Visualization of the hot chocolate sound effect by spectrograms

Trávníček, Z.; Fedorchenko, Alexander I.; Pavelka, Miroslav; Hrubý, Jan

doi:10.1016/j.jsv.2012.07.038

Cited by 13 publications

(13 citation statements)

References 7 publications

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“…A detailed and comprehensive outline of the principles and underlying processes involved in BARDS analysis is given by Fitzpatrick et al (4). The reproducibility of the acoustic phenomenon used in BARDS has been also demonstrated in a recent study by Trávníček et al (5). Several other references (6)(7)(8)(9)(10)(11) to the phenomenon have appeared intermittently in the literature over the decades.…”

Section: Introductionmentioning

confidence: 97%

pH Dependence of the Dissolution Rate of EntericCoated Drug Spheres Determined by Broadband Acoustic Resonance Dissolution Spectroscopy (BARDS)

Evans-Hurson¹,

McSweeney²,

Vos³

et al. 2016

Dissolution Technol.

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Enteric coatings are widely used in formulations of drug delivery spheres. The coating protects an active pharmaceutical ingredient (API) from acidic conditions in the low pH environment of the stomach. The coating breaks down readily at higher pH in the lower intestine to allow absorption of the API. The thickness of the enteric coating is one of the factors that determine the release rate of the drug in the gastrointestinal tract. It is difficult to determine the loading of the drug layer and enteric coating on the core support sphere without conventional dissolution testing during and post manufacture. Broadband acoustic resonance dissolution spectroscopy (BARDS) potentially offers a new, rapid approach to characterizing enteric coatings during their manufacture. BARDS applications are based on reproducible changes in the compressibility of a solvent during dissolution, which is monitored acoustically via associated changes in the frequency of induced acoustic resonances. Two drug sphere formulations that yield characteristic and reproducible data were investigated. A steady-state acoustic lag time is associated with the disintegration of the enteric coating and drug layer in basic solution. This lag time is pH dependent and is indicative of the rate at which the coating and layers dissolve. BARDS analysis has the potential to characterize drug sphere formulations at-line in very short timescales. BARDS represents a complementary technique to conventional dissolution testing that could be used in precompliance testing for quality assurance during manufacture. BARDS data, in the future, may also be indicative of the likely performance of a formulation under USP dissolution testing. KEYWORDS:Hypromellose; enteric-coated spheres; dissolution; BARDS.

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Section: Introductionmentioning

confidence: 97%

pH Dependence of the Dissolution Rate of EntericCoated Drug Spheres Determined by Broadband Acoustic Resonance Dissolution Spectroscopy (BARDS)

Evans-Hurson¹,

McSweeney²,

Vos³

et al. 2016

Dissolution Technol.

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“…The liquids used for sound experiments can be assumed as homogeneous mixture of hot water and air bubbles. Although the propagation of sound waves is very complex problem under these conditions, the speed of sound c can be expressed as the isentropic derivative, as was shown in [4]:…”

Section: Hot Chocolate Sound Effectmentioning

confidence: 99%

“…The liquid column in the glass behaves as one-quarter wavelength resonator [2] and [4], thus the sound effect is caused by longitudinal vibration of the liquid column. The frequency of the sound is simply:…”

Section: Hot Chocolate Sound Effectmentioning

confidence: 99%

“…The dependence of frequency on time was shown for the hot chocolate effect in [4] in the following form:…”

Section: Hot Chocolate Sound Effectmentioning

confidence: 99%

“…At first, the tone lowers in pitch -the reason is generation of bubbles from supersaturated liquid (sparkling wine effect). Sequentially, an increase of the tone is hearable as the bubbles disappear (see [2], [3], [4]). …”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Bubble dynamics in drinks

Broučková

Trávníček

Šafařík

2014

EPJ Web of Conferences

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Abstract. This study introduces two physical effects known from beverages: the effect of sinking bubbles and the hot chocolate sound effect. The paper presents two simple "kitchen" experiments. The first and second effects are indicated by means of a flow visualization and microphone measurement, respectively. To quantify the second (acoustic) effect, sound records are analyzed using time-frequency signal processing, and the obtained power spectra and spectrograms are discussed.

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