About this lecture
This lecture is in two main parts, viz, Drug delivery systems and Pharmaceutical
biotechnology. The former will be considered first. However, as you will observe
in the course of the lecture, there is significant overlap between the two topics.
Introduction to Drug Delivery Systems
Ever since man began to treat various disease states with medicinal agents, the
need to present medicines in the most suitable physical form for delivery to their
sites of action has persisted. Some of the earliest drug delivery forms include
solutions, suspensions and powders. Soon, cachets, pills, tablets and emulsions
In the early years and probably up to the middle of this century, formulation and
production of drug delivery systems were far more of an art than science. The
main objective then was to deliver the therapeutic agent in an administrable form.
Little attention was paid to such desirable formulation objectives as masking
unpleasant taste and odour, better aesthetics, controlled and/or prolonged drug
action, and enhanced patient acceptance. In the last four decades, however,
particularly with the advent of the use of synthetic polymers in pharmaceutical
formulation, there have been concerted and accelerated efforts to move towards
perfection in drug delivery. Today, far more progress than was thought possible
60 years ago has been made in this field.
Several of the new drug delivery systems are still not available in the West
African market due to their high cost. This situation is, however, expected to
change in the years ahead. Therefore, there is a need to continually keep
abreast of rapid developments in the highly dynamic area of drug delivery
technology. This lecture is an effort in this direction.
In this lecture, no attempt will be made to discuss all the new drug delivery
systems that have been invented nor will any of them be treated in great detail
since a rapidly expanding field such as this cannot be adequately treated in a
presentation of this nature. However, some of the more novel, exciting and
promising advances that have been attained in drug delivery design will be
highlighted. All the systems that will be examined have gone beyond the
conceptual stage. They are either at the laboratory stage, undergoing clinical
trials or already in the market.