One of the earliest impressions that many new pharmacy
and pharmaceutical science students have of
their chosen subject is the large number of long and
sometimes unusual~sounding names that are used to
describe the various subject areas within pharmacy.
The aim of this section is to explain to the reader
what is meant by the term 'pharmaceutics', how it
has been interpreted for the purpose of this book,
and how pharmaceutics fits into the overall scheme
of pharmaceutical science. It will also lead the reader
through the organization of this book and explain
why an understanding of the material contained in
its chapters is important in the design of modem
drug delivery systems.
The word pharmaceutics is used in pharmacy and
pharmaceutical science to encompass many subject
areas, which are all associated with the steps to
which a drug is subjected towards the end of its
development - i.e. it is the stages that foUow its discovery
or synthesis, its isolation and purification,
and testing for advantageous pharmacological
effects and the absence of serious toxicological problems.
Put at its most simplistic, pharmaceutics convert
a drug into a medicine. Pharmaceutics, and
therefore this book, is concerned with the scientific
and technological aspects of the design and manufacture
of dosage forms.
Pharmaceutics is arguably the most diverse of all
the subject areas in pharmaceutical science and
encompasses:
• an understanding of the basic physical chemistry
necessary for the efficient design of dosage forms
(physical pharmaceutics)
• the design and formulation of medicines (dosage
fonn design),
• the manufacture of these medicines on both a
smaU (compounding) and a large (pharmaceutical
technology) scale;
• the cultivation, avoidance and elimination of
microorganisms in medicines (microbiology).
Medicines are drug delivery systems. That is,
they are a means of administering drugs to the body
in a safe, efficient, reproducible and convenient
manner. The first chapter in the book introduces, in
a general way, the considerations that must be made
so that this conversion of drug to medicine can rake
place. It emphasizes the fact that medicines are
rarely drugs alone, but require additives to make
them into dosage forms and this in turn introduces
the concept of formulation. The chapter explains
that there are three major considerations in the
design of dosage forms:
1. The physicochemical properties of the drug
itself,
2. Biopharmaceutical considerations, such as how
the route of administration of a dosage form
affects the rare and extent of drug absorption
into the body, and
3. Therapeutic considerations of the disease state
to be treated, which in rum decide the most
suitable type of dosage fonn, possible routes of
administration and the most suitable duration
of action and dose frequency for the drug in
question.
This first chapter is an excellent introduction to
the book as a whole and the perfect justification for
the need tO understand the subject matter of this
text. New readers are encouraged to read this chapter
thoroughly and carefully so they can grasp the
basics before delving into the later, more detailed
information.
Part 1 of this book describes some of the more
important physicochemical knowledge that it is necessary
to have in order to study and understand the
design and preparation of dosage forms. The chapters
have been designed to give the reader an insight
into those scientific and physicochemical principles
that are important to the formulation scientist.
They are not intended as a subsrimre for a thorough