ABSTRACT
BACKGROUND: Vaginal cavity represents a good site for drug administration and delivery. AIM: The aim of this work was the design of new mucoadhesive semisolid dosage forms for vaginal delivery of benzydamine. METHOD: Simple gels, obtained by using sodium carboxymethylcellulose (NaCMC) and hydroxyethylcellulose (HEC), were employed as water phase of an oil-in-water emulsion (O/W cream) to obtain emulgels, more stable and manageable than gels. Successively, in order to modify the emulgel consistency, the ingredient cetostearylic alcohol was replaced by the same amount of gel or vaseline. All the preparations were submitted to mucoadhesion and rheological, extrusion, and release studies and compared to market vaginal cream Tantum Rosa. RESULTS: HEC formulations showed good drug release profiles and good rheological behavior but low mucoadhesion strength, whereas NaCMC (4% gel) formulations had better drug release and very high mucoadhesive strength. However, the presence of NaCMC 4% conferred too much viscosity to the preparation. Taking into consideration all performances, the most suitable formulations for vaginal applications resulted in those containing NaCMC (3% gel) and with gel replacing cetostearylic alcohol as they showed good ex vivo performances in terms of manageability and high bioadhesion to vaginal mucosa.
Subject(s)
Benzydamine/administration & dosage , Benzydamine/chemistry , Chemistry, Pharmaceutical/methods , Vagina/metabolism , Adhesiveness , Administration, Intravaginal , Animals , Benzydamine/pharmacokinetics , Female , Mucous Membrane/drug effects , Mucous Membrane/metabolism , Swine , Vagina/drug effects , Vaginal Creams, Foams, and Jellies/administration & dosage , Vaginal Creams, Foams, and Jellies/chemistry , Vaginal Creams, Foams, and Jellies/pharmacokinetics , ViscosityABSTRACT
New mucoadhesive formulations were designed and studied in order to improve local vaginal therapy by increasing formulation retention prolonging thus drug-mucosa contact time. Some gels were prepared using hydroxyethylcellulose (HEC) alone or mixed with chitosan (CS) or its derivative 5-methyl-pyrrolidinone-chitosan (MPCS) and were loaded with the antibacterial metronidazole (MET) (0.75%). All formulations showed pseudoplastic flow and viscosity increase was observed proportionally to chitosan content (CS>MPCS). Prepared gels showed better extrusion properties (yield stress) than market formulation Zidoval. Mucoadhesion force studies permitted to point out that: (i) CS decreases mucoadhesion force; (ii) MPCS addition increases the mucoadhesion force at high percentage; (iii) all gels containing chitosan showed better mucoadhesive performances than Zidoval. Gels containing MPCS showed higher and faster drug release than those containing CS. All the preparations were able to release higher drug amounts if compared to market formulation. In conclusion MPCS improved gel characteristics in terms of mucoadhesion force, rheological behaviour and drug release pointing out that this modified chitosan is very suitable to obtain manageable and more acceptable vaginal formulation.
