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Pharmaceutics: New Challenges, New Paradigms

Alexander T. Florence

Centre for Drug Delivery Research, The School of Pharmacy, University of London, London, U.K.

Juergen Siepmann

Department of Pharmaceutical Technology, College of Pharmacy, Universite Lille Nord de France, Lille, France

INTRODUCTION Background

The essence of pharmaceutics, as many of the chapters in the two volumes of this book illustrate, is the amalgamation of physical science (physical pharmacy) with aspects of biological science. It is a distinct discipline quite different from biophysics or chemical biology because at its center is not only the dosage form with its active and inactive ingredients but also the behavior of the ensemble in the environment in which these medicines are used, generally in human subjects. Pharmaceutics has existed as a discipline within pharmacy and the pharmaceutical sciences for a long time. It is difficult to discern the origins of the term, although one can deduce from the evolution of textbooks of pharmaceutics something about its development. From the early days of the 20th century to the mid-1950s, it was concerned primarily with the science and practice of the manufacture of medicines (dosage forms) on small and large scales and the preparation of galenicals. It was viewed sometimes as a discipline without much regard to the fate of the dosage form in vivo. However, this is not really the case. For example, the 1924 edition of Martindale and Wescott's The Extra Pharmacopeia (1) discusses enteric coating of tablets to minimize the effects of drugs on the intestinal mucosa in the following words:

Various substances have been proposed for the coating of pills, tablets and capsules to render them insoluble in the stomach but soluble in the intestines, i.e. on reaching the duodenum. Drugs, for example, which irritate the mucous membrane and the administration of which is liable to induce vomiting, and substances intended to act solely on the intestines and the anthelmintic drugs, have been so given. Keratin, as usually employed, seldom brings about the desired effect.

Here there is clear concern for the usefulness of formulations and the therapeutic consequences of their composition. The use of keratin-coated pills is reported in a Lancet paper in 1893 (2), but the process is accredited to a German, Dr Unna, who first marketed such products (3). There were concerns about the quality of such systems, particularly product ageing, and it is interesting that as early as 1938, an X-ray study was carried out on the disintegration in vivo of keratin-coated systems (4). The first commercial sustained-release preparations emerged in the late 1940s with the Spansuleā„¢, which contained wax-coated beads with different release properties in a soluble capsule, thus controlling release of the drug in the GI tract.

The term biopharmaceutics was an invention of the 1960s. The nature of the dosage form was from then on inextricably linked with its performance in patients. Micro-encapsulation of drugs, encouraged by the National Cash Register Company (NCR) patents on carbonless copy paper at the time (5), was adapted to the development of controlled- or sustained-release products, and this has more recently evolved into nanotechnological approaches. Nanotechnology began in the pharmaceutical domain, much before the current vogue for all things "nano," with Peter Speiser and his coworkers in the 1970s in Zurich developing "nanoparts" and nanocapsules (6). Pharmaceutical nanotechnology, therefore, is not as new as some of its proponents would have us to believe. Table 1 is a brief summary of just some of the key events in pharmaceutical technology.

Table 1 Key Development of Controlled-Release Systemsa

Date

System

Remark

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