PK results from heat-stable formulation of ritonavir

Simon Collins, HIV i-Base

Pharmocokinetic data for three prototypes of a heat-stable, meltrex formulation of ritonavir, was presented by George Hanna from Abbott Laboratories. When the development of meltrex formulation lopinavir/r was underway, many clinicians and advocates were equally keen to see the same approach applied to ritonavir.

Long-term stability evaluations under a variety of temperature and humidity conditions and additional bioavailability studies are ongoing to guide selection of a formulation suitable for registration.

Although equivalence results presented at the meeting looked impressive, no one was lead to believe that there would be a short approval time for this formulation.

Scale up to commercial batches, FDA approval based on the 600mg once-daily original ritonavir approval, and then stability assessments which commonly test commercial batches for up to a year prior to approval, are some of the hurdles that need to be achieved.

This makes the timeline for possible approval still several years away.


Cai Y, Klein C, Roggatz U et al. Bioequivalence of pilot tablet formulations of ritonavir to the marketed soft gel capsule at a dose of 100 mg. Oral abstract 52LB.

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