Controlled drug delivery

The transdermal route of drug delivery overcomes many of the limitations associated with the more common oral and parenteral routes. Micro needles are micronized needles made from biodegradable polymer, ranging from 25 to 2000 µm in height, made up of variety of the material and shape. Advantages associated with micro needles are ease of use, controlled drug delivery, avoidance of first pass metabolism and lack of pain. However, transdermal drug delivery is limited due to the barrier provided by our skin known as stratum corneum which is the outermost non-viable layer of the epidermis. Microneedles were developed with the advantage that these can deliver the drug in a non- invasive painless manner and along with this overcome stratum corneum. The upper layer of the skin is penetrated by the microneedles without reaching the nerve, there by delivering drug transdermally in a painless manner. The present poster discusses the various fabrication techniques of micro needles using microelectromechanical system the design, material consideration and the application of micro needles in transdermal drug delivery system.

Polymers have been used as a main tool to control the drug release rate from the formulations. Extensive applications of polymers in drug delivery have been realized because polymers offer unique properties which so far have not been attained by any other materials. Advances in polymer science have led to the development of several novel drug-delivery systems. A proper consideration of surface and bulk properties can aid in the designing of polymers for various drug-delivery applications. These newer technological developments include drug modification by chemical means, carrier based drug delivery and drug entrapment in polymeric matrices or within pumps that are placed in desired bodily compartments. These technical development in drug delivery/targeting approaches improve the efficacy of drug therapy thereby improve human health. Polymer chemists and chemical engineers, pharmaceutical scientists are engaged in bringing out design predictable, controlled delivery of bio active agents. Biodegradable polymers have been widely used in biomedical applications because of their known biocompatibility and biodegradability. In general natural polymers offer fewer advantages than synthetic polymers. The following review presents an overview of the different biodegradable polymers that are currently being used, their properties, as well as new developments in their applications.

  Periodontitis is an inflammatory disease of the supporting tissues of the teeth caused by groups of specific microorganisms. The concept that localized problem sites may be treated by local drug delivery appears attractive as the antimicrobial agent is delivered within periodontal pockets and the therapy is targeted on specific pathogenic microorganisms. Local delivery of antimicrobial agents using controlled release systems should be considered as adjunctive to mechanical debridement for the treatment of localized forms of periodontal destruction. Local delivery of in situ gelling system to periodontal pockets has the benefit of putting more drugs at target site while minimizing exposure of the total body to the drug. In situ gelling system helps in maintaining effective levels of drug in gingival cervicular fluid to produce desirable clinical effects. In situ gel for controlled drug delivery system of periodontal pocket has received greater interest and appears to hold some promise in periodontal therapy. They are designed to release drug slowly with more prolonged drug availability and sustained drug action. Controlled release systems offer an advantage of decrease in frequency of administration, improving patient compliance. The dose of the drug can also be decreased and hence, the toxicity when compared to conventional therapy. In controlled drug delivery, the drug is released over an extended period of time by zero order kinetics and hence constant plasma drug concentration can be achieved. Key words: Periodontitis, Periodontal pocket, In situ gel, Controlled drug delivery

  Drug development technologies constituting innovations at the formulation end in the pharmaceutical industry has received a lot of attention in past two decades. Drug delivery as an opportunity to extend product life cycles has indeed proved its place in the market with significant advantages of therapeutic gains as well as commercial success. Carrier technology offers an intelligent approach for drug delivery by coupling the drug to a carrier particle such as microspheres, nanoparticles, liposomes, etc. which modulates the release and absorption characteristics of the drug. Mucoadhesion is a topic of current interest in the design of drug delivery systems. Mucoadhesive microspheres exhibit a prolonged residence time at the site of application or absorption and facilitate an intimate contact with the underlying absorption surface and thus contribute to improved and/or better therapeutic performance of drugs. Hence, uptake and consequently bioavailability of the drug is increased and frequency of dosing reduced with the result that patient compliance is improved. In recent years such Mucoadhesive microspheres have been developed for oral, buccal, nasal, ocular, rectal and vaginal for either systemic or local effects. This review article aims to provide various aspects of mucoadhesion, theories of mucoadhesion and the polymers which will shows the excellent mucoadhesive properties. It also contains a number of available methods of preparation of microspheres and its evaluation including in vitro-wash off test for to determine the mucoadhesive property of prepared microspheres.

  Now a days as very few drugs are coming out of research and development and already existing drugs are suffering the problem of resistance due to their irrational use specifically in case of drugs like antibiotics. Hence, change in the operation is a suitable and optimized way to make the some drug more effective by slight alteration in the drug delivery. An appropriately designed controlled release drug delivery system can be a major advance towards solving problems concerning the targeting of a drug to a specific organ or tissue and controlling the rate of drug delivery to the target sites. The development of oral controlled release systems has been a challenge to formulation scientists due to their inability to restrain and localize the system at targeted areas of the gastrointestinal tract. Matrix type drug delivery systems are an interesting and promising option when developing an oral controlled release system. This review focuses on the progress made in the design of controlled release dosage forms employing various types of matrices as carriers for the active ingredients.   Key Words: Controlled drug delivery, Matrices, Oral controlled release system, Matrix tablets.