Development of Phenytoin Suspension Extemporaneous

Abstract

Objective : To develop extemporaneous phenytoin suspension with a strength of 25 mg/ml for Nakhonpathom Hospital.
Materials &methods: This is an experimental study. The formulations of phenytoin suspension with a strength of 25 mg/ml were prepared by grinding the chewable phenytoin tablets and dispersed in the vehicle of hospital formula which contains paraben concentrate, sodium carboxymethyl cellulose
(Na CMC) mucilage, sorbital, simple syrup USP and water. Then the formula was modified by adding 0.25 M NaOH and Na CMC mucilage at 0.5%, 0.3%, 0.1% and 0.05% w/v. The samples were stored in the glass bottle with tight light resistant containers at the room temperature (25^๐C) and each formula
was compared by analyzing it with High Performance Liquid Chromatography (HPLC) to determine the remaining phenytoin content (the USP 37 indicates the remaining phenytoin content which is neither less than 95% and nor more than 105% of the initial content). Samples with the remaining phenytoin
content met specification at USP 37 and they were chosen for analysis the remaining phenytoin content and the microbiological stability testing on days 0, 7, 14 and 21.
Results : The average remaining phenytoin content ± S.D. of phenytoin suspension which contain of 0.5%, 0.3%, 0.1%, 0.05% w/v of Na CMC mucilage were 78.50 ± 0.015%, 82.90 ± 0.045%, 88.35 ± 0.025%, 97.65 ± 0.025% .The average remaining pheytoin content ± S.D. of phenytoin suspension at 0.25M NaOH with 0.05% w/v Na CMC mucilage were 97.93 ± 0.67%, 96.40 ± 0.35%, 92.17 ± 0.21% and 90.27 ± 1.66% on days 0, 7, 14 and 21 respectively. The total microbial count
were not found all 21 days.
Conclusions : The results from this study showed that the extemporaneous phenytoin suspension prepared by the formula of 0.25M NaOH with 0.05% w/v Na CMC mucilage was stable for at least 7 days when it stored in glass bottles with tight light resistant containers at the room temperature (25^๐ C).