Effect of silica and poly(ethylene glycol) on thein vitro release rate of 2-pyridine aldoxime chloride from polysiloxane matrices
✍ Scribed by Gupta, D?C; Sumana, G; Jain, R; Pant, B?P; Jaiswal, D?K
- Publisher
- John Wiley and Sons
- Year
- 2000
- Tongue
- English
- Weight
- 84 KB
- Volume
- 49
- Category
- Article
- ISSN
- 0959-8103
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✦ Synopsis
The release rate of 2-pyridine aldoxime chloride (PAM-Cl) from polysiloxane matrices was found to be in the order poly(vinylmethyldiethylsiloxane) (P(VM-DE)S) b poly(dimethyldiethyl siloxane) P(DM-DE)S b poly(vinylmethylsiloxane) (PVMS) b poly(dimethylvinylmethylsiloxane) (P(DM-VM)S) b poly(dimethylsiloxane) (PDMS). The time for 80% PAM-Cl release from polysiloxane matrices was found to be in the range 5±14 h. Incorporation of silica (5±10%) as a ®ller in these matrices reduced the release of PAM-Cl and in some cases stopped drug release completely. However, the incorporation of crosslinked poly(ethylene glycol) (PEG) (5±20%) in polysiloxane matrices increased the release rate and reduced the time for 80% drug release. Slow release formulations were made by incorporating 5% silica and 5±20% PEG in PDMS, keeping the PAM-Cl and PEG ratio 1:1. The formulations PDMS 5% silica 5±20% PEG 5±20% PAM-Cl gave a slow release of PAM-Cl and the time for 80% drug release was found to be 12 h in each case at pH 7.4 and 37 °C. PVMS and siloxane copolymers showed times for 80% drug release of 6±10 h in comparison with 12 h for PDMS. Diffusion coef®cient values for PAM-Cl±PDMS system are also calculated.