title: Preactivated thiomers: permeation enhancing properties.
abstract: The study was aimed to prepare a series of poly(acrylic acid)-cysteine-2-mercaptonicotinic acid conjugates (preactivated thiomers) and to evaluate the influence of molecular mass or degree of preactivation with 2-mercaptonicotinic acid (2MNA) on their permeation enhancing properties. Preactivated thiomers with different molecular mass and different degree of preactivation were synthesized and categorized on the basis of their molecular mass and degree of preactivation as PAA(100)-Cys-2MNA (h), PAA(250)-Cys-2MNA (h), PAA(450)-Cys-2MNA (h), PAA(450)-Cys-2MNA (m) and PAA(450)-Cys-2MNA (l). In vitro permeation studies, the permeation enhancement ability for preactivated thiomers was ranked as PAA(450)-Cys-2MNA (h)>PAA(250)-Cys-2MNA (h)>PAA(100)-Cys-2MNA (h) on both Caco-2 cell monolayers and rat intestinal mucosa. Comparing the influence of degree of preactivation with 2MNA on permeation enhancement, the following order PAA(450)-Cys-2MNA (h)>PAA(450)-Cys-2MNA (m)≈PAA(450)-Cys-2MNA (l) on Caco-2 cell monolayers and PAA(450)-Cys-2MNA (m)>PAA(450)-Cys-2MNA (h)>PAA(450)-Cys-2MNA (l) on intestinal mucosa was observed. The P(app) of sodium fluorescein was 5.08-fold improved on Caco-2 cell monolayers for PAA(450)-Cys-2MNA (h) and 2.46-fold improved on intestinal mucosa for PAA(450)-Cys-2MNA (m), respectively, in comparison to sodium fluorescein in buffer only. These results indicated that preactivated thiomers could be considered as a promising macromolecular permeation enhancing polymer for non-invasive drug administration.
authors.affiliation: Department of Pharmaceutics, School of Pharmaceutical Sciences, Peking University, Beijing, China.
authors.forename: Xueqing
authors.initials: X
authors.lastname: Wang
authors.forename: Javed
authors.initials: J
authors.lastname: Iqbal
authors.forename: Deni
authors.initials: D
authors.lastname: Rahmat
authors.forename: Andreas
authors.initials: A
authors.lastname: Bernkop-Schnürch
mesh_terms: D000180:Acrylic Resins / Q000737:chemistry / Q000378:metabolism*; D000818:Animals; D001692:Biological Transport; D018938:Caco-2 Cells; D003545:Cysteine / Q000737:chemistry / Q000378:metabolism*; D016503:Drug Delivery Systems; D006801:Humans; D066298:In Vitro Techniques; D007408:Intestinal Absorption; D007413:Intestinal Mucosa / Q000378:metabolism; D008297:Male; D009539:Nicotinic Acids / Q000737:chemistry / Q000378:metabolism*; D010539:Permeability; D051381:Rats; D017207:Rats, Sprague-Dawley; D013438:Sulfhydryl Compounds / Q000032:analysis / Q000737:chemistry / Q000378:metabolism*
chemical_list: D000180:Acrylic Resins; D009539:Nicotinic Acids; D013438:Sulfhydryl Compounds; C006903:carbopol 940; C083470:2-mercaptonicotinic acid; D003545:Cysteine