By using the van't Hoff and Gibbs equations, the thermodynamic functions of Gibbs energy, enthalpy, and entropy of solution for procaine HCl in ethanol + water cosolvent mixtures were evaluated from solubility data determined at temperatures from (278.15 to 308.15) K. The drug solubility was greatest in neat water and lowest in neat ethanol at all of the temperatures studied. This behavior showed the negative cosolvent effect for this electrolyte drug in this solvent system. By means of enthalpy-entropy compensation analysis, a nonlinear ∆H soln 0-app versus ∆G soln 0-app plot with a positive slope from neat ethanol up to 0.10 mass fraction of water and negative from 0.10 to 0.30 mass fraction of water was obtained, whereas from this composition up to neat water a positive slope was obtained again. Accordingly to this result and to the transfer properties, it follows that the dissolution process of this drug in ethanol-rich and water-rich mixtures is enthalpydriven, whereas between 0.10 and 0.30 mass fraction of water, the process is entropy-driven.

♦ BACKGROUND: Peritonitis is the most important complication of peritoneal dialysis (PD), and early peritonitis rate is predictive of the subsequent course on PD. Our aim was to calculate the early peritonitis rate and to identify characteristics and predisposing factors in a large nationwide PD provider network in Colombia. ♦ METHODS: This was a historical observational cohort study of all adult patients starting PD between January 1, 2012, and December 31, 2013, in 49 renal facilities in the Renal Therapy Services in Colombia. We studied the peritonitis rate in the first 90 days of treatment, its causative micro-organisms, its predictors and its variation with time on PD and between individual facilities. ♦ RESULTS: A total of 3,525 patients initiated PD, with 176 episodes of peritonitis during 752 patient-years of follow-up for a rate of 0.23 episodes per patient year equivalent to 1 every 52 months. In 41 of 49 units, the rate was better than 1 per 33 months, and in 45, it was better than 1 per 24 months. Peritonitis rates did not differ with age, ethnicity, socioeconomic status, or PD modality. We identified high incidence risk periods at 2 to 5 weeks after initiation of PD and again at 10 to 12 weeks. ♦ CONCLUSION: An excellent peritonitis rate was achieved across a large nationwide network. This occurred in the context of high nationwide PD utilization and despite high rates of socioeconomic deprivation. We propose that a key factor in achieving this was a standardized approach to management of patients.

Apparent molal volumes of two local anesthetics, lidocaine HCl and procaine HCl, in water at (298.15, 303.15, and 310.15) K have been measured in the concentration range from (0.01 to 0.1) mol‚kg -1 . The densities were obtained with a magnetic float densimeter. The concentration dependence of V φ has been calculated using the Redlich and Meyer equation. The values of apparent molal volumes at infinite dilution, V φ 0 , the empirical constants B V , and the partial molal expansibilities, E φ 0 , were calculated. The results are interpreted in terms of competitive effects between electrostriction and hydrophobic solvation.

Low toxic resorcinarene can effectively inhibit Aβ fibrillation and delay the formation of toxic Aβ 42 species.

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The thermodynamic functions of Gibbs energy, enthalpy, and entropy for the solution processes of triclosan (TS) were calculated from solubility values obtained at the temperature interval from (293.15 to 313.15) K. TS solubility was determined in ethanol (EtOH), octanol (ROH), isopropyl myristate (IPM), chloroform (CLF), and heptane (HPT) as pure solvents. The excess Gibbs energy and the activity coefficients of the solutes were also calculated. The TS solubilities were higher in EtOH and CLF with respect to those obtained in ROH, IPM, and HPT. In addition, the thermodynamic quantities relative to the transfer process of this drug from HPT to the other organic solvents were also calculated to estimate the hydrogen bonding contributions.

Two sulfonated resorcinarenes were synthesized by reacting C-tetra(butyl) resorcinarene or C-tetra(2-(methylthio)ethyl)resorcinarene with formaldehyde in the presence of sodium sulfite. Their structures were determined via FT-IR, 1 H-NMR, 13 C-NMR and mass spectrometry. Thermal gravimetric analyses of the derivatives were also carried out and revealed the presence of water molecules in the solid state. The sulfonated product of C-tetra(butyl)resorcinarene was characterized by an X-ray crystal structure determination. The asymmetric unit contains eight molecules of water and two of acetone, and analysis indicated that sulfonated resorcinarene prefers a cone configuration (rccc conformation) in the solid state. In the crystal array, classical hydrogen bond interactions O-H···O and intermolecular contacts were observed. In the crystal packing, a linear array of capsules of sulfonated resorcinarenes was generated for a chain of sodium atoms and sulfonate groups.

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