STABILITY-INDICATING UV-SPECTROPHOTOMETRIC ASSAY
OF DIETHYLCARBAMAZINE CITRATE IN PHARMACEUTICALS
and N. Swamy
Original article submitted August 12, 2016.
Diethylcarbamazine citrate (DEC) is a piperazine anthelmintic agent indicated for the treatment of individual
patients with lymphatic filariasis. Two simple and sensitive UV-spectrophotometric techniques have been de
veloped and validated for the determination of this drug in bulk parent substance and tablets, based on the
measurement of the absorbance of DEC solution either in 0.1M HCl at 210 nm (method A) or in 0.1M H
at 209 nm (method B). Beer’s law was obeyed over the concentration ranges of 1.25 – 25.0 and
2.5 – 30.0 mg × mL
, for method A and method B, respectively, and the corresponding molar absorptivity val
ues were 2.02 ´ 10
and 1.21 ´ 10
. The limits of detection (LOD) and quantification (LOQ)
were, respectively, 0.26 and 0.78 mg × mL
(method A), and 0.16 and 0.49 mg × mL
(method B). These meth
ods were assessed for intra-day and inter-day accuracy and precision, as well as robustness and ruggedness.
Both methods were applied to one brand of tablets with percentage label claim of 101.7 and 100.8 for method
A and method B, respectively, and the standard deviation was below 2%. In order to establish the stability-in-
dicating ability of these methods, the drug was analyzed after subjecting it to acid and base hydrolysis, oxida-
tion, heat and light stress conditions and the results indicated that the drug degraded extensively under both
base- and oxidative-stress conditions, and remained intact under other stress conditions.
Keywords: diethylcarbamazine citrate; assay; UV spectrophotometry; stability-indicating method.
Diethylcarbamazine citrate (DEC), chemically known as
N,N-diethyl-4-methyl-1-piperazine carboxamide citrate
(Fig. 1), is an antiparasitic agent used in the treatment of
lymphatic filariasis (LF). LF results from infection with par
asitic round worms Wuchereria bancrofti, Brugia malayi,
and B. tomori. The infection is transmitted by mosquitoes.
Chronic manifestations of the disease include hydrocele,
lymphoedema, and elephantiasis, which may affect more
than 50% of adult population in insect-affected areas. Mass
treatment with DEC is recommended for the control of LF
The therapeutic importance of DEC has prompted many
researchers to develop analytical methods for its determina
tion in pharmaceuticals and body fluids. The British Pharma
copoeia  describes a non-aqueous titrimetric method,
whereas United States Pharmacopoeia  describes a liq
uid-chromatography technique for the drug assay in
pharmaceuticals. Several other methods based on titrimetry
, colorimetry [6 – 17], proton magnetic resonance (
NMR) spectrometry [18, 19], DC polarography , gas
chromatography  and high-performance liquid chroma
tography [22 – 26] are also found in the literature for DEC
Many of these methods [18 – 26] are undoubtedly sensi
tive and selective, but require expensive instruments, acces
sories, and solvents, besides involving several cleanup steps,
particularly those based on chromatography. Many
colorimetric methods are cumbersome, time-consuming, and
often less selective and sensitive.
The UV spectrophotometry, in spite of its simplicity, sen
sitivity and accessibility, has sparsely been applied to the as
say of DEC. Recently, Reddy, et al.  reported a UV
method for the simultaneous determination of DEC and
Pharmaceutical Chemistry Journal, Vol. 52, No. 3, June, 2018 (Russian Original Vol. 52, No. 3, March, 2018)
0091-150X/18/5203-0271 © 2018 Springer Science+Business Media, LLC
Department of Chemistry, University of Mysore, Manasagangothri,
Mysuru-570006, Karnataka, India.
Fig. 1. Chemical structure of DEC.