Enhancement of The Solubility of N-(3-acetylphenyl)-4-Oxo-2-Thioxo-1,2,3,4-Tetrahydropyrimidine-5-Sulfonamide Through Inclusion Complexation with Cyclodextrins

Abstract

Salam W.Ahjel, Samir M.Awad,Mohamed F. El-Shehry

A new thiouracil-5-sulfonamide derivative (1) was prepared from nucleophilic
condensation of 2-thiouracil-5-sulfonyl chloride with m-aminoacetophenone using
pyridine as an acid binder. The bad solubility of this sulfonamide is enhanced
through its inclusion complexation with cyclodextrins (CDs). The solubility of the
sulfonamide in water and in 0.1N HCl was determined at gradient temperatures.
The stability constants of the complexes were determined using ultrafilteration and
UV-spectrophotometric methods. The results showed that the sulfonamide has
low solubility in water (<5μg / ml) and in 0.1NHCl (<7μg / ml). The highest
solubility was obtained with HP-ß-CD while the least one was with ß-CD. We
arranged the apparent stability constants of the formed complexes as follow, ß-
CD > HE-ß-CD > HP-ß-CD and their values were decreased as the temperature
increased. The stability constants were attained using ultrafilteration method at
room temperature.