ABSTRACT
CONTEXT: Tuberculosis (TB) is a worldwide health concern. In 2011, about 8.7 million new cases developed TB and 1.4 million people died from it. OBJECTIVE: Enhancement of ethambutol hydrochloride activity and safety in treatment of TB through niosomal encapsulation. MATERIALS AND METHODS: Niosomes were prepared by the thin-film hydration method. They were characterized, investigated for in vitro release, lung disposition and in vivo biological evaluation. RESULTS: Entrapment efficiency of ethambutol hydrochloride ranged from 12.20% to 25.81%. Zeta potential values inferred stability of neutral and negatively charged formulations. In vitro release was biphasic. Lung targeting was increased by niosomal encapsulation. Biological evaluation revealed superiority of niosomal ethambutol hydrochloride over the free drug. DISCUSSION: Neutral and negatively charged niosomal vesicles are dispersed homogenously unlike positively charged vesicles. Niosomal encapsulation results in controlled drug release. Niosomal formulations targeted more drugs to mice lungs for a prolonged period of time resulting in: decreased root-specific lung weight, bacterial counts in lung homogenates and optimizing pathological effect on guinea pigs lungs, livers and spleens. CONCLUSION: Encapsulation of ethambutol hydrochloride in niosomal formulations for the treatment of TB provides higher efficacy and safety compared with the free drug.
