Scanning Electron Microscopy as an Analytical Tool for Particle Size Distribution and Aspect Ratio Analysis of Ciprofloxacin Mucoadhesive Polymeric Suspension

Abstract

Two types of mucoadhesive suspension of Ciprofloxacin were formulated by taking Carbopol934 and Carbopol940 polymers. The morphologies and mechanical properties of the resultant formulations were investigated. The dispersion of particle was observed using Scanning electron microscopy (SEM) techniques. The particle size distribution (PSD) and aspect ratio (AR) of particles in the polymeric suspension were obtained from SEM image analysis. It was found that SEM imaging displays directly the micron level dispersion of particles in polymeric formulation. The technique has significant potential for characterizing such formulation, having some advantages over „traditional‟ transmission electron microscopy in terms of generating representative data in a realistic timescale. Considering graphical analysis, the maximum particle size range for formulation containing Cipro and C934 is between 10 and 15 μm but in case of Cipro and C940, it is 5 to 10 μm. In the rod-like particles whose shapes are characterized by the two major and minor lengths of the particle, the length/width ratios are satisfactorily consistent with the aspect ratio value evaluated from the instrumental measurements. Formulation containing Cipro and C934 is more stable because it has lesser standard deviation and co-efficient of variation in aspect ratio analysis. The PSD and AR distribution and degree of dispersion in the formulation give insights into the modification of mechanical properties of the mucoadhesive formulation studied.