Transdermal patch technology

Transdermal patch technology represents an important area of biomaterials, due to its non-invasive character, ease to use, and a relatively high bioavailability. Generally, these patches could deliver drugs from one to seven days. Currently, 11 drugs, or drugs combinations are delivery through body via this method [195],... 

Advanced delivery systems include transdermal patches, which are now well established and accepted by patients. Technologies under development include, for example, iontophoresis, which uses a small electric current to propel the drag through the skin. Drag delivery via iontophoresis occurs at enhanced rates and amounts in comparison to patch technology, which uses simple passive diffusion. The development of safe, non-toxic absorption enhancers to facilitate transdermal absorption is a further focus of current research. 

McKinnie J. Transdermal market the future of transdermal drug delivery relies on active patch technology. Drug DeUv. Tech. 2006 6 54-58. 

The skin offers an even less naturally permeable boundary to macromolecules than the gastrointestinal tract. Thus, passive transdermal delivery of proteins and peptides using patch technology has not succeeded. Peptides and proteins can be shot through the skin into the body using high-pressure needle-less injection devices. The devices, which inject proteins like insulin, have been available for years, however they have failed to impress doctors or patients due to the associated discomfort and the potential for splash back to transmit blood-borne diseases such as AIDS or hepatitis. 

However, subjective and objective analyses of these devices are required to make sure both scientific, regulatory and consumer needs are met. The devices in development are costlier and more complicated when compared with conventional transdermal patch therapies. As such they may contain electrical and mechanical components which could increase the potential safety risks to patients because of poor operator technique or device malfunction. In addition, effects of the device on the skin must be reversible, since any permanent damage to the SC will result in the loss of its barrier properties and hence its function as a protective organ. Regulatory bodies will also require data to substantiate the safety of the device on the skin for either short- or long-term use. Thus, for any of these novel drug delivery technologies to succeed and compete with those already on the market, their safety, efficacy, portability, user-friendliness, cost-effectiveness and potential market have to be addressed. 

Lyophilization is a common process for manufacturing orally disintegrating tablets. However, the manufacturing of ODFs stands on the technology for producing transdermal patches, which is less expensive than lyophilization [8]. 

Kumar, Manish, Abhishek Kr Chauhan, Sachin Kumar, Arun Kumar, Sachin Malik. Design Evaluation of Pectin Based Metrics for Transdermal Patches of Meloxi-cam. Asian Journal of Pharmaceutical Science Healthcare 2, no 3 (2010) 244—247. Kumar, Manoj, Rakesh Kumar Mishra, Ajit K. Banthia. Ttevelopment of pectin based hydrogel membranes for biomedical apphcations. International Journal of Plastics Technology 14, no. 2 (2010), 213-223. 

Lin, W., et al. 2001. Transdermal delivery of antisense oligonucleotides with microprojection patch (Macroflux ) technology. Pharm Res 18 1789. 

Transbuccal drug delivery systems are a new technology and spinoff of transdermal/topical drug delivery systems. Similar to monolithic adhesive matrix—type skin patches, transbuccal systems are designed to adhere to mucosal tissue in the oral cavity. A number of compounds are being evaluated in clinical studies.88... 

M, whose experience in adhesive technology has been put to use in the transdermal field, has similarly built on its adhesive expertise in the development of a proprietary mucosal patch formulation (Cydot), which has demonstrated considerable potential for oral transmucosal delivery. The pill-sized patch uses a new bioadhesive which sticks to the gum, the cheek or the lip without causing irritation and is designed to deliver drugs for short and extended periods (up to 24 h). The small size, 0.5 to 3 cm2, helps patient compliance significantly. 

TransPharma-Medical, an Israeli-based pharmaceutical company, is investigating the transdermal delivery of human parathyroid hormone fragment for the treatment of osteoporosis in addition to the delivery of human growth hormone [41], This technology utilizes a 1-cm2 patch that creates small channels or holes in the stratum... 

Given the limitations imposed on transdermal systemic drug delivery by the barrier properties of the stratum corneum, new technologies have attempted to completely bypass this obstacle by either the creation of a physical conduit (microneedles) or direct powder delivery via compressed gas. The Alza Corporation technology (Macroflux ) comprises a patch system that contains a microprojection array designed to create superficial microchannels across the stratum corneum.When used in conjunction with their electrotransport system, the Macroflux system provides controlled in vivo delivery of therapeutic doses of... 

Subcutaneous still remains the predictable and controllable route of delivery for peptides and macromolecules. However, there is need for greater convenience and lower cost for prolonged and repeated delivery. An example of refinement of subcutaneous delivery is MEDIPAD (Elan Pharmaceutical Technologies), which is a combination of patch concept and a sophisticated miniaturized pump operated by gas generation. It was described in the report on transdermal drug delivery. 

Yuzhakov et al. [93] describe the production of an intracutaneous microneedle array and provide an account of its use (microfabrication technology). Various embodiments of this invention can include a microneedle array as part of a closed loop system smart patch to control drug delivery based on feedback information from analysis of body fluids. Dual purpose hollow microneedle systems for transdermal delivery and extraction which can be coupled with electrotransport methods are also described by Trautman et al. [91] and Allen et al. [100]. These mechanical microdevices which interface with electronics in order to achieve a programmed or controlled drug release are referred to as microelectromechanical systems (MEMS) devices. 

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