In-vitro Physicochemical properties and antibacterial activity of Ciprofloxacin-carrageenan inhalable microspheres

This study's aim is to characterize aerosolization properties of ciprofloxacin loaded kappa-carrageenan microspheres for pulmonary delivery. Ciprofloxacin-carrageenan microspheres by ionotropic gelation were prepared and characterized for moisture content, yield, drug loading, efficiency, aerosolization properties, activity and stability. Characteristics showed spherical microspheres, smooth and size below 2µm, moisture content of <4%, yield of 46-58%, encapsulation efficiency of 40-94% and loadings of 25-37%. Optimum microspheres containing 1%w/v carrageenan and 0.6% w/v KCl, showed 58% yield, 38% loading 94.5% efficiency with slowest release. The fine particle fraction was 30%. The increased concentration of polymers from 0.5% to 1% and crosslinker from 0.2% to 0.6% significantly increased moisture content, yield, drug loading, efficiency, and aerosolization. Ciprofloxacin-carrageenan microspheres were found to be stable up to 30 days storage and have high activity against Staphylococcus aureus and Pseudomonas aeruginosa at a low dose. Inhaled ciprofloxacin-carrageenan microspheres may be useful against respiratory tract infection.