The Drug Formulary Commission as authorized by M.G.L. c. 17, s. 13 and by regulation at 105 CMR 720.050 recommends whether drug products shall be placed on the Massachusetts Additional List of Interchangeable Drugs. According to statute and regulation, pharmaceutically equivalent drug products must meet one of two criteria in order to be considered by the Commission for addition to the list:
  • bioequivalence may be essential and has been established; or
  • bioequivalence is not essential.

Bioequivalence of drug products is defined at 105 CMR 720.021 as "drug products whose rate and extent of absorption do not show a significant difference when administered at the same molar dose of therapeutic moiety under similar conditions." Bioequivalence is considered essential when "bioinequivalence would have therapeutic significance i.e. use of different brands of the same drug product or different batches of the same drug would result in therapeutic failure or a hazard to the patient. This is most critical in drug products with a narrow therapeutic-toxicity range (i.e. the therapeutic and toxic concentrations of the drugs are similar) which requires careful patient titration and monitoring for safe and effective use."

Therapeutic equivalence of drug products is defined at 105 CMR 720.030 as drug products which

  • are pharmaceutically equivalent (same active ingredients, identical in strength, concentration, dosage form and route of administration);
  • meet applicable standards for strength, quality, purity and identity; and
  • are bioequivalent because (a) they present no known or potential bioequivalence problem and meet an acceptable in vitro standard; or (b) if they do present a known or potential bioequivalence problem, they are shown to meet an appropriate bioequivalence standard matching both rate and extent of absorption, are adequately labeled and are manufactured in compliance with current Good Manufacturing Practice regulations.

Factors For Consideration

To determine whether drug products are bioequivalent or therapeutically equivalent and should be interchangeable, the Commission should consider the following factors:

  • pertinent data
  • USP and supplements
  • pertinent FDA listings
  • other state formularies
  • formularies of Massachusetts hospitals
  • data submitted by manufacturers
  • chemical and laboratory testing data
  • clinical evidence.


Regulations at 105 CMR 720.060 specifically exclude the following categories of drugs from consideration by the DFC:

  • bioequivalence is essential but not established
  • subject of patent rights
  • single source.

This information is provided by the Drug Control Program within the Department of Public Health.