000378:metabolism; D013552:Swine; D013607:Tablets / Q000008:administration & dosage / Q000737:chemistry
chemical_list: D002241:Carbohydrates; D004337:Drug Carriers; D020100:Hydrogels; D000080385:Nanogels; D011108:Polymers; D013607:Tablets; C413692:polyethylene glycol polyethyleneimine nanogel; D011092:Polyethylene Glycols; D002351:Carrageenan; D011094:Polyethyleneimine; D048271:Chitosan