title: Bioadhesive emulsions for control release of progesterone resistant to vaginal fluids clearance.
abstract: The aim of this study is to propose that mucoadhesive vaginal emulsions can be able to resist the clearance effect of vaginal fluid and to have an effective control release of progesterone. With this goal, silicon derivative, cyclomethicone pentamer, was selected as the bioadhesive and water resistant material. In order to obtain a system which is insensitive to the dilution of aqueous fluids, water in silicone (W/S) emulsions were prepared and different proportions of cyclomethicone as well as 8% or 15% w/w of progesterone were employed. The rheological, mechanical and mucoadhesive properties of emulsions were characterized and the drug release was measured for each formulation. Mucoadhesive behavior was determined and the influence of simulated vaginal fluid (SVF) at bioadhesion was assessed using three commercial mucoadhesive vaginal gels (Crinone(®), K-Y jelly(®) and Zidoval(®)) as the bioadhesive references. All assayed emulsions have good rheological and mechanical properties and their consistence and viscosity increase when the proportion of the internal phase increases. Related to mucoadhesion, in the absence of SVF, W/S emulsions showed similar bioadhesive levels like the commercial formulations. However, in the presence of SVF, W/S emulsions are able to keep their mucoadhesive properties while the marketed references drastically lose their consistency and adherence to the vaginal mucosa. Drug release profiles from W/S emulsion show that progesterone is released with pseudo-order zero kinetics and a constant release rate is maintained for at least two weeks. The results of the in vivo studies developed in rats show that after a single vaginal administration, bioadhesive W/S emulsions increase the uterine tissue progesterone levels in young and postmenopausal rats. Moreover in postmenopausal rats, they provide high uterine levels of progesterone compared to the bioadhesive-marketed gel used as a reference. Therefore, W/S emulsions have an interesting potential as bioadhesive vaginal delivery systems for drug administration.
authors.affiliation: Department of Pharmacy and Pharmaceutical Technology, University of Santiago de Compostela, Campus Vida s/n, Santiago de Compostela 15782, Spain.
authors.forename: Maria
authors.initials: M
authors.lastname: Campaña-Seoane
authors.affiliation: Department of Pharmacology, University of Santiago de Compostela, Campus Vida s/n, Santiago de Compostela 15782, Spain.
authors.forename: Aaron
authors.initials: A
authors.lastname: Peleteiro
authors.affiliation: Department of Pharmacology, University of Santiago de Compostela, Campus Vida s/n, Santiago de Compostela 15782, Spain; Institute of Industrial Pharmacy, University of Santiago de Compostela, Campus Vida s/n, Santiago de Compostela 15782, Spain.
authors.forename: Reyes
authors.initials: R
authors.lastname: Laguna
authors.affiliation: Department of Pharmacy and Pharmaceutical Technology, University of Santiago de Compostela, Campus Vida s/n, Santiago de Compostela 15782, Spain; Institute of Industrial Pharmacy, University of Santiago de Compostela, Campus Vida s/n, Santiago de Compostela 15782, Spain. Electronic address: francisco.otero@usc.es.
authors.forename: Francisco J
authors.initials: FJ
authors.lastname: Otero-Espinar
mesh_terms: D000818:Animals; D012634:Bodily Secretions / Q000378:metabolism*; D002417:Cattle; D003692:Delayed-Action Preparations; D065546:Drug Liberation; D004655:Emulsions; D005260:Female; D006801:Humans; D009092:Mucous Membrane / Q000187:drug effects / Q000378:metabolism; D010316:Particle Size; D011374:Progesterone / Q000008:administration & dosage / Q000031:analogs & derivatives* / Q000493:pharmacokinetics; D017208:Rats, Wistar; D012212:Rheology; D012995:Solubility; D014014:Tissue Adhesives / Q000737:chemistry*; D014621:Vagina / Q000187:drug effects / Q000378:metabolism*; D066228:Vaginal Absorption / Q000187:drug effects
chemical_list: C400424:Crinone; D003692:Delayed-Action Preparations; D004655:Emulsions; D014014:Tissue Adhesives; D011374:Progesterone
keywords: Bioadhesion; Cyclomethicone pentamer (PubChem CID 10913); Glycerol (PubChem CID 753); Progesterone; Progesterone (PubChem CID 5994); Silicone emulsion; Vaginal delivery