Bioadhesive delivery systems tablets

FIGURE 22.15 Pharmacokinetic parameters for the Spherazole CR tablet, 100 mg, compared with the Sporanc IR capsule. (Note Types A and B differed in levels of rate-controlling excipients.) (Adapted from Jacob, J. Gastroretentive, bioadhesive drug delivery system for controlled release of itraconazole pharmacokinetics of Spherazole CR in healthy human volunteers. Controlled Release Society 34th Annual Meeting and... 

Carbopol resins also have been used in controlled-release dosage forms. Especially, the resins Noven AA-1 USP and Carbopol 934P NF are being extensively developed in bioadhesive drug delivery systems for topical, bucal or nasal, ocular, and rectal applications (e.g., Fentanyl ). Noven CA-1 USP and CA-2 USP are used as oral laxative and antidiarrheal products in swallowable and chewable tablets. 

The size of the delivery system varies with the type of formulation, i.e., a buccal tablet may be approximately 5-8 mm in diameter, whereas a flexible buccal patch may be as large as 10-15 cm in area. Mucoadhesive buccal patches with a surface area of 1-3 cm are most acceptable. It has been estimated that the total amount of drug that can be delivered across the buccal mucosa from a 2-cm system in 1 day is approximately 10-20 mg.f The shape of the delivery system may also vary, although for buccal drug administration, an ellipsoid shape appears to be most acceptable. The thickness of the delivery device is usually restricted to only a few millimeters. The location of the delivery device also needs to be considered. A mucoadhesive retentive system is preferred over a conventional dosage form. A bioadhesive buccal patch would appear to be the most appropriate delivery system because of its flexibility and the area of the buccal mucosa available for its application. The maximal duration of buccal drug retention and absorption is approximately 4-6 h because food and/or liquid intake may require removal of the delivery device. 

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