Drug delivery system definition

V. J. Stella, Prodrugs An overview and definition, in Prodrugs in Novel Drug Delivery Systems (T. Higuchi and V. Stella, eds.), American Chemical Society, Washington, DC, 1975, p. 1. 

Clearly, the definitive characteristic of any nanoparticulate drug delivery system will be its submicrometer diameter. Sizing such particles in the suboptical region can be difficult as the measuring technique itself may alter size and properties by either hydrating or aggregating the particles. This will have a profound influence on the size of the particle [59]. Haskell [134] has discussed the various optical techniques available to measure the size of nanoparticles. 

Figure 1 Increasingly complex drug-delivery systems erode definitive differentiation between drug and excipient. ...

Chickering, D.E., III, and E. Mathiowitz, eds. 1999. Definitions, mechanisms and theories of bioadhesion. In Bioadhesive drug delivery systems Fundamentals, novel approaches and development, 1. New York Marcel Dekker. 

Chickering, D. E., and Mathiowitz, E. Definitions, mechanisms, and theories of bioadhesion, in Bioadhesive Drug Delivery Systems Fundamentals, Novel Approaches, and Development, New York Marcel Dekker, 1999. 

This section focuses on adhesives that are used for the assembly of medical devices. In medical device assembly, the primary substrates are plastics, elastomers, and metals. The total medical adhesive market is much larger since it encompasses a broader definition of products. For example, medical adhesives can be used for bonding human tissue, transdermal drug delivery systems, dental restoration, and wound care in addition to medical device assembly. 

It is now conventional wisdom to point out that chemical engineering is rapidly spreading into new technical areas described by such words as electronic materials, green chemistry, ecology, smart materials, drug-delivery systems, etc., etc., and above all, biotechnology. Because it is so difficult to give a contemporary definition of... 

When new drugs and drug-delivery systems are developed in the laboratory, the correlation of the necessary production equipment may be very difficult indeed. For example, the shear needed to create the desired particle size of an emulsion with the help of laboratory equipment may pose serious problems in the selection of plant equipment necessary to reproduce the attributes of the product. Recording the speed of a laboratory mixer is not sufficient by itself for this task definition of the operating principle and equipment design is necessary to accomplish the task. 

Stella, V. Pro-drugs an overview and definition. In Pro-drugs as a Novel Drug Delivery System (Higuchi, T., Stella, V., Eds), Vol. 14. American Chemical Society Washington, DC, 1975, pp. 1—115. 

Huge advances have been made over the last 15 years in the research, development, application, commercialization and understanding of the mechanisms of action of nanoscale drug delivery systems. Many of these advances have had a spectacular impact on the prevention, diagnosis and treatment of a wide range of diseases. This is especially trae in the treatment of many cancers, and it is in the oncology field that the majority of the formulation advances have been made. Pharmaceutically, the most important nanotechnologies are exemplified and discussed below (see Table 39.10 for definitions and descriptions). 

By definition, drug delivery systems allow patients to take their medication in a convenient and effective manner. They are designed to be the most appropriate dosage form to suit the patient and to treat a specific disease. Ultimately, efficacy and safety while limiting side effects are improved along with compliance. 

Thompson D, Chaubal MV. Cyclodextrins (CDS)-excipients by definition, drug delivery systems by function (part F injectable applications), Drug Deliver Technol 2000 2 34-38. 

Sources Derjaguin, B.V. and Smilga, V.P., Adhesion Fundamentals and Practice, McLaren, London, U.K., 1%9 Chickering, D.E. and Mathiowitz, E., Definitions, mechanisms, and theories of bioadhesion, in Bioadhesive Drug Delivery Systems Fundamentals, Novel Approaches, and Development, Mathiowitz, E., Chickering, D.E., and Lehr, C.M., Eds., Marcel Dekker, Inc., New York, 1999. 

The results lately obtained, although very interesting and promising, definitely do not cover all the aspects and do not answer all the questions addressed by the fascinating field of lyotropic liquid crystals and their applications as drug delivery systems. Clearly, many additional experiments need to be carried out in order to clarify the detailed structure, the exact properties, and specific potential of these systems. We hope that we at least opened a new window and provided new thoughts and interest into this rapidly growing field of research. 

The third reason why biocompatibility cannot be equated with inertness is that there are several, and indeed an increasing number, of applications which involve intentionally degradable materials. The two most widely quoted situations here are absorbable sutures and implantable drug delivery systems but many more circumstances where degradable scaffolds and matrices could form an essential component of a device are envisaged. If biocompatibility is predicated on inertness, then degradable materials cannot, by definition, be biocompatible. This clearly does not make sense and suggests that the concept of biocompatibility needs to be altered. 

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