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

Effect of added surfactants on rheological, organoleptic properties and staling rate of pan bread.

Levels of 0.5%, 0.75% and 1% of surfactants, i.e. DUR-EM 207, Lonzest SMO, and Lonzest SMS-20 were used to retard staling of wheat pan bread. The effect of those surfactants on rheological and organoleptic properties, yeast gassing power and staling rate was investigated. The dough properties were improved by adding the previous mentioned surfactants according to Farinograph and Extensograph data, whereas, stability, departure time, mixing tolerance and development time increased, however, weakening of dough decreased by adding any of the three surfactants studied except for 0.75% DUR-EM 207. On the other hand, increasing the amount of surfactants caused a decrease in the extensibility. Moreover, the three used surfactants inhibited gas production. However, addition of the surfactants to dough, enhanced bread quality and induced higher scores for over all acceptability. The staling rate of the different samples of bread were evaluated by determining moisture migration and sensory panel test. Addition of the surfactants to wheat flour succeeded in retarding the staling of bread over the tested period [4 days] than the control bread. The highest improvements were for those containing 0.5% DUR-EM 207, 0.75% Lonzed SMO and 1% Lonzest SMS-20

Spectrophotometric methods for the determination of dapsone

Two spectrophotometric methods are proposed for the micro determination of dapsone [Bis- [4-aminophenyl] sulphone] which is commonly used for the treatment of leprosy as antimicrobial drug. In the first method 1, 2 naphthoquinone-4-sulfonate sodium salt was used as a reagent for the colorimetric determination of the cited drug. This reagent was largely used for the determination of primary aromatic amines, a deep red paraquinoid condensation product results which can be measured at 475 nm in 50% acetic acid medium. The second method is coupling of the diazotized primary aromatic amino- groups in dapsone with barbituric acid, a compound possessing an active methylenic group. The concentration range for Beer's law compliance is 1.28-9 mug ml-1 with mean percentage recovery 99.22 +/- 1.697%. The methods were successfully applied for the determination of dapsone in its dosage forms

Colorimetric determination of propranolol hydrochloride in formulation

The reaction of secondary amines with carbon disulphide to form dithiocarbamic acid was utilized as a base for analysis of propranolol hydrochloride. The dithiocarbamic acid formed reacts with Cu [II] to form a yellow colored complex measured at 440 nm after extraction with benzene. Conditions of the reaction were thoroughly studied including the effect of acetic acid and pyridine concentrations on the process of extraction of dithiocarbamate complex. The results obtained by this method were compared with the USP method. The results revealed that both the variance ratio and t test are within the theoretical limits, indicating that the suggested method is equally precise and accurate. Beer's law obeyed for the concentration range between 50 and 400 ug.m-1 with mean percentage recovery of 100.16 + 0.60