Pharmacokinetics of Tamoxifen (Nolvadex) of Tamoxifen was investigated following an oral dose of 20 mg tablet in eight healthy female volunteers. Plasma samples were collected at different time intervals following drug administration, and analyzed for Tamoxifen concentration by HPLC method. The mean ± SE (mean ± standard deviation) of Tamoxifen at 0.5 hour was calculated as 4.87 ± 0.82 ng/ml which shows drugs penetration in the blood immediately after oral dose. The minimum effective concentration of Tamoxifen is 30 ng/ml, that is 40ng/mL in another study (Santana et al., 2008). With the passage of time it reached at normal concentration at 2 hours 7.50 ± 0.13 ng/ml and then declined and at last became 26.1 ± 0.15 ng/ml at eight hours. But the Tamoxifen minimum effective concentration was maintained at 6 hours where it reaches at maximum concentration 32.04 ± 0.44 ng/ml. The minimum effective concentration of the Tamoxifen in plasma was persistent during the eight hours (0.05-8.0 hours) that will assure its pharmacotherapeutic action.
Cmax is defined as the maximum concentration of drug achieved in the plasma. The peak plasma concentration is the factor which depends on both the rate of drug absorption and extent of drug absorption in the plasma. If less time is required for the drug absorption then maximum drug concentration achieved very
…show more content…
The value of the distribution phase constant of Tamoxifen 20 mg after oral administration with mean ± S.E was 0.120 ± 0.09 hr-1 under the ranged of 0.04- 0.125 hr-1. The extrapolated zero time drug concentration of distribution phase of present study ranged from 0.07-0.19 μg/ml with mean ± S.D was 0.14 ± 0.02 μg/ml and distribution half-life of 5.26 ±