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Text A The scope of pharmacology
Background
Definition of Pharmacology
The study of drugs, their sources, their
nature, and their properties. Pharmacology is
the study of the body's reaction to drugs. It
emerged as a major area in American medicine
largely due to the efforts of John Jacob Abel
(1857- 1938) who stressed the importance of
chemistry in medicine, did research on the
endocrine glands内分泌, first isolated
epinephrine肾上腺素(adrenaline), crystallized
insulin结晶胰岛素 (1926), and became the first
pharmacology professor in the U.S.
phar‘ma·co·log’ic
 phar‘ma·co·log’i·cal （adj.）
 phar‘ma·co·log’i·cal·ly （adv.）
phar'ma·col'o·gist n.
World of the Body: pharmacology
 Pharmacology deals with all aspects of the actions of drugs
on living tissues, particularly their effects on man. Drugs'
actions, both at the molecular level (interaction of drug
molecules with receptors) and also at the macroscopic or
whole-body level (such as drug effects on the cardiovascular
system), are considered. The subject can be divided into two
main sections; pharmacodynamics药效动力学 and
pharmacokinetics药物代谢动力学 . The first is concerned with
how the effects of a drug are generated, while the second is
concerned with how drugs are distributed around the body,
how they are metabolized, and how they are finally excreted
or eliminated from the body. Discovery of new drugs
proceeds by considering how chemical agents can be used
to potentiate使成为可能 , inhibit, or modify some cellular or
bodily process.
Britannica Concise Encyclopedia（简明不列颠百科全书）:
pharmacology
Branch of medicine dealing with the actions of drugs in
the body — both therapeutic and toxic effects — and
development and testing of new drugs and new uses
of existing ones. Though the first Western
pharmacological treatise论文;专著(a listing of herbal
plants) was compiled in the 1st century AD, scientific
pharmacology was possible only from the 18th century
on, when drugs could be purified and standardized.
Pharmacologists develop drugs from plant and
animal sources and create synthetic versions of
these, along with new drugs based on them or their
chemical structure. They also test drugs, first in
vitro (in the laboratory) for biochemical activity and
then in vivo (on animals, human volunteers, and
patients) for safety, effectiveness, side effects, and
interactions with other drugs and to find the best
dose, timing, and route (mouth, injection, etc.).
Drug products are constantly tested for potency
and purity. See also drug poisoning; pharmacy;
pharmaceutical industry.
pharmacology /phar·ma·col·o·gy/ (-kol´ah-je)
the science that deals with the origin, nature,
chemistry, effects, and uses of drugs; it includes
pharmacognosy生药学, pharmacokinetics药代动
力学, pharmacodynamics 药效学,
pharmacotherapeutics药物治疗学, and
toxicology毒理学.
New words and expressions
 1、biotransformation 生物转化
transform； transformation 转变
 2、chemotherapeutic 化学治疗的；化学治疗剂
chemotherapy 化学治疗
 3、clinician 临床医生
clinic 诊所
preclinical 临床前的
GCP good clinical practice 药品临床研究质量管理规范
 4、diagnosis 诊断
diagnostic 诊断的
diagnostics 诊断学
 5、excretion （排泄物）
excrete 排泄
metabolism 代谢
metabolize 代谢
distribution 分布
distribute 分布
absorption 吸收
absorb 吸收
 6、genetics 遗传学
gene 基因,遗传因子
 7、intoxication 中毒，醉酒
 8 、microbiology 微生物学
biology
生物学
 9、parasite 寄生生物
 10、pathogenesis 发病机制
pathology 病理学
 11、 pharmacognosy 生药学，药材学
 12、 pharmacotherapeutics 药物治疗学
 13、 renal 肾脏的
 14、intelligent 智能
 15、ramification 分枝
Note to text
1、Pharmacotherapeutics deals with the use of
drugs in the prevention and treatment of disease.
Many drugs stimulate or depress biochemical or
physiological function in man in a sufficiently
reproducible manner to provide relief of
symptoms or, ideally, to alter favorably the
course of disease. Conversely,
chemotherapeutic agents are useful in therapy
because they have only minimal effects on man
but can destroy or eliminate parasites. Whether
a drug is useful for therapy is crucially
dependent upon its ability to produce its desired
effects with only tolerable undesired effects.
Exercises
Thus, from the standpoint of the physician
interested in the therapeutic uses of a drug, the
selectivity of its effects is one of the most
important characteristics. Drug therapy is
rationally based upon the correlation of the
actions and effects of drugs with the
physiological, biochemical, microbiological,
immunological and behavioral aspects of
disease. Pharmacodynamics provides one of
best opportunities for this correlation during the
study of both the preclinical and the clinical
medical sciences.
Unit 11
Text B Biopharmacology
New words and expressions
Background
biopharmaceutics
The study of the physical and chemical
properties of a drug and its dosage form as
related to the onset, duration, and intensity of its
action.
Biopharmaceutics is the study of the
interrelationship of the physicochemical
properties of the drug [active pharmaceutical
ingredient, (API)] and the drug product (dosage
form in which the drug is fabricated) based on
the biological performance of the drug.
Table 1 Biopharmaceutic considerations in
drug product design
Active
pharmaceutic
al ingredient
(API)
Stability ,
Solubility ,
pH and pKa,
Crystalline form (polymorph),
Excipient interaction and
computability ,
Impurities ,
Salt form ,
Particle size ,
Drug product
Type of drug product
(capsule, tablet, solution,
etc.) ,
Immediate or modified
release ,
Dosage strength ,
Bioavailability
Stability,
Excipients,
Manufacturing
variables
Complication ,
Physiologic
factors
Route of administration ,
Permeation of drug
across cell membranes ,
Binding to
macromolecules,
Pharmacod- Bioavailability ,
ynamic and Therapeutic objective ,
pharmacoki- Adverse reactions .
netic
consideratio
-ns
Blood flow ,
Surface area ,
Biotransformation
Pharmacokinetics ,
Dose ,
Toxic effects .
Manufacturing Production
considerations methodology and
technology ,
Quality control/quality
assurance,
Specification of raw
materials
Cost ,
Stability testing
Patient
Compliance, labeling,
considerations and product
acceptance
Cost
bi·o·a·vail·a·bil·i·ty
Origin:
1965–70; bio- + availability
The degree to which or rate at which a drug or
other substance is absorbed or becomes
available at the site of physiological activity after
administration.
The physiological availability of a given amount
of a drug, as distinct from its chemical potency.
What is Bioavailability?
Bioavailability is a term used by several
branches of scientific study to describe the way
chemicals are absorbed by humans and other
animals. Bioavailability was once strictly
ascribed to pharmacology, but now has broad
applications in environmental sciences as well.
Examining a substance’s bioavailability in
pharmacological studies helps to determine
dosages of particular medications. A
bioavailability measurement of a medication,
when it reaches circulation in the body,
describes aspects like absorbency and half-life.
It can evaluate medication delivery as well.
Intravenous administrations of medications are
considered to have 100% bioavailability because
they do not pass through the stomach. They are
immediately in the circulatory system. However,
other medications administered at the same time
may reduce the effects of an intravenous
administration and affect its bioavailability.
Pharmacology also distinguishes between
absolute bioavailability and relative
bioavailability. Absolute bioavailability is the
measurement of a medication once it passes
through the gut and is released into the
circulatory system. Relative bioavailability is a
term used to compare different formulations of
the same medication, for example brand name
versus generic.
 Some studies have found that certain generic
preparations are not equivalent in bioavailability to brand
name versions of medications. One example of this is
the drug Synthroid, which is usually marketed in generic
form as thyroxidine. Many patients who use thyroid
replacement therapy find that thyroxidine is not as
effective as Synthroid. Technically, the two medications
should be equivalent, but differences in the bioavailability
of the two forms have been noted in studies. This does
not, however, change most insurance coverage in
regards to this medication. Generally, one will still have
to pay extra to purchase Synthroid.
Other factors can affect bioavailability when
drugs are taken orally. Slow or quick metabolism
can change the absorption rate of medication.
Factors outside of the body, like improper
storage of medications, can lead to less than
expected bioavailability results.
Bioavailability, when used in environmental
sciences, evaluates the rate and amount of toxic
substances that may occur in the body. One
example of this is the recent concern over
mercury levels in fish. Some fish contain high
levels of mercury, a poison, which can lead to
severe illness when ingested in high quantities.
People who eat a lot of fish may be subject to
mercury poisoning. Recent recommendations by
the US FDA suggest consuming mercury-high
fish no more than once a week.
Another bioavailability study that has raised
concern about our relationship to the
environment is the discovery of small amounts of
jet fuel secreted in human breast milk. At this
point, no one has suggested that mothers stop
breastfeeding their children, but the study raises
concerns about many things we take for granted,
like flying planes or rockets, which may in fact
increase risk of health problems to children and
adults.
Bioavailability studies may also compare animal
or plant populations to the presence of toxic
chemicals in an environment. Of concern is the
degree to which these chemicals are present in
animals when they reach the circulatory system,
and what possible effects this may have on
animal populations.
For instance, animal populations, which were
later consumed by humans, consumed plant
populations covered with DDT. Some effects in
humans were increases in certain cancers and
autoimmune disorders. Humans could also
consume DDT through plant material, creating
similar issues. These studies resulted in bans on
DDT, which was once commonly used as a
pesticide.
The bioavailability of toxins in our environment,
when studied, may make significant impacts on
our life quality and choices. These studies are
invaluable, as they can help us approach our
ecology with a sense of responsibility and a view
to the future.
 生物利用度 bioavailability 是指药物被机体吸收进入循环
的相对量和速率，用F表示，F=（A/D）X100%,A为进入
体循环的量，D为口服剂量。影响生物利用度的因素较多，
包括药物颗粒的大小、晶型、填充剂的紧密度、赋型剂及
生产工艺等，生物利用度是药物制剂质量的一个重要指标。
 影响生物利用度的因素包括剂型因素和生理因素两个方面：
剂型因素如药物的脂溶性、水溶性和pKa值，药物的剂型
特性（如崩解时限、溶出速率）及一些工艺条件的差别；
生理因素包括胃肠道内液体的作用，药物在胃肠道内的转
运情况，吸收部位的表面积与局部血流，药物代谢的影响，
肠道菌株及某些影响药物吸收的疾病等。
血药浓度（Plasma Concentration）系指药物吸
收后在血浆内的总浓度，包括与血浆蛋白结合的
或在血浆游离的药物，有时也可泛指药物在全血
中的浓度。药物作用的强度与药物在血浆中的浓
度成正比，药物在体内的浓度随着时间而变化。
Note to text