caa a22 4500 477128017 CHVBK 20180405111655.0 cr unu---uuuuu 170330e19970501xx s 000 0 eng 10.1023/A:1012148910975 doi (NATIONALLICENCE)springer-10.1023/A:1012148910975 Differential Molar Heat Capacities to Test Ideal Solubility Estimations [Elektronische Daten] [Steven Neau, Satej Bhandarkar, Eckhard Hellmuth] Purpose. Calculation of the ideal solubility of a crystalline solute in a liquid solvent requires knowledge of the difference in the molar heat capacity at constant pressure of the solid and the supercooled liquid forms of the solute, ΔCp. Since this parameter is not usually known, two assumptions have been used to simplify the expression. The first is that ΔCp can be considered equal to zero; the alternate assumption is that the molar entropy of fusion, ΔSf, is an estimate of ΔCp. Reports claiming the superiority of one assumption over the other, on the basis of calculations done using experimentally determined parameters, have appeared in the literature. The validity of the assumptions in predicting the ideal solubility of five structurally unrelated compounds of pharmaceutical interest, with melting points in the range 420 to 470K, was evaluated in this study. Methods. Solid and liquid heat capacities of each compound near its melting point were determined using differential scanning calorimetry. Linear equations describing the heat capacities were extrapolated to the melting point to generate the differential molar heat capacity. Results. Linear data were obtained for both crystal and liquid heat capacities of sample and test compounds. For each sample, ideal solubility at 298K was calculated and compared to the two estimates generated using literature equations based on the differential molar heat capacity assumptions. Conclusions. For the compounds studied, ΔCp was not negligible and was closer to ΔSf than to zero. However, neither of the two assumptions was valid for accurately estimating the ideal solubility as given by the full equation. Plenum Publishing Corporation, 1997 differential heat capacity nationallicence differential scanning calorimetry nationallicence heat capacity nationallicence heat capacity assumptions nationallicence ideal solutions nationallicence Neau Steven School of Pharmacy, University of Missouri— Kansas City, 5100 Rockhill Road, 64110-2499, Kansas City, Missouri aut Bhandarkar Satej School of Pharmacy, University of Missouri— Kansas City, 5100 Rockhill Road, 64110-2499, Kansas City, Missouri aut Hellmuth Eckhard Chemistry Department, University of Missouri—Kansas City, 5100, Rockhill Road, 64110-2499, Kansas City, Missouri aut Pharmaceutical Research Kluwer Academic Publishers-Plenum Publishers 14/5(1997-05-01), 601-605 0724-8741 14:5<601 1997 14 11095 https://doi.org/10.1023/A:1012148910975 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1023/A:1012148910975 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Neau Steven School of Pharmacy, University of Missouri— Kansas City, 5100 Rockhill Road, 64110-2499, Kansas City, Missouri aut NATIONALLICENCE 700 1- Bhandarkar Satej School of Pharmacy, University of Missouri— Kansas City, 5100 Rockhill Road, 64110-2499, Kansas City, Missouri aut NATIONALLICENCE 700 1- Hellmuth Eckhard Chemistry Department, University of Missouri—Kansas City, 5100, Rockhill Road, 64110-2499, Kansas City, Missouri aut NATIONALLICENCE 773 0- Pharmaceutical Research Kluwer Academic Publishers-Plenum Publishers 14/5(1997-05-01), 601-605 0724-8741 14:5<601 1997 14 11095 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer