Applications development of broadband acoustic resonance dissolution spectroscopy (BARDS) in the pharmaceutical, food and animal nutrition industries
Ahmed, M. Rizwan
University College Cork
Broadband Acoustic Resonance Dissolution Spectroscopy (BARDS) is a novel analytical tool for the characterisation of powders, blends, tablets and a myriad of formulations. It is based on a phenomenon which occurs during the dissolution of solid material in solution. When the sample is added the solution undergoes changes in its compressibility due to gas evolution in solution. This has the effect of slowing down a resonant frequency which is induced in the dissolution vessel. These frequency changes are very reproducible and can be used as a signature for the sample in question. This also infers that what may have been previously understood to be a random and chaotic dissolution of a sample, is in fact highly ordered in terms of gas evolution and loss. The results chapters will highlight new and exciting applications which have been developed using BARDS for several industries. These include the analysis of a variety of milk protein concentrates, whey protein concentrates and isolates. An example of this is a new method to track the hydration of milk protein concentrates which has been developed and modelled. In addition, tracking the agglomeration of milk protein isolates has also been developed which takes a fraction of the time and cost of current approaches. Data generated in collaboration with industry partners have also shown that BARDS can be used to track the degree of hydrosylation of soy proteins. It is also demonstrated that profiles could be established for yeast and soy protein-based supplement products with different manufacturing provenance. Samples showed excellent intra-batch consistency whilst inter-batch comparisons were clearly discernible depending on the manufacturing site. The research in this thesis has also lead to the major discovery of a new approach to determine pH and acid base reactions which is probeless, contactless and non-titrimetric. Additionally, synthesis of gold nanoparticles due to reduction reaction between acid and base were also monitored. Important pharmaceutical applications have also been developed for continuous batch manufacturing relating to wettability of lubricated and unlubricated blends. Results show the degree of blending of lubricants and their likely effect on tablet hardness. The speed of conveyancing of powder material is also assessed as are the final compressed tablets using BARDS. Finally, applications to parameterise yeast metabolism have also been developed which produce data for the uptake rate of carbon sources and the rate of CO2 production. The relationship between CO2 production and ethanol production have also been achieved. A quantitative value for gas production by individual cells has been established by BARDS experiments. In conclusion, multiple applications with extreme novelty of this platform technology have been demonstrated with scope for many more to be developed. The broader impacts of the research are both academically and commercially.
Ahmed, M. R. 2018. Applications development of broadband acoustic resonance dissolution spectroscopy (BARDS) in the pharmaceutical, food and animal nutrition industries. PhD Thesis, University College Cork.