ABSTRACT:
Propanolol a non-selective b-adrenergic blocking agent inhibits response to adrenergic stimuli by completely blocking b-adrenergic receptors within the myocardium and within bronchial and vascular smooth muscle. It has been widely used in the treatment of hypertension and many other cardiac disorders. Propanolol is highly lipophilic and is almost completely absorbed after oral administration. However much of the drug is metabolized by the liver during its first passage through the portal circulation only 20-25% reaches the systemic circulation. The clinical disadvantage of propanolol is its multiple and increased dose may be required over time. The physicochemical parameters such as short half life of 3-4 hrs, low molecular weight i.e.259.3 g mol-1 makes this a suitable candidate for administration by the transdermal route. Propanolol is prescribed at a dose 10-40 mg daily in divided dose by peroral route. Long term oral administration of propanolol 30-120 mg/day for prolonged revealed gastrointestinal pathology and drug tolerance. Hence the present work was designed to develop once a day transdermal therapeutic system of propanolol hydrochloride Transdermal drug delivery of propanolol hydrochloride was carried out by matrix dispersion type transdermal patches using different polymers such as Eudragit RL100, Eudragit RS100, Hydroxy propyl methyl cellulose, methyl cellulose, ethyl cellulose in varying proportions and combinations. In vitro dissolution studies were carried out till the complete exhaustion of the loaded drug. In order to find out the order of release and mechanism, graphical treatment according to higuchi equation was plotted and it has shown the drug release was diffusion mediated. In this study Eudragit RL100-2.4% and HPMC-1.6% was found best because of its consistent release rate, extent of drug release, reduced frequency of administration, greater therapeutic efficacy and avoids the first pass effect.