(Re)Formulating rotigotine: a potential molecule with unmet needs

Abstract

Rotigotine (RTG), a non-ergoline D3/D2/D1 dopamine receptor agonist, is indicated for Parkinson’s disease (PD) and restless leg syndrome (RLS)[1]. It also has an affinity toward serotonin (5-HT1A, 5-HT2B, and 5-HT7) and α2B-adrenergic receptors [2]. At present, RTG is commercially available as an extended-release transdermal patch since it shows poor oral bioavailability because of its extensive first-pass metabolism [3]. Although successfully marketed, RTG potential has not been fully utilized owing to the challenges and drawbacks associated with its delivery. For instance, the absolute bioavailability from the transdermal patch is reported to be only 37%. The absolute bioavailability of transdermal patches varies depending on its site of application [3]. Moreover, RTG forms crystals in the transdermal patch upon storage and shows variations in drug release and bioavailability as well