Effects of high-shear granulation on granulate homogeneity.
Pharm Dev Technol
; 4(3): 297-303, 1999 Aug.
Article
em En
| MEDLINE
| ID: mdl-10434275
ABSTRACT
This study considers the effects of particle size of the powder constituents, and of impeller speed on the homogeneity of drug distribution on granulations produced in high-speed mixers. When a micronized low-dose steroid hormone was granulated together with unmicronized lactose in a Vactron 75 high-shear granulator at 250 rpm, strong inhomogeneities of the drug distribution arose. The coarse particle size fractions of the granules were found to be superpotent up to 150% of the mean drug content, whereas the fine size fraction showed a corresponding subpotency of 50%. Both particle size and impeller speed attributed to this phenomenon. At an impeller speed of 75 rpm, a significantly better drug distribution was obtained. Results show that the inhomogeneities found are mainly a consequence of the balance between the impact pressure as exerted by the impeller on the one hand and the shear resistance of the nuclei on the other hand. At a speed of 250 rpm, the tensile strength of 3 x 10(3) N/m2 of the initially formed nuclei is too weak to resist an impact pressure of 30 x 10(3) N/m2. For that reason, particle rearrangement takes place, which results in inhomogeneity. Because an impeller speed of 75 rpm is equal to an impact pressure of 2.6 x 10(3) N/m2, significantly less demixing occurs. Similar results can be obtained when the particle size of all constituents is reduced, which increases the tensile strength of the nuclei.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Pós
/
Composição de Medicamentos
Idioma:
En
Revista:
Pharm Dev Technol
Assunto da revista:
FARMACIA
Ano de publicação:
1999
Tipo de documento:
Article
País de afiliação:
Holanda