Controlled Delivery of Dutasteride Using Dissolvable Microarrays: Initial Formulation and In-vivo Evaluation

Dutasteride is prescribed as a once daily oral capsule for the treatment of symptomatic benign prostatic hyperplasia.

As an alternative and patient focused drug product, this laboratory evaluated the potential to deliver dutasteride in a controlled/sustained manner when formulated as a microarray. The low oral dose, low aqueous solubility and slow rate of elimination of dutasteride were considered ideal properties which may enable a once-weekly microarray option for patients.

The concept of sustained release was initially proven in mini-pigs whereby simple intradermal administration of a nano-milled dutasteride suspension (0.12 mg/kg) was associated with an exposure period of at least 1 month. Dissolvable microarrays were successfully manufactured using a nano-milled suspension and were administered to rats at doses up to 0.32 mg/kg.

In these studies, serum dutasteride was quantifiable for approximately 2 weeks following a single application. In-silico modelling of the rat data using a two-compartment intradermal model was conducted and predicted that, in humans, a once weekly dose of 2 mg, given as a microarray, could deliver cumulative and therapeutically relevant levels of dutasteride in a manner which is comparable to that observed with the current oral regimen. More on dissolvable microarrays