Influence of honey on orally and intravenously administered diltiazem kinetics in rabbits.

Effect of honey on plasma concentration of diltiazem after oral and intravenous administration in rabbits, has been studied. For oral study, single dose of diltiazem (5 mg/kg, p.o.) along with saline was administered to New Zealand white rabbits (n=8). Blood samples were collected at 0, 0.25, 0.5, 0.75, 1, 1.5, 2, 3, 4, 6 and 8 hr after drug administration from marginal ear vein. After a washout period of one week, diltiazem was administered with honey (2.34 ml/kg; p.o.) and the blood samples were collected as above. To the same animals honey (2.34 ml/kg; p.o.) was continued once daily for 7 days. On 8th day, honey and diltiazem were administered simultaneously and blood samples were collected at similar time intervals as mentioned above. For intravenous study the pharmacokinetic was done in each animal on two occasions. The first study was done after single dose administration of diltiazem (5 mg/kg; i.v.) along with saline (2.34 ml/kg; p.o.). Blood samples were collected at 0, 0.083, 0.25, 0.5, 0.75, 1, 1.5, 2, 3, 4 and 6 hr after i.v. diltiazem administration. The same animals were treated with honey (2.34 ml/kg; p.o.) for seven days. On day 8, the second study was carried out with single dose i.v. administration of diltiazem along with honey (2.34 ml/kg; p.o.) and blood samples were collected. In the oral study, single dose administration of honey decreased the AUC and Cmax of diltiazem associated with significant increase in clearance and volume of distribution when compared to saline treated group. After one week administration of honey, diltiazem kinetic data showed further reduction in AUC and Cmax and increase in clearance and volume of distribution. In the i.v. study also, multiple dose administration of honey significantly reduced the AUC and increased the clearance value of diltiazem. The results suggest that honey may decrease the plasma concentration of diltiazem after its oral or i.v. administration in rabbits.

Effect of honey on carbamazepine kinetics in rabbits.

The study was undertaken to determine the effect of honey on carbamazepine kinetics in rabbits. The study was done on three occasions in each animal. Study 1 was carried out after single dose administration of carbamazepine (80 mg/kg, po), along with saline (2.34 ml/kg, po). After a wash out period of one week, the second study was carried out by co-administration of carbamazepine with honey (2.34ml/kg, po). After this, the animals continued to receive honey (2.34ml/kg, po), once daily, for 7 days. On the eighth day of honey treatment, the carbamazepine kinetics was studied again. Pharmacokinetic analysis revealed that single as well as multiple dose honey treatment showed a significant decrease in area under the plasma time concentration curve (AUC) when compared with saline treated control. A significant increase in the clearance (CL/F) rate of carbamazepine was observed only after multiple dose honey treatment. Both single and multiple dose honey treatment did not show any significant effect on other pharmacokinetic parameters like t1/2, Cmax, Tmax and Vd when compared with saline treated group. Data thus obtained suggested that honey decreases the bioavailability of carbamazepine.

Effect of two types of Indian breakfast on bioavailability of cefuroxime axetil.

BACKGROUND & OBJECTIVES: The oral bioavailability of cefuroxime axetil is enhanced by food. This study was done to compare the effect of two types of Indian breakfast on the bioavailability of cefuroxime axetil in healthy volunteers. METHODS: Eight healthy male volunteers participated in the crossover study. Subjects were randomized to receive either one of the two types of breakfast, Diet-A or Diet-B, 10 min before single dose of 500 mg cefuroxime axetil. After a washout period of one week the study was repeated with the other type of diet. Diet-A included idly with chutney. Diet-B included poori and dal-fry. Blood samples for pharmacokinetic analysis were obtained prior to dosing and at 0.25, 0.50, 0.75, 1.0, 1.5, 2.0, 2.5, 3.0, 4.0, 5.0, 6.0 and 8.0 h following dosing and urine collections were done for 8 h. The serum and urine samples were assayed by using HPLC. RESULTS: The AUC and Cmax were significantly increased after oral administration of cefuroxime axetil with Diet-B, when compared to Diet-A (P < 0.01 and P < 0.02 respectively). The values of apparent absorption rate constant, lag-time, Tmax and t1/2 beta for the two regimens were not significantly different. The volume of distribution and plasma clearance for cefuroxime were significantly lower (P < 0.02, P < 0.001 respectively) in the regimen with Diet-B. The 8 h urinary recovery of cefuroxime was 16.59 and 28.44 per cent (P < 0.005) with Diet-A and Diet-B respectively. INTERPRETATION & CONCLUSIONS: The administration of cefuroxime axetil with poori and dal-fry may enhance the bioavailability when compared with idly and chutney.