Limits...
Chitosan-genipin microspheres for the controlled release of drugs: clarithromycin, tramadol and heparin.

Harris R, Lecumberri E, Heras A - Mar Drugs (2010)

Bottom Line: Once the crosslinking process was characterized as a function of the factors mentioned above, drug loaded hydrochloride chitosan microspheres with different degrees of crosslinking were obtained.In conclusion, genipin showed to be eligible as a chemical-crosslinking agent delaying the outflow of drugs from the microspheres.However, more studies in vitro and in vivo must be carried out to determine adequate crosslinking conditions for different drugs.

View Article: PubMed Central - PubMed

Affiliation: Instituto de Estudios Biofuncionales, Departamento Química-Física II, Universidad Complutense Paseo Juan XXIII, Madrid, Spain. ruthharris@ieb.ucm.es

ABSTRACT
The aim of this study was to first evaluate whether the chitosan hydrochloride-genipin crosslinking reaction is influenced by factors such as time, and polymer/genipin concentration, and second, to develop crosslinked drug loaded microspheres to improve the control over drug release. Once the crosslinking process was characterized as a function of the factors mentioned above, drug loaded hydrochloride chitosan microspheres with different degrees of crosslinking were obtained. Microspheres were characterized in terms of size, morphology, drug content, surface charge and capacity to control in vitro drug release. Clarithromycin, tramadol hydrochloride, and low molecular weight heparin (LMWH) were used as model drugs. The obtained particles were spherical, positively charged, with a diameter of 1-10 microm. X-Ray diffraction showed that there was an interaction of genipin and each drug with chitosan in the microspheres. In relation to the release profiles, a higher degree of crosslinking led to more control of drug release in the case of clarithromycin and tramadol. For these drugs, optimal release profiles were obtained for microspheres crosslinked with 1 mM genipin at 50 °C for 5 h and with 5 mM genipin at 50 °C for 5 h, respectively. In LMWH microspheres, the best release profile corresponded to 0.5 mM genipin, 50 °C, 5 h. In conclusion, genipin showed to be eligible as a chemical-crosslinking agent delaying the outflow of drugs from the microspheres. However, more studies in vitro and in vivo must be carried out to determine adequate crosslinking conditions for different drugs.

Show MeSH
Release profiles of clarithromycin in SGF from chitosan hydrochloride (5 mg/mL) microspheres loaded with clarithromycin (50% w/w) without genipin (0 mM) and crosslinked with 1mM genipin at 50 ºC for 5 h.
© Copyright Policy - open-access
Related In: Results  -  Collection

License 1 - License 2
getmorefigures.php?uid=PMC2901822&req=5

f7-marinedrugs-08-01750: Release profiles of clarithromycin in SGF from chitosan hydrochloride (5 mg/mL) microspheres loaded with clarithromycin (50% w/w) without genipin (0 mM) and crosslinked with 1mM genipin at 50 ºC for 5 h.

Mentions: The effect of crosslinking microspheres with genipin on clarithromycin release in simulated gastric fluid (SGF) was studied. The addition of the crosslinking agent led to the slower release of the drug. Figure 7 shows clarithromycin release profiles of non crosslinked chitosan microspheres and from microspheres crosslinked with 1 mM genipin for 5 h at 50 ºC. After 3 h, microspheres without genipin had released 100% of the drug, while crosslinked microspheres had released 60% of clarithromycin. The release from microspheres crosslinked with 0.5 mM genipin did not show significant differences with microspheres with 1mM genipin (results not shown).


Chitosan-genipin microspheres for the controlled release of drugs: clarithromycin, tramadol and heparin.

Harris R, Lecumberri E, Heras A - Mar Drugs (2010)

Release profiles of clarithromycin in SGF from chitosan hydrochloride (5 mg/mL) microspheres loaded with clarithromycin (50% w/w) without genipin (0 mM) and crosslinked with 1mM genipin at 50 ºC for 5 h.
© Copyright Policy - open-access
Related In: Results  -  Collection

License 1 - License 2
Show All Figures
getmorefigures.php?uid=PMC2901822&req=5

f7-marinedrugs-08-01750: Release profiles of clarithromycin in SGF from chitosan hydrochloride (5 mg/mL) microspheres loaded with clarithromycin (50% w/w) without genipin (0 mM) and crosslinked with 1mM genipin at 50 ºC for 5 h.
Mentions: The effect of crosslinking microspheres with genipin on clarithromycin release in simulated gastric fluid (SGF) was studied. The addition of the crosslinking agent led to the slower release of the drug. Figure 7 shows clarithromycin release profiles of non crosslinked chitosan microspheres and from microspheres crosslinked with 1 mM genipin for 5 h at 50 ºC. After 3 h, microspheres without genipin had released 100% of the drug, while crosslinked microspheres had released 60% of clarithromycin. The release from microspheres crosslinked with 0.5 mM genipin did not show significant differences with microspheres with 1mM genipin (results not shown).

Bottom Line: Once the crosslinking process was characterized as a function of the factors mentioned above, drug loaded hydrochloride chitosan microspheres with different degrees of crosslinking were obtained.In conclusion, genipin showed to be eligible as a chemical-crosslinking agent delaying the outflow of drugs from the microspheres.However, more studies in vitro and in vivo must be carried out to determine adequate crosslinking conditions for different drugs.

View Article: PubMed Central - PubMed

Affiliation: Instituto de Estudios Biofuncionales, Departamento Química-Física II, Universidad Complutense Paseo Juan XXIII, Madrid, Spain. ruthharris@ieb.ucm.es

ABSTRACT
The aim of this study was to first evaluate whether the chitosan hydrochloride-genipin crosslinking reaction is influenced by factors such as time, and polymer/genipin concentration, and second, to develop crosslinked drug loaded microspheres to improve the control over drug release. Once the crosslinking process was characterized as a function of the factors mentioned above, drug loaded hydrochloride chitosan microspheres with different degrees of crosslinking were obtained. Microspheres were characterized in terms of size, morphology, drug content, surface charge and capacity to control in vitro drug release. Clarithromycin, tramadol hydrochloride, and low molecular weight heparin (LMWH) were used as model drugs. The obtained particles were spherical, positively charged, with a diameter of 1-10 microm. X-Ray diffraction showed that there was an interaction of genipin and each drug with chitosan in the microspheres. In relation to the release profiles, a higher degree of crosslinking led to more control of drug release in the case of clarithromycin and tramadol. For these drugs, optimal release profiles were obtained for microspheres crosslinked with 1 mM genipin at 50 °C for 5 h and with 5 mM genipin at 50 °C for 5 h, respectively. In LMWH microspheres, the best release profile corresponded to 0.5 mM genipin, 50 °C, 5 h. In conclusion, genipin showed to be eligible as a chemical-crosslinking agent delaying the outflow of drugs from the microspheres. However, more studies in vitro and in vivo must be carried out to determine adequate crosslinking conditions for different drugs.

Show MeSH