title: Niosomal encapsulation of ethambutol hydrochloride for increasing its efficacy and safety.
abstract: BACKGROUND
  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.
  
  
  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.
  
  
  CONCLUSIONS
  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.
  
  
  CONCLUSIONS
  Encapsulation of ethambutol hydrochloride in niosomal formulations for the treatment of TB provides higher efficacy and safety compared with the free drug.
authors.affiliation: Department of Pharmaceutical Technology, National Research Centre (NRC) , Dokki, Cairo , Egypt .
authors.forename: Mohammed Shafik
authors.initials: MS
authors.lastname: El-Ridy
authors.forename: Soad Aly
authors.initials: SA
authors.lastname: Yehia
authors.forename: Mahfouz Abd-El-Megeid
authors.initials: MA
authors.lastname: Kassem
authors.forename: Dina Mahmoud
authors.initials: DM
authors.lastname: Mostafa
authors.forename: Essam Amin
authors.initials: EA
authors.lastname: Nasr
authors.forename: Marwa Hasanin
authors.initials: MH
authors.lastname: Asfour
mesh_terms: D000818:Animals; D000995:Antitubercular Agents / Q000008:administration & dosage* / Q000493:pharmacokinetics / Q000633:toxicity; D002626:Chemistry, Pharmaceutical; D003692:Delayed-Action Preparations; D016503:Drug Delivery Systems; D004355:Drug Stability; D004977:Ethambutol / Q000008:administration & dosage* / Q000493:pharmacokinetics / Q000633:toxicity; D006168:Guinea Pigs; D008081:Liposomes; D008168:Lung / Q000378:metabolism*; D051379:Mice; D013997:Time Factors; D014018:Tissue Distribution
chemical_list: D000995:Antitubercular Agents; D003692:Delayed-Action Preparations; D008081:Liposomes; D004977:Ethambutol
keywords: Biological evaluation; characterization; intracellular targeting; nano-drug delivery; tuberculosis