Today about 70% of drugs are taken orally and are found not to be as effective as desired. To improve such characters transdermal drug delivery system was emerged. 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 and differs from traditional topical drug delivery. Transdermal Drug Delivery System is the system in which the delivery of the active ingredients of the drug occurs by means of skin. Several important advantages of transdermal drug delivery are limitation of hepatic first pass metabolism, enhancement of therapeutic efficiency and maintenance of steady plasma level of the drug. Various types of transdermal patches are used to incorporate the active ingredients into the circulatory system via skin. This review article covers a brief outline of the principles of transdermal permeation, various components of transdermal patch, approaches of transdermal patch, evaluation of transdermal system, its application with its limitation.

Aquasomes are the self-assembling nanobiopharmaceutical carrier system, contains nanocrystalline calcium phosphate or ceramic diamond, is covered by a glassy polyhydroxyl oligomeric film. Aquasomes are spherical (5-925nm) particles used for drug and antigen delivery. Aquasomes are called as "bodies of water" their water like properties protect and preserve fragile biological molecules. Its high degree of surface exposure is used in targeting of bio-active molecules to specific sites. Three types of core materials are mainly used for producing aquasomes: Tin oxide, Nanocrystalline carbon ceramics and Brushite. Calcium phosphate is the core of interest, due to its natural presence in the body. The brushite is unstable and converts to hydroxyapatite upon prolong storage and seems a better core for the preparation of aquasomes. It is widely used for the preparation of implants. Aquasomes exploited as a RBC substitutes, vaccines for delivery of viral antigen and as targeted system for intracellular gene therapy. Enzyme activity and sensitivity towards molecular conformation made aquasome as a novel carrier for enzymes like DNAses and pigment/dyes. This report reviews the principles of self assembly, the challenges of maintaining both the conformational integrity and biochemical activity of immobilized surface pairs. KEYWORDS Aquasomes, Self assembling carrier system, Carbon ceramics (diamonds) and Brushite (calcium phosphate dihydrate)

The number of medications and the ways in which they can be administered have expanded dramatically over the years. One such advance has been the development of transdermal delivery systems. The transdermal route of drug delivery has attracted researchers due to many biomedical advantages associated with it. However, excellent impervious nature of skin is the greatest challenge that has to be overcome for successfully delivery of the drug molecules to the systemic circulation via this route. Various types of transdermal approaches used to incorporate the active ingredients include use of prodrugs/lipophilic analogs, permeation enhancers, sub saturated systems and entrapment into vesicular systems. Innovations in technologies continue to occur at a positive rate, making the technology a fertile and vibrant. This article deals with the innovations in the field of TDDS to improve the release rate and other parameters and most suitable to the patient.

Gas filled microbubbles are well known as ultrasound contrast agents for medical ultrasound imaging and for non-invasive delivery of drugs and genes to different tissues. Microbubbles designate air or gas filled microspheres suspended in a liquid carrier phase which generally results from the introduction of air or gas. The liquid phase contains surfactants to control the surface properties as well as stability of the bubble. Microbubbles are manufactured from biocompatible materials, so they can be injected intravenously. Microbubbles have an average size (1-8 µm) less than that of RBC's i.e. they are capable of penetrating even into the smallest blood capillaries & releasing drugs or genes, incorporated on their surface, under the action of ultrasound. Ultrasound radiation are used which are non hazardous. Most of the physicians today prefer imaging with ultrasound in combination with microbubbles compared to other diagnostic techniques for low cost and rapidity. The ultrasonic field can be focused at the target tissues and organs; thus, selectivity of the treatment can be improved, reducing undesirable side effects. Recently, targeting ligands are attached to the surface of the microbubbles, which have been widely used in cardiovascular system, tumour diagnosis and therapy. This review focuses on the characteristics of microbubbles that give them therapeutic properties and some important aspects of ultrasound parameters that are known to influence microbubble-mediated drug delivery. In addition, current studies involve discussion of novel therapeutical application of microbubbles.