A Study of Emission Power and Spectrum of LT-GaAs Based THz Photoconductive Antennas

AbstractEmission spectra of LT-GaAs photoconductive antennas based on epitaxial films of “low-temperature” gallium arsenide (LT-GaAs) are measured in the terahertz frequency region by the Fourier transform spectroscopy

A Study of Emission Power and Spectrum of LT-GaAs Based THz Photoconductive Antennas

AbstractEmission spectra of LT-GaAs photoconductive antennas based on epitaxial films of “low-temperature” gallium arsenide (LT-GaAs) are measured in the terahertz frequency region by the Fourier transform spectroscopy

Preparation of micronized ibuprofen substance and assessment of its bioavailability

A Buchi B-290 mini spray dryer (Switzerland) designed to dry aqueous solutions or suspensions was used to prepare micronized ibuprofen substance, which differed from the starting substance in terms of decreased crystal size. The bioavailability of ibuprofen given as oral capsules containing micronized ibuprofen substance (crystal size 30 μm) and capsules containing commercial ibuprofen substance (crystal size 150 μm) was studied in Chinchilla rabbits. Concentrations of unaltered ibuprofen were measured by reverse-phase HPLC with spectrophotometric detection at 220 nm. Ibuprofen was extracted from rabbit serum by liquid:liquid extraction and averaged 78 %. The detection limit was 0.1 μg/ml. The bioavailability of micronized ibuprofen was more than twice that of the commercial substance (mean crystal size 150 μm). There were no differences in the rates of absorption or elimination of ibuprofen from the systemic circulation. © 2013 Springer Science+Business Media New York

Получение микронизированной субстанции ибупрофена и оценка его биодоступности

С применением нанораспылительной сушилки BUCHI B-290 (Mini Spray Dryer B-290, Швейцария), предназначенной для сушки водных растворов или суспензий, получена микронизированная субстанция ибупрофена, отличающаяся от исходной субстанции уменьшенными размерами кристаллов. На кроликах породы шиншилла исследована биодоступность ибупрофена при пероральном применении капсул, содержащих микронизированную субстанцию ибупрофена (размер кристаллов 30 мкм) и капсул, содержащих коммерческую субстанцию ибупрофена (размер кристаллов 150 мкм). Концентрацию неизмененного ибупрофена определяли методом обращенно-фазной ВЭЖХ со спектрофотометрическим детектированием при 220 нм. Для извлечения ибупрофена из сыворотки крови кроликов использовали жидкостно-жидкостную экстракцию. Извлечение ибупрофена из сыворотки составило, в среднем, 78 %. Предел обнаружения — 0,1 мкг/мл. Установлено, что по сравнению с коммерческой субстанцией (средний размер кристаллов 150 мкм), биодоступность ибупрофена микронизированного повышается более чем в 2 раза. При этом скорость всасывания ибупрофена и скорость элиминации из системного кровотока остаются одинаковыми

Preparation of micronized ibuprofen substance and assessment of its bioavailability

A Buchi B-290 mini spray dryer (Switzerland) designed to dry aqueous solutions or suspensions was used to prepare micronized ibuprofen substance, which differed from the starting substance in terms of decreased crystal size. The bioavailability of ibuprofen given as oral capsules containing micronized ibuprofen substance (crystal size 30 μm) and capsules containing commercial ibuprofen substance (crystal size 150 μm) was studied in Chinchilla rabbits. Concentrations of unaltered ibuprofen were measured by reverse-phase HPLC with spectrophotometric detection at 220 nm. Ibuprofen was extracted from rabbit serum by liquid:liquid extraction and averaged 78 %. The detection limit was 0.1 μg/ml. The bioavailability of micronized ibuprofen was more than twice that of the commercial substance (mean crystal size 150 μm). There were no differences in the rates of absorption or elimination of ibuprofen from the systemic circulation. © 2013 Springer Science+Business Media New York