Drug MechanismPSKNCT06431984
Pharmacology Space Kit (PSK) - Dried Blood Spot for Caffeine Pharmacokinetics Under Microgravity Conditions
A study testing prick test in people with Drug Mechanism and Metabolism Medication Toxicity, run by Institut National de la Santé Et de la Recherche Médicale, France at 1 site in France.
Trial summary
The PSK study is preliminary to the study of drug metabolism in space flight conditions. The investigators propose to use simplified blood sampling methods that can be applied in microgravity. Read more about this study
- Who is it for?
- Ages 18 to 70 yearsHealthy volunteers can take part
- Conditions the study is for
- Drug Mechanism, Metabolism Medication Toxicity, Space Motion Sickness
- What is being tested?
- prick test
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 30 participants
- Where
- 1 siteFrance
- Study dates
- 27 Mar 2023to 3 Apr 2024
- Phase
- Interventional
- Are there results?
- None posted in the registry
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 to 70 years
- All sexes
- Healthy volunteers accepted
- Adult, Older adult
Who may be able to join
- Be affiliated to a social security scheme or benefit from such a scheme.
- Have obtained a medical certificate stating that they are fit for parabolic flights.
- Be aged between 18 and 70
- Be in good health: no chronic treatment that could interact with the metabolism of caffeine, no progressive disease
- Must not have any contraindications to taking caffeine (30 to 100 mg). Volunteers will also be asked not to consume caffeine (coffee, chocolate, energy drinks, tea, cola, etc.) in the 24 hours preceding the experiment.
Who cannot join
- Be the subject of a legal protection measure (safeguard of justice, curatorship or guardianship)
- suffer from haematophobia (irrational fear of blood)
- Have a current infectious disease, particularly viral
- Have an active chronic illness
- Have a high usual intake of caffeine (>4 espressos, >4 cups of tea, >100g dark chocolate per day)
- Total intolerance to all forms of caffeine
Show all 11Show fewer
- Smoke more than 20 cigarettes a day
- Have weaned themselves off smoking for less than a month
- Have a history of severe Raynaud's phenomenon
- Have a history of naupathy
- Suffering from naupathy during a flight
Trial locations and contacts
1 site in 1 country.
About this study
Official title: Kit de Pharmacologie Spatial - Analyse de l'Utilisation Des Dried Blood Spot Pour le Dosage de la caféine Chez Des Volontaires Sains en microgravité au Cours Des Vols Paraboliques
The PSK study is preliminary to the study of drug metabolism in space flight conditions. The investigators propose to use simplified blood sampling methods that can be applied in microgravity. This method is based on the use of capillary blood, obtained using an automatic lancet for diabetics, the blood droplet then being deposited on specific blotting paper, and then studied in the laboratory. In 2022, the investigators validated the transfer of artificial blood in parabolic flight conditions, as well as the validity of cardiovascular drug dosage.
The objective of the 2023 study is to validate the collection and transfer of capillary blood, on themselves, by healthy volunteers with little training, for the blood dosage of caffeine after intake of standard doses of alimentary caffeine.
The primary objective is a feasibility of 90% of sampling in microgravity, compared with 95% on ground. Secondary objectives are the pharmacokinetic of different forms of caffeine, according to genetic background and other modifiers of CYP1A2.
Read the detailed description
The investigators propose to use simplified blood sampling methods that can be applied in microgravity. This method is based on the use of capillary blood, obtained using an automatic lancet for diabetics, the blood droplet then being deposited on specific blotting paper, and then studied in the laboratory.
The objective of the study is to validate the collection and transfer of capillary blood from finger prick test, performed on themselves, by healthy volunteers after a short training, for the blood dosage of caffeine. Dietary caffeine will be used, issued from standardized espresso, tea or dark chocolate.
Caffeine is a universally used food substance and is metabolised by a pathway common to many drugs (CYP 1A2). The aim is to show that it is possible to collect blood in this way, and to carry out assays of caffeine. Secondary objectives are to assess the kinetics of caffeine metabolism through the metabolic ratio (AUC paraxanthine/AUC caffeine), and to correlate these kinetics with genetic variations in CYP 1A2 activity.
Participants are healthy volunteers already selected to take part in the parabolic flight campaign.
A success rate of 95% for ground sampling, and 90% for in-flight sampling is assumed as satisfactory. If 5 volunteer participants during the 3 days of flying carry out 2 in-flight samplings, this results in 30 in-flight samplings. If the other 25 flying volunteers take only one in-flight sample, means 25 in-flight samples (total 55). On the ground, the 30 volunteers will take 90 samples, for a total of 145 minimum samples. An equivalence threshold for a maximum 20% difference between flight and ground conditions is considered. For a difference of 10, 15 and 20%, the power is 34, 79 and 97% respectively. It can therefore conclude that the difference between the two sampling conditions is not clinically significant.
- Being tested
- prick test
- Medical subject headings
- Space Motion Sickness
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
prick testDiagnostic test
self-sampling of capillary blood using the finger prick test method
| Study group | Role | What they receive |
|---|---|---|
| Healthy subjects | Experimental | Participants are healthy volunteers selected by the investigating team. The size of the study is limited by the number of individuals authorised to board the aircraft.
The flying participants in the experiment will be the aircraft crew, i.e. volunteers from the research teams taking part in the parabolic flight.
Healthy volunteers over the age of majority will be included in the study. Receives: Diagnostic Test: prick test |
What is being measured
The primary outcome is the main question the study is designed to answer.
Percentage of valid capillary blood deposit on dry support
A blood transfer is considered as successful IF the 3 following criteria are fulfilled
- Blood spot covering > 8 mm2 (3 mm punch circle)
- Obtaining a drop of blood within the allotted time of 22 sec of microgravity
- The drop is neither smeared nor smashed on the blotting paper
Measured: through study completion, an average of 3 days
Secondary outcomes (6)
Identification of factors leading to self-sampling failure a. Time too short b. Insufficient drop c. Inadequate transfer
Identification of self-sampling failure factors
- Deposition time in flight > 22 seconds of weightlessness
- Blood stain covering 80% or more of the reference circle: diameter of the stain taken by photography
Measured: through study completion, an average of 1 year
Caffeine kinetic under different formulations and dosages
Area under the curve of caffeine and paraxanthine, metabolic ratio (para/caffeine)
Measured: through study completion, an average of 3 days
Caffeine kinetic under different CYP1A2 genotypes
Area under the curve of caffeine and paraxanthine, metabolic ratio (para/caffeine)
Measured: through study completion, an average of 3 days
Caffeine kinetic under different gravity conditions
Area under the curve of caffeine and paraxanthine, metabolic ratio (para/caffeine)
Measured: through study completion, an average of 3 days
Acceptability
A paper questionnaire will be handed out just after the parabolic flight at the time of the last sampling. It will be made up of closed questions based on 3 dimensions of satisfaction:
- The quality of the information given by the investigating team on the capillary blood sampling process in order to improve our paper-based operating procedure.
- Their physical and psychological well-being during the finger prick test demonstration phase before the flight, during the flight and at the end of the flight campaign to ensure that the participants felt comfortable and confident in the sampling situation.
- Assessment of their performance during the study in flight and on the ground, and whether they would be interested in self-sampling for a future space mission.
Measured: through study completion, an average of 1 year
Stability of dry blood spots
Area under the curve of caffeine and paraxanthin, metabolic ratio (para/caffeine) at 6 months interval
- Visual appearance (degradation, colour change, etc.)
- Comparison of relative areas obtained during the study with those obtained in a conventional laboratory situation
Measured: through study completion, an average of 1 year
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted29 May 2024
- Study start27 Mar 2023
- Primary completion3 Apr 2024
- Study completion3 Apr 2024
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (1)Papers the sponsor has linked to this study.
- Other trials for Drug MechanismStudies of the same condition, open and under way.
- More trials run by Institut National de la Santé Et de la Recherche Médicale, FranceThe sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Other
- Allocation
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Enrolment
- 30 participants (actual)
Sponsor and investigators
- Sponsor type
- Other government
- Responsible party
- Sponsor
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT06431984
- Sponsor's protocol ID
- C22-80
- Other IDs
- 2022-A02794-39
- Acronym
- PSK
- Status last verified
- May 2024
- First submitted
- 15 May 2024
- Last updated
- 2 Sep 2025
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
Publications
Derobertmasure A, Toh LS, Verstuyft C, Lukic S, De Sousa Carvalho C, Couronne R, Beauvalet M, Chhun S, Boutouyrie P. Feasibility of dried blood spot collection for caffeine pharmacokinetic studies in microgravity: Insights from parabolic flight campaigns. Br J Clin Pharmacol. 2026 Jan;92(1):35-47. doi: 10.1111/bcp.16320. Epub 2024 Oct 29.
PubMed 39473131
Study at a glance
From the registry record, last updated by the sponsor on 2 Sep 2025. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Kit de Pharmacologie Spatial - Analyse de l'Utilisation Des Dried Blood Spot Pour le Dosage de la caféine Chez Des Volontaires Sains en microgravité au Cours Des Vols Paraboliques
- ClinicalTrials.gov ID
- NCT06431984
- Acronym / sponsor ID
- PSK / C22-80
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 30 participants (actual)
- Lead sponsor
- Institut National de la Santé Et de la Recherche Médicale, FranceOther government
- Study start
- 27 Mar 2023 (actual)
- Primary completion
- 3 Apr 2024 (actual)
- Study completion
- 3 Apr 2024 (actual)
- First posted
- 29 May 2024 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
The PSK study is preliminary to the study of drug metabolism in space flight conditions. The investigators propose to use simplified blood sampling methods that can be applied in microgravity. This method is based on the use of capillary blood, obtained using an automatic lancet for diabetics, the blood droplet then being deposited on specific blotting paper, and then studied in the laboratory. In 2022, the investigators validated the transfer of artificial blood in parabolic flight conditions, as well as the validity of cardiovascular drug dosage.
The objective of the 2023 study is to validate the collection and transfer of capillary blood, on themselves, by healthy volunteers with little training, for the blood dosage of caffeine after intake of standard doses of alimentary caffeine.
The primary objective is a feasibility of 90% of sampling in microgravity, compared with 95% on ground. Secondary objectives are the pharmacokinetic of different forms of caffeine, according to genetic background and other modifiers of CYP1A2.
Detailed description
The investigators propose to use simplified blood sampling methods that can be applied in microgravity. This method is based on the use of capillary blood, obtained using an automatic lancet for diabetics, the blood droplet then being deposited on specific blotting paper, and then studied in the laboratory.
The objective of the study is to validate the collection and transfer of capillary blood from finger prick test, performed on themselves, by healthy volunteers after a short training, for the blood dosage of caffeine. Dietary caffeine will be used, issued from standardized espresso, tea or dark chocolate.
Caffeine is a universally used food substance and is metabolised by a pathway common to many drugs (CYP 1A2). The aim is to show that it is possible to collect blood in this way, and to carry out assays of caffeine. Secondary objectives are to assess the kinetics of caffeine metabolism through the metabolic ratio (AUC paraxanthine/AUC caffeine), and to correlate these kinetics with genetic variations in CYP 1A2 activity.
Participants are healthy volunteers already selected to take part in the parabolic flight campaign.
A success rate of 95% for ground sampling, and 90% for in-flight sampling is assumed as satisfactory. If 5 volunteer participants during the 3 days of flying carry out 2 in-flight samplings, this results in 30 in-flight samplings. If the other 25 flying volunteers take only one in-flight sample, means 25 in-flight samples (total 55). On the ground, the 30 volunteers will take 90 samples, for a total of 145 minimum samples. An equivalence threshold for a maximum 20% difference between flight and ground conditions is considered. For a difference of 10, 15 and 20%, the power is 34, 79 and 97% respectively. It can therefore conclude that the difference between the two sampling conditions is not clinically significant.
Study design
- Primary purpose
- Other
- Allocation
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Number of arms
- 1
| Arm | Type | Receives |
|---|---|---|
| Healthy subjects | Experimental | Diagnostic Test: prick testParticipants are healthy volunteers selected by the investigating team. The size of the study is limited by the number of individuals authorised to board the aircraft. The flying participants in the experiment will be the aircraft crew, i.e. volunteers from the research teams taking part in the parabolic flight. Healthy volunteers over the age of majority will be included in the study. |
Who may qualify
- Ages
- 18 to 70 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (5 listed)
- Be affiliated to a social security scheme or benefit from such a scheme.
- Have obtained a medical certificate stating that they are fit for parabolic flights.
- Be aged between 18 and 70
- Be in good health: no chronic treatment that could interact with the metabolism of caffeine, no progressive disease
- Must not have any contraindications to taking caffeine (30 to 100 mg). Volunteers will also be asked not to consume caffeine (coffee, chocolate, energy drinks, tea, cola, etc.) in the 24 hours preceding the experiment.
Key exclusion criteria (11 listed)
- Be the subject of a legal protection measure (safeguard of justice, curatorship or guardianship)
- suffer from haematophobia (irrational fear of blood)
- Have a current infectious disease, particularly viral
- Have an active chronic illness
- Have a high usual intake of caffeine (>4 espressos, >4 cups of tea, >100g dark chocolate per day)
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| prick testself-sampling of capillary blood using the finger prick test method | Diagnostic test | Healthy subjects |
Primary outcome
Percentage of valid capillary blood deposit on dry support
Time frame: through study completion, an average of 3 days
A blood transfer is considered as successful IF the 3 following criteria are fulfilled 1. Blood spot covering > 8 mm2 (3 mm punch circle) 2. Obtaining a drop of blood within the allotted time of 22 sec of microgravity 3. The drop is neither smeared nor smashed on the blotting paper
6 secondary outcomes
Identification of factors leading to self-sampling failure a. Time too short b. Insufficient drop c. Inadequate transfer
Time frame: through study completion, an average of 1 year
Caffeine kinetic under different formulations and dosages
Time frame: through study completion, an average of 3 days
Caffeine kinetic under different CYP1A2 genotypes
Time frame: through study completion, an average of 3 days
Caffeine kinetic under different gravity conditions
Time frame: through study completion, an average of 3 days
Acceptability
Time frame: through study completion, an average of 1 year
Stability of dry blood spots
Time frame: through study completion, an average of 1 year
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 2 Sep 2025.
- Results publication: PubMed 39473131Derobertmasure A, Toh LS, Verstuyft C, Lukic S, De Sousa Carvalho C, Couronne R, Beauvalet M, Chhun S, Boutouyrie P. Feasibility of dried blood spot collection for caffeine pharmacokinetic studies in microgravity: Insights from parabolic flight campaigns. Br J Clin Pharmacol. 2026 Jan;92(1):35-47. doi: 10.1111/bcp.16320. Epub 2024 Oct 29.
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
The record lists no contact. Use the official record to reach the sponsor.
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing prick test in people with Drug Mechanism and Metabolism Medication Toxicity, run by Institut National de la Santé Et de la Recherche Médicale, France at 1 site in France.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 5 inclusion and 11 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: finished, as of the sponsor's last update on 2 Sep 2025. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in France. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Percentage of valid capillary blood deposit on dry support (time frame: through study completion, an average of 3 days). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
On the ClinicalTrials.gov record for NCT06431984, which also lists 1 linked publication.
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 2 Sep 2025.