Paper Title
Optimized Polymer-Lipid Hybrid Nanoparticles for Enhancing The Delivery of Ciprofloxacin

Abstract
The aim of this project is to optimize a polymer-lipid hybrid nanoparticles (PLN) system for the per-oral delivery of a model BCS class IV drug, ciprofloxacin, in an attempt to enhance its therapeutic performance by increasing both solubility and dissolution. Cipro-loaded PLN systems were prepared using a new direct emulsification-solvent-evaporation method. Number of factors including type of lipid, the ratio of lipid to polymer, and drug to polymer/lipid ratio were optimized to give low particle size and high cipro entrapment efficiency (EE%). The prepared PLN were evaluated for their particle size, polydispersity index, zeta potential, physical stability, and drug entrapment efficiency. The drug release profile and release kinetics were also evaluated. The prepared Cipro-loaded PLN showed average sizes in the range from 133.93±1.74 nm to 217.15±0.88 nm. All the prepared formulations showed polydispersity index values in the range of 0.02 to 0.25 indicating high particle size uniformity. The determined zeta-potential values were low and with varying charge type less than 2.5 mV. The entrapment efficiency was generally around 80%. The DSC thermograms of the Cipro-loaded PLN showed disappearance of the characteristic melting peak for Cipro after incorporation into PLN. This highly suggests the existence of the PLN loaded cipro in the amorphous state. The release profile of cipro from PLN formulae showed a uniform prolonged drug profile extended for a week from most formulations with a zero order kinetics. PLN systems has been successfully prepared with a new single-step method. The prepared Cipro-loaded PLN formulas showed low particle size and good size uniformity in addition to reasonably high EE%. Keywords - Dynasan, Polycaprolactone, Emulsification-Solvent-Evaporation, DSC, Polymer-Lipid Hybrid