ph for weeks it is a poorly absorbed drug after oral administration with erratic bioavailability the parenteral preparation is the major dosage form used intravenously bolus or continuous infusion after parenteral administration of 5 fluorouracil there is a rapid distribution of the drug and rapid elimination with an apparent terminal half life of approximately 8 to 20 minutes in order to maintain therapeutic concentrations of the drug in the blood long term infusion has thusfar been preferred to evaluate the use of oxidized cellulose esters as drug carriers for water soluble drugs 5 fluorouracil was chosen as a model drug oxidized cellulose esters containing methyl octyl and cetyl substituted carboxylic acid ester groups were used to study the substitution effect on the release characteristics of the drug the release studies were performed in ph 7 4 phosphate buffer saline pbs solution ionic strength u02dc 0 165 m about 1 0 g of 5 fluorouracil with reduced particle size was accurately weighed and suspended in 10 0 ml of methylene dichloride to this mixture 1 0 g of polymer ocam20 ocaoct20 or ocacet20 was added the mixture was stirred until the polymer completely dissolved in the solution the resulting solution was then added drop wise using a syringe to 50 ml of 1 w v solution of poly vinyl alcohol pva in water with vigorous stirring u02dc 400 r p m at room temperature the mixture was then allowed to stir at.