Cellulose derivatives The cellulose derivatives widely used in mucoadhesive formulations are hydroxyethylcellulose, hydroxylpropylmethylcellulose, hydroxypropylcellulose and carboxymethylcellulose etc.
• Hydroxylpropylmethylcellulose (HPMC): Hydroxylpropylmethylcellulose is semi synthetic, inert, viscoelastic polymers, extensively used not only for mucoadhesion properties but also for its controlled release mechanism. It has been applied to deliver various drugs via different type of dosage forms. HPMC is a non-ionic polymer and lacking of proton donating carboxylic group which causes lesser hydrogen bonding than carboxymethyl cellulose.
• Carboxymethylcellulose (CMC): CMC, specifically sodium salt of CMC (Na-CMC) is an extensively used mucoadhesive polymer.CMC possesses better mucoadhesion than HPMC. CMC is an anionic polymer which causes higher hydrogen bonding than nonionic cellulose polymers. Mucoadhesion nature of CMC depends on the pH of the medium used …show more content…
These are hydrophilic macromolecules exhibiting free thiol groups on the polymeric backbone. Thiomers are capable of forming intra and inter chain disulphide bonds within the polymeric network leading to strongly improved cohesive properties and stability of drug delivery systems such as matrix systems. Due to the formation of strong covalent bonds with mucus glycoproteins, thiomers show the strongest mucoadhesive properties. Thiolated polymers includes,
• Chitosan–iminothiolane, Chitosan–thioglycolic acid
• Poly(acrylic acid)–cysteine, poly(acrylic acid)–homocysteine etc 20
Bioadhesive nanopolymers as drug
• Hydroxylpropylmethylcellulose (HPMC): Hydroxylpropylmethylcellulose is semi synthetic, inert, viscoelastic polymers, extensively used not only for mucoadhesion properties but also for its controlled release mechanism. It has been applied to deliver various drugs via different type of dosage forms. HPMC is a non-ionic polymer and lacking of proton donating carboxylic group which causes lesser hydrogen bonding than carboxymethyl cellulose.
• Carboxymethylcellulose (CMC): CMC, specifically sodium salt of CMC (Na-CMC) is an extensively used mucoadhesive polymer.CMC possesses better mucoadhesion than HPMC. CMC is an anionic polymer which causes higher hydrogen bonding than nonionic cellulose polymers. Mucoadhesion nature of CMC depends on the pH of the medium used …show more content…
These are hydrophilic macromolecules exhibiting free thiol groups on the polymeric backbone. Thiomers are capable of forming intra and inter chain disulphide bonds within the polymeric network leading to strongly improved cohesive properties and stability of drug delivery systems such as matrix systems. Due to the formation of strong covalent bonds with mucus glycoproteins, thiomers show the strongest mucoadhesive properties. Thiolated polymers includes,
• Chitosan–iminothiolane, Chitosan–thioglycolic acid
• Poly(acrylic acid)–cysteine, poly(acrylic acid)–homocysteine etc 20
Bioadhesive nanopolymers as drug