Comparison of mucoadhesive and cohesive features of poly(acrylic acid)-conjugates respective their molecular mass

Abstract Objectives This study aimed to assess the impact of molecular mass as well as the differences between poly(acrylic acid)-thiol-conjugates (PAA100,250,450 KDa) on their mucoadhesive and cohesive qualities. Methods Covalent attachment of cysteine (CYS), cysteamine (CYSM) and l -gluthathione (GSH) to poly(acrylic acid) was achieved by formation of amide bonds between primary amino group of the amino acid (in the case of cysteine and glutathione), respectively the amino group of the aminothiol cysteamine and carboxylic acid group of the polymer. Obtained polymer conjugates were evaluated in regard to their safety profile, mucoadhesive properties on the buccal mucosa by rotating cylinder, tensile strength and rheological investigations, respectively. Furthermore, stability, cohesive and water uptake studies were performed. Key findings Mucoadhesive studies revealed that maximum detachment force of PAACYS450 was 24.3-fold higher in comparison to the respective controls. Stability studies revealed for PAACYS450 a 50.2-fold higher stability compared to controls. Conclusion Taken together, among all polymers tested, PAACYS450 evinced the most favorable qualities regarding mucoadhesion and cohesion, followed by PAACYSM450 and PAACYS250.