Bioequivalence of generic aerosol bronchodilators: what are the issues?

I have attempted to address some critical issues relating to the introduction of generic aerosol bronchodilators in Canada. I approached Genpharm to obtain information on the data submitted to the HPB, including the number of subjects involved, but the company refused to divulge this information because it was concerned about the use of such information by its competitors. In addition to the in-vitro testing conducted by the HPB, should a single pharmacodynamic study be sufficient to demonstrate the safety and efficacy of a drug that serves such a critical role in the prevention of serious illness and possibly death? If so, what will constitute the minimum requirements for the design of such a study? In general, what should be the minimum standards required for safety, efficacy and bioequivalence of aerosol bronchodilators? The next phase rests with the provincial governments. What criteria will they use to determine whether a generic aerosol bronchodilator will be considered bioequivalent? It is essential that the criteria for bioequivalence be developed by experts, and ideally those criteria should be agreed upon and accepted by federal and provincial regulatory bodies before a product is given the status of bioequivalence. Unless such a step is taken it will be difficult to have confidence that products can be considered interchangeable. The issue of interchangeability of aerosol bronchodilators demands immediate attention. Regulatory agencies are caught between those groups with vested interests on both sides. Since patients will either benefit or suffer as a consequence of regulatory decisions, action must be taken to ensure that the best decisions are made. Scientists, clinicians and government officials should convene as soon as possible to formulate a satisfactory approach to this problem of interchangeability. The medical and pharmaceutical professions need reliable information, and patients should not be denied less expensive generic drugs if it can be determined that they are comparable to the innovator's product.