This document defines different types of drug equivalents and the processes used to determine equivalence. It discusses pharmaceutical equivalents which must have the same active ingredients and dosage form but inactive ingredients can vary. Bioequivalence describes products that have comparable absorption rates. A bioequivalence study compares the bioavailability of a drug to a standard and is considered equivalent if absorption is within 20-25% of the standard. The FDA determines therapeutic equivalence based on products being pharmaceutical equivalents, bioequivalent, adequately labeled and manufactured according to good practices.

1. equivalence
•pharmaceutical equivalents---drugs must have
same active ingredients, in same strength, in
same dosage form, same RofA. Inactive
ingredients can vary.
•pharmaceutical alternatives---they have same
moiety(chemistry) but different salts,esters.
tetracycline HCl vs tetracycline phosphate
•bioavailability----measures rate and extent to
which active ingredient is absorbed from a
dosage form and becomes available at site of
action.

2. equivalence
• bioequivalent drug products---describes pharm equip or pharm
alternative products that have comparable bioavailability when
studies done under similar experimental conditions. not much
difference in rate and extent of absorption.
• therapeutic equivalents---drugs must be pharmaceutical equ
and bioequivalent. FDA says drugs are equivalent if
• 1--safe and effective
• 2--pharm equ of same amount active ingredient and standard of
purity/quality
• 3—bioequivalent
• 4--- adequately labeled
• 5---in compliance with current good manufacturing practice
regulations.

3. bioequivalence study
• used to determine if a second drug is
bioequivalent to a standard drug. study
includes 24-36 healthy adults. standard drug is
measured in the person then second drug is
done. bioequivalence of results are 20%less to
25%over standard drug bioavailability.
• 20-25% range is clinically insignificant.

4. therapeutic equivalence ratings
• FDA determines the standard drug.
• this is called ‘orange book’
• you can use the book to determine if a product
has been tested or approved as their
equivalent.
• rating A = equiv approved B=not equiv or no
comparison found
• DESI---Drug Efficacy Study Implementation.
older drugs were tested in 1973 and most
found ‘ineffective’. Insurance companies
usually deny DESI drugs.