Physical and dielectric properties of pharmaceutical powders

McLoughlin, Conor; McMinn, W.A.M.; Magee, T.R.A.

doi:10.1016/s0032-5910(03)00133-5

Cited by 64 publications

(41 citation statements)

References 8 publications

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“…where α is the polarizability, cm 3 ; N a is the Avogadro number, 6.022 × 10 23 mol −1 ; R m is the molar refractivity, cm 3 · mol −1 ; n is the refractive index at the frequency of the sodium-D line; and V is the molar volume, cm 3 · mol −1 . From the L-L equation, Vargas et al [6] proposed the one-third value for the specific refractivity of different nonpolar hydrocarbons.…”

Section: One-third Rulementioning

confidence: 99%

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A Simple Method for Estimation of Dielectric Constants and Polarizabilities of Nonpolar and Slightly Polar Hydrocarbons

et al. 2016

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Many of the liquids that are used as electrical insulators are nonpolar or slightly polar petroleum-derived hydrocarbons, such as the ones used for cable and/or transformer oils. In this work, semi-empirical expressions with no adjustable parameters for the dielectric constant and the polarizability of nonpolar and slightly polar hydrocarbons and their mixtures are proposed and validated. The expressions that were derived using the Vargas-Chapman One-Third rule require the mass density and the molecular weight of the substance of interest. The equations were successfully tested for various hydrocarbons and polymers with dipole moments <0.23 and densities from 500 to 1200 kg·m −3 . The predictions are in good agreement with the experimental data in a wide range of temperatures and pressures. The proposed expressions eliminate the need of extensive experimental data and require less input parameters compared to existing correlations.

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Section: One-third Rulementioning

confidence: 99%

“…Dielectric constant measurements are also essential for understanding the results obtained from remote radar sensing experiments [1]. In pharmaceutical and analytical sciences, the dielectric constant of mixed solvents is required to predict the solubility and chemical stability of a drug [2,3].…”

Section: Introductionmentioning

confidence: 99%

A Simple Method for Estimation of Dielectric Constants and Polarizabilities of Nonpolar and Slightly Polar Hydrocarbons

et al. 2016

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“…Except for a few select systems, the majority of the compiled solubility data was measured at 298.15 K. Maia and Giulietti 61 determined the solubility of 2-acetoxybenzoic acid in ethanol (from 276 to 336 K), 2-propanol (from 282 to 330 K), 1,2-propanediol (from 295 to 334 K), and propanone (from 282 to 326 K) as a function of temperature using a dynamic solubility method that recorded the temperature at which the last crystal of aspirin dissolved in the respective solvent. McLoughlin et al 62 reported the solubility of aspirin in ethanol at both 293 and 333 K, while Lindenberg et al 63 performed solubility measurements of aspirin in ethanol at 298, 308, and 323 K. The authors compared the experimental values determined using an in situ ATR-FTIR spectroscopic method to measured values based on a gravimetric method. The compiled solubility data were correlated with the Abraham solvation parameter model.…”

Section: Critical Evaluation Of Experimental Solubility Datamentioning

confidence: 99%

IUPAC-NIST Solubility Data Series. 102. Solubility of Nonsteroidal Anti-inflammatory Drugs (NSAIDs) in Neat Organic Solvents and Organic Solvent Mixtures

Acree

2014

Journal of Physical and Chemical Reference Data

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“…[16][17][18][19][20][21][22][23] However, despite the widespread use, microwave drying has not been used up to now as a tool to speed up the LOD determination in saccharides. Considering that LOD is performed routinely the use of microwaves could reduce the time of analysis allowing fast response regarding to the quality of sample.…”

Section: Introductionmentioning

confidence: 99%

A fast microwave-assisted procedure for loss on drying determination in saccharides

Bizzi

Barin

Hermes

et al. 2011

J. Braz. Chem. Soc.

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Um procedimento rápido para determinação de perda por dessecação (LOD) foi desenvolvido empregando aquecimento por radiação micro-ondas. Amostras de sacarídeos foram utilizadas e diferentes parâmetros foram avaliados, tais como a posição da amostra na cavidade do micro-ondas, massa de amostra e tempo de irradiação. Massas de amostra de 1 g e tempo de irradiação entre 15 e 25 min foram suficientes para a determinação da perda por dessecação de todos sacarídeos. Os resultados obtidos para perda por dessecação assistida por micro-ondas (MALOD) foram comparados com os resultados obtidos por LOD convencional em estufa e não apresentaram diferença significativa. O tempo de análise foi reduzido de 2,4 a 15 vezes, quando comparado ao sistema convencional de LOD e o desvio padrão relativo das medidas foi inferior a 1%. Até 16 amostras podem ser processadas simultaneamente, tornando o procedimento MALOD apropriado para análise de rotina.A fast procedure for loss on drying (LOD) determination was developed using microwave radiation. Samples of commercial saccharides were dried and the influence of sample position inside the microwave cavity, sample mass and irradiation time were evaluated. Sample mass of 1 g and irradiation time between 15 to 25 min were enough to LOD determination for all saccharides. Results obtained using the proposed microwave-assisted loss on drying (MALOD) procedure were compared with those obtained by conventional LOD determination using an oven and no statistical difference was found among results of these techniques. Using MALOD procedure the relative standard deviation was below 1%. The time for analysis was reduced from 2.4 to 15 times when compared to conventional LOD determination and up to 16 samples could be simultaneously processed making MALOD procedure suitable for routine analysis.Keywords: loss on drying, saccharides, microwave, food and pharmaceutical samples IntroductionLoss on drying (LOD) determination is a parameter often evaluated to access the quality of products. Several applications of LOD can be found in industry, in special for food and pharmaceutical industries, which currently use LOD to determine the amount of volatile matter (in general, water) that is driven off under specific conditions. 1-3 The LOD determination is relatively simple to be performed and results with relatively good precision can be obtained resulting in a widespread use. For example, in the 30 th edition of The United States Pharmacopeia more than one thousand monographs recommended the use of LOD in their tests that makes it a parameter that must be routinely evaluated in current quality control. 4 The procedures recommended for LOD determination can be performed at different conditions of drying such as pressure (atmospheric or vacuum) and temperature (with or without heating). [1][2][3] In some cases, the use of a desiccant to help the drying process (e.g. diphosphorus pentoxide) is recommended, Bizzi et al. 377 Vol. 22, No. 2, 2011 specially for mild drying conditions used for samples that can...

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Physical and dielectric properties of pharmaceutical powders

Cited by 64 publications

References 8 publications

A Simple Method for Estimation of Dielectric Constants and Polarizabilities of Nonpolar and Slightly Polar Hydrocarbons

A Simple Method for Estimation of Dielectric Constants and Polarizabilities of Nonpolar and Slightly Polar Hydrocarbons

IUPAC-NIST Solubility Data Series. 102. Solubility of Nonsteroidal Anti-inflammatory Drugs (NSAIDs) in Neat Organic Solvents and Organic Solvent Mixtures

A fast microwave-assisted procedure for loss on drying determination in saccharides

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