Redressing drugs for success: A review of dosage form solutions
The path for discovery and approval of novel drug candidates consists of numerous stages (Figure 1) and most candidates fail in pre-clinical phase.
The number of new drugs approved has reached its all-time low since the 1950s, with an estimated less than 12% of drugs that passed pre-clinical testing will be approved for human treatment (1-2). Furthermore, since the estimated costs of development for novel drugs from bench to market is $2.6 billion and takes approximately 15 years, it is no wonder that the pharma companies prefer to take “the path of least resistance” and opt for producing generics rather than novel drugs (2-3).
The main reasons why drug candidates fail to reach the market include low bioavailability and efficacy, toxicity and safety issues, poor metabolism and elimination (ADME) properties, as well as commercial and manufacturing issues, like patient compliance (Figure 1).
Reformulation of drugs into a different dosage form can address most of these issues and speed up the process for regulatory approval (1, 3-4, 6).
The ideal dosage form must provide the mechanism for the safe and convenient delivery of the optimum dosage to the desired site of action. Therefore choosing the right dosage form requires careful consideration of the physical, chemical, ...