Gel channels with essential oils

Dear professor, I have a prescription for essential oils in gelules. 7 different oils, 20 mg each per Gelule. I have already understood from the question box that a filler of starch with AEROSIL can be used for this. Does the literature also mention a certain amount of filler that is needed so that the essential oils do not work with the gelules? Do you need enteric enveloling? Thanks in advance for your comment.