EFFECTS OF SILICIUM DIOXIDE OIL DRUG-RELEASE FROM SUPPOSITORIES

Citation
N. Realdon et al., EFFECTS OF SILICIUM DIOXIDE OIL DRUG-RELEASE FROM SUPPOSITORIES, Drug development and industrial pharmacy, 23(11), 1997, pp. 1025-1041
Citations number
15
Categorie Soggetti
Chemistry Medicinal","Pharmacology & Pharmacy
ISSN journal
03639045
Volume
23
Issue
11
Year of publication
1997
Pages
1025 - 1041
Database
ISI
SICI code
0363-9045(1997)23:11<1025:EOSDOD>2.0.ZU;2-R
Abstract
Silica gel is frequently introduced into lipophilic excipients for sup positories as a viscosity agent, to, prevent drug sedimentation in the melted mass, and to decrease release rate. The effect of silica gel ( Aerosil 200) concentration on the availability of some drugs frequentl y used in suppositories in different unitary doses was studied. When s ilica gel concentration in the excipient was increased, a decrease in aminophylline and aminophenazone release rate was observed. Paracetamo l in small unitary doses has shown a tendency to increase release rate at higher silica gel concentrations. This behavior was even more evid ent in suppositories containing promethazine hydrochloride, while for those containing benzydamine hydrochloride the increase in release rat e with increasing silica gel concentration was evident for all drug do ses. However, the behavior was a consequence of the trend of supposito ry viscosity during drug release. As a consequence of both the drug an d silica gel being discharged, the viscosity progressively decreased w ith an increased silica gel concentration. The effect on drug availabi lity was conditioned by silica gel concentration, as well as the type and dose of the drug, which could act on the shape of the suppository inner structure that is responsible for viscosity and mobility of drug particles.