Diphenylpyraline hydrochloride (Di-HCl) has been determined in raw material and its pharmaceutical preparation
Eskornade capsule (5mg/capsule) using differential pulse voltammetry (DPV) and conductimetric determination. It
was found that Di-HCl gives a characteristic cyclic voltammetric (CV) and differential pulse voltammetric (DPV) peak in
acetonitrile using platinum and glassy carbon sensors as working electrodes. The peak current (Ip) of the DPV peak increases
linearly within the concentration range 4.5 x 10-4-1x10-2 mol/L of the investigated drug. The concentration of Di-
HCl in raw drug material and in its pharmaceutical preparations was determined using standard addition method, Randles-
Sevcik equation and indirectly via its complexation with sodium tetra phenylborate (NaTPB), the obtained average recoveries
were 101.44 and 100.49 with standard deviation (SD) 0.45 and 0.38 (n = 4) for platinum and glassy carbon electrodes
respectively. The effect of scan rate, sample concentration and supporting electrolyte on the peak current (Ip) and
peak potential (Ep)was investigated.
In addition a simple and sensitive conductimetric method was used for determination of Di-HCl based on its ion association
with sodium tetraphenylborate (NaTPB). The effect of solvent, reagent concentration, temperature and molar ratio
was studied. The obtained average recovery was 101.44 with SD 0.45 (n = 4).