Example for extravascular route of drug administration

Concentration versus time data for administration of 500 mg dose of dmg are given in Table 6.5 and plotted on rectilinear and semilogarithmic paper 

The elimination half life and the elimination rate constant are obtained from the semiloga- 

The absorption rate constant and the absorption phase half life are obtained from the residual or feathering method. From the data in Fig. 6.20, the differences between the observed and the extrapolated plasma concentrations are calculated (Table 6.6, column 4) and are then plotted against time (column 1) on semilogarithmic paper. 

Please note that absorption rate constant is much greater than the elimination rate constant (Ka K). 

The apparent volume of distribution is calculated from the amount (mass) of absorbable drug at the site of administration at time t=0, (Xa)(=o This 

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