Vaginal bioadhesive formulations

Baloglu, E., et al. 2003. An in vitro investigation for vaginal bioadhesive formulations Bioadhesive properties and swelling states of polymer mixtures. Farmaco 58 391. 

A review of vaginal bioadhesive formulations indicates that bioadhesive tablets have been used for localized treatment of diseases in the vaginal tissue.F ° l For example. Bleomycin, an antitumor agent, was incorporated into a flat-faced disk fabricated from a combination of hydroxypropyl cellulose and poly-(acrylic acid) (Carbopol 934). ° The tablet was designed to release Bleomycin at a slow rate to minimize irritation to healthy mucosa. Another vaginal tablet is formulated from the combination of poly(acrylic acid) with hydroxypropyl methylcellulose and ethylcellu-lose. Other polymer combinations evaluated for potential bioadhesive vaginal delivery include poly(acrylic acid) and sodium carboxymethyl cellulose with Avicel PH102 (methylcellulose) as the diluent. Insulin has been formulated in a cross-linked poly(acrylic acid) gel... 

Site-specific delivery will require the use of a self-locating system, typically a bioadhesive formulation, although an IVR, due to its elastomeric nature, will remain located high in the vaginal space. Conversely, for rapid distribution throughout the space, semisolid or fast-dissolving solid systems will be required. For semisolids, flow properties and viscoelastic character will be the critical determinants of their ability to spread rapidly from their point of application. 

The key objective of our efforts has been to develop a vaginal formulation that optimizes spermicidal and antiviral activity while enhancing spreading and true bioadhesiveness. Utilization of strict design principles for an excipient delivery vehicle, which included substantivity to vaginal mucosa, saline compatibility, compatibility with a wide range of spermicidal and antiviral compounds, low irritation potential, sperm impedance, system stability, and efficacy after stressed storage conditions, resulted in the development of DCE s [11,12,13]. Based on the results from in vitro studies, the DCE vehicle was selected for clinical development. 

Richardson, J.L., and Armstrong, T.I., Vaginal Delivery of Calcitonin by Hyaluronic Acid Formulations. In Bioadhesive Drug Delivery Systems (E. Mathiowitz, D.E. Chickering, III, and C.-M. Lehr, eds.), Marcel Dekker, Inc., New York, 1999, pp. 563-599. 

A host of bioadhesive controlled release systems have been proposed in recent years. Among the most commonly studied applications of bioadhesive materials is the area of buccal controlled delivery [408], The buccal delivery of small peptides from bioadhesive polymers was studied by Bodde and coworkers [409], and a wide range of compositions based on poly(butyl acrylate) and/or poly(acrylic acid) gave satisfactory performance. Bioadhesive poly(acrylic add)-based formulations have also been used for oral applications [402,410] for the sustained delivery of chlorothiazide [410] and for a thin bioadhesive patch for treatment of gingivitis and periodontal disease [411]. Other bioadhesive applications of polyelectrolytes include materials for ophthalmic vehicles [412,413], and systems for oral [410,414,415-419], rectal [420,421] vaginal [422] and nasal [423] drug delivery. 

To achieve more effective treatment of vaginal candidosis, ketoconazole was formulated in bioadhesive tablets that increase the time of contact of drug with the vaginal mucosa and thus its therapeutic effect [77]. The tablets were based on sodium carboxymethylcellulose (NaCMC), polyvinylpyrrolidone, or HPMC. 

Garg, S., et al. 2001. Properties of a new acid-buffering bioadhesive vaginal formulation (ACID-FORM). Contraception 64 67. 

Xanthan gum can be used to increase the bioadhesive strength in vaginal formulations and as a binder in colon specific drug delivery systems. ... 

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