Volumetric and Viscometric Properties of Some Sulpha Drugs in Aqueous Solutions of Sodium Chloride at T = (288.15 to 318.15) K

Abstract

The partial molar volumes V 2° and viscosity B-coefficient have been measured from density and flow time measurements for sulphanilamide, sulphanilic acid, and sulphosalicylic acid dihydrate in water and in aqueous solutions of (0.05, 0.1, 0.3, and 0.5) mol·kg−1 sodium chloride at temperatures from (288.15 to 318.15) K, by the use of a vibrating tube digital densimeter and Micro-Ubbelohde type capillary viscometer, respectively. The transfer volumes at infinite dilution calculated from partial molar volumes have both positive and negative values. The overall positive values at higher concentrations of sodium chloride are in the following order: sulphosalicylic acid dihydrate > sulphanilic acid > sulphanilamide, which is also the order of hydrophilicity of these drugs. The interaction coefficients, partial molar expansibilities V E°, and second-order derivative have also been calculated. The transfer B-coefficient values, Δtr B, are calculated from viscosity B-coefficient data. Transition state theory has been used to calculate Δμo#, the activation free energy for the viscous flow of solutions. The related activation parameters like ΔH o# and ΔS o# have been calculated. Also the excess molecular volume and contribution of various groups of the drug compound to V 2° have been calculated.

Physicochemical properties of an anticonvulsant drug sodium valproate in aqueous and in mixed aqueous solutions at different temperatures

“…The density values used for the solutions of co-solutes i.e., aqueous 0.06 mol·kg -1 sodium chloride and aqueous 0.06 mol·kg -1 dextrose solution were found in well agreement with those of literature values [29,30]. We have also compared our data of density of 0.06 mol·kg -1 of aqueous NaCl solutions with the data of Millero [25] and Banipal et al [31]. [33].…”

“…It is evident from table 5 that 0 V φ values for sodium valproate in 0.06 mol·kg -1 aqueous dextrose solution is high and is followed by 0 V φ values in 0.06 mol·kg -1 sodium chloride solution and aqueous binary solution. It can also be observed that 0 V φ values increase with increase in temperature for binary and ternary systems, this may be attributed to decreasing of electrostriction or hydration from second solvation layer of the ionic (-COO -/Na + ) group of drug sodium valproate [31,39].…”

Volumetric studies on nucleic acid bases and nucleosides in aqueous guanidine hydrochloride solutions at T=(288.15 to 318.15)K and at atmospheric pressure

“…First type of interactions will contribute positively whereas second type will contribute negatively to D tr V o 2;/ values according to cosphere overlap model [25]. The positively observed D tr V o 2;/ values at higher concentrations of GnHCl for the studied systems indicate that (ionic + hydrophilic) (type (i)) interactions dominate over (ionic + hydrophobic) (type (ii)) interactions.…”

Interactions of amino acids and peptides with the drug pentoxifylline in aqueous solution at various temperatures: A volumetric approach

“…The partial molar isobaric expansion at infinite dilution, E 2 0 , derived from the polynomial coefficients are given in [4] and glycine [22].…”

“…Therefore, for a better understanding of the hydration behaviour of proteins, one useful approach is to study simpler model compounds such as amino acids and small peptides. From the literature survey we found that there are extensive studies of drugs in aqueous and aqueous additive solutions [3][4][5][6][7][8][9], but the study of amino acids and peptides in aqueous drug solution are scare [10,11]. Pentoxifylline (figure 1) is used to treat intermittent claudication resulting from obstructed arteries in the limbs, and vascular dementia [12].…”