[Experimental studies on absorption, distribution and excretion of a new antibiotic, fosfomycin. II. Absorption of oral preparations of fosfomycin calcium salt in dogs (author's transl)].

To establish the best usage and dosage of fosfomycin granule and capsules which had been prepared based on our fundamental experiences as described in the first report, absorption of calcium salt contained in both preparations was evaluated using dogs as test animals. (1) Granule containing the calcium salt equivalent to 200 mg of fosfomycin free acid per g showed almost the same absorption as the bulk (fosfomycin calcium), having no disadvantage due to processing. (2) Capsules containing the calcium salt equivalent to 250 mg and 500 mg of the free acid per capsule showed slightly more retarded absorption than the bulk, probably due to some inevitable factors such as disintegration rate of capsules and dispersion rate of the calcium salt. But, once dispersed, the calcium salt in capsules was well absorbed as well as the bulk material. (3) Gastrointestinal absorption of granule and the capsule contents was almost the same. (4) Simultaneous administration of capsules and water improved the absorption efficiency. Though administration after feeding caused somewhat retarded absorption of the drug, the serum levels were rather well sustained with a slight drop but sufficiency of absorption, suggesting better clinical advantages than in the fasted animals. (5) Fosfomycin calcium salt in both preparations was well absorbed in the test animals through gastrointestinal tract as well as the bulk calcium salt, without any possible disadvantage caused by processing. In addition, the absorption efficiency was improved by giving with water or meal to the animals.