Stable sugar and sugar-free suspensions of pretomanid

BACKGROUND: Pretomanid (PMD) tablets are indicated as part of a combination regimen for the treatment of adults with pulmonary extensively drug-resistant, treatment-intolerant or non-responsive multidrug-resistant TB. No commercial liquid formulation is currently available for patients unable to swallow these tablets.OBJECTIVE: To develop stable extemporaneous liquid formulations of PMD that can be stored at room temperature or 30°C for at least 4 weeks.METHODS: Crushed PMD tablets were formulated into 20 mg/mL suspensions in a simple syrup and sugar-free formulation. The PMD formulations were stored at room temperature and at 30°C for 30 days in dispensing bottles. Appearance, pH, potency and microbial counts of the suspensions were determined on Days 0, 15 and 30.RESULTS: The potency of PMD remained at 99.7-103.4% of the theoretical concentration in each formulation. The appearance, pH and microbial count did not change during the 30-day storage period. Simple syrup formulations did not require preservatives for microbial stability.CONCLUSIONS: PMD oral suspension formulations in simple syrup or in sugar-free vehicle were easily prepared by utilising commonly available equipment and ingredients and were stable for 30 days. These formulations are appropriate alternatives for patients with swallowing difficulties.