5
Health Products
5.1 The health industry
Along with plastics, organic compounds used for health purposes were the great growth area in
synthetic chemistry in the 20th century. Taken as a whole, the health product industry is quite
diverse in its areas of contact with consumers, covering such products as:

pharmaceuticals

herbal medicines

toiletries

cosmetics
Is there a difference between these four sectors of the health product industry? In some ways yes,
but when you try to define how each differs, the distinctions can be hard to draw at the edges.
CLASS EXERCISE 5.1
Define what you understand by the products in these four sectors. Give some examples of products
that you are aware of, belonging to each category.
Pharmaceuticals
Herbal medicines
Toiletries
Cosmetics
In Australia, there is at least a division for pharmaceuticals, which are tightly regulated by law – the
Therapeutic Goods Act, which controls the manufacture, distribution, marketing and sale of a range
of products used in the health area. Currently, the Australian Register of Therapeutic Goods holds
information on approximately 25,000 drug and 30,000 device products.
Commonwealth legislation, through the national Health and Medical Research Council
(NHMRC) has also created a Standard for Uniform Scheduling of Drugs and Poisons, which sets out
the basic control mechanism for a large number of chemicals, not just pharmaceuticals. Table 5.1
shows this set of schedules. The Schedule number for a given product used to be printed on the
label of the medicine (eg S2 on Panadols), but is no longer done.
5. Health Products
TABLE 5.1 NHMRC Drug & Poison Schedules
Schedule
Property of Poison
Availability
1
Not currently in use (applied to substances
not in normal use)
2
Drugs (medicinal poisons for therapeutic use) Pharmacy retail
3
Drugs of higher potency
Restricted pharmacy retail
4
Prescription (dangerous) drugs
Medical/dental/veterinary prescription
5
Domestic poisons
General retail
6
Industrial and agricultural poisons
Restricted retail
7
Special poisons (including industrial
chemicals)
Restricted wholesale
8
Drugs of addiction
Restricted medical/dental/vet
prescription
9
Prohibited substances
CLASS EXERCISE 5.2
Provide an example of each of the classes of goods.
Schedule
Examples
2
3
4
5
6
7
8
9
5.2 Pharmaceuticals
The use of chemical substances to deal with health problems dates back into ancient history. There
are references in ancient Egyptian records (1550 BC) to the use of plant materials for curing disease
(or at least attempting to!). During the 19th century, the extraction, isolation and examination of
active components of plant materials became common. Early medications were mainly alkaloids –
nitrogen‐containing organic compounds with a bitter flavour, and very often highly pharmaceutically
active. The toxic properties of the mandrake, poppy and nux vomica plants are due in most part to
their alkaloid constituents, atropine, morphine and strychnine, respectively. Nicotine and caffeine
are also alkaloids.
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5. Health Products
Examples of non‐alkaloid compounds, now widely used as modern pharmaceuticals, which
were originally derived from plant origins are aspirin, which was isolated from willow bark potions
used to treat pain and fever, and ephedrine (a bronchodilator ‐ opens the breathing tubes in the
lungs) which was isolated from a Chinese herbal remedy. The structures of these compounds are
shown in Figure 5.1. Today most drugs are manufactured rather than extracted from other plants
and animals (although genetic engineers are reversing this trend).
Table 5.2 shows the evolution of the pharmaceutical industries, through important discoveries.
Table 5.3 shows the most commonly used pharmaceuticals worldwide and in Australia.
TABLE 5.2 A brief history of the development of the pharmaceutical industry
1785
1803
1818
1820
1831
1844
1846
1847
1867
1876
1884
1898
1899
1902
1903
1905
1907
1910
1911
1912
1921
1929
1933
1935
1936
1937
1941
1943
1948
1950
1952
Use of digitalis for heart disease
Morphine isolated from opium poppy
Strychnine isolated
Quinine isolated from cinchona bark
Atropine isolated
Nitrous oxide used as an anaesthetic
Ether used as an anaesthetic in surgery
Chloroform used as an anaesthetic
Amyl nitrite used for angina
Salicylates found to be painkillers
Cocaine found to be local anaesthetic
Barbital used as sedative
Aspirin synthesised and marketed by Bayer
Adrenalin isolated from the adrenal gland
Veronal (barbital – the first barbiturate) synthesised
Organic arsenic compounds used for treatment of syphilis
Ergot alkaloids found to counteract adrenaline
Non‐arsenic compound (salvarsan) used against syphilis
Vitamin studies started
Phenobarbital used as anti‐epilepsy treatment
Insulin isolated
Penicillin discovered
Vitamin C synthesised
Antibacterial activity of sulfonamides discovered and used on humans
Pethidine, the first synthetic narcotic, synthesised
Antihistamines discovered
Penicillin first used for treatment of infection
Diphenylhydramine becomes the first practical antihistamine
Chlortetacycline and chloramphenicol (antibiotics) discovered
Development of the first major tranquiliser, chlorpromazine
Tetracycline discovered
First anti‐inflammatory steroids synthesised
1957
Imipramine used as antidepressant
1960
Oral drugs for mature onset diabetes.
post 1960 It gets really busy!!
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5. Health Products
(a)
(b)
(c)
N CH3
CH3
N
N
O
HO
O
N
O
HO
OH
O
O
(e)
(d)
CH3
CH3
N
N
N
N
O
N
N
CH3
CH3
O
FIGURE 5.1 Common alkaloids (a) atropine (b) morphine (c) strychnine (d) nicotine (e) caffeine
TABLE 5.3 The most prescribed drugs in Australia (12 months to June 30, 1996)
Item
Example of drug name
Drug Type
No. of scripts (‘000s)
Paracetamol
Panamax
Analgesic
3,754
Simvastatin
Zocor
Cholesterol reducing
2,871
Panadeine
Analgesic
2,704
Enalapril
Renitec
Blood pressure
2,519
Ranitidine
Zantac
Antacid (ulcers)
2,475
Temazepam
Normison
Sedative
2,362
Salbutamol
Ventolin
Anti‐asthmatic
2,078
Atenolol
Tenormin
Beta‐blocking agent
1,930
Fluvax
Vaccine
1,715
Oxazepam
Serepax
Sedative
1,423
Diazepam
Valium
Sedative
1,175
Frusemide
Lasix
Diuretic
1,103
Amoxycillin
Amoxil
Antibiotic
1,087
Roxithromycin
Rulide
Antibiotic
987
Isosorbide
Imdur
Cardiac therapy
980
Paracetamol + codeine
Influenza vaccine
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5. Health Products
How Does a Drug Work?
This is a very difficult question to answer as there are thousands of drugs and thousands of different
modes of drug action, but many drugs work on the principle that their specific shape, size and
localised chemical structures (eg functional groups, polarity, charge) allows them to bind to an active
site in the body, and this causes a desirable effect (such as suppression or release of a pain causing
substance etc.). From this you may deduce that the three dimensional shape of many drugs is vitally
important for them to work. This is why it is often less expensive to obtain drugs from nature rather
than manufacture them, as nature uses enzymes which get all of the chiral centres shaped just right.
If even one chiral centre is wrong the chances are that the drug will be the wrong shape and
therefore totally inactive.
Developing a Pharmaceutical Product
Pharmaceutical products are simply not discovered and sold. There are many steps in between the
discovery of a substance with important pharmaceutical properties, and its appearance in the
pharmacists shop. These steps would normally take up to 10 years, as rigorous government codes
control the sale and development of any product intended for pharmaceutical use.
The steps involved in the development of a typical prescription pharmaceutical product
include;
 discovery of the active substance
 isolation of the active compound
 toxicological testing and clinical trials
 sale under prescription
Generally it is only a small part of the structure of an active drug which is responsible for the
pharmaceutical effect (see Figure 5.2 for a series of local anaesthetics). Often undesirable side effects
(such as addiction and hallucinogenic episodes) can be reduced or removed from a commercial
product as they are caused by a different part of the chemical structure. Hence the chemist’s job is:
1. to identify the active substance in a pharmaceutical preparation
2. to identify the parts of the chemical structure of active substance which give rise to the desired
effect (an those which cause undesirable side effects)
3. to design and prepare
(a)
(b)
CH3
O
N
CO2CH3
O
N
H
H2N
O
H
C
O
(c)
(d)
CH3
NH
O
CCH2N
CH2CH3
CH2CH3
O
H2N
CH3
O
FIGURE 5.2 Common local anaesthetics (a) cocaine (b) procaine (c) xylocaine (d) benzocaine
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5. Health Products
Pharmaceuticals of a particular class (eg local anaesthetics) are also designed to meet other
requirements, such as length of duration. This is essentially reflected by the rate at which the
compound is decomposed (metabolised) in the body. The slower it is broken down, the longer it will
remain active in the body. This is often achieved by “tinkering around the edges” of the active part
of the structure, changing the attached chains or introducing groups that allow more rapid
breakdown. Table 5.4 shows the half‐lives of some common drugs: the time for half of the dose to be
metabolised in the body.
TABLE 5.4 Half‐lives of common drugs in the body
Drug
Aspirin
Amoxycillin
Time (hours)
0.25
1
Caffeine
4‐6
Cocaine
0.5‐1
Diazepam
12‐24
Erythromycin
Nicotine
1‐2
1.5‐2.5
Nitroglycerine
2 minutes
Phenobarbital
100
Phenylbutazone
60
Streptomycin
4‐6
Tetracycline
10‐12
The synthesis of modern pharmaceuticals is exceedingly complex and the organic chemistry is very
involved. Firstly, the drugs are quite complex in their structure, and secondly, they need to be made
on an industrial scale, even though they will be first made in the laboratory.
Important Classes of Pharmaceutical Products
There are now huge numbers of prescription drugs on the market. It would be almost impossible to
cover them , even briefly in this course so we will choose a few of the more important classes any
examine their chemical structures and its link to biological activity. Some of the more important
classes of drugs include:
 analgesics ‐ responsible for alleviating pain
 general anaesthetics ‐ used to place the patient in an unconscious state
 local anaesthetics ‐ used to prevent the patient feeling pain in a specific area of the body
 tranquilisers ‐ promote a feeling of calm and remove stress
 stimulants ‐ increase the rate of biological activity of the recipient
 sedatives – reduce worry and anxiety
 antibacterial agents ‐ kill bacterial infestations
 anti‐inflammatory agents ‐ prevent tissue inflammation (swelling and reddening)
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5. Health Products
5.3 Complementary Medicines
Complementary medicines include herbal or traditional medicines, together with vitamins and
mineral supplements.
The herbal extract group is based on thousands of years of tradition in
various cultures, eg Chinese, where certain extracts from natural materials (plant and animal) are
known to be medically effective, though hard scientific proof may not be necessarily available.
Vitamins and minerals are proven dietary requirements, a deficiency of which is associated
with various health problems, eg vitamin C with scurvy. Some diets may be lacking in one or more of
the substances, therefore requiring a top‐up by way of a capsule or tablet.
These products are not subject to the same level of control as the mainstream
pharmaceuticals. In Australia, they still require listing, but not registration under the Therapeutical
Goods Administration.
Listed medicines are usually considered to be relatively benign, so the regulations allow for
sponsors to 'self assess' their products in some situations The majority of Listed medicines are self‐
selected by consumers and used for self‐treatment.
They are all unscheduled medicines (i.e. not described in the SUSDP) with well‐known
established ingredients, usually with a long history of use, such as vitamin and mineral products or
sunscreens. These are assessed by the TGA for quality and safety but not efficacy.
This does not mean that they do not work. It simply means that the TGA has not evaluated
them individually to see if they work. It is a requirement under the Act that sponsors hold
information to substantiate all of their product's claims.
5.4 Surfactants
Polar and non‐polar substances do not mix under normal circumstances. Surfactants are special
substances whose molecules possess both polar and non‐polar portions which encourage two
normally immiscible substances to mix.
The polar portion of the molecule can be ionic (positively or negatively charged or both) or
possess polar organic functional groups (eg OH), and will be a relatively small part of the molecule. It
is often referred to as the head.
The non‐polar portion of the molecule will be organic, and feature a long chain of carbons
atoms, sometimes purely singly‐bonded, sometimes with a few double bonds, and in some cases, an
aromatic ring. The chain can be straight or branched. It will be the larger portion of the molecule,
and is often referred to as the tail. Figure 5.2 shows the structure of a generic surfactant.
non-polar tail
polar head
FIGURE 5.2 A generic surfactant
The term surfactant in general means surface active agent, and applies to all substances which
allow polar and non‐polar substances to mix. The most common examples of this are soaps,
detergents and emulsifying agents. In this chapter we will examine the chemical and physical
properties of these substances, and discuss some typical applications.
Soap
The term soap refers to any molecule with the general formula RCOO‐Y+ where R = a long
hydrocarbon chain CH3(CH2)10‐16 and Y = Na+ or K+, i.e. the salt of a long chain alkanoic acid. Figure 5.3
below shows a typical soap molecule.
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5. Health Products
O
+
Na
O
FIGURE 5.3 Typical soap molecule ‐ sodium palmitate
Soap Manufacture
Soaps are normally produced by the hydrolysis of triglycerides with strong alkalis such as sodium or
potassium hydroxide.
EXERCISE 5.3
What is the structure of a typical triglyceride?
The least expensive source of triglycerides are animal fats and vegetable oils, hence soaps are
normally produced, which is essentially just the reverse of the esterification reaction which produces
the triglyceride. This reaction is known as saponification.
EXERCISE 5.4
(a) Draw the structure of the products of the saponification by NaOH of the following triglyceride.
CH2-O-CO-(CH2)13CH3
CH-O-CO-(CH2)15CH3
CH2-O-CO-(CH2)13CH3
(b)
What type of molecule is the soap molecule – acid, base, neutral?
The properties of the soap are determined by:
the nature of the cation, and

the length and functionality of the non‐polar region of the molecule.

Soaps produced using sodium hydroxide (sodium salts of fatty acids), are known as hard soaps and
are generally used in the production of cake soaps for the bathroom and laundry. Those produced
from potassium salts are known as soft soaps, and are generally used in liquid soap preparation and
as shaving creams.
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5. Health Products
Cations other than sodium and potassium (eg calcium and magnesium) tend to produce insoluble
soap compounds (eg the so‐called “ring around the bath”), and are the cause of soap failure in hard
water (no lathering or cleaning action)
The use of different triglycerides in the manufacturing process also modifies the properties of
soap. The most common sources of triglycerides are beef fat (commonly known as tallow) and palm
oil. Beef fat gives a soap which is principally sodium stearate, whilst palm oil gives a soap which is
mostly sodium palmitate. Other special purpose soaps use more exotic triglycerides, such as tea tree
oil, or avocado to change the cleansing properties of the soap or to provide some mild antiseptic
action (medicated soaps).
Detergents
Soaps are good cleaning agents, in that they are biodegradable (are readily broken down by
bacteria), and inexpensive, but they do not work in hard water areas and their alkalinity can be a
problem in some circumstances. For this reason other surfactant molecules have been developed
which do work in hard water and are not manufactured from fatty acid anions.
Detergents are synthetically produced surfactant molecules. Like soaps, they contain a polar
head and a non‐polar tail. The tail portion is again a long hydrocarbon chain or a hydrocarbon chain
with branches and/or aromatic groups substituents, but the head group is a species which will not
form precipitates in hard water.
There are four basic polar group types:

anionic ‐ have a head group which carries a negative charge like soap molecules, but have a
different functional group, such as a sulfonic acid salt (SO3‐); an example of this is a alkyl
sulfonate shown in Figure 5.4(a)

cationic ‐ have a head group which carries a positive charge such as a alkylammonium group
(NR3+) (see Figure 5.4(b))
non‐ionic ‐ have a polar non‐ionic head group such as a polyalkanol (see Figure 5.4(c))

amphoteric ‐ carry both positive and negative head groups (see Figure 5.4(d))

(a) sodium lauryl sulfate
O
S
O
Na
+
O
(b) cetyl trimethyl ammonium bromide
N(CH3)3+
Br
(c) lauryl alcohol ethoxylate
CH3(CH2)10CH2O(CH2CH2O)5CH2CH2OH
(d) coco imidazoline betaine
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5. Health Productss
CH3
N+--CH2COO-CH3
FIGUR
RE 5.4 Structurres of typical surfactants (a) an
nionic (b) cation
nic (c) non‐ionicc (d) amphoteriic
TABLEE 5.5 Common applications
a
off different surfactant types
Surfa
actant Type
Applicattions
Anion
nic
Cleaningg – hard water hand
d washing, dishwashin
ng liquids, toothpaste,,
shampo
oo, carpet cleeaner
Catio
onic
Mouthw
wash, fabric softener,
s
bacctericide
Non‐ionic
Emulsifyying agents (foods, cosmetics)
hoteric
Amph
Shower gel, hair shaampoo for seensitive skinss (eg babies)
Surfa
actant behavviour
When
n a very sm
mall amount of surfactan
nt is added to water, the
t molecule
es dissolve through
t
the
e
solveent, but are unstable
u
because of the large
l
hydrocarbon chains. Thereforee, as more molecules
m
are
e
added, they tend
d to gather into
i
small cllusters called
d micelles (aas shown in Figure 5.5).. Moleculess
mselves in a single layer (known as a monolayer) so that th
he non‐polarr
near the surface orient them
ns stick out in
nto the air (ssee Figure 5.6
6).
chain
FIGUR
RE 5.5 A micelle
FIGUR
RE 5.6 Surface monolayer
m
ning ability
Clean
Dirt, grease, oil and
a similar materials
m
are
e mixtures off non‐polar substances,
s
which is whyy they don’tt
a
The
T bipolar nature
n
of surfactant mollecules allow
ws the dirt to
o
wash away in watter without assistance.
w
and rin
nsed away by creating sm
mall “drople
ets” of dirt su
urrounded by
b surfactantt
be dispersed in water
(essentially the saame as a purre micelle) (ssee Figure 5.7).
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5.10
5. Health Products
FIGURE 5.7 The cleaning process
Emulsification
These are colloids formed between oil and water e.g. mayonnaise, margarine, cosmetic creams.
These come in two forms:
 oil/water emulsions ‐ where the oil is the dispersed phase (equivalent to the solute) and the
water is the dispersing medium (equivalent to the solvent), e.g. mayonnaise.
 water/oil emulsions ‐ where the opposite is the case i.e. water is the dispersed phase and oil is
the dispersing medium, e.g. cream.
Surfactants are used to stabilise emulsions (known as emulsification), by forming micelles and
preventing re‐agglutination of the oily droplets. It is basically the same process that occurs in
cleaning a greasy surface, differing only in that the proportions of the two phases are likely to be
closer together.
Biodegradability
The term biodegradable with regard to surfactants refers to the natural decomposition of the
surfactant substance by micro‐organisms commonly found in our waterways. The first detergents
were branched chain sulfonates. The branching prevented bacteria and other natural organisms
from breaking the compounds down, meaning that they accumulated in waterways, causing
substantial problems, such as foaming, suffocation of marine organisms and high biological oxygen
demand
Newer surfactants, such as alkylbenzene sulfonates (ABS) and linear alkyl sulfonates (LAS), are
designed so that they biodegrade much faster than older surfactants.
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5. Health Products
5.5 Toiletries and cosmetics
Cosmetics and toiletries are substances which are mostly applied to the outside surface of the body
(almost always the skin) to improve the feeling of well being of those being treated. In general they
are not used to improve health, but some are used to prevent damage or infection of the body. In
general the terms cosmetic and toiletry are too closely related to distinguish, and apply to the
following classes of products:

make up
perfumes and fragrances

body soaps

hair shampoos and conditioners


toothpaste
skin care products (including moisturisers, cleansers and lotions)

deodorants

sunscreens

Some of these products are examined in the following parts of this chapter.
Sunscreens
Sunburn is caused by irradiation of the cells in the skin with excessive amounts of UV light. This
causes cellular damage by opening little pockets of enzymes which attack the cell causing pain. The
body has a natural response to UV exposure whereby it increases the concentration of a skin pigment
called melanin. This limits further cellular absorption of UV light, but is a slow process. Sunscreens
act to limit the amount of UV‐visible light reaching the skin by absorbing it and allowing tanning to
proceed at a much slower and safer rate.
Substances which are effective sunscreens must contain chemical groups which will absorb UV
light in the region of 290‐320nm (known as UV‐B, UV‐A is higher wavelength, UV‐C lower), but allow
transmission of other light frequencies. The substances which do this best contain an aromatic ring.
The efficiency of a sunscreen is measured by its sunscreen protection factor (SPF). Typical
values are 4, 8, 15 and 30+. The number is a ratio of the amount of time skin protected by the
sunscreen takes to redden compared to unprotected skin. An higher SPF is due to higher
concentrations of the absorbing compound. A SPF4 may have 2‐3% of absorber, while SPF30+ will
have up to 20%.
Soaps & detergents
As you have seen in the Surfactants section, these do the same thing, but differ chemically and in
their source of production: soaps from animal and plant fats, detergents from synthetic sources.
Their properties are determined by:

the nature of the polar head, and
the length and functionality of the non‐polar region of the molecule.

Soaps produced using sodium hydroxide (sodium salts of fatty acids), are known as hard soaps and
are generally used in the production of cake soaps for the bathroom and laundry. Those produced
from potassium salts are known as soft soaps, and are generally used in liquid soap preparation and
as shaving creams. In Australian personal soaps, the fatty acid content must be greater than 70%.
Cations other than sodium and potassium (eg calcium and magnesium) tend to produce
insoluble soap compounds (eg the so‐called “ring around the bath”), and are the cause of soap
failure in hard water (no lathering or cleaning action)
The use of different triglycerides in the manufacturing process also modifies the properties of
soap. The most common sources of triglycerides are beef fat (commonly known as tallow) and palm
oil. Beef fat gives a soap which is principally sodium stearate, whilst palm oil gives a soap which is
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5. Health Products
mostly sodium palmitate. Other special purpose soaps use more exotic triglycerides, such as tea tree
oil, or avocado to change the cleansing properties of the soap or to provide some mild antiseptic
action (medicated soaps).
Soaps are good cleaning agents, in that they are biodegradable (are readily broken down by
bacteria), and inexpensive, but they do not work in hard water areas and their alkalinity can be a
problem in some circumstances. For this reason other surfactant molecules have been developed
which do work in hard water and are not manufactured from fatty acid anions.
Toothpastes
Toothpaste performs three basic functions:
removal of stain from the teeth

improve the health of teeth and gums

freshening of the breath and mouth

Mild abrasives, fluoride and various flavours, respectively achieve these purposes. These ingredients
must be presented in a medium to allow convenient consumer use. This is normally a soft paste,
whose rheology – the study of the deformation and flow of materials – is absolutely critical in
determining the usability of the product.
TABLE 5.7 Ingredients of toothpastes
Ingredient
Function
Examples
Typical %w/w
Abrasive
Helps to remove stains and adhered
particles
Calcium carbonate
Hydrated silica
15‐50
Humectant
To provide a creamy base which
doesn’t dry out
Sorbitol
20‐50
Binder
To improve the rheology
Carboxymethyl cellulose
Calcium carrageenate
10
Surfactant
To provide foam and cleaning action
Sodium lauryl sulfate
1‐2
Flavour
To improve mouth freshness and
flavour of paste
Peppermint oil,
saccharin
1‐2
Active agents
To improve health of teeth and gums
Fluoride
Water
To assist formulation
Others
Colour/fragrance/ preservatives
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1
20
Sodium benzoate (pres.)
1
5.13