Controlling the erosion rates of mucoadhesive devices that deliver actives and other compounds and providing increased and variable therapeutic blood levels
The present invention relates to the delivery of pharmaceuticals and other compounds to any wet tissue surface with a preferred application on mucosal surfaces. The device consists of a layered film comprising an adhesive layer, an erodible backing layer and an optional outer layer to improve mouth feel. Upon application, the device adheres to a wet tissue surface, and based on the composition of the erodible backing layer which is laminated to the adhesive layer, the device erodes uniformly and at a constant rate from the outside in. Due to this constant and unexpected uniform erosion characteristic, any compound present in the adhesive layer will be delivered to the treatment site at a rate dependent only on the erosion rate of the device. A pseudo zero order delivery rate is attained when an active is delivered on the oral mucosa and this rate can be regulated simply by changing the composition and thickness of the erodible backing layer. This backing layer is composed of both water soluble and water insoluble polymers, and by careful manipulation of the amount of each, the erosion rates can be regulated and subsequent drug delivery rates can be reproducibly altered. In addition, by keeping the device attached to the mucosa for extended and controlled periods of time, the active will pass through the intercellular pathway and provide more rapid and increased therapeutic blood levels. By changing only the backing layer of the device, peak blood levels can be altered.
