Placebo Formulation Development

Placebos that look the part

Drug product placebos are made to match the active product physical properties such as colour, shape and size in order to facilitate blinded clinical studies. In other cases, the placebo formulation may be identical to the active formulation with the obvious exception of absence of the active drug.

The placebo, in the case of a tablet, should possess the same shape and color compared to the active product. This presents a challenge to the formulator because many active pharmaceutical ingredients (API’s) are colored.  

Active and placebo are often film-coated with a non-functional coating that renders the two tablets virtually indistinguishable to patient and clinician alike.

Another challenge with tablets or powders is taste. Often active dosage forms have a significant taste with many drug substances tasting very bitter or leaving an unpleasant after-taste. Matching these attributes is critical but can be very difficult as any materials used must be approved for use in pharmaceutical products and assessment of such properties can be difficult to determine.

For liquid nasal drug products, the formulation of a placebo should consider factors such as pH, osmolality viscosity which may result in patients noticing a different effect on actuation of the device (e.g., spray characteristics) and in the sensory characteristics experienced after dosing.