Randomised, crossover bioequivalence clinical trial of donepezil 5 mg capsules vs donepezil 5 mg film-coated tablets, after a single oral dose administration to healthy volunteers under fasting conditions
This study is a research project looking into a medicine called donepezil, which is used for Alzheimer's disease. We want to see if a 5mg capsule version of this medicine works in the body in the same way as a 5mg tablet. Healthy volunteers will take both forms of the medicine at different times, always on an empty stomach. By comparing how the body handles each form, we can make sure that both deliver the medicine equally well. This type of study is an early stage of testing, focusing on how a medicine behaves in the body.
At a glance
What is this study about?
This study is about a medicine called donepezil, which is used to help people with Alzheimer's disease. You might have heard of it as Aricept. The main purpose of this research is to check if two different forms of this medicine – a 5mg capsule and a 5mg tablet – work in the body in the same way. This is very important because even if medicines contain the same active ingredient, they can sometimes behave differently depending on how they are made and delivered, for example, as a capsule or a tablet.
Imagine you have two different brands of a common painkiller; you'd expect them to both relieve pain. This study is similar: we're checking if the donepezil 5mg capsule delivers the medicine to the body in the same amount and at the same speed as the donepezil 5mg tablet. This helps doctors and pharmacists know that if someone switches from one form to another, they are still getting the same benefits from the medicine.
This kind of research is called a 'bioequivalence' study. It's an early but crucial step in developing medicines or introducing new forms of existing ones. It helps ensure that any new version of a medication is just as effective and safe as an established one, giving confidence to patients and healthcare providers.
Key takeaways
- This study compares two forms (capsule and tablet) of an Alzheimer's medicine called donepezil.
- It aims to ensure both forms work the same way in the body.
- Healthy adults (18 years or older, any gender) are needed as volunteers.
- Participants will take both capsule and tablet versions at different times, on an empty stomach.
- Blood samples will be taken to measure medicine levels in the body.
- Your participation helps improve understanding of medicines for future patients.
Who may be eligible?
This study is looking for healthy adults aged 18 or over. This means you should generally be in good health and not have any serious ongoing medical conditions.
There are no age limits on the upper end, so if you're 18 or older, you could potentially take part. Both men and women are welcome to participate in this study.
Before you can join, a medical team would carefully check your health to make sure it's safe for you to take part and that the study results will be accurate. They will ask you about your medical history and do some health checks.
- Are you 18 years old or older?
- Are you generally in good health?
- Are you able to visit a clinic multiple times for study appointments?
- Are you comfortable with having blood samples taken regularly?
- Are you able to follow specific instructions, such as taking medicine on an empty stomach?
This is a guide only — the research team will confirm whether you can take part.
What does participation involve?
If you decide to take part, you would be a 'healthy volunteer'. You would visit a research clinic multiple times. During these visits, you would receive a single dose of either the donepezil 5mg capsule or the donepezil 5mg tablet, but not both at the same time. You'd be asked to take the medicine on an empty stomach.
After taking the medicine, you'd stay at the clinic for a period. During this time, the research team would regularly take small blood samples. These samples help them measure how much of the medicine is in your body and how quickly it's absorbed and cleared. You would also have regular health checks, like measuring your blood pressure and heart rate.
After a break (so the first dose fully leaves your system), you would repeat the process, taking the other form of the medicine (if you had the capsule first, you'd then have the tablet, or vice versa). The total time you would spend in the study, including all visits and follow-up, would be fully explained to you before you agree to take part.
Potential risks and benefits
Locations (1)
- —Spain
Common questions
What is donepezil?
Donepezil is a medicine commonly used to help manage the symptoms of Alzheimer's disease.
Why are you comparing a capsule and a tablet?
We want to check that both forms of the medicine deliver the active ingredient to your body in the same way, ensuring they work equally well.
Will I get paid to participate?
Payment for participation to cover time and travel expenses is common in these types of studies, but details would be provided by the study team.
Do I need to have Alzheimer's disease to join?
No, this study is specifically looking for healthy volunteers, not people with Alzheimer's disease.
What does 'on an empty stomach' mean?
It means you won't have eaten for a certain number of hours before taking the medicine, usually overnight, to ensure consistent results.
How to find out more
Always speak to your GP or specialist before deciding to take part in a study.
Discussion
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