Thiomers: potential excipients for non-invasive peptide delivery systems.
Eur J Pharm Biopharm
; 58(2): 253-63, 2004 Sep.
Article
en En
| MEDLINE
| ID: mdl-15296953
ABSTRACT
In recent years thiolated polymers or so-called thiomers have appeared as a promising alternative in the arena of non-invasive peptide delivery. Thiomers are generated by the immobilisation of thiol-bearing ligands to mucoadhesive polymeric excipients. By formation of disulfide bonds with mucus glycoproteins, the mucoadhesive properties of these polymers are improved up to 130-fold. Due to formation of inter- and intramolecular disulfide bonds within the thiomer itself, dosage forms such as tablets or microparticles display strong cohesive properties resulting in comparatively higher stability, prolonged disintegration times and a more controlled release of the embedded peptide drug. The permeation of peptide drugs through mucosa can be improved by the use of thiolated polymers. Additionally some thiomers exhibit improved inhibitory properties towards peptidases. The efficacy of thiomers in non-invasive peptide delivery could be demonstrated by various in vivo studies. Tablets comprising a thiomer and pegylated insulin, for instance, resulted in a pharmacological efficacy of 7% after oral application to diabetic mice. Furthermore, a pharmacological efficacy of 1.3% was achieved in rats by oral administration of calcitonin tablets comprising a thiomer. Human growth hormone in a thiomer-gel was applied nasally to rats and led to a bioavailability of 2.75%. In all these studies, formulations comprising the corresponding unmodified polymer had only a marginal or no effect. According to these results drug carrier systems based on thiomers seem to be a promising tool for non-invasive peptide drug delivery.
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Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Péptidos
/
Polímeros
/
Compuestos de Sulfhidrilo
/
Sistemas de Liberación de Medicamentos
/
Excipientes
Límite:
Animals
/
Humans
Idioma:
En
Revista:
Eur J Pharm Biopharm
Asunto de la revista:
FARMACIA
/
FARMACOLOGIA
Año:
2004
Tipo del documento:
Article
País de afiliación:
Austria