Structural characterisation of water-Tween 40/Imwitor 308-isopropyl myristate microemulsions using different experimental methods.
Int J Pharm
; 276(1-2): 115-28, 2004 May 19.
Article
em En
| MEDLINE
| ID: mdl-15113620
ABSTRACT
Pharmaceutically usable microemulsion systems were prepared from water and isopropyl myristate with a constant amount of Tween 40 and Imwitor 308 at a mass ratio of 1. Their type and structure were examined by measuring density and surface tension, and by viscometry, electric conductivity, differential scanning calorimetry (DSC) and small-angle X-ray scattering (SAXS), and the degree of agreement between the techniques was assessed. A model based on monodisperse hard spheres adequately fits the SAXS data in W/O microemulsions predicting, depending on composition, elongated or spherical droplets. It also suggests the involvement of strong attractive interactions in O/W systems. Results of conductivity, viscosity, density and surface tension measurements confirm the prediction of a percolation transition to a bicontinuous structure. DSC detects the degree of water interaction with surfactants thus identifying the type of microemulsion. The conclusions from all the techniques agree well and indicate that such studies could also be carried out on more complex systems. In future, the ability to determine type and structure of such microemulsion systems could enable partitioning and release rates of drugs from microemulsions to be predicted.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Polissorbatos
/
Triglicerídeos
/
Caprilatos
/
Água
/
Química Farmacêutica
/
Sistemas de Liberação de Medicamentos
/
Miristatos
Tipo de estudo:
Prognostic_studies
Idioma:
En
Ano de publicação:
2004
Tipo de documento:
Article