PHARMACOLOGY

 SIGNIFICANCE OF BIOEQUIVALENCE ::

(1) It is a better and an alternate method for the evaluation of clinical efficacy and clinical inequivalences 

(2) It is a quantitative measure of bioavailability 

    Bioequivalence of a drug may be determined by evaluating following three parameters 

(1) Plateau level concentration 

(2) Time for the peak concentration 

(3) Area under the curve 

Therapeutic Equivalence ::

Pharmaceutical formulation that produce equal therapeutic effects are termed as therapeutically equivalent preparations While considering principles of bioavailability one assumes that the extent of drug effect is proportional to its serum concentrations This may not be true for all cases Likewise two preparations showing bioequivalence may not be therapeutically equivalent in other words the link between pharmacokinetics and pharmacodynamics may not always be simple Some drugs combine quickly with receptors and dissociate quickly e.g. sodium nitroprusside Some drugs combine with receptors but do not readily dissociate with action Such drugs show effects even if plasma concentration has fallen e.g. monoamine oxidase inhibitors like isocarboxazide in some cases drugs combine with receptors and irrespective of rate of association or dissociation set in certain a sequence of events which run on despite of falling plasma concentration e.g. corticosteroids 

        Thus therapeautic equivalence should be considered separately with bioavailability