Antibiotic potency

AH steps of manufacture are monitored for antibiotic potency, purity, stabiUty, and bioavailabihty by quaUty control methods. In addition, each batch of bulk powder and each lot of finished pharmaceutical dosage form must be certified by the FDA. During all stages of manufacture the FDA requires compliance with specified standards. 

When tested for antibiotic potency against Bacillus cereus var. mycoides ATCC 9634 (diffusion method), the product is shown to present an antibiotic potency equivalent to 97% of the tetracycline present therein. 

In common clinical practice, in our hospital, the protection of fluoroquinolone injections during administration does not appear necessary. Visible radiation sources did not reduce the antibiotic potency of fluoroquinolones, under the conditions of our experimental studies. No experimental studies on the exposure of infusion solutions to sunlight were performed. 

The antibiotic potency toward numerous organisms and the toxicity of dihydrostreptomycin differed but slightly from those of streptomycin. The former was not inactivated by carbonyl reagents... 

It has been shown, and this seems to be a rule for pro-drugs, that pivampicillin and bacampicilhn are inactive per se, the antibiotic potency appearing only in vivo after the release of free ampiciUin. 

Benzylpenicillinic Acid. 3,3>Dimerhyf-7-oxo-6-[tphenylacetyllamino]-4-th ia-l-azabicyclo 3.2.0]heptane-2-carboxylic acid free benzyl penicillin free penicillin G free penicillin II. C,jHI8Nj04S mol wt 334.38, C 57.47%, H 5.43%, N 8.38%, O 19.14%, S9,59%. Obtained by extraction at ice temp of the acidified (pH 2) aq soln of sodium benzyl -penicillin with ether Or chloroform. Shows correct analytical composition only it moisture is excluded completely during iis isoln from the ether extract (by lyophilizing from benzene). When kept dry the acid retains its antibiotic potency for limited periods, bui it is rapidly inactivated by small amounts of water. The product formed on slow inactivation by moisture seems to be benzylpenicilloic acid, cf. Clarke et [., The Chemistry of Penicillin (Princeton, 1949). Prepn of methyl ester Dan. pet. 85,976 (1958 to Leo Pharm.). Pharmacokinetics in humans M. Barza, L. Weinstein, Clin. 

This procedure was applied to the syntheses of pentabromo- and pentachloro-pseudilin. Pentabromopseudilin (20) was isolated from Pseudomonas bromoutilis [32, 33] and amarine species of Chromobacterium [34]. Pentabromopseudilin (20) is a highly active antibiotic and also shows anti-tumor and phytotoxic activity [34, 35]. Pentachloropseudilin (23) was first isolated from an Actinoplanes strain (ATCC 33002) [36]. Pentachloropseudilin (23) has a lower antibiotic potency than pentabromopseudilin (20). 

To increase the ability of broad-spectrum peptide antibiotics to differentiate bacteria from mammalian cells, a focused library of tyrocidine analogs was synthesized based on known structure-activity relationship information (Figure 11.33). Significant side-chain changes of most constituent residues of the tyrocidine template result in the loss of antibiotic potency or the... 

Nugrahani I, Asyarie S, Soewandhi SN, Ibrahim S (2007) The antibiotic potency of amoxicillin-clavulanate co-crystal. Int J Pharm 3 475 81... 

Apparently, the high antibiotic potency and oral activity of 3-meth-oxycephalosporins provided the impetus for collaboration between Ciba-Geigy and Woodward Research Institute chemists to find new chemical routes to these agents using an inexpensive penicillin as starting material (Gosteli, 1976 Pfaendler et al., 1976 Scartazzini, 1977 W. Ger. Patent 2,506,330). This joint venture culminated in a more practical synthesis of the 3-methoxy-3-cephem nucleus (149). The sequence of reactions is outlined below ... 

Nomi, Nimi and Miyazaki (1966) reported that, upon incubation of supernatants from suspensions of S. griseus in glucose and sodium chloride, streptomycin production was observed. When the pH of the suspension fluid reached 6.8 to 7.0, the suspension was centrifuged and the supernatant removed. When the supernatant preparations were adjusted to a pH of about 9 2tnd shaken for 24 hrs. the antibiotic potency, as determined by bioassay, increased considerably. This increase in potency was inhibited by the addition of phosphate or EDTA to the supernatant solution. The system was heat labile above 50 C. 

A low molecular weight cationic component and a high molecular weight anionic component (as determined by chromatographic behavior) were fractionated from the supernatant by chromatography on Sephadex and cellulose exchangers. Neither fraction was active by itself but when the two fractions were combined, made alkaline (pH 8.5) and shaken for 24 hours a marked increase in antibiotic potency was observed. 

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