What is a good formula for a cough drink for horses? (Genre Lyptonol?)

Lyptonol ampoules contain per ml: 0.1 g Eucalyptol and 0.02 g guaiacol in an oil solution, which contains 0.005 g phenol as a preservative.

The daily dose is 1 x 5ml per 100kg body weight; Intramuskulair injected.

The waiting time for milk processing is three days and for meat processing 5 days.

a syrup-based cough drink is not an easy task given the high concentration of eucalyptol. Guaiacol can possibly be replaced by kaliumsulfoguajacolate (Thiocol) but from eucalyptol I do not know any water-soluble form. Eucalyptol seems to be able to be put in solution via Solubilisation. But I do not own a tailor-made formula.