Chitosan Chemische Eigenschaften,Einsatz,Produktion Methoden
R-S?tze Betriebsanweisung:
R20/21/22:Gesundheitssch?dlich beim Einatmen,Verschlucken und Berührung mit der Haut.
R36/37/38:Reizt die Augen, die Atmungsorgane und die Haut.
S-S?tze Betriebsanweisung:
S24/25:Berührung mit den Augen und der Haut vermeiden.
S36:DE: Bei der Arbeit geeignete Schutzkleidung tragen.
S26:Bei Berührung mit den Augen sofort gründlich mit Wasser abspülen und Arzt konsultieren.
Chemische Eigenschaften
Chitosan occurs as odorless, white or creamy-white powder or
flakes. Fiber formation is quite common during precipitation and
the chitosan may look ‘cottonlike’.
Occurrence
Chitosan comes from the shell of marine crustaceans.
Verwenden
Forms gels with multivalent anions. Gives clear solutions that dry to strong, clear films.Flocculant, protein precipitation, encapsulating agent and aqueous thickener.
Chitosan is a natural polycationic linear polysaccharide derived from chitin. The low solubility of chitosan in neutral and alkaline solution limits its application.
Chitosan: An Update on Potential Biomedical and Pharmaceutical Applications
Vorbereitung Methode
Chitosan is manufactured commercially by chemically treating the
shells of crustaceans such as shrimps and crabs. The basic
manufacturing process involves the removal of proteins by
treatment with alkali and of minerals such as calcium carbonate
and calcium phosphate by treatment with acid. Before these
treatments, the shells are ground to make them more accessible. The
shells are initially deproteinized by treatment with an aqueous
sodium hydroxide 3–5% solution. The resulting product is
neutralized and calcium is removed by treatment with an aqueous
hydrochloric acid 3–5% solution at room temperature to precipitate
chitin. The chitin is dried so that it can be stored as a stable
intermediate for deacetylation to chitosan at a later stage. NDeacetylation
of chitin is achieved by treatment with an aqueous
sodium hydroxide 40–45% solution at elevated temperature
(1108℃), and the precipitate is washed with water. The crude
sample is dissolved in acetic acid 2% and the insoluble material is
removed. The resulting clear supernatant solution is neutralized
with aqueous sodium hydroxide solution to give a purified white
precipitate of chitosan. The product can then be further purified and
ground to a fine uniform powder or granules. The animals from
which chitosan is derived must fulfil the requirements for the health
of animals suitable for human consumption to the satisfaction of the
competent authority. The method of production must consider
inactivation or removal of any contamination by viruses or other
infectious agents.
benefits
Chitosan is a fibrous substance that might reduce how much fat and cholesterol the body absorbs from foods. It also helps blood clot when applied to wounds.
Allgemeine Beschreibung
Chitosan is a linear amino polysaccharide composed of approximately 20% β1,4-linked N-acetyl-D-glucosamine (GlcNAc) and approximately 80% β1,4-linked D-glucosamine (GlcN) that is prepared by the partial deacetylation of chitin in hot alkali.
Pharmazeutische Anwendungen
Chitosan is used in cosmetics and is under investigation for use in a
number of pharmaceutical formulations. The suitability and
performance of chitosan as a component of pharmaceutical
formulations for drug delivery applications has been investigated
in numerous studies. These include controlled drug delivery
applications, use as a component of mucoadhesive dosage
forms, rapid release dosage forms, improved peptide
delivery, colonic drug delivery systems, and use for gene
delivery. Chitosan has been processed into several pharmaceutical
forms including gels, films, beads, microspheres, tablets, and coatings for liposomes.
Furthermore, chitosan may be processed into drug delivery systems
using several techniques including spray-drying, coacervation, direct compression, and conventional granulation
processes.
Sicherheit(Safety)
Chitosan is being investigated widely for use as an excipient in oral
and other pharmaceutical formulations. It is also used in cosmetics.
Chitosan is generally regarded as a nontoxic and nonirritant
material. It is biocompatible with both healthy and infected
skin. Chitosan has been shown to be biodegradable.
LD
50 (mouse, oral): >16 g/kg
Lager
Chitosan powder is a stable material at room temperature, although
it is hygroscopic after drying. Chitosan should be stored in a tightly
closed container in a cool, dry place. The PhEur 6.5 specifies that
chitosan should be stored at a temperature of 2–88℃.
Inkompatibilit?ten
Chitosan is incompatible with strong oxidizing agents.
Regulatory Status
Chitosan is registered as a food supplement in some countries.
Chitosan Upstream-Materialien And Downstream Produkte
Upstream-Materialien
Downstream Produkte
