Decomposition of Benzoic Acid Derivatives in Solid State

Separation of Multisized Drug Suspensions into Narrow Distributions by Centrifugal Elutriation

“…Each fraction was distributed according to an apparent log-normal distribution. This fact is significant because of the widespread use of log-normal distributions in dissolution modeling (1)(2)(3)(4)(5)(6)(7)11,21,22). Veng Pedersen (22), for example, assumed a log-normal distribution in successfully characterizing the dissolution of micronized glyburide using the cube root law.…”

“…For example, the dissolution kinetics for multisized particle populations have been discussed (1)(2)(3)(4)(5)(6)(7). In some cases (8,9), the experimental data were treated without calculation of the effect of particle-size distribution.…”

Solid-state Decomposition of Alkoxyfuroic Acids

“…The compounds were identified with the help of NMR and mass spectra and, where possible, differential scanning calorimetry. Melting points were determined and are listed in Table I. Kinetic Studies-Kinetic studies were carried out by preparing a sample in uacuo in a sample bulb with an attached mercury manometer such as was described previously (3,6). The whole assem6ly was placed in a tall thermostatically controlled bath with either water or mineral oil as the medium; temperature control was k0.2'.…”

“…Since, in the manner described, the decomposition takes place in a system that is evacuated but that contains mercury vapor in the headspace, several control studies were done in break-seal tubes (3) to ascertain that the mercury vapor did not affect reaction rates. Vapor Pressure Studies-Since the possibility exists that the decomposition of a solid at constant volume occurs in the vapor phase, the vapor pressure of the various solids was determined.…”

Model Systems for Dissolution of Finely Divided (Multisized) Drug Powders

“…Diffusional models for the description of the dissolution rate of a multisize particle population have been discussed previously (1)(2)(3). Higuchi and Hiestand (1) derived equations describing the dissolution rate of finely divided (multisized) particles in a diffusioncontrolled dissolution process.…”