RESEARCH ARTICLE Synthesis and characterisation of starch tartrate and its application as novel disintegrant in telmisartan tablets Fathi H. Assaleh 1 , Prakash Katakam 1 , Ramesh Botcha 2 , Babu Rao Chandu 1 and Shanta Kumari Adiki 2 1 Faculty of Pharmacy, University of Zawia, Al-Zawia, Libya 2 Nirmala College of Pharmacy, Guntur, Andhra Pradesh, India The aim of the present study was to synthesize potato starch (PS) derivatives of tartaric acid (TA) under semi-dry conditions and to evaluate the physicochemical properties as per official compendia requirements. Starch tartrate (ST) was synthesized by reacting PS (St–OH) and TA in semi-dry condition using sodium hypophosphite (SHP) as a catalyst. Further we have applied its use as disintegrant in directly compressed telmisartan tablets. The microscopic, spectroscopic (FTIR), thermal (DSC) and crystallographic (XRD) studies confirmed the formation of ST. No gelling was observed at 100°C but it was converted to a clear solution with a swelling index of 1.666 times. ST was found to have suitable compression properties required for directly compressible tablets. The tablets formulated employing ST (5–15% w/w) as disintegrant gave rapid disintegration and dissolution rates compared to those prepared using commercial superdisintegrants (sodium starch glycolate and crosscarmellose sodium). The optimized formulation showed disintegration time of 31  3 s which is found superior to that of others. It is concluded that the synthesized ST could be employed as a promising disintegrant in dispersible tablet formulations. Received: May 30, 2013 Revised: July 12, 2013 Accepted: July 17, 2013 Keywords: Characterization / Disintegrant / Starch tartrate / Telmisartan : Additional supporting information may be found in the online version of this article at the publisher’s web-site. 1 Introduction Starch and its derivatives enjoy a myriad of applications in the pharmaceutical industry due to their biodegradability and biocompatibility [1]. Starch is a versatile excipient used primarily in pharmaceutical formulations as thickening agent, emulsifier, binder, diluent, disintegrant, film former and bioadhesive [2–4]. Starch is used as a tablet disintegrant in the concentrations of 3–25% and other site-specific delivery systems [5–7]. Modified starches have achieved a wide range of functions from binding or disintegrating and imbibing or inhibiting moisture in tablet formulations [8, 9]. The modified starches generally show better paste clarity, better stability, increased resistance to retrogradation and increased freeze-thaw stability [10]. Chemical modifications of starch are carried out for improvement of specific properties. Different techniques are employed such as substitution reactions, cross linking reactions, degrading reactions and starch fractionation. Cross linking of starch could be attained with bifunctional and polyfunctional compounds. A low degree of substitution could result in key changes of the starch functionality. The investigations on modification of starch by reacting with various acids were carried out in the last decade [11]. Starch citrate was prepared from icacina starch and its properties were evaluated [12]. Carboxymethyl starch, sulfonic starch and starch succinate half ester were synthesized in recent years [13, 14]. Alkenyl succinate of starch was synthesized and used in nonalcoholic beverages for the stabilisation of flavours [15]. Calcium starch, a controlled release polymer, was prepared by reacting potato starch (PS) with calcium Correspondence: Dr. Prakash Katakam, Faculty of Pharmacy, University of Zawia, Al-Zawia, Libya E-mail: pkatakam9@gmail.com Fax: þ218-237-631-775 Abbreviations: CCS, crosscarmellose sodium; MCC, micro- crystalline cellulose; PS, potato starch; SHP, sodium hypo- phosphite; SLS, sodium lauryl sulphate; SSG, sodium starch glycolate; ST, starch tartrate; TA, tartaric acid DOI 10.1002/star.201300136 Starch/Stärke 2014, 66, 409–417 409 ß 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim www.starch-journal.com