Calorimetric method for rapid determination of critical water vapor pressure and kinetics of water sorption on hygroscopic compounds

Hansen, Lee D.; Crawford, John W.; Keiser, D.; Wood, R. W.

doi:10.1016/0378-5173(96)04494-8

Cited by 11 publications

(5 citation statements)

References 11 publications

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“…However, the critical humidity is still unclearly defined and very few theoretical studies are reported [22] . Usually the critical humidity is determined in sorption experiments by means of classical static, or more modern dynamic water sorption (DVS) methods [23] , [24] , [25] , but calorimetry also can be used to determine this characteristic [26] .…”

Section: Resultsmentioning

confidence: 99%

Thermally decarboxylated sodium bicarbonate: Interactions with water vapour, calorimetric study

Volkova

Hansson

Ljunggren

2013

Journal of Pharmaceutical Analysis

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Isothermal titration calorimetry (ITC) was used to study interactions between water vapour and the surface of thermally converted sodium bicarbonate (NaHCO3). The decarboxylation degree of the samples was varied from 3% to 35% and the humidity range was 54–100%. The obtained enthalpy values were all exothermic and showed a positive linear correlation with decarboxylation degrees for each humidity studied. The critical humidity, 75% (RHo), was determined as the inflection point on a plot of the mean−ΔH kJ/mole Na2CO3 against RH. Humidities above the critical humidity lead to complete surface dissolution. The water uptake (m) was determined after each calorimetric experiment, complementing the enthalpy data. A mechanism of water vapour interaction with decarboxylated samples, including the formation of trona and Wegscheider’s salt on the bicarbonate surface is proposed for humidities below RHo.

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Section: Resultsmentioning

confidence: 99%

Thermally decarboxylated sodium bicarbonate: Interactions with water vapour, calorimetric study

Volkova

Hansson

Ljunggren

2013

Journal of Pharmaceutical Analysis

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“…Calorimetry has been extensively used to measure heat of water adsorption by pharmaceutical solids (Hansen et al 1996;Hansen 2000;Gaisford and Buckton 2001). The heat-flow to or from a sample is measured as a function of time (isothermal calorimetry) or temperature (scanning calorimetry).…”

Section: Analytical Techniques Used To Characterize Water In Solidsmentioning

confidence: 99%

Excipient Selection in Oral Solid Dosage Formulations Containing Moisture Sensitive Drugs

Rajabi‐Siahboomi

Levina²,

Upadhye

et al. 2015

Excipient Applications in Formulation Design and Drug Delivery

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Moisture sensitivity of active pharmaceutical ingredients (APIs) presents a formidable challenge in the formulation of oral dosage forms. The interaction of moisture with APIs is crucial to an understanding of water-based processes, e.g. manufacturing or prediction of solid dosage form stability and shelf-life. Unwarranted moisture sorption by either APIs or excipients can result in unstable oral solid formulations. The appropriate selection of excipients for the core formulation and appropriate moisture barrier film coating helps to remedy the moisture-related issues with APIs and thus can improve the storage stability of the final formulations. In this chapter, we review the nature and extent of the moisture sensitivity and possible approaches taken to overcome it. Use of excipients that bind tightly with water reduce its potential interaction with the API. In addition, application of a barrier coating to reduce rate and extent of moisture ingress into the core of the solid dosage form during the storage (in original packaging or while in-use), are some of the many simple options that have been considered and described.Keywords Calorimetry · Degradation · Differential scanning calorimetry · Dynamic vapor sorption · Equilibrium relative humidity · Excipients · Isothermal microcalorimetry · Moisture · Moisture-barrier coating · Near-infra red Spectroscopy · Opadry · Optical waveguide spectroscopy · Packaging · Stability · Water · Water vapor transmission rate Abbreviations AluAluminum API Active pharmaceutical ingredient

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“…39 Alternatively, the headspace over the sample may be perfused with a gas stream of known temperature, composition, and constant flow rate. 40 Perfusion usually leads to greater baseline uncertainty and the possibility of unwanted reactions, however.…”

Section: Sample Preparationmentioning

confidence: 99%

“…A rapid calorimetric method for determining the equilibrium water vapor pressure over a hydrate or saturated solution has been developed. 40 The vapor space over the sample in an isothermal calorimeter is titrated with water vapor generated by continuously scanning the temperature of a container of water outside the calorimeter or by mixing dry and saturated gas streams. The rate of heat production in the sample, which is proportional to the rate of water sorption by the sample, remains very small until the equilibrium water vapor pressure of the phase being formed is reached.…”

Section: Illustrative Examples Of Applicationsmentioning

confidence: 99%

“…Sorption of Water: Thermodynamic Information from Kinetic Data. A rapid calorimetric method for determining the equilibrium water vapor pressure over a hydrate or saturated solution has been developed . The vapor space over the sample in an isothermal calorimeter is titrated with water vapor generated by continuously scanning the temperature of a container of water outside the calorimeter or by mixing dry and saturated gas streams.…”

Section: Illustrative Examples Of Applicationsmentioning

confidence: 99%

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Calorimetric Measurement of the Kinetics of Slow Reactions

Hansen

2000

Ind. Eng. Chem. Res.

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A brief review of the application of calorimetry to measurement of the kinetics of slow processes is presented. Processes degrading or otherwise changing the properties of materials often occur too slowly to be readily measured by conventional chemical analyses but can be measured in a relatively short period of time by heat conduction calorimetry. Instrument selection and derivation of rate laws from calorimetric data are discussed, and illustrative examples are presented.

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Calorimetric method for rapid determination of critical water vapor pressure and kinetics of water sorption on hygroscopic compounds

Cited by 11 publications

References 11 publications

Thermally decarboxylated sodium bicarbonate: Interactions with water vapour, calorimetric study

Thermally decarboxylated sodium bicarbonate: Interactions with water vapour, calorimetric study

Excipient Selection in Oral Solid Dosage Formulations Containing Moisture Sensitive Drugs

Calorimetric Measurement of the Kinetics of Slow Reactions

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