title: Investigation of formulation variables affecting the properties of lamotrigine nanosuspension using fractional factorial design.
abstract: OBJECTIVE
  Lamotrigine (LMG) undergoes extensive hepatic metabolism upon oral administration and its absorption is affected in the presence of food. This study was aimed to develop nanosuspension of LMG and investigate its formulation characteristics using L(9) orthogonal array.
  
  
  METHODS
  Nanosuspension was prepared using emulsification-solvent diffusion method. All the formulations were subjected to in-vitro evaluation and the statistically optimized one was used for stability, scanning electron microscopic and differential scanning calorimetric studies.
  
  
  RESULTS
  Nanoparticles were spherical with little surface adsorbed drug. Formulation characteristics in terms of size, zeta potential, polydispersity index (PDI), entrapment efficiency (EE), drug content and in vitro drug release were consistent and within their acceptable range. All the batches provided a burst release profile during first 1 hr, followed by a controlled release extending up to 24 hrs. The values of n in Peppas model ranged between 0.2-0.4 for all the formulations indicative of Fickian release mechanism. The formulation remained reasonably stable up to 3 months. No interaction was observed among the drug and polymers.
  
  
  CONCLUSIONS
  Results of in vitro drug release studies suggested that nanosuspension might be used as a sustained delivery vehicle for LMG. Statistical analysis revealed that size of the nanoparticles was most strongly affected by stabilizer type while EE was influenced by the drug-to-polymer ratio.
authors.affiliation: Department of Pharmaceutics, Institute of Technology, Banaras Hindu University, Varanasi, India.
authors.forename: Mishra
authors.initials: M
authors.lastname: B
authors.forename: Arya
authors.initials: A
authors.lastname: N
authors.forename: Tiwari
authors.initials: T
authors.lastname: S