Chitin is a nitrogen-containing polysaccharide, related chemically to cellulose. It is a principal constituent of the exoskeleton crustaceans. Due to their biocompatibility and less toxic nature, it has been developed as new physiologically bioactive materials since they possess various biological activities. Chemical extraction of chitin from shells, of the white shrimp Parapenaeus longirostri...

Despite numerous scientific efforts many challenges need to be overcome in the ocular delivery because eyes have special and complex anatomic structures. The main problem with the conventional dosage forms is poor ocular bioavailability due to minimum ocular residence time, because of various anatomical and pathophysiological barriers prevailing in the eye. For this reason, much effort has been...

The focus of this review is to provide an overview of the chitosan based nanoparticles for various non-parenteral applications and also to put a spotlight on current research including sustained release and mucoadhesive chitosan dosage forms. Chitosan is a biodegradable, biocompatible polymer regarded as safe for human dietary use and approved for wound dressing applications. Chitosan has been ...

If we take a look on Scopus website from the last 5 years, we could see that chitosan and its chemical/enzymatic derivatives are ranked in one of the first bio-polysaccharide described for pharmaceutical applications. As for example, in 2012 using “chitosan” and a combination of “chitosan and pharmaceutical” we found, respectively, 4027 and 1588 publications whereas for 2016 we found respective...

The polyfunctional and highly reactive bio-polymer, the chitosan was first regioselectively converted into dialkylated chitosan using dimsyl anionic solution(NaH in DMSO) and bromodecane after protecting amino groups by phthalic anhydride. The dibenzo-18-crown-6-ether, on the other hand, was converted into its carbonyl derivatives via Duff reaction prior to incorporate into chitosan by Schiff b...

We examined the effects of four kinds of chitosan derivatives on initial adherence of oral bacteria onto human anterior teeth surfaces. The buccal surfaces of anterior teeth were used as the experimental surfaces. They were divided into five rectangle areas with outer dimensions of about 2 mm x 4 mm. After applying two ml of a sample solution onto the tooth surfaces, an examiner wiped each rect...

With the specialty of improving the water solubility of chitosan, quaternary ammonium salts have broadened the application of this polysaccharide in food, medicine and pesticides. To identify the effect of quaternary ammonium salts' quantity, single quaternized chitosan N-phenmethyl-N,N-dimethyl chitosan (PDCS), double quaternized chitosan N-(1-pyridylmethyl-2-ylmethyl)-N,N-dimethyl chitosan (M...

Naturally occurring polymers, particularly of the polysaccharide type, have been used pharmaceutically for the delivery of a wide variety of therapeutic agents. Chitosan, the second abundant naturally occurring polysaccharide next to cellulose, is a biocompatible and biodegradable mucoadhesive polymer that has been extensively used in the preparation of micro-as well as nanoparticles. The prepa...

Chitosan has received much attention as a functional biopolymer for diverse applications, especially in pharmaceutics and medicine. Our recent efforts focused on the chemical and biological modification of chitosan in order to increase its solubility in aqueous solutions and absorbability in the in vivo system, thus for a better use of chitosan. This review summarizes chitosan modification and ...

Chitosan is a natural based polymer, obtained by alkaline deacetylation of chitin, which presents excellent biological properties such as biodegradability and immunological, antibacterial and wound-healing activity. Recently, there has been a growing interest in the chemical modification of chitosan in order to improve its solubility and widen its applications. The main chemical modifications o...