The study focused on elaborating and validating a quantitative assay method for 5-fluorouracil (5-FU) from vaginal bioadhesive tablets, using HPLC. For the quantitative assessment of 5-FU from the bioadhesive tablets it was used the internal standard method. Pyridine 3-carbohydrazide (P3C) was chosen to be the internal standard used as its physical and chemical features were similar to those of 5-FU. The method relies on using HPLC for separating the two compounds, with UV detection at 270 nm. Using the validation procedure we established the system's compatibility represented by the injection repeatability (RSD%(5Fu) = 1.1006; RSD%(P3C) = 1.9053), the confidence interval at a safety level of 95%, repeatability of retention time (RSD%(5Fu) = 1.8117; RSD%(P3C) = 1.8694), the separation degree of two consecutive peaks (Rs(5FU/P3C)=5.38), the number of theoretical plates of the column (N-5FU = 3757; N-P3C = 3110). The method elaborated is accurate for the studied concentration range 0.0005 - 0.012mg/mL, with the average retrieval percentage of 103,4854 individual standard deviation 0.0148, relative standard deviation of 1.4127 and the maximum value of percent deviation of 4.16.
