Biophysical elucidation of the mechanism of enhanced drug release and topical delivery from polymeric film-forming systems.
J Control Release
; 212: 103-12, 2015 Aug 28.
Article
en En
| MEDLINE
| ID: mdl-26087467
The effect of incorporating the lipidic medium-chain triglyceride (MCT) into polymeric film-forming systems (FFS) for topical drug delivery has been evaluated. First, the in vitro release of betamethasone-17-valerate (BMV), a representative dermatological drug, was determined from FFS comprising either hydrophobic polyacrylate co-polymers, or hydrophilic hydroxypropyl cellulose, with and without MCT. Release was enhanced from both polymers in the presence of MCT. Atomic force microscopy imaging and nanoindentation of FFS with MCT revealed two-phase structured films with softer inclusions (0.5 to 4µm in diameter) surrounded by a more rigid structure. Chemical mapping with Raman micro-spectroscopy showed that MCT was primarily confined to the inclusions within the polymer, which predominated in the surrounding film. BMV was distributed throughout the film but was more concentrated outside the inclusions. Furthermore, while BMV dissolved better into the hydrophobic films, it was more soluble in the MCT inclusions in hydrophilic films, suggesting its increased availability for diffusion from these softer regions of the polymer and explaining the release enhancement observed. Second, ex vivo skin penetration studies clearly revealed that uptake of BMV was higher from hydrophobic FFS than that from the more hydrophilic polymer due, at least in part, to the superior anti-nucleation efficiency of the former. Drug was quickly taken up into the SC from which it then diffused continuously over a sustained period into the lower, viable skin layers. In the presence of MCT, the overall uptake of BMV was increased and provides the basis for further optimisation of FFS as simple, convenient and sustained formulations for topical therapy.
Palabras clave
Texto completo:
1
Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Polímeros
/
Triglicéridos
/
Valerato de Betametasona
/
Sistemas de Liberación de Medicamentos
Límite:
Animals
Idioma:
En
Revista:
J Control Release
Asunto de la revista:
FARMACOLOGIA
Año:
2015
Tipo del documento:
Article
Pais de publicación:
Países Bajos