The relationship between dissolution, gas oversaturation and outgassing of solutions determined by Broadband Acoustic Resonance Dissolution Spectroscopy (BARDS)

Abstract

The addition of a solute to a solvent is known to reduce the solubility of dissolved gases in solution which leads to gas oversaturation and outgassing of the solvent. The importance of the processes involved have received relatively little attention due to a limited capacity to elucidate their effects in real time. Broadband Acoustic Resonance Dissolution Spectroscopy (BARDS) is a recently introduced acoustic approach which can monitor changes in the compressibility of a solvent due to outgassing. BARDS spectra show that a time dependent and quantitative reduction in gas oversaturation, following the dissolution of a simple salt, takes place over several hours. It is shown how vigorous agitation quickly equilibrates a solution, post dissolution, by removing gas oversaturation consistently. The level of oversaturation can be elucidated by further dissolving a marker compound into a solution consecutively. BARDS spectra indicate that the dissolution of a compound produces a consistent and quantifiable oversaturation of a solvent and a consistent and quantifiable outgassing. Low frequency sonication in an immersion bath is also shown to play no significant role in removing gas oversaturation post dissolution.

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

“…All experiments were performed in duplicate, and average readings with error bars representing the data spread are presented. The time courses of the observed acoustic profiles were highly reproducible under standardized conditions of constant volume, mass, temperature, and stirring rate (12). In general, the dissolution process is complete at the frequency minimum.…”

“…A custom prototype spectrometer was built and used to investigate the BARDS responses (12,13). It consists of a chamber with a glass dissolution vessel, a microphone (Sony ECM-CS10, range 100-16 kHz), a magnetic stirrer, and a stir bar.…”

New insights into the mechanism of rehydration of milk protein concentrate powders determined by Broadband Acoustic Resonance Dissolution Spectroscopy (BARDS)

“…Results from BARDS analysis indicated that water transfer into MPC powder particles became inhibited as the protein content of the MPC powders increased (Figures 2, 3, Table 1). For example, rehydration of MPC35 yielded a minimal BARDS response and a rapid return to steady-state (<400 s), while the time (60 min) required to reach steady-state for MPC90 (0.2%) (Figure 2) is unprecedented in its length compared to previous BARDS studies (Fitzpatrick et al, 2012a(Fitzpatrick et al, , 2012b(Fitzpatrick et al, , 2013(Fitzpatrick et al, , 2014. Release of gas from powders can be used to indirectly investigate water transfer in dairy powders (Richard et al, 2012;Hauser and Amamcharla, 2016;).…”

“…The pitch of the resonance modes in the solution change significantly when the powder is added 10 min. Otherwise, remaining gas oversaturation may lead to an over-response (Fitzpatrick et al 2013).…”

Rapid profiling of enteric coated drug delivery spheres via Broadband Acoustic Resonance Dissolution Spectroscopy (BARDS)

“…A custom prototype spectrometer was built and used to investigate the BARDS responses. 8,9 It consists of a chamber with a glass tumbler, microphone (Sony ECM-CS10, range 100 Hz to 16 kHz), a magnetic stirrer and follower. There is access at the front for the dissolution vessel and at the top in order to place a sample in a weighing boat on a tipper motor for introduction of the solute.…”