Multilayered membrane-controlled microcapsules for controlled delivery of isoniazid

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]. CaCO[3] particles, prepared by colloidal crystallization of CaCl[2] and Na2CO[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. 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

Design of a controlled release liquid formulation of lamotrigine

Lamotrigine is a broad spectrum anticonvulsant drug widely used as mono- or adjunct- therapy in adults and children. The aim of this study was to develop controlled release liquid formulation of lamotrigine to improve bioavailability and compliance of pediatric and geriatric epileptic patients. Multiple [w/o/w] emulsion was prepared using one step emulsification technique. It was evaluated for entrapment efficiency [EE], morphology, zeta potential [ZP], polydispersity index [PI], rheology, thermal property, in vitro drug release behavior and stability. In vivo studies in albino mice were carried out using maximal electroshock seizure [MES] test and strychnine induced seizure [SIS] pattern test and results were compared with marketed formulation. The EE of the formulations varied from 84.37% to 98.11%. The ZP and PI values of the prepared batches were in the range of+23.46 to +28.07 and 0.256 and 0.365, respectively. Microscopic observation clearly indicated the stability of the emulsions during the storage period. All batches exhibited controlled in vitro drug release up to 12 hrs. Batch C11 exhibited significantly longer duration of protection of seizure in mice against MES and exhibited comparable efficacy in SIS as compared to the marketed formulation. Multiple emulsion of lamotrigine compared to the marketed tablet showed plasma drug concentration within therapeutic range for longer time and comparable efficacy