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 equiv 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 what are some B rating drugs?--warfarin, digoxin, synthroid..because dosage is very delicate to work. DESI---Drug Efficacy Study Implementation. older drugs(1938-1962) were tested in 1973 and most found ‘ineffective’. Insurance companies usually deny DESI drugs.