Parkinson’s Disease Care Advances with Weekly Injectable

A new weekly injectable formulation of levodopa and carbidopa, developed by the University of South Australia (UniSA), could dramatically improve the treatment experience for individuals living with Parkinson’s disease, one of the most common and challenging neurological disorders worldwide.

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This biodegradable injectable drug aims to replace the burdensome daily oral dosing with a once-a-week injection, significantly improving patient adherence, minimizing motor fluctuations, and enhancing treatment outcomes for those with moderate to advanced disease stages.

How the Biodegradable Formulation Works on Parkinson’s: In-Situ Implant Ensures Controlled Drug Release

Parkinson’s disease is primarily managed with levodopa-carbidopa, which restores depleted dopamine levels. However, these oral medications must be taken multiple times per day due to their short half-life, making it difficult for patients, especially the elderly, to maintain consistent dosing schedules.

To overcome this, UniSA researchers developed a long-acting injectable formulation using FDA-approved biodegradable polymers, specifically poly(lactic-co-glycolic acid) (PLGA) and Eudragit L-100. The injectable transforms into an in-situ implant post-administration, forming a small drug depot under the skin. This depot gradually releases medication at a steady dose, maintaining consistent therapeutic levels over the course of a week.

“Our goal was to create a formulation that simplifies treatment, improves patient compliance, and maintains consistent therapeutic levels of medication. This weekly injection could be a game-changer for Parkinson’s care.

Levodopa is the gold-standard therapy for Parkinson’s, but its short life span means it must be taken several times a day.”

• Professor Sanjay Garg, from UniSA’s Centre for Pharmaceutical Innovation

By delivering the drug in a controlled manner, this formulation can minimize the peak-trough fluctuations associated with oral levodopa, which often lead to “on-off” motor symptoms and reduced quality of life.

Clinical Potential and Future of Commercialisation in Chronic Neurology

This innovation holds substantial potential not only for Parkinson’s disease but also for a wide range of chronic conditions that require consistent drug levels. The team is currently evaluating the safety and effectiveness of the injectable in preclinical and early clinical trials, with results showing promising pharmacokinetics and tolerability.

Additionally, the formulation’s use of biodegradable materials means it doesn’t require surgical removal, making it practical and scalable. The researchers also note strong commercialisation opportunities for this platform, especially in neurology, psychiatry, and endocrinology, where controlled drug release is crucial.

Conclusion:

The development of this weekly injectable levodopa-carbidopa formulation marks a significant stride toward simplifying the management of Parkinson’s disease. By ensuring steady therapeutic levels and enhancing patient adherence, this biodegradable, long-acting injectable addresses key limitations of current oral therapies. As clinical trials advance and data mature, this innovation may soon offer neurologists and healthcare providers a powerful, more sustainable treatment option for a growing population of patients with chronic neurological disorders.

For More Information: 

Nakmode, D. D., et al. (2025). Development of an in-situ forming implant system for levodopa and carbidopa for the treatment of parkinson’s disease. Drug Delivery and Translational Research. doi.org/10.1007/s13346-025-01892-y.