Objective: The aim of this study was to develop a bioadhesive gel of gatifloxacin for the treatment of periodontal diseases.Methods: Periodontal gels of gatifloxacin were prepared using different hydrophilic polymers such as carbopol 940 (CP 940), carboxymethyl cellulose (CMC) and hydroxypropylmethyl cellulose (HPMC) in varied concentrations, either alone or as a combination. The prepared gels were evaluated for their physical appearance, pH, drug content, viscosity, bioadhesiveness and in vitro drug release profile. The influence of the type and the concentration of polymer on the drug release as well as on viscosity and mucoadhesiveness of prepared gels were investigated. Results:The prepared gels showed acceptable physical properties concerning color, homogeneity, consistency, spreadability, and pH value. Using different polymer types at different concentrations, as well as different polymer combinations, play a significant role in the variation of overall characteristics of formulations. Increasing the concentration of polymer increased the viscosity as well as mucoadhesion, and reduced drug release rate. Formulation F 11 (1 % CP 940 and 5 % CMC) was selected as the formula of choice based on the data of various evaluation parameters such as pH, drug content, viscosity, spreadability and bioadhesion as well as its ability to show a prolonged drug release pattern. Conclusion:The obtained results show that a bioadhesive periodontal gel of gatifloxacin can be prepared using hydrophilic polymers, and by using a combination of polymers the viscosity, mucoadhesiveness, spreadability and release behavior can be optimized.

Objective: The present study was aimed to develop a pH-triggered in situ gel for local release of lidocaine hydrochloride (lidocaine HCL) in the buccal cavity to improve the anesthetic effect of this amino amide drug which has very high water solubility. The formulations were introduced to the oral cavity as a spray to improve compliance and for easier administration.Methods: In this work, two grades of carbopol (934 and 940)-based in situ gel spray were designed. The formulations containing lidocaine HCl 5% were prepared by mixing different concentrations of carbopol with xanthan gum. Eight formulations were investigated and evaluated for gelation capacity, spray angle, volume of solution delivered per each actuation, rheological properties, and release kinetic model. Similarity factor (f2) was used for the comparison of dissolution profiles.Results: The prepared formulations undergo gelation after it had been actuated to the buccal cavity as a spray solution. The results showed that, as the concentration of polymer was increased, the release of drug decreased and the viscosity increased for both grades. The spray angle and volume of solution delivered per each actuation varied according to the composition of each formulation. The in situ gel containing 0.3% carbopol 934 and 0.2% xanthan gum regarded as a better candidate which had a good gelation and release property compared to other formulations. Drug release from optimized in situ gel spray followed Korsmeyer–Peppas model and was mediated by Fickian diffusion mechanism.Conclusion: Lidocaine HCl-loaded pH-sensitive in situ gel was successfully developed using carbopol 934 as polymer to be applied to the buccal cavity as spray solution for more effective anesthetic effect and painless treatment.