The use of biodegradable polymeric carriers for the drug delivery systems has gained a wide interest, mainly for their biocompatibility and, among the microparticulate systems, microspheres show a special importance for providing local as well as temporal controlled release of the drug. Different types of polymers are encountered in the literature used to this purpose. In the case of the release of diclofenac are available: poly-3-caprolactone, poly-/vinylalcohol, poly-lactide-co-glycolide. Also natural polymers found their application in this field: albumin, alginate, carboxymethyl-cellulose, chitosan. The preparation and characterization of the samples are quite similar in most cases. The anti-inflammatory drug (as sodium salt) is dissolved in an aqueous solution containing the soluble polymer and, in the case of carboxylate-containing polymers (alginate, carboxymethyl cellulose), the formation of microspheres was obtained by the addition of Ca2+ or Al3+: the hydrophilic colloids interact with metal ions to form crosslinked insoluble complexes, that precipitate incorporating the drug. In this paper, we prepared microspheres of alginate containing sodium diclofenac and examined the different influence of Ca2+ or Al3+ ions on the microsphere morphology and the influence of different amounts of chitosan on the release of diclofenac. Among polyanionic polymers alginate has been widely studied and applied for its possibilità to modulate the release, according to the properties of its carboxyl groups as well as its biodegradability and absence of toxicity. Also chitosan finds wide applications in pharmaceutical technology as tablet disintegrant, for the production of controlled release solid dosage forms or for improvement of drug dissolution Diclofenac is a suitable candidate for incorporation into microspheres to minimize its adverse effect after oral administration; in fact, alginate microspheres containing diclofenac start to release the drug after the pH of the environment increases above 7, by-passing the gastric environment and avoid direct contact between the drug and the gastric mucosa.
Microencapsulation of sodium diclofenac in alginate/chitosan particulate systems / M.L. Gonzalez Rodriguez; M.A. Holgado; C. Sanchez-Lafuente; A.M. Rabasco; A.Fini. - STAMPA. - (2005), pp. 413-413. (Intervento presentato al convegno 15th International Symposium on Microencapsulation tenutosi a Parma, Italy nel 18-21 settembre 2005).
Microencapsulation of sodium diclofenac in alginate/chitosan particulate systems
FINI, ADAMO
2005
Abstract
The use of biodegradable polymeric carriers for the drug delivery systems has gained a wide interest, mainly for their biocompatibility and, among the microparticulate systems, microspheres show a special importance for providing local as well as temporal controlled release of the drug. Different types of polymers are encountered in the literature used to this purpose. In the case of the release of diclofenac are available: poly-3-caprolactone, poly-/vinylalcohol, poly-lactide-co-glycolide. Also natural polymers found their application in this field: albumin, alginate, carboxymethyl-cellulose, chitosan. The preparation and characterization of the samples are quite similar in most cases. The anti-inflammatory drug (as sodium salt) is dissolved in an aqueous solution containing the soluble polymer and, in the case of carboxylate-containing polymers (alginate, carboxymethyl cellulose), the formation of microspheres was obtained by the addition of Ca2+ or Al3+: the hydrophilic colloids interact with metal ions to form crosslinked insoluble complexes, that precipitate incorporating the drug. In this paper, we prepared microspheres of alginate containing sodium diclofenac and examined the different influence of Ca2+ or Al3+ ions on the microsphere morphology and the influence of different amounts of chitosan on the release of diclofenac. Among polyanionic polymers alginate has been widely studied and applied for its possibilità to modulate the release, according to the properties of its carboxyl groups as well as its biodegradability and absence of toxicity. Also chitosan finds wide applications in pharmaceutical technology as tablet disintegrant, for the production of controlled release solid dosage forms or for improvement of drug dissolution Diclofenac is a suitable candidate for incorporation into microspheres to minimize its adverse effect after oral administration; in fact, alginate microspheres containing diclofenac start to release the drug after the pH of the environment increases above 7, by-passing the gastric environment and avoid direct contact between the drug and the gastric mucosa.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
