Solvation behaviour of an antihelmintic drug in aqueous solutions of sodium chloride and glucose at different temperatures Doyel M. Bhattacharya a , Sudhakar S. Dhondge b , Sangesh P. Zodape a,⇑ a Department of Chemistry, Visvesvaraya National Institute of Technology, Nagpur 440 010, India b P. G. Department of Chemistry, S. K. Porwal College, Kamptee, Nagpur 441 001, India article info Article history: Received 11 February 2016 Received in revised form 16 May 2016 Accepted 28 May 2016 Available online 30 May 2016 Keywords: Density Speed of sound Relative viscosities Solute-solvent interactions Co-sphere overlap model abstract The experimental values of densities (q), speeds of sound (u) and relative viscosities (g r ) of piperazine citrate in aqueous solution and in 0.06 molkg 1 of sodium chloride and D-glucose as a function of con- centration have been obtained at T =K = (293.15, 303.15 and 313.15). The thermodynamic parameters such as apparent molar volume ðV / Þ of solute, isentropic compressibility ðj s Þ, apparent molar isentropic compressibility ðj / Þ of solute, piperazine citrate in water and in aqueous solutions of sodium chloride and D-glucose have been computed using the density and speed of sound data. The limiting apparent molar volume of solute ðV 0 / Þ, limiting apparent molar compressibility ðj 0 / Þ in binary and ternary solution have been obtained using apparent molar volume and apparent molar compressibility data. The limiting apparent molar expansivity ðE 0 / Þ of solute and thermal expansion coefficient ða  Þ in both aqueous binary and ternary solutions has been computed. Transfer volumes ðD tr V 0 / Þ and transfer compressibilities ðD tr j 0 / Þ of piperazine citrate from water to aqueous solutions of sodium chloride and D-glucose at different temperatures have been obtained. The Jones-Dole viscosity coefficients A, B, D, variation of viscosity B coefficient with temperature i.e. dB=dT ; hydration number for aqueous solutions of piperazine citrate and in aqueous solutions of sodium chloride and D-glucose have been determined. The above parameters have been used to throw light on the various interactions occurring between binary and ternary systems. Ó 2016 Published by Elsevier Ltd. 1. Introduction Drugs are biologically important macromolecules that have been used since ages for diagnosis, alleviation, treatment, cure or anticipation of diseases in living systems. Nowadays there has been a rampant growth in the development of drug delivery sys- tems for the treatment of diseases. The main concern of these ever changing delivery systems is to increase the efficacy of the drug and to diminish the toxicity of the drug. The action of the drug with the biological membranes is also of prominence. This action of the drug or the affinity of the drug for the membrane can be thought of as a measure of the hydrophobic-hydrophillic interactions in the molecule and can be thought of as an extension to surface activity at the air/solution interface [1]. Water is a universal solvent. It is known of its ubiquity and the striking aspects of it make it a mar- vellous substance [2]. Also water is the host of many biochemical processes. Thus the study of the thermodynamic parameters of drug in aqueous medium and in the presence of various co-solutes such as carbohydrates, proteins, vitamins, amino acids, nucleosides, nucleotides, and inorganic salts of many ions, enhances the understanding of the molecular interactions of drug molecules [3]. Also the drug water interactions at different temper- atures are central to the understanding of drug action in living sys- tems [4]. Physicochemical and thermodynamic investigations are important from the point of view of understanding the nature and the extent of the patterns of the molecular aggregations that exist in binary liquid mixtures and their sensitivities to variations in composition and the molecular structure of the pure compo- nents. Piperazine citrate is mainly known for its excellent anti- helmintic property. Its mode of action is generally by paralyzing parasites, which allows the host body to easily remove or expel the invading organisms [5]. The neuromuscular effects are thought to be caused by blocking acetylcholine at the myoneural junction. Electrolytes greatly influence the stability of the biomolecules and are necessary for the balance of the osmotic pressure in the living systems. Sodium chloride is one of the major electrolytes present in the body fluids and affects the metabolic processes. The body fluid contains isotonic solutions of sodium chloride (0.06 molkg 1 ) and so it is worthwhile to examine the action of drug on the body fluid [6]. Apart from the electrolytes, the non-electrolytes also play equally important role in understanding http://dx.doi.org/10.1016/j.jct.2016.05.025 0021-9614/Ó 2016 Published by Elsevier Ltd. ⇑ Corresponding author. E-mail address: sangesh02@gmail.com (S.P. Zodape). J. Chem. Thermodynamics 101 (2016) 207–220 Contents lists available at ScienceDirect J. Chem. Thermodynamics journal homepage: www.elsevier.com/locate/jct