Conjugation of cysteine and its derivatives (including NAC) to polymers (hyaluronic acid, chitosan, alginate, polyesters, polyurethanes, poly(ethylene glycol), poly(acrylic acid), polycarbophil, and carboxymethyl cellulose) significantly increased their tissue adhesion, particularly mucoadhesion, stability at physiological pH, drug encapsulation efficiency, drug release, and drug permeation
doi: 10.3892/ol.2019.9933 111 LiuTChenXGuanGZouCShenSWuJet al
Szener ZC, Cevhertas L, Nadeau K, Akdis M, Akdis CA
Example: cysteine, methionine
Shen H, Tsuchida S, Tamai K and Sato K
Safety and efficacy of ethoxyquin (6-ethoxy-1,2- dihydro-2,2,4-trimethylquinoline) for all animal species