Polymorph Applications: The Mexican Approach

In the summer of 1998, Abbot Laboratories was forced to remove from the market a first crystalline form of its medicament ritonavir, a peptidomimetic drug used to treat HIV-1 infection, in favor of a second molecular form, or polymorph, which had different dissolution properties. The first molecule was originally formulated as an encapsulated solution in ethanol/water. After some time, this compound began to precipitate inside the capsule and consequently affected the oral bioavailability of the drug. Consequently, it was considered that the dissolution properties were not adequate and the medicament was not considered effective anymore. Therefore, Abbot was forced to look for a more favorable vehicle for this newly formed molecule, the more stable polymorph that showed a different solubility from the originally marketed product in order to be able to commercialize again this very important medicament.