New Alkaline-Stable Species for Selected Members of the Tetracycline Family

Metal-Gluconate Complexes

“…A number of applications of gluconic acid have been reported for stabilizing tetracycline (1,50,87,107,112).…”

“…These have involved complexation of zirconyl halides (87) as well as a number of complexes formed by the aluminum-gluconate-tetracycline system with the ions of calcium, antimony, cadmium, chromium, cobalt, copper, gold, iron, manganese, nickel, selenium, silver, strontium, tin, and zinc (112). Aluminum and copper ions have been used together with gluconic acid to stabilize tetracycline-type antibiotics (107). The addition of aluminum ion and gluconic acid is reported to permit a higher level of the antibiotic in the blood (1).…”

Metal-Acid Complexes with Members of the Tetracycline Family I

“…Enhanced Alkaline Stability.-The enhanced alkaline stability of aluminum-gluconate complexes with graduated amounts of calcium has been reported by Remmers el al. (6), where the incorporation of 1.0 or more molar parts of calcium into the complex markedly increased the alkaline stability of most, but not all, of the tetracycline antibiotics. Of those tested to date, only chlortetracycline is unusual since studies with this antibiotic have repeatedly failed to demonstrate greatly enhanced alkaline stability.…”

“…Disk diffusion studies performed on several microbiological media indicated that DMCTC-metal-acid complexes diffused as rapidly as uncomplexed DMCTC.HCl. 6 Blood Levels.-A thiid important property observed with selected metal-acid complexes is the enhanced blood levels obtained compared to levels resulting from salts of the corresponding uncomplexed antibiotic. Figure 2 shows blood levels obtained with DMCTC-aluminum-magnesium-gluconate (molar ratio 1:4:5:12) and DMCTC.HC1 when administered intramuscularly to dogs a t a level of 1.5 mg. antibiotic per pound of body weight.…”