A new long-acting injectable formulation developed by researchers at the University of South Australia could revolutionise how Parkinson’s disease is managed, potentially replacing the need for multiple daily tablets with a single weekly injection.
The innovation combines two of the most commonly prescribed medications for Parkinson’s, levodopa and carbidopa, into a biodegradable gel that forms an implant under the skin. This implant gradually releases medication over seven days, aiming to maintain consistent therapeutic levels and reduce the burden of frequent dosing.
Why This Matters
Parkinson’s is a progressive neurological condition that affects more than 150,000 Australians. While oral medications remain the cornerstone of symptom management, many people, especially older adults, struggle with the complexity of taking tablets three to five times a day. Missed doses can lead to sudden symptom deterioration, including difficulty walking, tremors, and fatigue.
University of South Australia PhD candidate Deepa Nakmode explained, “Even if they miss a single dose, they can’t perform day-to-day activities normally.” The new injectable aims to simplify this routine and improve quality of life.
What’s Inside the Injection?
The formulation uses a combination of PLGA, an FDA-approved biodegradable polymer, and Eudragit L-100, a pH-sensitive polymer. Together, they ensure a controlled and sustained release of medication. Lab tests showed:
- Over 90% of levodopa and 81% of carbidopa were released over seven days
- The implant degraded by more than 80% within a week
- No significant toxicity was observed in cell viability tests.
The injection is administered using a fine 22-gauge needle, avoiding the need for surgery or invasive procedures.
Parkinson’s Australia Responds
Parkinson’s Australia CEO Olivia Nassaris welcomed the breakthrough, calling it “a game-changer” for the community. “There hasn’t been much progress in Parkinson’s medications for a number of years, and the community is mostly on oral medications,” she said. “It will reduce falls risk. It will mean that people can still actively participate in everyday life like work and sports and volunteering.”
What’s Next?
While the lab results are promising, animal trials are still six months away, pending ethics approval. Human clinical trials will follow only if animal testing confirms safety and effectiveness. Lead researcher Professor Sanjay Garg emphasised that this is not a new drug, but a new delivery method. “We’re not just improving how the drug is delivered, we’re improving patients’ lives,” he said.
Broader Potential
Beyond Parkinson’s, researchers believe this delivery system could be adapted for other chronic conditions requiring long-term medication, such as:
- Diabetes
- Cancer
- Chronic pain
- Other neurodegenerative disorders.
While we remain hopeful, it’s important to be cautiously optimistic. This innovation could offer more freedom and stability for people living with Parkinson’s, but it’s still early days. Parkinson’s Australia will continue to monitor developments and advocate for accessible, effective treatments.
Research publication: Drug Delivery and Translational Research https://medicalxpress.com/news/2025-07-weekly-steady-parkinson-medication-daily.html
Read the full story by Rachael Merritt on https://www.abc.net.au/news/2025-07-14/new-injection-aims-to-simplify-treatment-for-parkinsons/105502026
Read the UniSA article here: https://www.unisa.edu.au/media-centre/Releases/2025/weekly-injection-could-be-life-changing-for-parkinsons-patients/
