TITLE:
Investigation of Iron Complex Formation of Anti-Hypertensive Drug: Methyldopa
AUTHORS:
Tehmina Fiaz, Nasreen Fatima, S. Zafar Abbas Zaidi, Tanveer Abbas, Mohib R. Kazimi
KEYWORDS:
Iron, Methyldopa, Stoichiometry, Formation Constant, UV-Spectrophotometery
JOURNAL NAME:
American Journal of Analytical Chemistry,
Vol.6 No.6,
May
20,
2015
ABSTRACT: The
drug administered for any disease may play an unwanted function in biological
system. They may have multiple counter effects, one of which is their
interaction to bioactive metals. Iron is most common bio essential metal and is
reported to interact with antihypertensive drug methyldopa. In the present
study, above said complex is analyzed by UV-Visible spectrophotometry. Formation
constant of the complex is calculated by using mole ratio method and single
point statistical method which is in the range of 1010, values are
also calculated which are independent of pH like formation constant. Absorbance
maxima were found to be dependent on pH. At lower pH complex shows two broad
bands centered at 430 nm and 730 nm. With the rise in pH later peak shifts
toward lower wavelength, so 615 nm is selected for further studies. Molar
extinction coefficient of the complex is explored by serial dilution method. At
all wavelengths it increases with increase in pH. Mole ratio and slope ratio
methods are used for exploring stoichiometry. Metal to ligand combining ratio
in the complex is 1:2 at pH 4.0 and pH 4.5 while 1:3 at pH 5.0 and pH 5.5.