title: Multilayered membrane-controlled microcapsules for controlled delivery of isoniazid.
abstract: OBJECTIVE
  Layer-by-layer (LbL) deposition of polyelectrolytes (PEs) has received a great attention in the area of drug delivery due to its simplicity and versatility. This research was aimed to develop multilayered microcapsules through LbL deposition of chitosan (CHI) and sodium alginate (NaALG) and utilize them as vehicle for controlled delivery of isoniazid (INH).
  
  
  METHODS
  CaCO(3) particles, prepared by colloidal crystallization of CaCl(2) and Na(2)CO(3) solutions, were used as micro-templates for LbL deposition of CHI and NaALG. Subsequent to the deposition, templates were decomposed to obtain hollow microcapsules. Prepared microcapsules were subjected to physicochemical evaluations, drug release and stability studies.
  
  
  CONCLUSIONS
  Though CaCO(3) particles possessed a rough and irregular surface, prepared hollow microcapsules were spherical in shape, having smooth surface and regular thickness. Following deposition of each layer, alternating values of zeta potential were observed, indicating the formation of multilayered films. Microcapsules with 5 bilayers, i.e. (CHI/NaALG)(5) provided 39% entrapment efficiency and exhibited a controlled release behavior, lasting up to 24 hrs. An improvement in drug release rate and stability profile of the formulation was observed by increasing the number of deposition steps and performing the crosslinking of polyelectrolytes. This study showed that the prepared formulation could promisingly be utilized as controlled delivery vehicle for INH.
authors.affiliation: Department of Pharmaceutics, Institute of Technology, Banaras Hindu University, Varanasi (U.P.), India.
authors.forename: S
authors.initials: S
authors.lastname: Tiwari
authors.forename: B
authors.initials: B
authors.lastname: Mishra