Oral systems advantages over

The transdermal route of drug administration offers several advantages over other methods of delivery. For some cases, oral delivery may be contraindicated, or the drug may be poorly absorbed. This would also include situations for which the drug undergoes a substantial first-pass effect [173] and systemic therapy is desired. 

Topical CAls offer distinct advantages over other inhibitors of aqueous humor formation. Compared with P-blockers, CAls reduce the nocturnal aqueous flow rate by 25%. P-Blockers lack the ability to suppress aqueous formation below the already reduced flow rate that occurs during sleep. In contrast to systemic CAls, topical CAls lack most of the systemic side effects while producing a comparable ocular hypotensive effect. None of the topical CAls, however, has the ability to reduce lOP to the level achieved by 500 mg of oral acetazolamide.Topical agents are used in place of systemic CAls for chronic treatment of primary and secondary open-angle glaucomas. Other recently developed medications have probably relegated the position of topical CAls to second- or third-line therapy. Cosopt may simplify therapy and improve compliance for patients who require treatment with both timolol and dorzolamide. 

Transdermal drug delivery (TDD) is known to offer many advantages over the oral and injectable routes for systemic drug delivery. However, the skin is a complex and dynamic organ with marked barrier function, which results in limitations and variations in the amount and nature of drugs that can be delivered across the skin and into the bloodstream. Thus a continual search for ways to optimize the permeation of drugs across the skin exists, in an attempt to enhance delivery and improve patient compliance. 

The replacement of systemic corticosteroid therapy and its attendant side effects in asthmatic and allergy patients with locally acting corticosteroids by way of aerosol inhalation devices is a gratifying success story. Even though dexamethasone phosphate was initially used for brief periods, the development of systemic effects such as adrenal suppression offered no advantage over oral therapy. Beclomethasone diproprionate showed itself to be hundreds of times more potent, and it produced no systemic symptoms even even on prolonged use with 400 pg daily doses. Some systemic symptoms developed at three to four times higher doses. 

The use of hydrophilic polymers in the development of controlled release formulations for the delivery of drugs for oral route has proven to be advantageous over conventional drug delivery systems. Polymeric delivery systems have the... 

The oral mucosal route offers a number of advantages over parenteral and other non-invasive routes for the systemic delivery of biologically active peptides and proteins as well as conventional dmgs [78]. However, most drugs absorbed via the... 

---