Answer
Doxycycline hyclate is a salt form used in the capsule; the labelled active amount is expressed as the equivalent quantity of doxycycline.
Sources for this answer
- Doxycycline 100 mg Capsules — Current selected SmPCemc · Summary of Product Characteristics
General medicine information. Follow the instructions for your own medicine and speak to a pharmacist or clinician about your individual circumstances.