The nitrogen adsorption isotherm of alpha-lactose monohydrate
A complete nitrogen adsorption isotherm was measured for alpha-lactose monohydrate, from 0.001 to 0.995 relative pressure at 77 K. The isotherm was qualitatively classified as Type II, and was quantitatively analyzed for surface area, porosity, and surface heterogeneity. Surface area results revealed that the normal Brunauer Emmett Teller (BET) range of 0.05-0.35 relative pressure was not suitable for this grade of lactose, but having full isotherm data enabled a more appropriate analytical range to be found, illustrating the importance of measuring the entire isotherm as an essential step in method development. The isotherm was analyzed for micro and mesoporosity, both of which were found to be insignificant for lactose. The low relative pressure range 0.001-0.005 did not obey Henry's law, indicating the presence of surface heterogeneity. Density functional theory was exploited to quantitatively measure heterogeneity in the surface energy of lactose, using the full nitrogen adsorption profile. As expected for a crystalline material with multiple faces and likely presence of imperfections on the surface, the surface energy distribution function was broad with more than one mode.
| Medienart: |
Artikel |
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| Erscheinungsjahr: |
2006 |
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| Erschienen: |
2006 |
| Enthalten in: |
Zur Gesamtaufnahme - volume:11 |
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| Enthalten in: |
Pharmaceutical development and technology - 11(2006), 3 vom: 01., Seite 351-8 |
| Sprache: |
Englisch |
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| Beteiligte Personen: |
Sacchetti, Mark [VerfasserIn] |
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| Themen: |
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| Anmerkungen: |
Date Completed 17.10.2006 Date Revised 10.11.2019 published: Print Citation Status MEDLINE |
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| Förderinstitution / Projekttitel: |
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| PPN (Katalog-ID): |
NLM164653368 |
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| 245 | 1 | 4 | |a The nitrogen adsorption isotherm of alpha-lactose monohydrate |
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| 500 | |a Date Completed 17.10.2006 | ||
| 500 | |a Date Revised 10.11.2019 | ||
| 500 | |a published: Print | ||
| 500 | |a Citation Status MEDLINE | ||
| 520 | |a A complete nitrogen adsorption isotherm was measured for alpha-lactose monohydrate, from 0.001 to 0.995 relative pressure at 77 K. The isotherm was qualitatively classified as Type II, and was quantitatively analyzed for surface area, porosity, and surface heterogeneity. Surface area results revealed that the normal Brunauer Emmett Teller (BET) range of 0.05-0.35 relative pressure was not suitable for this grade of lactose, but having full isotherm data enabled a more appropriate analytical range to be found, illustrating the importance of measuring the entire isotherm as an essential step in method development. The isotherm was analyzed for micro and mesoporosity, both of which were found to be insignificant for lactose. The low relative pressure range 0.001-0.005 did not obey Henry's law, indicating the presence of surface heterogeneity. Density functional theory was exploited to quantitatively measure heterogeneity in the surface energy of lactose, using the full nitrogen adsorption profile. As expected for a crystalline material with multiple faces and likely presence of imperfections on the surface, the surface energy distribution function was broad with more than one mode | ||
| 650 | 4 | |a Journal Article | |
| 650 | 7 | |a Lactose |2 NLM | |
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| 650 | 7 | |a Nitrogen |2 NLM | |
| 650 | 7 | |a N762921K75 |2 NLM | |
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