Mucoadhesion: A Neoteric Physician’s Approach

Mucoadhesion is a newstrategy to prolong the residence time of various drugs. The capability to adhere to the mucus gel layer which covers the epithelial tissues makes such mucoadhesive polymers very useful excipients in drug delivery.The oral mucosa is highly perfused with blood vessels, hence therapeutic concentrations of the drug can be achieved rapidly. Mucoadhesion is known to increase the intimacy and duration of contact between drugcontaining polymer and a mucous surface.The bioavailability of the drug is improved becauseof the combined effects of the direct drug absorption and the decrease in excretion rate.Presently there is a plethora of drugs which are being used by mucoadhesion for various oral mucosal lesions ,the most common being aphthous stomatitis. This article intends to evaluate the newfangled contraptionAdhesive strips in treating aphthous ulcer. At the same time we are trying to evaluate the difficulties faced by the clinician while opting for such a modality. INTRODUCTION : Pharmaceutics is a science of possibilities.The journey from conventional system of drug delivery like oral and parenteral to the new targeted drug delivery has been epoch making.Professor Joseph R Robinson of the University of Wiscosin pioneered the concept of mucoadhesion in the late 1980’s.This was targeted to prolong the residence time of drugs. Leung and Robinson in 1988 described mucoadhesion as the interaction between a mucin surface and a synthetic or natural polymer. The oral mucosa has many properties which makes it an attractive site for drug delivery but also provides several challenges for researchers investigating novel delivery techniques to overcome many different formulations including sprays, tablets, mouthwashes, gels, pastes and patches which are presently used for delivery into and or across the oral mucosa. Recurrent aphthous stomatitis (RAS), also known as canker sores, is one of the most common oral mucosal diseases. In the largest study on RAS, involving a sample of over 10,000 young adults in 21 countries, 38.7% of men and 49.7% of women had suffered from at least two episodes of RAS in their lifetime. Approximately 25% of the study population reported that an episode had occurred in the year prior to the study. Presently,there is a plethora of drugs used for treatment of Aphthous stomatitis.The primary goals of therapy for RAU are relief of pain, reduction of ulcer duration, and restoration of normal oral function. Secondary goals include reduction in the frequency and severity of recurrences and maintenance of remission. Topical medications, such as antimicrobial mouth washes and topical corticosteroids, canachieve the primary goals but have notbeen shown to alter recurrence or remission rates. Systemic medications can be tried if topical therapy is ineffective. Mucoadhesion : The term bioadhesion can be defined as the state in which two materials, at least one biological in nature, are held together for an extended period of time by interfacial forces(Good, 1983). In biological systems, bioadhesion can be classified into 3 types: • Type 1, adhesion between two biologicalphases, for example, platelet aggregation and wound healing. • Type 2, adhesion of a biological phase to an artificial substrate, for example, cell adhesion to culture dishes and bio-film formation on prosthetic devices and inserts. • Type 3, adhesion of an artificial material to a biological substrate, for example, adhesion of synthetic hydro gels to soft tissues (Henriksenet al., 1996) and adhesion of sealants to dental enamel . For drug delivery purposes, the term bioadhesion implies attachment of a drug carriersystem to a specified biological location. The biological surface can be epithelial tissue or themucus coat on the surface of a tissue. If adhesive attachment is to a mucus coat, the phenomenon is referred to as mucoadhesion. H N Santosh et al /J. Pharm. Sci. & Res. Vol. 6(11), 2014, 356-359