Sustained release of transgenic human factor IX: preparation, characterization, and in vivo efficacy.

The current regimen of factor IX (FIX) injection is of an episodic format, which leads to limited efficacy. A sustained release dosage form is beneficial in terms of reducing the injection frequency and improving the therapeutic effectiveness. The aim of this study was to formulate a new microsphere form of a FIX-containing preparation to diminish these shortcomings.