TY - BOOK AU - Marwa Hamdy Sayed Dawoud AU - Ahmed Abdelfattah Aboelwafa , AU - Nadia Mohamed Morsi , TI - A Pharmaceutical study on formulation of certain drugs through transdermal drug delivery system / PY - 2014/// CY - Cairo : PB - Marwa Hamdy Sayed Dawoud , KW - Formulation of certain drugs KW - Timolol Maleate KW - Transdermal drug delivery system N1 - Thesis (M.Sc.) - Cairo University - Faculty of Pharmacy - Department of Pharmaceutics; Issued also as CD N2 - Timolol Maleate, a Ý-adrenergic receptor blocker is used as an antihypertensive agent and prevents cardiac attacks. It undergoes extensive presystemic metabolism, with per-oral bioavailability of 50% and per-oral elimination half-life 4h, its main side effect is the probability of bronchospasm. In an attempt to solve the per-oral problems, Timolol Maleate can be formulated transdermally using transfersomes technique. The effects of pre-formulation variables were studied and optimized using full factorial designs by evaluation of individual and combined effects. Three independent process variables were used each at two levels, which were studied on the particle size of transfersomes, drug entrapment efficiency and the release rate of the drug through cellophane mebrane. Also the permeation of the optimized formulae through hairless rat skin was evaluated. The particle size of transfersomes allowed them to be permeated even if their size were larger than the skin pores, due to their high flexibility; they can squeeze through the skin pores. The formulae had excellent permeation and a sustained release to an extended time. Transfersomal and protransfersomal vesicles could constitute a promising approach for transdermal delivery of Timolol Maleate, which bypass the first pass effect, sustain the release of the drug up to 72 hours, thus lowering the dose with the subsequence of lowering the dose related side effects which will increase the patient compliance and reduce the cost ER -