CARBOXYMETHYLCELLULOSE-SODIUM BASED TRANSDERMAL DRUG-DELIVERY SYSTEM FOR PROPRANOLOL

Propranolol, a beta-adrenoceptor blocker, suffers from a high degree o f first-pass metabolism resulting in very low bioavailability (<10%) f ollowing administration with conventional oral formulations. To circum vent this significant therapeutic hurdle, we formulated a carboxymethy lcellulose-sodium (CMC-Na) based transdermal system for propranolol an d evaluated the patch for its in-vitro and in-vivo performance. In-vit ro permeation studies using the excised hair-free rat skin model resul ted in 66.54% permeation at the end of 24 h in a modified Franz diffus ion cell. This zero-order permeation profile was characterized by a dr ug permeation rate of 52.87 +/- 11.63 mu g cm(-2) h(-1). Skin irritati on studies in rats (n = 5), evaluated for flare-and-wheal with respect to a formalin control, indicated that the drug-containing patch evoke d only a mild response over a 7-day period. Preliminary in-vivo studie s in male albino rabbits (n = 3), indicated that plasma drug levels av eraged 11.75 +/- 3.40 ng mL(-1) in a 24-h study period before patch re moval.