Maha S Abd Elhafeez - Academia.edu (original) (raw)
Papers by Maha S Abd Elhafeez
Advances in Animal and Veterinary Sciences
Bacterial respiratory diseases cause economic casualties in rabbit industry. Tildipirosin injecti... more Bacterial respiratory diseases cause economic casualties in rabbit industry. Tildipirosin injection characterized by rapid onset and prolonged effect and the single injection manner can reduce stress from overuse. The study was intended to examine tissue depletion of tildipirosin macrolide antibiotic in 21 New-Zealand rabbits after single intramuscular injection at a dosage of 4 mg kg-1 b.wt. Three rabbits were massacred on the 1 st , 3 rd , 5 th , 7 th , 9 th , 15 th , and 21 st day after injection of tildipirosin. Specimens from muscle, kidneys, liver, and blood were occupied from massacred rabbits and analyzed for tildipirosin residues using simple, accurate and validated HPLC assay. Tildipirosin was extremely concentrated in kidneys followed by liver, whereas small amounts were found in the muscle. Tildipirosin remained within detectable limit till the 7 th day in muscle, 9 th day in serum and liver and till the 15 th day in kidneys after drug administration. According to the MRLs settled by regulatory organizations and EMA, medicated rabbits with tildipirosin must not be slaughtered before 4 days from drug injection to be safe for human consumption.
Egyptian Journal of Animal Health
A ntibiotics are extensively used in animal husbandry practices for the treatment of diseases. Fo... more A ntibiotics are extensively used in animal husbandry practices for the treatment of diseases. Four tetracyclines are commercially available as veterinary medicines, of which oxytetracycline (OTC), tetracycline (TC), chlortetracycline (CTC), and doxycycline (DOX). In the present investigation, a novel simple, sensitive, and inexpensive method of analysis was verified for tetracyclines by RP-HPLC system in bulk drug substance and pharmaceutical forms via two stationary phases (C8 & C18). The separation was attained on a 250 mm column length, 4.6 mm internal diameter, 5 µm particle size, C18 and C8 columns with a (55:25:20) 5% glacial acetic acid: acetonitrile: methanolic acid as elution solution at a 355 nm wavelength. The method was performed at a0.8 ml/m inflow rate. This method was applied without an extraction process. The method was validated following ICH and USP guidelines. It was proved to be reproducible and more economical due to the short retention time of less than 6 min by C8 column and 8 min by C18 column which enabled analysis of tetracycline pharmaceutical products with a relatively lower volume of mobile phase. The result of formulation analysis was statistically validated with a high recovery percentage. Furthermore, the developed method was free from the interference of excipients used in the formulation. The validated method was accurate, precise, linear, and reproducible. The data suggest the possibility of using the method in quality control laboratories with better routine analysis of tetracyclines in their dosage forms.
M ycotoxins existence in rabbit fodder has toxic effects on animal health. Mycotoxin binders are ... more M ycotoxins existence in rabbit fodder has toxic effects on animal health. Mycotoxin binders are feed supplements adsorb mycotoxins in the intestine to prevent oral mycotoxins from being absorbed. Concerns about an unspecified association with oral veterinary drugs were raised in 2010 by the European Food Safety Authority. This study evaluated the effect of dietary supplementation of esterified glucomannan yeast extract (0.1% for 15 days) as a mycotoxin binder (EGM) on doxycycline (DOX) bioavailability and residues in different rabbits tissues after oral administration at a dosage of 6 mg kg b.wt; single dose for oral bioavailability study and for 15 successive days for evaluation tissue residue of doxycycline. Pharmacokinetic investigation of DOX in group received DOX alone shows that AUC0−inf, Tmax and Cmax are diminished significantly when EGM is used with DOX as a feed additive. The 67% decline in AUC0−24 in the group fed EGM results in a significant decrease in oral bioavailabi...
Advances in Animal and Veterinary Sciences
Advances in Animal and Veterinary Sciences
Bacterial respiratory diseases cause economic casualties in rabbit industry. Tildipirosin injecti... more Bacterial respiratory diseases cause economic casualties in rabbit industry. Tildipirosin injection characterized by rapid onset and prolonged effect and the single injection manner can reduce stress from overuse. The study was intended to examine tissue depletion of tildipirosin macrolide antibiotic in 21 New-Zealand rabbits after single intramuscular injection at a dosage of 4 mg kg-1 b.wt. Three rabbits were massacred on the 1 st , 3 rd , 5 th , 7 th , 9 th , 15 th , and 21 st day after injection of tildipirosin. Specimens from muscle, kidneys, liver, and blood were occupied from massacred rabbits and analyzed for tildipirosin residues using simple, accurate and validated HPLC assay. Tildipirosin was extremely concentrated in kidneys followed by liver, whereas small amounts were found in the muscle. Tildipirosin remained within detectable limit till the 7 th day in muscle, 9 th day in serum and liver and till the 15 th day in kidneys after drug administration. According to the MRLs settled by regulatory organizations and EMA, medicated rabbits with tildipirosin must not be slaughtered before 4 days from drug injection to be safe for human consumption.
Egyptian Journal of Animal Health
A ntibiotics are extensively used in animal husbandry practices for the treatment of diseases. Fo... more A ntibiotics are extensively used in animal husbandry practices for the treatment of diseases. Four tetracyclines are commercially available as veterinary medicines, of which oxytetracycline (OTC), tetracycline (TC), chlortetracycline (CTC), and doxycycline (DOX). In the present investigation, a novel simple, sensitive, and inexpensive method of analysis was verified for tetracyclines by RP-HPLC system in bulk drug substance and pharmaceutical forms via two stationary phases (C8 & C18). The separation was attained on a 250 mm column length, 4.6 mm internal diameter, 5 µm particle size, C18 and C8 columns with a (55:25:20) 5% glacial acetic acid: acetonitrile: methanolic acid as elution solution at a 355 nm wavelength. The method was performed at a0.8 ml/m inflow rate. This method was applied without an extraction process. The method was validated following ICH and USP guidelines. It was proved to be reproducible and more economical due to the short retention time of less than 6 min by C8 column and 8 min by C18 column which enabled analysis of tetracycline pharmaceutical products with a relatively lower volume of mobile phase. The result of formulation analysis was statistically validated with a high recovery percentage. Furthermore, the developed method was free from the interference of excipients used in the formulation. The validated method was accurate, precise, linear, and reproducible. The data suggest the possibility of using the method in quality control laboratories with better routine analysis of tetracyclines in their dosage forms.
M ycotoxins existence in rabbit fodder has toxic effects on animal health. Mycotoxin binders are ... more M ycotoxins existence in rabbit fodder has toxic effects on animal health. Mycotoxin binders are feed supplements adsorb mycotoxins in the intestine to prevent oral mycotoxins from being absorbed. Concerns about an unspecified association with oral veterinary drugs were raised in 2010 by the European Food Safety Authority. This study evaluated the effect of dietary supplementation of esterified glucomannan yeast extract (0.1% for 15 days) as a mycotoxin binder (EGM) on doxycycline (DOX) bioavailability and residues in different rabbits tissues after oral administration at a dosage of 6 mg kg b.wt; single dose for oral bioavailability study and for 15 successive days for evaluation tissue residue of doxycycline. Pharmacokinetic investigation of DOX in group received DOX alone shows that AUC0−inf, Tmax and Cmax are diminished significantly when EGM is used with DOX as a feed additive. The 67% decline in AUC0−24 in the group fed EGM results in a significant decrease in oral bioavailabi...
Advances in Animal and Veterinary Sciences