Classes of Mucoadhesive Polymers

6.3.3.1 Polyacrylates

The term polyacrylates includes synthetic, high molecular weight polymers of acrylic acid (polyacrylic acid or PAA) (Fig. 6.3a) that are also known as Car-bomers. They are either linear or (weakly) crosslinked (either by allyl sucrose (Carbomers) or divinyl glycol (Polycarbophils)) polymers that are broadly applied in pharmaceutical and cosmetic industry (mostly as excipient for controlled drug release for oral dosage forms and as stabilizers for gels). Crosslinked Carbomers, manufactured by the Performance Materials Segment of the BF Goodrich company under the commercial name Carbopols and Polycarbophils (PCPs), are also used as mucoadhesive platforms for drug delivery. Carbopols and PCPs have

OH NH

Figure 6.3. Structural formulas of mucoadhesives: (a) poly(acrylic acid) (PAA), (b) sodium carboxymethylcellulose (NaCMC), (c) chitosan and carboxylic methylester derivative, (d) thiolated polymer of PAA, (e) chitosan-thioglycolic acid (TGA) conjugate, and (f) chitosan-4-thio-butyl-amidine (chitosan-TBA) conjugates. The dashed boxes indicate the side groups that are responsible for mucoadhesiveness. With permission from Dodou et al. (2005)

OH NH

oh2ch

Figure 6.3. Structural formulas of mucoadhesives: (a) poly(acrylic acid) (PAA), (b) sodium carboxymethylcellulose (NaCMC), (c) chitosan and carboxylic methylester derivative, (d) thiolated polymer of PAA, (e) chitosan-thioglycolic acid (TGA) conjugate, and (f) chitosan-4-thio-butyl-amidine (chitosan-TBA) conjugates. The dashed boxes indicate the side groups that are responsible for mucoadhesiveness. With permission from Dodou et al. (2005)

received extensive review and toxicological evaluation. The PCPs and calcium PCPs are classified as category 1 GRAS materials (Goodrich, 2002). Polyacry-lates interact with mucus by hydrogen and van der Waals bonds, created between the carboxylic groups of the polyacrylates and the sulfate and sialic acid residues of mucin glycoproteins (Dodou et al., 2005). However, polyacrylates do possess also properties as absorption enhancers for the paracellular absorption of hydrophilic compounds as peptides and are additionally able to inhibit the activities of enzymes present in the intestinal fluid (LueBen et al., 1996a).

Was this article helpful?

0 0
Natural Treatments For Dandruff

Natural Treatments For Dandruff

Stop Your Scalp From Snowing! Finally... A Real Cure for Dandruff! No medication! No weird cures! No messy creams, smelly solutions or strange diets! Are you sick to death of being sold products that could make the problem worse? Are you sick of the shampoos and conditioners that make your head smell like sulphur? If so then try a permanent revolutionary treatment for dandruff!

Get My Free Ebook


Post a comment