Dissolution and stability of vigabatrin powder in water, fruit juice, milk, and infant formula

The prescribing information for the antiseizure medication Vigadrone® (vigabatrin) Powder for Oral Solution advises only reconstituting the powder in water prior to administration and discarding unused solution. However, caregivers may seek to reconstitute vigabatrin in a pediatric patient's preferred liquid rather than water to ease administration. We performed an in-use dissolution and stability study of vigabatrin powder reconstituted in 4 liquids-water, apple juice, whole milk, and infant formula-with testing performed 0, 24, and 48 h after preparation with storage at 2-8 °C in a capped, glass container. Vigabatrin reconstituted in each liquid was clear and free of visible particulates compared with matched drug-free liquid controls. In subsequent analyses using US Pharmacopeia (USP) procedures, high-performance liquid chromatography spectra and chromatograms for each sample solution matched the vigabatrin reference standard. At all time points, all sample solutions met USP-acceptance criteria of 95.0-105.0 % for product stability and USP-acceptance criteria for related substances/organic impurities testing for total impurities. Together, these results indicate that vigabatrin powder reconstituted in liquids other than water was stable for up to 48 h of refrigeration. This study provides useful information to help healthcare providers address real-world medication questions from caregivers.