Characterization of Mucoadhesive Ciprofloxacin Suspensions by Fourier Transform Infrared Spectroscopy

Ciprofloxacin, an antibacterial agent, is having low solubility in aqueous solution and high rate of absorption from the stomach. It is precipitated at alkaline pH leading to erratic absorption of the drug from small intestine. To overcome these difficulties, controlled release mucoadhesive suspensions have been designed so that safe and effective blood level of Ciprofloxacin can be maintained for a prolonged period. The chemical interaction between Ciprofloxacin and different polymers in suspensions has been studied to know their compatibility by Fourier Transform Infrared Spectroscopy (FTIR). Ultrasonication method was used for the preparation of different formulations, taking Carbopol 934, Carbopol 940 and Hydroxypropyl methyl cellulose polymers. FTIR (400 cm to 4000 cm region) Spectroscopic study was carried out and its spectra were used for interpretation. From the spectral interpretation, it was found that in formulations, the carboxylic groups of Ciprofloxacin and hydroxyl groups of respective polymers encountered chemical interaction leading to esterification and hydrogen bonding (both intermolecular and polymeric). It may be concluded that Ciprofloxacin is compatible with three polymers used in the study. Formation of micelles due to esterification and intermolecular hydrogen bonding causes more drug entrapment. In addition, stable suspensions are formed without hampering the C-F bond of the quinolone nucleus, which is responsible for the antibacterial activity of the drug. As a result of which, stable mucoadhesive suspensions of Ciprofloxacin could be produced and hence, these polymers may be considered as effective carriers for Ciprofloxacin.