I have worked on several pieces of equipment in the past so would like to pass along some information I know about their hydraulic systems as it applies to your question.
Equipment is very expensive so to make up for that companies run them as much as possible. Machinery ran at some sites (e.g. mines) go for 24 hours a day and are only 'down' when performing maintenance. The equivalent for hydraulic hoses service time in regards to permeability failure is easily years (which can be seen by the hours meter and maintenance logs of the equipment).
Permeation for your case is likely negligible, here is why.
Most high pressure hydraulic systems (e.g. like that found on a loader) operate at several thousand psi (10's of MPa like your example). They also have to deal with several instances of 'surging' (sudden increase in pressures) throughout their service life.
The fluids also heat up as the machine is used so the hoses have to deal with an elevated temperature environment. This lowers the viscosity increasing permeability through the hose material and of course any chemical reactions that may occur will now happen more quickly. It is not unusual to have temperatures above 80C (not recommended but this is common).
Working machinery also has to contend with constant hose movement (if it is polymer based instead of steel it is because there is movement). This in turn means the hoses also have to fight abrasion where they are tied to and rub against the chassis.
These hoses are also located outdoors where they see all kinds of weather conditions and temperatures fluctuations from frigid cold to over 120F while contending with spilled diesel, motor oil, etc.
Permeation does occur in some instances but it is usually only seen on hoses that are put into service for the wrong application (e.g. wrong pressure rating). Lifetime of the hose (from a permeability standpoint) is easily several years of service life and it is not unusual to see them last substantially longer in this regard (even in harsh environments).
For your experiment I assume this is a static hose rated for these pressures and fluid types. I am also assuming this is in an ambient indoor temperature environment with clean hydraulic fluid and no hose movement.
If this is the case it should be expected that any issues with permeability will be at minimum when compared to the standard service seen by these hoses. Good quality hoses are engineered to last for a long duration in much more severe environments than your lab. If it is installed properly there really should not be a concern.
I suggest making a trip to your local Catapillar, John Deere, Case, etc., etc. dealer and speak with one of their hose technicians. Just be sure to convert your requirements to standard (psi, inches, feet, etc.) and they will be happy to answer any further questions.
Hope this helps!