Novobiocin calcium salt

The sodium or potassium salts of weak acids have higher absorption rate than those of acids themselves. For example, the biological activity of sodium salt of novobiocin (weak acid) is twice as compared to its calcium salt, and about 50 times larger in comparison to its free acid. 

Examples of the use of soluble salts to increase drag absorption include novobiocin, in which the bioavailability of the sodium salt of the drag is twice that of the calcium salt and 50 times that of the free acid. 

The enolic hydroxyl group on the coumarin moiety behaves as a rather strong acid (pKa 4.3) and is the group by which the commercially available sodium and calcium salts arc formed. The phenolic -OH group on the benzamido moiety also behaves as an acid but is weaker than the former, with a pKa of 9.1. Disodium salts of novobiocin have been prepared. The. sodium salt is stable in dry air but loses activity in the presence of moisture. The calcium salt is quite water insoluble and is used to make aqueous oral suspensions. Because of its acidic characteristics, novobiocin combines to form salt complexes with basic antibiotics. Some of the.se saits have been investigated for their combined antibiotic effect, but none has been placed on the market, as they offer no advantage. 

Novobiocin is marketed under the following trade names Albamydn, Biotexin, Cathocin, Cathomycin, Inamycin, Spheromycin, Vulcamycin and Vulkamycin. The antibiotic is soluble in aqueous solution above pH 7-5 [7] and in polar organic solvents. It is stable in the dark, but is slightly light-sensitive (7]. In practice, it is used either as the mono- or di-sodium salt or as the calcium salt. 

Incompatibilities Do not mix IV minocycline before or during administration with any solutions containing the following Adrenocorticotropic hormone (ACTH), aminophylline, amobarbital sodium, amphotericin B, bicarbonate infusion mixtures, calcium gluconate or chloride, carbenicillin, cephalothin sodium, cefazolin sodium, chloramphenicol succinate, colistin sulfate, heparin sodium, hydrocortisone sodium succinate, iodine sodium, methicillin sodium, novobiocin, penicillin, pentobarbital, phenytoin sodium, polymyxin, prochlorperazine, sodium ascorbate, sulfadiazine, sulfisoxazole, thiopental sodium, vitamin K (sodium bisulfate or sodium salt), whole blood. 

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