Effect of diminazine aceturate on the pharmacokinetic of a long acting oxytetracycline formulation in lactating goats

Oxytetracycline [OTC] and diminazene aceturate are commonly administered to diseased ruminants with mixed bacterial and protozoal infections. We were therefore interested in characterizing the pharmacokinetics of a new long acting OTC formulation after IV or IM administration, and whether concurrent administration of diminazene altered the pharmacokinetics. Ten clinically healthy lactating female Baladi goats were used in a sequential order. Goats received the treatments in sequential order with a 2 week wash out period between each study: 1] a single dose of OTC [30 mg/kg BW] by TV or TM injection in non-treated and diminazine aceturate pre-treated goats [3.5 mg/kg BW] 2 hours before OTC treatment. Blood, milk and urine samples were collected periodically and OTC concentration was assayed using a microbiological method. The extent of protein binding in serum and milk was determined using an in vitro ultra filtration method and assayed using the same method as serum Pharmacokinetic analysis indicated that serum OTC concentrations after IV administration could be fit to a two-compartment model, and that pre-treatment with diminazene aceturate increased serum OTC concentrations. Following IV injection [t[0.5] beta] was 25.9 +/- 5.1 and 24.5 +/- 2.7 hours, and [Vd[area]] was 22.0 +/- 0.8 and 23.7 +/- 0.4 L.kg[-1], in non-treated and diminazine pre-treated goats, respectively. The maximum OTC concentration after IM injection [1.25 +/- 0.02 micro g ml[-1] and 1.39 +0.04 micro g ml[-1] was obtained at 1.8 +0.3 hours and 2.4 +/- 0.4 hours in non-treated and diminazine pretreated goats, respectively. Moreover, effective milk concentrations were detected for 24 to 48 h, and effective urine concentrations were detected for 96 to 120 h after IM injection. The LA-OTC formulation was moderately bound to goat serum protein [46.0 +3.2% for OTC alone and 40.0 +/- 2.3% for OTC +diminazine]. The binding of the LA-OTC formulation was lower in milk [29.3 +/- 3.6%] than plasma. We conclude that concurrent administration of LA-OTC and diminazine aceturate alters the serum concentration-time profile and pharmacokinetics of a new long acting OTC formulation and could therefore potentially alter treatment efficacy

Impact of toxy-nil as antimycotoxin on the disposition kinetics of lincomycin in broiler chickens

Pharmacokinetics of lincomycin was studied following single intravenous [I.V.] and oral administrations [20 mg. kg -1 b. wt] in both control and toxy-nil medicated chickens. Lincomycin plasma concentration was determined by microbological assay method. Following I.V. injection, lincomycin plasma concentration versus time curve was best fitted a 2-compartment open model. Toxynil significantly decreased both the distribution and elimination half-lives of lincomycin from 0.28 +/- 0.01 and 1.27 +/- 0.06h in the control group to 0.19 +/- 0.006 and 0.95 +/- 0.04 h in toxy-nil medicated chickens, respectively. The volume of drug distribution at steady state [V dss] and the rate of its total body clearance [CL B] were significantly increased in toxy-nil medicated chickens [1.72 +/- 0.08 L.Kg -1 and 1.95 +/- 0.07 L.Kg -1.h -1 respectively] as compared with that in the control ones [1.38 +/- 0.05 L.Kg -1 and 0.85 +/- 0.03 L.Kg -1.h -1, respectively]. Following oral administration, the absorption half-life [t 1/2 ab]was significantly prolonged in toxy-nil medicated birds than in the control ones [0.22 +/- 0.016 and 0.163 +/- 0.0 13 h, respectively]. This associated with a significant decrease in the drug peak plasma concentration [3.54 +/- 0.24 micro g. ml -1] than in the control one [11.56 +/- 0.75 micro g.ml -l]. The systemic bioavailability [F] was significantly decreased from 73.25 +/- 5.08% in the control group to 38.25 +/- 2.89% in toxy-nil medicated one. In concomitant administration of lincomycin and toxy-nil in broiler chickens should be hindered, as the interaction between both significantly reduces lincomycin oral absorption and enhance its elimination which consequently decreases its therapeutic efficacy

Some pharmacological properties of lupinus termis seeds

The ethanolic extract, total alkaloid, flavonoid and saponin fractions of Lupinus termis seeds were prepared. These plant materials were pharmacologically tested for hypoglycemic and antiinflammatory activities in rats and for the antmicrobial effect against certain bacteria and fungi in vitro. The extract and the total alkaloids fraction of Lupinus termis seeds caused a significant hypoglycemic effect in both fasted and diazoxide-treated rats, whereas the total flavonoid and saponin fractions were devoid of this property. In alloxan diabetic rats, all tested plant material had no antidiabetic effect. Both the extract and the total saponins fraction of lupinus termis seeds evoked a marked anti-inflammatory effect as manifested by the significant decrease in thickness of the inflamed paw in rats after oral administration and local application. However, the total alkaloid and flavonoid fractions of the seeds were devoid of this activity when given orally. Results of antimicrobial study showed that both the ethanolic extract and total flavonoid and saponin fractions of Lupinus termis seeds caused pronounced antibacterial and antifungal effects against certain microorganisms in vitro. On the other hand, the total alkaloids fraction of the seeds had neither antibacterial nor antifungal activity against the selected microorganisms