Patent / 1973
Antibiotic tetracycline complexes
Complexes of doxycycline and its salts with metaphosphoric acid were prepd. that gave higher blood antibiotic levels faster than doxycycline hydrochloride hemiethanolate hemihydrate. Thus 23.1 g doxycycline was treated with 4 g metaphosphoric acid to give 24.9 g of a 1:1-complex.