Bioavailability of 14 Nitrofurantoin Products

Meyer, Marvin C.; Slywka, Gerald W.A.; Dann, R.E.; Whyatt, Philip L.

doi:10.1002/jps.2600631105

Cited by 37 publications

(5 citation statements)

References 6 publications

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“…In man, about 40% of nitrofurantoin is excreted in the urine unchanged. 12 A relationship was demonstrated in man between blood levels of nitrofurantoin and its rate of urinary excretion. l1 Hence, the urinary excretion of nitrofurantoin provides a valid estimate for the determination of its absorption 20 and, consequently, was adopted by us.…”

Section: Resultsmentioning

confidence: 99%

Effect of magnesium trisilicate on nitrofurantoin absorption

Naggar

Khalil

1979

Clin Pharma and Therapeutics

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In vitro adsorption studies revealed that for an identical initial concentration of nitrofurantoin, magnesium trisilicate exhibited the greatest adsorptive capacity with bismuth oxycarbonate, talc, kaolin, and magnesium oxide exhibiting intermediate adsorptive powers, while aluminum hydroxide and calcium carbonate exhibited low or no adsorption properties. Trials to elute the drug with acidic or alkaline solution were unsuccessful. The in vivo absorption characteristics of nitrofurantoin and nitrofurantoin-magnesium trisilicate combination were evaluated in 6 healthy males. Administration of magnesium trisilicate with nitrofurantoin reduced the rate and extent of its excretion reflecting decrease in both rate and extent of absorption. The time during which the drug concentration in the urine was above the minimum effective concentration of 32 microgram/ml was also significantly reduced after administration of the antacid.

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Section: Resultsmentioning

confidence: 99%

Effect of magnesium trisilicate on nitrofurantoin absorption

Naggar

Khalil

1979

Clin Pharma and Therapeutics

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“…Such results in no way imply equivalent effect under in vivo conditions, no adequate correlation between the two parameters having been found by Meyer et al (1974) for a series of nitrofurantoin products including MacrodantinB capsules. No official requirements exist for nitrofurantoin in capsules, thus the fact that the t60 values are somewhat in excess of the maximum 60% prescribed for tablets is of minor importance.…”

Section: Release Ratementioning

confidence: 86%

Extemporaneous Reduction of Commercial Capsule Dosage-Macrodantin ®

Dingwall

Karanjah

1977

J Clin Pharm Ther

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“…After a single oral administration of 50 or 150 mg nitrofurantoin to healthy male volunteers years old, 63-96 kg), the terminal elimination half-life was 1 .2 or 1.7 hours, respectively (Liedtke et al, 1980). Intravenous administration of 50 mg nitrofurantoin (male, [25][26][27][28][29][30][31][32][33][34][35] A decrease in urine pH increased the half-life, which suggests that changes in pH may influence dissolution, bioavailability, and/or the rate of excretion in humans (Bron et al, 1979 was also influenced by the presence and size of the macrocrystals in the formulation (Bates et al, 1974;Meyer et al, 1974). During conditions of renal impairment, nitrofurantoin excretion is greatly diminished (Kunin, 1972).…”

Section: Absorption Metabolism and Excretionmentioning

confidence: 99%

NTP technical report on the toxicology and carcinogenesis studies of nitrofurantoin (CAS no. 67-20-9) in F344/N rats and B6C3F mice (feed studies) / National Toxicology Program.

1989

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Nitrofurantoin was studied and evaluated because of its widespread use as a drug for treating urinary tract infections in humans, its structural relationship to known carcinogenic 5-nitrofuran compounds, and the lack of adequate studies to assess its carcinogenicity Toxicology and carcinogenesis studies of nitrofurantoin were conducted by administering nitrofurantoin (greater than 99% pure) in feed to groups of F344/N rats and B6C3Fi mice of each sex for 14 days, 13 weeks, or 2 years. Fourteen-Day and Thirteen-Week Studies: None of the rats (at dietary concentrations up to 20,000 ppm) died before the end of the 14-day studies. Rats that received 5,000, 10,000, or 20,000 ppm lost weight. Four of five male and 4/5 female mice that received 10,000 ppm and 1/5 females that received 5,000 ppm nitrofurantoin died before the end of the studies. Mice that received 5,000 ppm and male mice that received 10,000 ppm lost weight. In the 13-week studies, final mean body weights of rats that received 2,500, 5,000, or 10,000 ppm were 10%, 34%, or 47% lower than that of the controls for males and 15%, 31%, or 41% lower for females. Feed consumption by dosed and control rats was generally similar. Degeneration of the germinal epithelium of the seminiferous tubules of the testis was observed in male rats that received 2,500 to 10,000 ppm nitrofurantoin. Necrosis of the ovarian follicles was observed in 8/10 female rats that received 10,000 ppm, in 3/10 females that received 5,000 ppm, and in 1/10 that received 2,500 ppm. For mice, final mean body weights of the 5,000-ppm groups were 13% lower than that of the controls for males and 15% lower for females. Two of 10 male mice that received 5,000 ppm and 1/10 males that received 300 ppm died before the end of the 13-week studies. Estimated feed consumption was similar for dosed and control groups. Degeneration of the germinal epithelium of the testis was observed in males that received 1,300 to 5,000 ppm; necrosis of the ovarian follicles was observed in females that received 5,000 ppm but not in the lower dose groups. Necrosis of the renal tubular epithelium was observed in 2/9 males that received 5,000 ppm. Based on these results, 2-year studies of nitrofurantoin were conducted by feeding diets containing 0, 1,300, or 2,500 ppm nitrofurantoin to groups of 50 male F344/N rats and to groups of 50 male and Nitrofurantoin, NTP TR 341 PEER REVIEW PANEL The members of the Peer Review Panel who evaluated the draft Technical Report on nitrofurantoin on July 14, 1987, and on April 18, 1988, are listed below. Panel members serve as independent scientists, not as representatives of any institution, company, or governmental agency. In this capacity, Panel members have five major responsibilities: (a) to ascertain that all relevant literature data have been adequately cited and interpreted, (b) to determine if the design and conditions of the NTP studies were appropriate, (c) to ensure that the Technical Report presents the experimental results and conclusions fully and clearly, (d) to judge the...

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Bioavailability of 14 Nitrofurantoin Products

Cited by 37 publications

References 6 publications

Effect of magnesium trisilicate on nitrofurantoin absorption

Effect of magnesium trisilicate on nitrofurantoin absorption

Extemporaneous Reduction of Commercial Capsule Dosage-Macrodantin ®

NTP technical report on the toxicology and carcinogenesis studies of nitrofurantoin (CAS no. 67-20-9) in F344/N rats and B6C3F mice (feed studies) / National Toxicology Program.

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