2004/07/01 by I. B. Eltayeb · 1 citation
Medicine · Agricultural and Biological Sciences · Dentistry · Chemistry · #Diet and metabolism studies #Pharmacology and Obesity Treatment #Polysaccharides Composition and Applications #Amoxicillin #Arabic #Medicine #Gum arabic #Absorption (acoustics) #Dentistry #Traditional medicine #Antibiotics #Chemistry #Microbiology #Materials science #Biology #Food science #Linguistics #Philosophy
paper · doi:10.1093/jac/dkh372
openalex publication_date 2004/07/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/15
Sir, Gum arabic is defined as the dried gummy exudate from the stems and branches of Acacia Senegal, Willdenow or other related African species of Acacia (Leguminosae). It is a complex of very high molecular weight acidic heteropolysaccharides, which is widely used in pharmaceutical preparations as a suspending, demulcent, soothing and emulsifying agent. It was reported that gum arabic increased faecal nitrogen excretion, decreased urea production and decreased urea-nitrogen recycling. A study in animal models of experimental chronic renal failure showed that consumption of diets containing fermentable carbohydrates resulted in a greater faecal nitrogen excretion coupled with a reduction in serum urea concentration. In 1996, Bliss et al. reported that patients with chronic renal failure consuming a low-protein diet with 50 g gum arabic/day had a greater faecal nitrogen excretion and lower serum urea than patients consuming only a low-protein diet. Gum arabic is commonly prescribed for chronic renal failure in patients in Sudan; it results in decreased uraemia and reduces the frequency of dialysis, hence improving the quality of life. This study was conducted to investigate the effect of gum arabic on the absorption of amoxicillin, an antibiotic commonly prescribed for the treatment of urinary tract infections in patients with chronic renal failure. The study design was open and randomized; 24 healthy adult volunteers were allocated into four groups, six in each group. They gave written consent. None of them had a history of hypersensitivity to penicillin. Ethical approval was obtained from the Sudanese Ethical Committee. In the control group (group I), a single oral dose of amoxicillin capsules 500 mg (SmithKline Beecham, Brentford, UK) was administered after 12 h overnight fasting; in the test groups the same dose of amoxicillin was given after 12 h overnight fasting as follows: concurrently with gum arabic (group II); 2 or 4 h after gum arabic ingestion (groups III and IV, respectively). Blood samples (5 mL) were taken at 0, 0.5, 1, 1.5, 2, 4 and 6 h after amoxicillin administration. The serum was separated and stored at 708C until assay, which was within 1 week of collection. Determination of amoxicillin concentrations in the serum samples was carried out by a validated cup-plate agar diffusion method using Staphylococcus aureus (ATCC 25923) as the test organism. The standard inoculum of the test organism was prepared as described by Cheesbrough. The standard amoxicillin concentrations (0.25–8 mg/L) were prepared under aseptic conditions. All samples were assayed in quadruplicate in pooled human serum, and all the samples from each adult were analysed in parallel. The log of the known concentrations of amoxicillin standards was plotted against the mean inhibition zone diameter; it was linear over the concentration range studied with r > 0.98. The within-day precision of replicate samples of 0.5 mg/L (n = 6) and 5.0 mg/L (n = 6) gave relative standard deviations of 2.5% and 1.1%. The day-to-day relative standard deviations for the standards 0.5 and 5 mg/L (n = 6) were 3.2% and 1.2%, respectively. The assay detection limit in serum was 0.02 mg/L. Determination of the maximum peak concentration of amoxicillin (Cmax) and the time it was attained (Tmax) were obtained by visual inspection of individual patient data. The calculation of the terminal elimination rate constant (kel), terminal half-life (t1/2) and area under the curve (AUC0 –1) was conducted according to a non-compartmental model using WinNonlin Professional 4.1 (Pharsight Corporation, Cray, NC, USA). Statistical analysis was carried out with SPSS for Windows Version 12. Mean pharmacokinetic data were compared at a statistical significance level of P<0.05 and 95% confidence interval. The administration of amoxicillin concurrently with gum arabic (group II) and 2 h following the ingestion of gum arabic (group III) significantly decreased the Cmax from (mean ± S.D.) 7.31 ± 0.99 mg/L to 2.00 ± 0.67 mg/L and 3.19 ± 1.5 mg/L, respectively (Figure 1), and the AUC0 –1 of amoxicillin from (mean ± S.D.) 21.34 ± 1.85 mg·h/L to 4.56 ± 1.45 mg·h/L and 10.97 ± 3.99 mg·h/L, respectively when compared with the control group (P < 0.05). In group IV, the Cmax and AUC0 –1 were not significantly different from those in the control group. The Tmax was not significantly different in the four groups; it was (mean±S.D.) 2.00±0.00, 1.67±0.26, 1.75±0.27 and 1.83±0.41 h in