The use of inverse phase gas chromatography to study the change of surface energy of amorphous lactose as a function of relative humidity and the processes of collapse and crystallisation

Newell, Helen; Buckton, Graham; Butler, David A.; Thielmann, Frank; Williams, Daryl R.

doi:10.1016/s0378-5173(01)00589-0

Cited by 80 publications

(34 citation statements)

References 17 publications

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“…For the LW dispersion component of the surface energy, it was found that usually it decreases or remains unchanged with an increase in RH. [55][56][57] For the Lewis acid-base component of the surface energy, it was found that it either increases 58 or decreases. 55 Although it would be interesting to examine how drycoated samples are affected by conditioning or aging in contrast to uncoated samples, it is not within the scope of the present study.…”

Section: Particle Scale Characteristicsmentioning

confidence: 99%

Passivation of High-Surface-Energy Sites of Milled Ibuprofen Crystals via Dry Coating for Reduced Cohesion and Improved Flowability

Han

Jallo

et al. 2013

Journal of Pharmaceutical Sciences

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Section: Particle Scale Characteristicsmentioning

confidence: 99%

Passivation of High-Surface-Energy Sites of Milled Ibuprofen Crystals via Dry Coating for Reduced Cohesion and Improved Flowability

Han

Jallo

et al. 2013

Journal of Pharmaceutical Sciences

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“…These include differential scanning calorimetry (DSC) [12,92,153] and temperature-modulated differential scanning calorimetry (MDSC) [23,61,85,87,124,155,183,184], dilatometry (DIL) also known as thermomechanical analysis (TMA) [25,80,125,201], dynamic mechanical analysis (DMA) also known as dynamic mechanical thermal analysis (DMTA) [12,153], inverse gas chromatography (IGC) [6,75,133,134,136], and nuclear magnetic resonance (NMR) [2,92,98,116,161,162], dielectric relaxation spectroscopy (DRS) [4,56,57,135,139], and other emerging technologies such as oscillatory squeezing flow (OSF) [1], thermal mechanical compression test (TMCT) [25], positron annihilation lifetime spectroscopy (PALS) [43, 89, 104-106, 115, 211], thermally stimulated depolarization current (TSDC) [4,45,52,175,176,196], and scanning probe microscopy (SPM) also known as atomic force microscopy (AFM) [88,…”

Section: Methods For Measuring Glass Transitionsmentioning

confidence: 99%

“…IGC may be used to determine batch-to-batch variations, study the surface heterogeneity, or even measure the glass transition temperature of the solid material [6,134,136,209]. Unlike conventional gas chromatography, where the stationary phase serves as a detector for the various gaseous components passing through the column, IGC uses different gaseous solute probes to identify interactions between the solutes and the stationary solid column packing.…”

Section: Inverse Gas Chromatographymentioning

confidence: 99%

A Review on Methods and Theories to Describe the Glass Transition Phenomenon: Applications in Food and Pharmaceutical Products

2009

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Given the complexity in composition and the various environmental conditions to which foods and pharmaceuticals are exposed during processing and storage, stability, functionality, and quality are key attributes that deserve careful attention. Quality and stability of foods and pharmaceuticals are mainly affected by environmental conditions such as temperature, humidity, and time, and for processing conditions (e.g., shear, pressure) under which they may undergo physical and chemical transformations. Glass transition is a key phenomenon which is useful to understand how external conditions affect physical changes on materials. Consequently, theories that predict and describe the glass transition phenomenon are of a great interest not only for the food industry but also it extends to the pharmaceutical and polymer industries. It is important to emphasize that the materials of relevance in these industries are interchangeably sharing similar issues on functionality and their association with the glass transition phenomenon. Development of new materials and understanding the physicochemical behavior of existing ones require a scientific foundation that translates into safe and high-quality foods, improved quality of pharmaceuticals and nutraceuticals with lower risk to patients, and functional efficacy of polymers used in food and medicinal products. This review addresses the glass transition phenomenon from a kinetics and thermodynamics standpoint by presenting existing models that are able to estimate the glass transition temperature. It also explores traditional and novel methods used for the characterization of the glass transition phenomenon.

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“…A volume of 1 mL was used for each probe. The ambient temperature and RH were recorded for each measurement, as these can affect the surface energy determined [19]. The temperature was in the range of 22 to 25°C, and the RH was in the range of 35% to 50%.…”

Section: Surface Characterizationmentioning

confidence: 99%

Powder properties and their influence on dry powder inhaler delivery of an antitubercular drug

Sethuraman

Hickey

2002

AAPS PharmSciTech

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The purpose of this study was to determine if aerosol delivery of drug loaded microparticles to lungs infected with Mycobacterium tuberculosis may be achieved by predicting dispersion of dry powders through knowledge of particle surface properties. Particle sizes of rifampicin-loaded poly(lactide-co-glycolide) microparticles (R-PLGA), rifampicin alone, and lactose and maltodextrin carrier particles (bulk and 75-125-µm sieved fractions) were determined by electron microscopy for the projected area diameter (D p ) and laser diffraction for the volume diameter (D v ). Surface energies (γ) of R-PLGA, rifampicin alone, lactose, and maltodextrin were obtained by inverse phase gas chromatography, surface areas (S a ) by N 2 adsorption, and cohesive energy densities by calculation. Particle dispersion was evaluated (Andersen nonviable impactor) for 10% blends of R-PLGA and rifampicin alone with bulk and sieved fractions of the carriers. D p for R-PLGA and rifampicin alone was 3.02 and 2.83 µm, respectively. D v was 13 ± 1 and 2 ± 1 µm for R-PLGA and rifampicin alone, respectively, indicating that R-PLGA was more aggregated. This was evident in γ of 35 ± 1 and 19 ± 6 mJ/m 2 for R-PLGA and rifampicin alone. D p for lactose and maltodextrin (sieved and bulk) was approximately 40 mm. Bulk maltodextrin (D v = 119 ± 6 mm) was more aggregated than bulk lactose (D v = 54 ± 2 mm). This was a result of the higher S a for maltodextrin (0.54 m 2 /g) than for lactose (0.21 m 2 /g). The γ of bulk lactose and maltodextrin was 40 ± 4 and 60 ± 6 mJ/m 2 and of sieved lactose and maltodextrin was 39 ± 1 and 50 ± 1 mJ/m 2 . Impaction studies yielded higher fine particle fractions of R-PLGA from sieved lactose, 13% ± 3%, than from sieved maltodextrin, 7% ± 1%, at 90 L/min. An expression, based on these data, is proposed as a predictor of drug dispersion from carrier particles.Delivery of dry powder formulations can be achieved by characterizing particle surfaces and predicting impact on dispersion.

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The use of inverse phase gas chromatography to study the change of surface energy of amorphous lactose as a function of relative humidity and the processes of collapse and crystallisation

Cited by 80 publications

References 17 publications

Passivation of High-Surface-Energy Sites of Milled Ibuprofen Crystals via Dry Coating for Reduced Cohesion and Improved Flowability

Passivation of High-Surface-Energy Sites of Milled Ibuprofen Crystals via Dry Coating for Reduced Cohesion and Improved Flowability

A Review on Methods and Theories to Describe the Glass Transition Phenomenon: Applications in Food and Pharmaceutical Products

Powder properties and their influence on dry powder inhaler delivery of an antitubercular drug

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