INTRODUCTION Bendamustine hydrochloride {(4-{5-[bis- (2-chloroethyl) amino]-1-methyl-1Hbenzimidazol- 2-yl} butanoic acid)} (Fig. 1) is a bifunctional alkylating agent that is used to treat chronic lymphocytic leukemia (CLL) and non-Hodgkin lymphoma and may be used for other types of ORIENTAL JOURNAL OF CHEMISTRY www.orientjchem.org An International Open Free Access, Peer Reviewed Research Journal ISSN: 0970-020 X CODEN: OJCHEG 2014, Vol. 30, No. (2): Pg. 905-910 Determination of Bendamustine Hydrochloride in Pure and Dosage Forms by Ion-Associative Complex Formation KATARE KIRAN KUMAR 1 , RATNAKARAM VENKATA NADH 2 * and K.E.V. NAGOJI 3 1 Department of Chemistry, Nalanda P.G. College, Vijayawada - 520001, India. 2 School of Biotechnology, Vignan University, Vadlamudi - 522213, India. 3 Department of Pharmacy, Sri Venkateswara College of Pharmacy, Etcherla, Srikakulam - 532410, India. *Corresponding author E-mail: kevnagoji1966@yahoo.co.in http://dx.doi.org/10.13005/ojc/300272 (Received: March 03, 2014; Accepted: April 07, 2014) ABSTRACT The present study is aimed to develop visible spectrophotometric methods for the determination of Bendamustine hydrochloride. The developed methods involve the formation of chloroform extractable colored ion-association complexes of Bendamustine hydrochloride with tropaeolineo-oo (Method A) and Alizarin Red S (Method B). The chloroform extracted coloured complexes showed absorbance maxima at wavelengths 480 and 460nm in methods A and B respectively. Beer’s law obeyed in the concentration range of 2.5–12.5 μg/mL in both the cases. Correlation coefficients were found to be 0.9991 and 0.9998 for methods A and B respectively. In addition molar absorptivity, Sandell sensitivity and the optimum conditions for quantitative analysis of the Bendamustine hydrogenchloride were determined. The developed ion-association complex methods were rapid, simple and economically viable compared to other reported analytical methods which require expensive instruments and are not available in common laboratories. Thus the proposed methods for Bendamustine determination in bulk and pharmaceutical formulations can be used in commercial laboratories. Key words: Bendamustine hydrochloride, TPooo, ARS, Ion-association complex, Validation. cancer 1,2 . Literature survey revealed that one each UV spectrophotometric 3 , HPLC 4 , LC–MS 5 and capillariy GC method 6 have been developed for its determination in various biological fluids. Though, the above methods have vivid benefits like multi component determination, rapidness, precision etc., they suffer from noteworthy disadvantage – expensive equipments which unavailable for