Tahnee Dening’s research into improving the oral absorption of antipsychotic medications for schizophrenic patients has won her an Endeavour Postgraduate Scholarship.
The internationally competitive, merit-based scholarship funded by the Australian Government will support Tahnee’s PhD research at Lundbeck, a global pharmaceutical company in Denmark.
The Minister for International Education, Richard Colbeck awarded Tahnee and 30 other recipients at an official dinner held at the National Museum of Australia in a recent trip to Canberra.
“We visited Parliament House and watched Question Time before a meet and greet with the Minister for International Education and Prime Minister Malcolm Turnbull,” Tahnee says.
“We had some photos taken, and had a group chat with Mr Turnbull for 5 or 10 minutes – he was very charismatic and friendly.
“The Minister for Education, Simon Birmingham also randomly popped down to say hello, after hearing our voices in the courtyard,” says Tahnee.
Tahnee, a PhD student with the School of Pharmacy and Medical Sciences is working on the development of smart oil-based tablets/capsules for poorly water-soluble antipsychotic drugs.
The majority of antipsychotic drugs are poorly absorbed from the gastrointestinal tract after oral dosing as a tablet or capsule due to their low solubility in the watery gastrointestinal environment, and Tahnee’s research therefore aims to increase their absorption and effectiveness to improve the treatment of schizophrenia.
“Several drugs show improved oral absorption when they are taken with food, which led scientists to understand that the fats and oils from food can help dissolve poorly water-soluble drugs, therefore enabling a greater extent of absorption and increased treatment efficacy,” Tahnee says.
“We can take this knowledge and develop tablet or capsule formulations which contain drug dissolved in pharmaceutical grade oils – these formulations then “mimic” the natural food effect and increase the absorption of the drug.
“Because antipsychotic drugs are poorly absorbed orally, if we can increase their oral absorption, we can also increase their effectiveness. The main issue with some of the antipsychotic drugs, however, is that they show this “food effect”, where they must be taken with food by the patient to allow enough drug to be absorbed and be effective at controlling the patient’s symptoms.
“Schizophrenic patients are notoriously non-compliant with their medication use.
“If the patient sometimes takes the drug with food, sometimes takes it without food – this can make it hard to achieve the correct dose, and can result in either under dosing (lack of efficacy) or over dosing (risk of side effects).
“If we can take away the need for these patients to take their medicine with food, their treatment will likely be more effective as they can take it with food, or without food, and get the same level of (optimised) drug absorption and efficacy/symptom control every time.”
Presently she is working on developing various smart oil-based formulations and undertaking studies to characterise these formulations and investigate how they impact drug dissolution and the processes of lipid digestion within the gastrointestinal tract.
Tahnee will have developed and optimised the smart hybrid oil-based formulations before heading to Lundbeck, Denmark to test in animals in November 2016.
“Whilst we can gain an idea of how the formulations might work when dosed orally by doing various studies in the lab, the gold standard is to obviously test them in animals.
“This gives us real data showing that these formulations either do or don’t work.
“The in vivo studies in rats will form the major and most significant part of my Endeavour programme at Lundbeck.
“Here, we will orally dose a number of the developed formulations to rats, and measure the concentration of drug in the blood over time.
“Importantly, we can investigate a number of different formulations, and this allows us a really amazing opportunity to compare and understand why each formulation performs as it does.
“We also dose pure drug and commercial product, which serve as control groups for us to compare against.
“From the blood samples, we can measure the extent of drug absorption, but we can also look more specifically at other parameters too – how quickly or slowly is the drug absorbed, what is the maximum concentration that is reached in the blood?
“If promising results are obtained, then we can consider patenting and progressing the formulations for potential commercial application and use in humans,” says Tahnee.
By designing smart oil-based formulations with certain performance characteristics Tahnee says the potential for using these formulations with other drugs is also promising.
“It is estimated that approximately 70% of all new drug candidates coming out of drug discovery pipelines may be considered as poorly water-soluble (as well as 40-70% of all current drug products on the market) – and these drugs therefore pose significant oral delivery challenges,” Tahnee says.
“If we can develop new oral formulations for these drugs which increase their absorption from the gastrointestinal tract, then we can potentially “save” a number of these abandoned new molecules which may end up being highly effective drugs for various diseases.
Tahnee’s interest in pharmaceutical science stemmed from enjoying chemistry in high school.
Graduating from Kangaroo Inn Area School, in South Australia’s Limestone region, Tahnee went on to complete a double degree in Pharmacy (Honours) and Pharmaceutical Science at UniSA.
“After graduating in 2012, I spent the next year working at the Repatriation General Hospital in Daw Park as an Intern Pharmacist,” Tahnee says.
“Then I came back to UniSA to do my PhD under the supervision of Prof Clive Prestidge at the Ian Wark Research Institute after getting my general registration as a Pharmacist.”
Tahnee says the Endeavour Postgraduate Scholarship gives her the opportunity to conduct world-class studies at Lundbeck, increasing her experience and knowledge for the future.
Although she is not sure if she will stay in academia or work in industry, Tahnee hopes to have a career in research.
“The programme at Lundbeck will give me some experience in the pharmaceutical industry and hopefully help me decide which direction I’d like to go in.” says Tahnee.
“I’ve been at UniSA since leaving high school, so my current plan is to probably head overseas for a couple of years post-PhD and get some experience (and travel!).
“When I come back to Australia, I’d love to apply for a National Health and Medical Research Council or Australian Research Council fellowship.
“My supervisors, Prof Clive Prestidge, Dr Shasha Rao and Dr Nicky Thomas have all been a wonderful support to me during my PhD so far, and I would never have gotten this Endeavour scholarship without their help!
“The two days in Canberra was fantastic and the other scholarship winners were amazing and intelligent individuals.
“I think we are really lucky and I have made some lifelong friends because of it.”