title: Evaluation of carboxymethyl gellan gum as a mucoadhesive polymer.
abstract: The study was conducted to evaluate carboxymethyl gellan gum as bioadhesive polymer for drug delivery applications. Gellan gum was carboxymethylated by reacting it with monochloroacetic acid. Degree of carboxymethyl substitution was found to be 1.18. Further, carboxymethylation of gellan gum was found to increase its degree of crystallinity, surface roughness and diminish the cation-induced gelation. On comparative evaluation carboxymethyl gellan gum showed 2.71-fold higher mucoadhesive strength than gellan gum. Evaluation of ex vivo ocular tolerance using chorioallantoic membrane of hen's egg and cytotoxicity screening on Vero cells using resazurin assay revealed that caroboxymethyl gellan gum is non-irritant and biocompatible. Ionotiropically gelled beads of carboxymethyl gellan gum formulated using metformin as the model drug and calcium chloride as the cross-linking agent showed ex vivo bioadhesion of 100% over 24h. Further, it was observed that carboxymethyl gellan gum beads released metformin at a rate faster than gellan gum.
authors.affiliation: Drug Delivery Research Laboratory, Department of Pharmaceutical Sciences, Guru Jambheshwar University of Science and Technology, Hisar 125 001, India. munishahuja17@yahoo.co.in
authors.forename: Munish
authors.initials: M
authors.lastname: Ahuja
authors.forename: Seema
authors.initials: S
authors.lastname: Singh
authors.forename: Ashok
authors.initials: A
authors.lastname: Kumar
mesh_terms: D000269:Adhesives / Q000138:chemical synthesis / Q000737:chemistry* / Q000633:toxicity; D000818:Animals; D002118:Calcium / Q000737:chemistry; D002122:Calcium Chloride / Q000737:chemistry; D002152:Calorimetry, Differential Scanning; D002470:Cell Survival / Q000187:drug effects; D002642:Chick Embryo; D002522:Chlorocebus aethiops; D049033:Chorioallantoic Membrane / Q000187:drug effects; D003432:Cross-Linking Reagents / Q000737:chemistry; D004337:Drug Carriers / Q000138:chemical synthesis / Q000737:chemistry* / Q000633:toxicity; D007004:Hypoglycemic Agents / Q000737:chemistry; D007413:Intestinal Mucosa / Q000187:drug effects; D008567:Membranes, Artificial; D008687:Metformin / Q000737:chemistry; D009077:Mucins / Q000737:chemistry; D011135:Polysaccharides, Bacterial / Q000138:chemical synthesis / Q000737:chemistry* / Q000633:toxicity; D013499:Surface Properties; D013718:Tensile Strength; D014709:Vero Cells; D014961:X-Ray Diffraction
chemical_list: D000269:Adhesives; D003432:Cross-Linking Reagents; D004337:Drug Carriers; D007004:Hypoglycemic Agents; D008567:Membranes, Artificial; D009077:Mucins; D011135:Polysaccharides, Bacterial; C581366:carboxymethyl gellan gum; D008687:Metformin; D002122:Calcium Chloride; D002118:Calcium