Abstract
Purpose: :
Various protein molecules are being used in posterior segment eye diseases. Development of a nanoparticulate based formulation of protein molecule pose a major challenge for drug delivery scientist. Use of organic solvent, physical stress and lower entrapment efficiency are some of the major issues associated with development of nanoparticulate formulation of protein molecule. So, in the current work we have attempted to make nanoparticulate formulation of model basic protein molecule, lysozyme using hydrophobic ion pairing (HIP) complexation method. Nanoparticles were prepared using spontaneous solvent diffusion method.
Methods: :
HIP complex of lysozyme was prepared using dextran sulfate as complexing agent. HIP complex formation method was optimized by using various ratios of dextran sulfate. Effect of equilibrium time, pH of lysozyme solution and dissociation of complex was studied as well. Nanoparticles were prepared using spontaneous solvent diffusion method. PLGA 85:15 was used as a polymer. Nanoparticles were characterized for size, surface morphology and entrapment efficiency.
Results: :
HIP complexation resulted in more than 95% binding of Lysozyme with dextran sulfate. Equilibrium time had no effect on complexation of lysozyme with dextran sulfate. pH of lysozyme solution had significant effect on complexation efficiency with dextran sulfate. Nanoparticle size was highly dependent on the selection of solvent and ratio of PLGA polymer used in the preparation. More than 95% entrapment efficiency was obtained when ratio of HIP complex of lysozyme to PLGA 85:15 was used in 1:15. Prepared nanoparticles were round and smooth in surface.
Conclusions: :
Nanoparticles of basic protein molecule lysozyme was prepared without any physical stress and organic solvent. More than 95% of entrapment efficiency was obtained using spontaneous solvent diffusion method. HIP complexation approach and spontaneous solvent diffusion method can be very valuable method to prepare nanoparticulate formulation of various small and large macromolecules.
Keywords: retina • pH • protein structure/function