Transdermal

Historically, developments in transdermal drug delivery have been incremental, focusing on overcoming problems associated with the barrier properties of the skin, reducing skin irritation rates and improving the aesthetics associated with passive patch systems. Transdermally delivery of drugs avoid first pass metabolism, decrease dose to be administered, reduces side effects, eliminate gastrointestinal side effects. Drug with short half life and narrow therapeutic index can be safely administered since better control of release is possible. Transdermal drug delivery-the delivery of drugs across the skin into systemic circulation is distinct from topical drug penetration, which targets local areas11.Transdermal drug delivery takes advantage of the relative accessibility of skin2.“TRANSDERMAL”route is most promising and has received a lot of attention because the skin has minimal proteolytic enzyme activity7. Route for systemic drug administration has become very attractive since the introduction of transdermal therapeutic system (TTS) in the form of patches10 .The present invention relates to transdermal administration of tolterodine, for achieving more constant serum concentrations during a dosage interval; minimize side effects in comparison to immediate release tablets, while clinical efficacy is maintained.

In the present research work nifedipine transdermal patch were prepared and optimized by using D-optimal mixture design. The prepared transdermal patches were evaluated for various parameters like drug excipients compatibility study, physicochemical evaluation, mechanical properties, In vitro drug release and In vitro permeation study. The result of evaluation parameters demonstrated a successful development of transdermal patch with poly vinyl pyrrolidone (PVP) and ethyl cellulose (EC) as rate controlling polymer.

The objective of work was to formulate, evaluate the potential of ethosomes for delivering etodolace, a potent, water insoluble non‐steroidal anti‐inflammatory drug via skin to enhance skin permeation after topical application. The effects of pH and ethanol contents on etodolac solubility were evaluated to find out the suitable dispersion medium for the ethosome preparations. Drug loaded ethosomes had been prepared using phospholipid and ethanol, were optimized and characterized  for entrapment efficiency, zeta potential, particle size and size distribution. The ethosome were prepared by using the thin film hydration method. The optimized formulation composed of 0. 4% w/v Soya lecithin and 0.1 % pluronic F127 as lipid component and 30% v/v ethanol in phosphate buffer pH 7.4 as dispersion medium. The vesicular size and zeta potential of ethosome was found to be 458.7nm,-36.6 mV respectively The entrapment efficiency was found to be 68.4±0.4%. In final phase of formulation optimized ethosome containing drug, was converted  to gel using three different carbopol 930 concentrations(0.5, 0.7 and 1% w/w).The gel of 0.7% carbopol was found to be the optimized gel  which  shown  excellent in­vitro  drug  release 

The purpose of the present investigation was to enhance the dissolution properties and bioavailability of a poor water soluble drug (Glibenclamide) by matrix-type transdermal films. Eudragit S 100 (Ed S100) and Hydroxypropylmethyl cellulose (HPMC) were used individually or in mixtures to formulate the transdermal devices by solvent casting method. The physicomechanical evaluation of the polymer matrices was performed. The prepared films showed good physicomechanical characteristics as Ed S100 percent increased, where HPMC lowered these characters. In-vitro release studies of ideal films were evaluated and the results revealed that the amount of Glibenclamide released was affected to great extent by the polymer type and also the solvent used. HPMC films showed high release rates of the drug where Ed S100 retards and control the drug release rates. HPMC mixtures with Ed S100 in 1:1 ratio released about 100% of the drug after 6 hours. In vivo evaluation of the prepared films was investigated by testing the hypoglycaemic effects of the drug after transdermal application to diabetic rats. The observed results simulated that obtained after oral administration of Glibenclamide in a dose of 5 mg/kg. The obtained results revealed a good promise of using Glibenclamide via transdermal route which could be of excellent benefit when oral route is unavailable.

Transdermal drug delivery offers an attractive alternative to the conventional drug delivery methods of oral administration and injection. However, the stratum corneum acts as a barrier that limits the penetration of substances through the skin. Application of ultrasound to the skin increases its permeability (sonophoresis) and enables the delivery of various substances into and through the skin. Ultrasound has been used extensively for medical diagnostics and to a certain extent in medical therapy (physiotherapy, ultrasonic surgery, and hyperthermia). The generation of ultrasound and mechanism of sonophoresis with particular emphasis on the role of cavitation (both inside and outside the skin), thermal effects, convective transport, and mechanical effects also included. There are certain findings in the field of sonophoresis, namely transdermal drug delivery and transdermal monitoring. The article also encompasses a discussion on the variation of sonophoretic enhancement from drug to drug, possible applications of sonophoresis in near future, some commercially available sonophoretic systems and future trends. Particular attention is paid to proposed enhancement mechanisms and future trends in the field of cutaneous vaccination and gene delivery. Key words: Ultrasound, Sonophoresis, Transdermal, Stratum corneum, cavitation, thermal effects, convective transport, and mechanical effects, Hyperthermia.  

With oral and parenteral drug delivery systems, poor patient compliance is a frequent problem in daily clinical practice. So, the transdermal route of drug delivery has gained great interest of pharmaceutical research. But the big hurdle in transdermal delivery of drug is the skin, the stratum corneum, & the outermost envelop of the skin. Recently, various strategies have been used to augment the transdermal delivery of bioactive. Mainly, they include iontophoresis, electrophoresis, sonophoresis, chemical permeation enhancers, micro needles, and vesicular system (liposomes, niosomes, elastic liposomes such as ethosomes and transfersomes). Transfersomes possess an infrastructure consisting of hydrophobic and hydrophilic moieties together and as a result can accommodate drug molecules with wide range of solubility. The high and self-optimizing deformability of typical composite transfersomes membrane, which are adaptable to ambient tress allow the ultra deformable transfersomes to change its membrane composition locally and reversibly, when it is pressed against or attracted into narrow pore. Transfersomes can deform and pass through narrow constriction (from 5 to 10 times less than their own diameter) without measurable loss. This high deformability gives better penetration of intact vesicles. They can act as a carrier for low as well as high molecular weight drugs e.g. analgesic, anesthetic, corticosteroids, sex hormone, anticancer, insulin, gap junction protein, and albumin.