Functionalized and graft copolymers of chitosan and its pharmaceutical applications.
Chitosan is the second most abundant natural polysaccharide. It belongs a family of polycationic polymers comprised of repetitive units of glucosamine and N-acetylglucosamine. Its biodegradability, nontoxicity, non-immunogenicity and biocompatibility along with properties like mucoadhesion, fungistatic and bacteriogenic have made chitosan an appreciated polymer with numerous applications in the pharmaceutical, comestics and food industry. However, the limited solubility of chitosan at alkaline and neutral pH limits its widespread commercial use. This can be circumvented by fabrication of chitosan by graft copolymerization with acyl, alkyl, monomeric and polymeric moieties. Areas covered: Modifications like quarterization, thiolation, acylation and grafting result in copolymers with higher mucoadhesion strength, increased hydrophobic interactions (advantageous in hydrophobic drug entrapment), and increased solubility in alkaline pH, the ability for adsorption of metal ions, protein and peptide delivery and nutrient delivery. Insights on methods of polymerization, including atomic transfer radical polymerization and click chemistry are discussed. Applications of such modified chitosan copolymers in medical and surgical, and drug delivery, including nasal, oral and buccal delivery have also been covered. Expert opinion: Despite a number of successful investigations, commercialization of chitosan copolymers still remains a challenge. Further advancements in polymerization techniques may address the unmet needs of the healthcare industry.
a Department of Pharmaceutics, Dr. Bhanuben Nanavati College of Pharmacy , University of Mumbai , Mumbai , India.
Chintan
0000-0002-7571-4812
C
Bhavsar
a Department of Pharmaceutics, Dr. Bhanuben Nanavati College of Pharmacy , University of Mumbai , Mumbai , India.
Munira
0000-0001-5908-2627
M
Momin
a Department of Pharmaceutics, Dr. Bhanuben Nanavati College of Pharmacy , University of Mumbai , Mumbai , India.
Sankalp
0000-0002-8838-5317
S
Gharat
b The Novel Drug & Vaccine Delivery Systems Facility, Department of Chemistry and Biochemistry , Laurentian University , Sudbury , Canada.
Abdelwahab
0000-0002-4093-5762
A
Omri
D000818:Animals; D048271:Chitosan / Q000008:administration & dosage / Q000737:chemistry*; D016503:Drug Delivery Systems; D004864:Equipment and Supplies; D006801:Humans; D004364:Pharmaceutical Preparations / Q000008:administration & dosage / Q000737:chemistry; D058105:Polymerization
D004364:Pharmaceutical Preparations; D048271:Chitosan
Chitosan; copolymers; graft polymers