Spectrophotometric determination of some drugs acting on the GIT via complexation of the drugs hydroxamate with iron [III]

Simple spectrophotometric method for the determination of trimebutine maleate, mebevrine HCL, diloxanide furoate and oxyphenonium bromide by hydroxamic acid formation either in pure or dosage forms is described. The studied drugs react with hydroxyl amine in alkaline medium to form hydroxamic acid derivatives that were complexed with iron [III] in acidic medium to form brownish violet colored complexes having maximum absorbances at 535 nm for mebevrine HCL. trimebutine maleate and diloxanide furoate and at 510 nm for oxyphenonium bromide, Beer's law was obeyed in the concentration ranges of 50-450, 100-700, 40-200 and 100-700 .microg ml[-1] for mebevrine HCL, trimebutine maleate, diloxanide furoate and oxyphenonium bromide, respectively. Molar absorbtivities and Sandell's sensitivities were calculated and presented. The developed procedures were favorably applied for determination of the studied drugs in their pharmaceutical dosage forms. The obtained results were compared satisfactorily with the official and reported methods. There were no significant differences between the proposed, official and reported methods