1. Recent Advances In Transdermal Drug Delivery System (TDDS): A Review Singh H.P. 1*, Kaur I. 2, Gullaiya S. 1, Chauhan S. 1 1. Amity Institute of Pharmacy, Amity University (Uttar Pradesh). 2. Delhi Institute of Pharmaceutical Sciences & Research, New Delhi. Email id: harsharan.singh1992@gmail.comharsharan.singh1992@gmail.com Abstract References Introduction Conclusion Jain NK. Controlled and Novel drug delivery, Published by CBS Publishers & distributors, New Delhi-110002, 1st Edn, 1997; 100-129. Aulton ME. Pharmaceutics – The science of dosage form design’’, Published by Churchill living stone, 2nd Edn, 499-532. Winfield AJ, Richards RME. Pharmaceutical practice, Published by Churchill living stone, 3rd Edn, 215-217. Chien, YW, Novel drug delivery systems, Drugs and the Pharmaceutical Sciences, Vol.50, Marcel Dekker, New York, NY;1992;797. Prausnitz MR, Mitragotri S, Langer R. Current status and future potential of transdermal drug delivery. Nat Rev Drug Discov 2004;3:115–124. Transdermal drug delivery system (TDDS) provides a means to sustain drug release as well as reduce the intensity of action and thus reduce the side effects associated with its oral therapy. It delivers a drug through intact skin at a controlled rate into the systemic circulation. Delivery Rate is controlled by the skin or membrane in the delivery system. The materials of construction, configuration and combination of the drug with the proper co-solvent, excipient, penetration enhancer, and membrane are carefully selected and matched to optimize adhesive properties and drug delivery requirements. It is an approach used to deliver drugs through the skin for therapeutic use as an alternative to oral, intravascular, Subcutaneous and transmucosal routes. The Most commonly used transdermal system is the skin patch using various types of technologies.Transdermal technologies may be applied for several categories of pharmaceuticals used for the treatment of disorders of the skin or for systemic effect to treat diseases of other organs. Several transdermal products and applications include hormone replacement therapy, management of pain, angina pectoris, smoking cessation and neurological disorders such as Parkinson's disease. It enhances bioavailability via bypassing first pass metabolism, minimizing pharmaco- kinetic peaks and troughs, improving tolerability and dosing.. First-generation transdermal delivery systems The first generation of transdermal delivery systems is responsible for most of the transdermal patches that have thus far been in clinical use. Second-generation transdermal delivery systems The second generation of transdermal delivery systems recognizes that skin permeability enhancement is needed to expand the scope of transdermal drugs. The ideal enhancer should (i) increase skin permeability by reversibly disrupting stratum corneum structure, (ii) provide an added driving force for transport into the skin and (iii) avoid injury to deeper, living tissues. However, enhancement methods developed in this generation, such as conventional chemical enhancers, iontophoresis and non-avitational ultrasound, have struggled with the balance between achieving increased delivery across stratum corneum, while protecting deeper tissues from damage. Transdermal drug delivery is hardly an old technology, and the technology no longer is just adhesive patches. Due to the recent advances in technology and the incorporation of the drug to the site of action without rupturing the skin membrane transdermal route is becoming the most widely accepted route of drug administration. It promises to eliminate needles for administration of a wide variety of drugs in the future. TDDS have great potentials, being able to use for both hydrophobic and hydrophilic active substance into promising deliverable drugs. To optimize this drug delivery system, greater understanding of the different mechanisms of biological interactions, and polymer are required. TDDS realistic practical application as the next generation of drug delivery system. Transdermal drug delivery is defined as self contained, discrete dosage forms which, when applied to the intact skin, deliver the drug, through the skin at controlled rate to the systemic circulation. Transdermal drug delivery system (TDDS) established itself as an integral part of novel drug delivery systems. Advantages & Disadvantages of TDDS Advantages of TDDS Delivers a steady infusion of a drug over an extended period of time. Increase the therapeutic value of many drugs by avoiding specific problems associated with the drug Improved patient compliance and reduced inter & intra – patient variability. Maintenance of the drug concentration within the diphase is not desired. Self administration The drug input can be terminated at any point of time by removing transdermal patch. Disadvantages of TDDS The Drug must have some desirable physicochemical properties for penetration through stratum corneum Risk of Dermatitis at the site of application Examination of Clinical need in development of a transdermal product. Generations of TDDS Transdermal Patches A Transdermal patch or skin patch is a medicated adhesive patch that is placed on the skin to deliver a specific dose of medication through the skin and into the bloodstream. Types of Transdermal Patches Membrane moderated Transdermal drug delivery system (reservoir device) E.g.: Transderm-nitro : once a day Adhesive diffusion controlled Transdermal drug delivery system E.g.: Isosorbide dinitrate releasing transdermal drug delivery system - for once a day Matrix diffusion controlled Transdermal drug delivery system E.g.: NitroDur I & NitroDur II – Nitroglycerine for treatment of angina pectoris. Micro reservoir Transdermal drug delivery system E.g. Nitro disc Maximizing TDDS Presented at SPER 3 rd Annual Conference held at LPU on 8 th March 2014