Abstract

BIO-EQUIVALENCE STUDY OF TWO ORAL LEVAMISOLE-OXYCLOZANIDE FORMULATIONS (NILZAN® AND CLOZISTONE®) IN CALVES

Ashraf Elkomy* and Mohamed Aboubakr

ABSTRACT

The present study was designed to assess the comparative bio-equivalence of Nilzan® and Clozistone® in healthy calves after oral administration of both products in a dose of (7.5 mg levamisole Hcl/kg b.wt. and 15 mg oxyclozanide/kg b.wt). Ten calves were divided into two groups (each contains 5 calves). The first group was designed to study the pharmacokinetics of Nilzan ®, while the 2nd group was designed to study the pharmacokinetics of Clozistone®. Each calf in both groups was administered orally with (7.5 mg levamisole Hcl/kg b.wt. and 15 mg oxyclozanide/kg b.wt). Blood samples were obtained from the jugular vein and collected immediately before and at 0.15, 0.5, 1, 2, 4, 8, 12, 24, 36, 48, 72, 96, 120, 144, 168 and 192 hours after a single oral administration. The disposition kinetics of levamisole Hcl in Nilzan® and Clozistone® revealed that, the maximum blood concentrations [Cmax] were 1.15 and 1.04 μg/ml and attained at [tmax] of 1.21 and 1.22 hours, respectively. The disposition kinetics of oxyclozanide in Nilzan® and Clozistone® revealed that, the maximum blood concentrations [Cmax] were 9.81 and 9.11 μg/ml and attained at [tmax] of 17.98 and 18.29 hours, respectively. In conclusion: Clozistone® is bioequivalent to Nilzan® since the ratios of Cmax, AUC0-36 and AUC0-∞ (T/R) for levamisole Hcl were 0.90, 0.82 and 0.80 respectively and the ratios of Cmax, AUC0-192 and AUC0-∞ (T/R) for oxyclozanide were 0.92, 0.91 and 0.91 respectively. These are within the Bio-equivalence acceptance range. Nilzan® and Clozistone® are therefore bioequivalent and interchangeable in calves.

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