oral solutions

1. PHARMACEUTICAL ORAL SOLUTIONS
DR SAMIA GHANI
M.PHIL PHARMACEUTICS
1

2. LIQUID DOSAGE
FORMS
2
• One of the oldest dosage forms used in treatment.
• Rapid & High absorption of soluble medicinal products .
Particular use for individuals having difficulty in swallowing SDF
(e.g.: Pediatric, Geriatric, Intensive care & Psychiatric)
Patients. Solutions are homogeneous liquid preparation
containing one or more completely dissolved components
(One-phase system).
• Active ingredients dissolved within vehicles to obtain uniform
sols.
• In general, water used as vehicle in w medicaments dissolved,
water is Non-toxic, Nonirritant, Tasteless,
Relativelycheap, and many drugs are water soluble
(Aqueous sol.)
• Some drugs not water soluble so mixed with other solvents
NonAqueous
2

3. SOLUTIONS:
DEFINITION
3
• Pharmaceutical solutions are extensively used as dosage forms for
the oral administration of therapeutic agents.
• Pharmaceutical solutions defined as liquid preparations in which the
therapeutic agent and the various excipients are dissolved in the
chosen solvent system.
• Pharmaceutical solutions are homogeneous, i.e. the therapeutic
agent(s) and excipients are dissolved in the vehicle.
• Pharmaceutical solutions for oral administration are in non-sterile
dosage forms.
• Pharmaceutical sol. classified according to their intended use
as
- Otic solution
- Topical solution.
Oral solution,
Ophthalmic solution,
Parenteral preparations
• Sol. categorized by a traditional name related to the solvent
system used and/or their intended function (e.g. Spirits,
Syrups Tinctures, Aromatic waters, and Elixirs).
3

4. 4
• Pharmaceutical solutions contain a range of excipients, each
with a defined pharmaceutical purpose. Examples include:
• The vehicle, usually purified water
• Co-solvents, e.g. propylene glycol, glycerin, alcohol
• Surface-active agents specifically to enhance solubility of
the therapeutic agent in the vehicle.
• Preservatives, e.g. parahydroxybenzoate esters
(methylhydroxybenzoate and propylhydroxybenzoate),
boric acid and borate salts, sorbic acid and sorbate salts.
• Sweeteners, e.g. glucose, saccharin, aspartame
• Rheology (viscosity) modifiers, e.g. hydrophilic polymers
• (cellulose derivatives, alginic acid, polyvinylpyrrolidone)
• Antioxidants, e.g. sodium formaldehyde sulphoxylate,
• butylated hydroxyanisole, butylated hydroxytoluene
• Buffers to regulate the pH of the formulation, e.g. citrate buffer.
4

5. ADVANTAGES OF PHARMACEUTICAL
SOLUTIONS
5
1.The drug immediately available for absorption.
By providing drug in a solution, the dissolution phase
absorption can bypassed → quicker absorption.
2.Flexible dosing is possible. The active ingredient within sol.
present in a certain Conc. per unit volume.
3.Solutions are designed for any route of absorption: the oral
route of administration , via Parenteral preparations
(injections), enemas for rectal use, Topical (for use on skin)
& ophthalmic preparations are all sols.
4.No need to shake the container. Unlike suspensions as
the active ingredient is dissolved within the vehicle.
5.Facilitate swallowing in difficult cases (e.g. infants or the
elderly). It is more easier for patients to take solution
5

6. DISADVANTAGES OF SOLUTIONS
6
1.Drug stability is reduced in Sol by hydrolysis or oxidation.
For this reason, Sol. is commonly has a shorter expiry date
than equivalent solid dosage forms.
2.It is difficult to mask unpleasant tastes.
3.A major disadvantage ; they are much larger & more bulky,
difficult to transport.
Liquids packed in glass bottles are obviously prone to breakage
and cause loss of the preparation.
4.Technical accuracy is needed to measure the dose on admin.
patient accuracy in measuring a dose is required
5.Some drugs are poorly soluble so it is necessary to alter
vehicle or drug form in order to formulate a convenient prep.
6.A measuring device is needed for admin. so need to be
supplied to the patient to be able to measure an accurate dose
6

7. ADVANTAGES & DISADVANTAGES OF PHARMACEUTICAL
SOLUTIONS FOR ORAL ADMINISTRATION
• 1. DRUG AVAILABLE
IMMEDIATELY FOR
ABSORPTION→
BIOAVAILABILITY OF
SOLS IS GREATER THAN THAT
OF ORAL SOLID-DOSAGE
FORMS.
• 2. FLEXIBLE DOSING.
• 3. DESIGNED FOR ANY ROUTE
OF ADMINISTRATION.
• 4. NOT NEED TO SHAKE
CONTAINER.
• 5. FACILITATES SWALLOWING
IN DIFFICULT CASES.
• 1.DRUG STABILITY REDUCED IN
SOL.
• 2. DIFFICULT TO MASK
UNPLEASANT TASTES.
• 3. BULKY, DIFFICULT TO
TRANSPORT & PRONE TO
CONTAINER BREAKAGES.
• 4. TECHNICAL ACCURACY
NEEDED
• TO MEASURE DOSE ON
ADMINIST.
• 5. MEASURING DEVICE
NEEDED FOR
ADMINISTRATION.
• 6. SOME DRUGS POORLY
7
Advantages Disadvantages
7

8. DRUGSOLUBILITY
8
• In pharmaceutical sols both therapeutic drugs and the
excipients are required to be present in sol over the shelf-life.
• As a result solutions are termed homogeneous.
• 1.IF the aqueous solubility of drug is high at the selected pH of
formulation, → therapeutic drug is readily incorporated into
vehicle and formulated as oral sol.
• 2.IF aqueous solubility of drug is moderate at selected pH , i.e.
aqueous solubility is less than requested conc. of drug→ the
solubility of drug in sol. must be enhanced using co-solvents.
• 3.IF aqueous solubility of drug is low at selected pH of
formulation. The difference between aqueous solubility of drug
and the required conc. is too great to the use of cosolvents or
surfactants in the solubilised form & toxic when administered
orally. The drug therefore formulated as a suspension
9

9. FACTORS AFFECTING SOLUBILITY
9
• Physicochemical properties of Therapeutic agent :
• The solubility of drug molecules in a solvent are dependent on
several physicochemical properties, including molecular weight,
volume, density, and number of hydrogen bonds.
• Particle size:
• Reduction of particle size increase the rate of solubility.
• The solubility of a chemically related series of drugs is
inversely related to their melting points; so as the melting
point of drug increased, the solubility decrease.
• The solubility of a drug is directly affected by the type of
chemical substituent groups.
• The solubility of drugs containing hydrophilic groups (e.g.
OH, COO, ammonium ion) will accordingly be greater than
those containing lipophilic substituent groups, e.g.
methyl, ethyl, or chlorine groups.
10

10. 11
• Temperature:
• Most compounds are more soluble in higher temperature.
• pH
• The vast majority of drug subs. are either acids or bases .
• The solubility of therapeutic agents are pH-dependent.
• The solubility of acids & bases increases as the degree of
ionization increases.
• The solubility of acidic compounds increases as the pH
of the sol. is increased (above the pKa) & solubility of
basic comps increase as the pH is lowered below the pKa
Polarity:
Polar comp. more soluble in Polar solvents as water & ethanol .
Non polar comps more soluble in non polar solvents as chloroform
Conc. acid or alkali added to form water- soluble salts.
Conversilly,The organic bases more soluble in organic
solvents than the corresponding salt forms.
10

11. METHODS TO ENHANCE/OPTIMIZE THE
SOLUBILITY
11
1. Appropriate selection of drug salt:
• The majority of therapeutic agents are available in a salt
form, each form a different aqueous solubility.
• Select the drug salt provide the required solubility in
the dosage form.
• 2. Optimization of the pH of the formulation:
• The solubility of ionized therapeutic agent is a function of both
the pKa and the pH of the formulation.
• The acceptable pH range for oral sols is large, ranging from 5 to
8 pH units.
• The selection of a pH value for formulation to optimize the
ionization and solubility of the therapeutic agent is important.
• The Control of pH in formulation is achieved by using a buffer
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12. 13
3. Use of co-solvents :
• Co-solvents are liquid components incorporated into a
formulation to enhance the solubility of poorly soluble drugs.
The Commonly employed co solvents include , glycerol,
propylene glycol, ethanol and polyethylene glycol.
• The final choice of the co-solvent system for a particular
formulation involves consideration of the solubility of the
therapeutic agent in the vehicle, the toxicity of the vehicle and
the cost of formulation.
• The range of concentrations of each co-solvent used in oral
formulations is primarily limited by concerns regarding toxicity.
12

13. FORMULATION OF PHARMACEUTICAL SOL.
13
Drug(s) + Range of excipients include:
The vehicle ( Solvent):
 - Purified Water.
 - Oil
• Co-solvents, e.g. propylene glycol , glycerol, ethanol
surface-active agents
- To enhance solubility of the therapeutic sub. in vehicle.
Preservatives,
- Against microbial contamination
Sweetening agents, e.g. glucose, saccharin, aspartame
Viscosity modifiers, e.g. cellulose derivatives,
Antioxidants, e.g. butylated hydroxytoluene
Coloring & Flavoring agents (oral only)
Buffering agents , to regulate the pH of the formulation,
8

14. EXCIPIENTS USED IN PHARMACEUTICAL
SOLUTIONS
FOR ORAL ADMINISTRATION
14
• Excipients are pharmacologlly inert compounds that are
included in the pharmaceutical formulations.
• T
o facilitate the administration of the dosage form, e.g.
pourability, and palatability,
• To protect the formulation from issues regarding physical
and chemical stability.
• To enhance the solubility of the therapeutic agent.
• Pharmaceutical sols contain a wide range of excipients.
• l- The vehicle:
• The preferred & most commonly used vehicle in sols for
oral administration is Purified Water USP, due to the low
cost and low toxicity .
14

15. VEHICLES (SOLVENTS) FOR LIQUID DOSAGE
FORMS
15
• A vehicle is the medium containing the ingredients of a
drug. In solutions, the vehicle is the solvent.
• The choice of a vehicle depends on:
 The intended use of the preparation
The nature & physicochemical properties of active ingredients.
1. Water as a vehicle
• Water used as the primary solvent; widely available,
relatively inexpensive, palatable and non-toxic for
oral use, non-irritant for external use.
• Water is also a good solvent for many ionizable drugs.
Salts of organic compounds are more soluble in water
• water is the preferred solvent. for solutions to be taken
orally, used ophthalmic ally, or injected.
15

16. TYPES OF WATER
16
Purified Water is intended for use in preparation of
aqueous DF, except those intended for Parenteral
1.Potable water : drinking water, should be palatable &
safe for drinking, Its chemical composition may include
mineral impurities which could react with drugs, e.g. the
presence of calcium carbonate in hard water.
2.Purified water USP, obtained from potable water by
distillation, ion exchange treatment,or reverse osmosis.
Distilled water is purified water prepared by distillation.
Compared with ordinary drinking water:
Purified Water, more free of solid impurities.
When evaporated to dryness, not yield greater than
0.001% of residue (1 mg of total solids /100 mL of sample
evaporated).
administration (injections).
16

17. WATER AS A
VEHICLE
17
3.Water for preparations : potable or freshly boiled and cooled
water, used in oral or external LDF not intended to be sterile.
4.Water for injections: is pyrogen-free distilled water, sterilized
immediately after collection and used for Parenteral
preparations.
5. Chloroform water : used as antimicrobial preservative and
also adds sweetness to preparations. chloroform available as:
Chloroform BP = 100% v/v
6. Aromatic water : saturated solution of volatile oils in water
and are used to provide a pleasant flavor or aroma, e.g.
Peppermint Water, USP.
Used as a vehicle in oral sol. Some have mild carminative action
For example diluted Aromatic waters are usually prepared from
a conc. ethanolic sol. in a dilution of 1 part to 39 parts with water.
17

18. 18
therapeutic agent
• II. Co-solvents
• Employed to increase the solubility of
within the formulation.
• Co-solvents used in the formulation of oral solutions are :
• Glycerol (also termed glycerin)
• Glycerol is a clear odorless, viscous liquid, with a sweet taste
, and miscible with both water and alcohol.
• Its co-solvency properties due to the presence of three
hydroxyl gps;oH. It has similar co-solvency properties to ethanol
Alcohol USP (CH3CH2OH):
• Contain between 94.9 and 96.0% v/v ethyl alcohol(ethanol).
• Commonly used as a co-solvent, both as a single and with
other co-solvents, e.g. glycerol.
• The known pharmacological & toxicological effects of alcohol
have compromised its use in pharmaceutical preparations.
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19. 19
Propylene Glycol USP
• Propylene Glycol is an odourless, colourless, viscous liquid
that contains two hydroxyl groups; oH .
• Used in pharmaceutical preparations as a co-solvent,
generally as a replacement for glycerin.
• III. Miscellaneous agents used to enhance solubility of
• therapeutic agents.
• These include the use of surface-active agents & Complexation.
• A. Surface-active agents
• These are chemicals that possess both hydrophilic (water-liking)
and hydrophobic (water-disliking) regions.
• At dilute conc. surface-active agents will orient at the interface
between two phases (e.g. water/oil), with the hydrophilic and
hydrophobic regions of the molecule being positioned to the
hydrophilic and hydrophobic phases, respectively. 19

20. • DILUTED ALCOHOL, NF:
 EQUAL VOLUMES OF ACOHOL USP AND PURIFIED WATER USP.
 RESULTING MIXTURE IS NOT THE SOME OF INDIVIDUAL
VOLUMES, RATHER 3% LESS DUE TO CONTRACTION OF
LIQUIDS.
 SO THE STRENGTH IS NOT EXACTLY HALF RATHER 49%
• RUBBING ALCOHOL:
 70% ETHYL ALCOHOL BY VOLUME, REMAINDER CONTAINS
WATER, DENATURANTS WITH OR WITHOUT COLOUR ADITIVES,
PERFUME OILS, STABILIZERS.
 EACH 100ML CONTAINS BITTER SUBSTANCE SUCH AS 1.4MG
DENATONIUM BENZOATE OR 355 MG OF SUCROSE OCTA
ACETATE TO DISCOURAGE MIS USE.
 VOLATILE, FLAMMABLE, APPLIED AS RUBEFACIENT EXTERNALLY
AND SOOTHING RUB FOR BED RIDDEN PATIENTS, GERMICIDE
FOR INSTRUMENTS, SKIN CLEANER PRIOR INJ, VEHICLE FOR
20

21. • GLYCERIN, USP (GLYCEROL):
CLEAR SYRUPY LIQUID WITH SWEET TASTE. MISCIBLE WITH
BOTH WATER AND ALCOHOL. AS A SOLVENT, COMPARABLE
WITH ALCOHOL BUT VISCOUS SO SOLUTES ARE SLOWLY
SOLBLE.
LESS VISCOUS RENDERED BY HEATING.
PRESERVATIVE, STABILIZER AND AUXILARY SOLVENT IN
CONJUCTION WITH WATER, USED INTERNALLY.
• PROPYLENE GLYCOL USP:
VISCOUS LIQUID, MISCIBLE WITH WATER AND ALCOHOL.
USED AS SUBSTITUENT OF GLYCERIN
21

22. III. SURFACE-ACTIVE AGENTS
22
• As the conc. increased, the interface will become saturated with
surface-active agent & the molecules that are present in the
shield the
bulk aqueous phase will orient themselves to
hydrophobic regions of surface-active agent.
• This orientation is referred to as a micelle
• The conc. of surface-active agent at this occurs is termed the
critical micelle concentration (CMC).
• In this the core of the micelle represents a hydrophobic
region into which the poorly water-soluble drugs partition.
• For example, if the therapeutic agent is poorly soluble, the
molecule will locate exclusively within the micelle.
• if the drug is water-insoluble but contains polar groups, the
molecule will orient within the micelle, w & drug solubilised
within the colloidal micelles; due to their small size →the
resulting sol. appears homogeneous to the naked eye.
20

23. B. COMPLEXATION
23
• Complexation refers to the interaction of a poorly
soluble therapeutic agent with an organic molecule,
e.g. surface-active agents, hydrophilic polymers to
generate a soluble intermolecular complex.
• One particular concern regarding the use of solution of
drug complexes is the ability of the complex to dissociate
following administration.
• This is particularly important in situations where the
complexing agent is a hydrophilic polymer, as the
high molecular weight of the drug–polymer complex
would prevent drug absorption across biological
membranes.
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24. 24
IV. Buffers:
• Buffers employed within pharmaceutical sols to control pH of
the physicochemical
the formulated product and, to optimize
performance of the product.
• Typically pH control is performed:
To maintain the solubility of therapeutic agent in formulated prod
• The solubility of drugs is pH-dependent , therefore, solubility
of therapeutic agent compromised by small changes in pH
To enhance the stability of the products in which the
chemical stability of the active agent is pH-dependent.

25. 23
• The conc. of buffer salts employed in the oral solutions
should be selected to offer sufficient control of the pH of the
formulation but yet should be overcome by biological fluids
following administration.
• Examples of buffer salts used in pharmaceutical solutions
include:
• ■ Acetates (acetic acid and sodium acetate): about 1–2%
• ■ Citrates (citric acid and sodium citrate): about 1–5%
• ■ Phosphates (sodium phosphate and disodium
phosphate): about 0.8–2%.
• the buffer system used in solution formulations should not
adversely affect the solubility of the therapeutic agent, e.g.
the solubility of drugs may be affected in the presence of
phosphate salts.
25

26. V- SWEETENING AGENTS
26
• Sweetening agents are employed in liquid formulations
designed for oral administration specifically to increase
the palatability of the therapeutic agent.
• The main sweetening agents
preparations are sucrose, liquid
employed in oral
glucose, glycerol,
sorbitol, saccharin sodium and aspartame.
• The use of artificial sweetening agents in formulations
is increasing and, in many formulations, saccharin
sodium is used either as the sole sweetening agent or in
• combination with sugars or sorbitol to reduce the sugar
• concentration in the formulation.
• The use of sugars in oral formulations for children and
patients with diabetes mellitus is to be avoided.

27. VI. VISCOSITY ENHANCING
AGENTS
27
• The administration of oral solutions to patients by using a
syringe, a small-metered cup or a traditional 5-ml spoon.
• The viscosity of formulation must be controlled to ensure the
accurate measurement of the dispensed volume.
• increasing the viscosity of → increase the palatability.
• Certain liquid formulations do not require the addition of VEA,
e.g. syrups, due to their inherent viscosity.
• The viscosity of pharmaceutical solutions increased by the
addition of non-ionic or ionic hydrophilic polymers.
1. Non-ionic (neutral) polymers: – cellulose derivatives e.g.:
● methylcellulose ●hydroxyethylcellulose
• ● hydroxypropylcellulose
• –– Polyvinylpyrrolidone
2. Ionic polymers: – sodium carboxymethylcellulose (anionic)
• – sodium alginate (anionic).
25

28. VII- ANTIOXIDANTS
28
• Antioxidants included in pharm. Sol. to enhance the stability of
drugs that susceptible to chemical degradation by oxidation.
• Antioxidants are compounds that inhibit free radical-induced
drug decomposition.
• Both water-soluble & water-insoluble antioxidants are available.
• Antioxidants for aqueous formulationse eg; Sodium sulphite,
sod. metabisulphite, sod. formaldehyde sulphoxylate and
ascorbic acid.
• Antioxidants used in oil-based solutions e.g; butylated
hydroxytoluene (BHT), butylated hydroxyanisole (BHA) and
propyl gallate.
• Antioxidants employed in low concentrations ( ˂0.2% w/w) .
• Antioxidants employed in conjunction with chelating agents,
e.g. ethylenediamine tetraacetic acid, that act to form
complexes with heavy-metal ions.
26

29. VIII.
PRESERVATIVES
29
• Preservatives are included in pharmaceutical solutions to
reduce or prevent the microbial growth of the formulation.
• Ideally, preservatives should exhibit the following properties:
• 1. possess a broad spectrum of antimicrobial activity
includes Gram-positive,Gram-negative bacteria & fungi.
• 2.be chemically and physically stable over the shelf-life
of the product. 3. have low toxicity.
• Preservatives for use in oral pharmaceutical solutions :
• ■ benzoic acid and salts (0.1–0.3%).
• ■ sorbic acid and its salts (0.05–0.2%).
• ■ Alkyl esters of parahydroxybenzoic acid (0.001-0.2%).
• A combination of two preservatives employed in solutions
to enhance the antimicrobial spectrum.
• Methyl & propyl parahydroxybenzoates (in a ratio 9:1).
27

30. IX. FLAVOURS AND COLOURANTS
30
• The vast majority of drugs in solution are unpalatable,→ so
the addition of flavors to mask the taste of drug subs.
• Flavours added to make a medicine more acceptable to take.
• Four basic taste sensations are salty, sweet, bitter & sour
• – Flavours used to mask a salty taste include:
● butterscotch ● apricot ● peach ● vanilla● wintergreen mint.
• – Flavours used to mask a bitter taste include:
● cherry. ● mint. ● anise.
• – Flavours used to mask a sweet taste include:
● vanilla. ● fruit and berry.
• – Flavours used to mask a sour taste include:
● citrus flavours. ● raspberry.
• A combination of flavours is used to achieve the optimal
taste-masking property.
28

31. X. FLAVOUR
ADJUNCTS
31
• Certain excipients added to oral solution formulations, referred
to as flavour adjuncts (e.g. menthol, chloroform).
• flavour adjuncts add flavor to formulation and in addition, act to
desensitise the taste receptors.
• These agents augment the taste-masking properties .
• Colourants:
• Colours are pharmaceutical ingredients that impart the preferred
colour to the formulation.
• When used in combination with flavours, the selected colour
should ‘match’ the flavour of the formulation,
• e.g. green with mint-flavoured solutions,
• red for strawberry-flavoured formulations.
• Although colours is not a prerequisite for all pharmaceutical sol.,
certain categories of solution (e.g. mouthwashes/gargles) are
normally coloured.
29

32. TYPES OF PHARMACEUTICAL SOLUTIONS
32
.
• Pharmaceutical sols for oral administration:
• 3 principal types of sol. formulations administered
orally: oral solutions, oral syrups and oral elixirs
• Other sol. formulations employed for a local effect, e.g.
• mouthwashes/gargles .
30

33. ORAL SOLUTIONS
33
• Oral solutions are administered to the GIT to
provide systemic
absorption of the therapeutic agent.
• Oral solutions formulated over a broad pH
range due to the flexibility of GI
environment.
• The usual pH of oral solutions is about 7.0,
unless there are
issues regarding the solubility or stability of drug.
31

34. ORAL SYRUPS
34
• Syrups are highly concentrated, aqueous preparations of
sugar or a sugar substitute with or without flavouring agent
(e.g. cherry syrup, orange syrup, raspberry syrup) and
medicinal substances.
• Unflavored (Traditional syrup) composed of aqueous sol.
containing 85% sucrose.
• It is important to ensure that:
• 1.The drug substance soluble within the syrup base.
• 2. The syrup vehicle is appropriate to physicochemical
properties of drug subs. For example, cherry syrup &
orange syrup are acidic, therefore solubility of acidic drugs
lowered & resulting in precipitation of drug subs.
• The use of acidic syrups additionally result in reduced
chemical stability for acid-labile therapeutic agents.
32

35. 33
• The major components of syrups are as follows:
• ■ Purified water
• ■ Sugar (sucrose) or sugar substitutes(Artificial
sweeteners.
• ■ anti microbial Preservatives. ■ Flavours. ■ Colours.
• Traditionally syrups composed of sucrose (60 and 80%)
and purified water. [Not need the addition of other
sweetening agents
,viscosity-modifying agents , or preservatives].
• Sorbitol is a non-sucrose bases replace traditional syrup In
some formulations.
• Sorbitol Sol. USP contains 64% w/w sorbitol (a polyhydric
alcohol)
• Other alternatives based on mixtures of sorbitol & glycerin
available
• Non-sucrose bases mixed with traditional syrups, if the
oral syrups
35

36. MEDICATED SUGAR-FREE
SYRUP
36
• All Medicinal products designed for
administration to children & diabetic
patients must be sugar-free.
• Syrup Substitutes must provide an
equivalent sweetness, viscosity and
preservation to the original syrup.
• Artificial sweeteners:
• Artificial sweeteners include Saccharin sodium, and Aspartame.
• Non-glycogenetic viscosity modifiers (e.g.methylcellulose, and
hydroxy ethyl cellulose) .
• Preservatives(e.g. sodium benzoate, benzoic acid &parahydroxy
benzoate ester ) are included in medicated sugar-free syrup.
34

37. PRESERVATIVES
• Preservatives are not required in traditional syrups
containing
high conc. of sucrose.
• Addition of preservatives is required in: 1. sugar-free
syrups,
2. syrups in which sucrose substituted by polyhydric alcohol.
3. traditional syrups contain lower conc. of sucrose,
• Examples of commonly used preservatives include:
• Mixtures of parahydroxybenzoate esters
(methylhydroxy benzoate and propylhydroxybenzoate
in a ratio of 9:1).
• The typical concentration range is 0.1–0.2% w/v.
• The preservative efficacy decreased in the presence
of hydrophilic polymers (generally employed to
enhance
3
5

38. FLAVOURS
38
• Flavours employed to the unpalatable taste of a therapeutic
agent even in presence of the sweeteningagents.
• The conc. of flavour in oral syrups is that which required
to provide the required degree of taste-masking effectively.
• 1.The flavours of natural origin (e.g. peppermint, lemon, herbs
)
and available as oils, extracts, spirits or aqueous sol.
• 2. synthetic flavours:
• Certain flavors also associated with a (mild) therapeutic activity,
e.g; antacids contain mint due to the carminative effect.
• flavours offer a taste-masking effect by eliciting a mild local
anesthetic
effect on the taste receptors,e.g;peppermint oil, chloroform,
menthol.
Colours: natural or synthetic water soluble, photo-stable
ingredients that selected according to flavour of preparation.
• E.g;, mint-flavoured formulations with a green colour, banana-
36

39. 39

40. 40

41. 41

42. PREPARATION OF SYRUPS
• FOUR METHODS EMPLOYED TO PREPARE SYRUPS NAMELY;
1. SOLUTIONS OF THE INGREDIENTS WITH THE AID OF HEAT.
2. SOLUTIONS OF THE INGREDIENTS BY AGITATION WITHOUT
THE AID OF HEAT OR SIMPLE ADMIXTURE OF LIQUID
COMPONENTS.
3. ADDITION OD SUCROSE TO A PREPARED MEDICATED LIQUID
OR TO A FLAVOURED LIQUID (TINCTURE OR FLUID
EXTRACT).
4. PERCOLATION OF EITHER THE SUCROSE OF MEDICATING
SUBSTANCE OF SUCROSE. (IPECAC SYRUP)
• PREPARATION OF EXTRACTIVE OF THE DRUG
• PREPARATION OF SYRUP
42

43. ORAL ELIXIRS
43
• Elixir is a clear, sweetened hydroalcoholic sol. intended for
oral use and are usually flavoured to enhance their
palatability.
• The presence of alcohol in elixirs cause a problem in
paediatric
formulations and, for adults who wish to avoid alcohol.
• The typical components of an elixir are as follows:
• ■ Purified water.
• ■ Alcohol: employed as a co-solvent to ensure solubility of
all ingredients. the conc. Of alcohol varies depending on
formulation.
• Generally, Alcohol conc. is greater than 10% v/v; however,
in
some preparations, alcohol conc. greater than 40% v/v.
• ■ Polyol co-solvents. e.g. propylene glycol, glycerol,
employed in elixirs to enhance the solubility of drug subs.
37

44. 38
• 1. Phenobarbital Elixir:
• Phenobarbital (therapeutic agent)
• Orange oil (flavour)
• Propylene glycol (co-solvent)
• Alcohol
• Sorbitol solution (sweetener)
• Colour
• Purified water
0.4% w/v
0.025% v/v
10% v/v
20% v/v
60% v/v
As required
ad 100%

45. 45
• 2. Theophylline Elixir
• Theophylline (therapeutic agent)
• Citric acid (pH regulation)
• Liquid glucose (sweetening agent)
• Syrup (sweetening agent)
• Saccharin sodium (sweetening agent)
• Glycerin (co-solvent)
• Sorbitol solution (co-solvent)
• Alcohol
• Lemon oil (flavour)
• FDC yellow no 5
• Purified water to make
0.53% w/v
1.0% w/v
4.4% w/v
13.2% v/v
0.5% w/v
5.0% v/v
32.4% v/v
20% v/v
0.01% w/v
0.0001%
100%

46. PREPARATION OF ELIXIRS
• PREPARED AS SIMPLE SOLUTION BY AGITATION
• BY ADMIXTURE OF TWO OR MORE LIQUID INGREDIENTS.
• ALCOHOL-SOLUBLE AND WATER-SOLUBLE COMPONENTS ARE
GENERALLYDISSOLVED SEPARATELY IN ALCOHOL AND IN
PURIFIEDWATER, RESPECTIVELY.
• THE AQUEOUS SOLUTION IS ADDED TO THE ALCOHOLIC SOLUTION, TO
MAINTAIN THE HIGHEST POSSIBLE ALCOHOLICSTRENGTH AT ALL TIMES
SO THAT MINIMAL SEPARATIONOF THE ALCOHOL-SOLUBLE
COMPONENTS OCCURS.
• THE PRESENCE OF GLYC-ERIN, SYRUP, SORBITOL, AND PROPYLENE
GLYCOL INELIXIRS GENERALLY CONTRIBUTES TO THE SOLVENT
EFFECTOF THE HYDROALCOHOLIC VEHICLE, ASSISTS IN THE DIS-
SOLUTION OF THE SOLUTE, AND ENHANCES THE STABILITYOF THE
PREPARATION. HOWEVER, THE PRESENCE OFTHESE MATERIALS ADDS
TO THE VISCOSITY OF THE ELIXIRAND SLOWS THE RATE OF
46

47. MEDICATED ELIXIRS
• MEDICATED ELIXIRS AREEMPLOYED FOR THE THERAPEUTIC
BENEFIT OF THEMEDICINAL AGENT.
• MOST OFFICIAL AND COMMERCIALELIXIRS CONTAIN A
SINGLE THERAPEUTIC AGENT.
• THEMAIN ADVANTAGE OF HAVING ONLY A SINGLE THERA-
PEUTIC AGENT IS THAT THE DOSAGE OF THAT SINGLEDRUG
MAY BE INCREASED OR DECREASED BY SIMPLYTAKING
MORE OR LESS OF THE ELIXIR.
47

48. NON-MEDICATED ELIXIRS
• NONMEDICATED ELIXIRS MAY BE USEFUL TO THE PHAR-MACIST IN THE
EXTEMPORANEOUS FILLING OF PRESCRIP-TIONS INVOLVING
(A) THE ADDITION OF A THERAPEUTICAGENT TO A PLEASANT-TASTING
VEHICLE.
(B) DILUTION OF AN EXISTING MEDICATED ELIXIR
SELECTION OF VEHICLE IS TRICKY; IF A HYDROALCOHOLIC VEHICLE IS
SELECTED, THEPROPORTION OF ALCOHOL SHOULD BE ONLY SLIGHTLYABOVE
THE AMOUNT NEEDED TO EFFECT AND MAINTAINTHE DRUG’S SOLUTION.
IN YEARS PAST, WHEN PHARMACISTS WERE CALLEDON MORE FREQUENTLY
THAN TODAY TO COMPOUNDPRESCRIPTIONS, THE THREE MOST COMMONLY
USEDNONMEDICATED ELIXIRS WERE AROMATIC ELIXIR, COM-POUND
BENZALDEHYDE ELIXIR, AND ISOALCOHOLIC ELIXIR.
48

49. 49

50. 50

51. TINCTURES
• TINCTURES ARE ALCOHOLIC OR HYDROALCOHOLIC SOLU-
TIONS PREPARED FROM VEGETABLE MATERIALS OR
FROMCHEMICAL SUBSTANCES.
• DEPENDING ON THE PREPARATION, TINCTURESCONTAIN
ALCOHOL IN AMOUNTS RANGING FROM APPROX-IMATELY 15%
TO 80%.
• PREVENT FROM EXCESSIVE EXPOSURE FROM TEMPERATURE
AND LIGHT.
• MEDICATED TINCTURES TAKEN ORALLY INCLUDE PAR-EGORIC,
USP, OR CAMPHORATED TINCTURE OF OPIUM. 51

52. LINCTUSES
• THERAPEUTIC AGENT DISSOLVED IN A VEHICLE COMPOSED
OF A HIGH PERCENTAGE OF SUCROSE AND, IF REQUIRED,
OTHER SWEETENING AGENTS.
• THESE FORMULATIONS ARE ADMINISTERED ORALLY.
• PRIMARILY EMPLOYED FOR TREATMENT OF COUGH, DUE TO
THEIR SOOTHING ACTIONS ON THE INFLAMED MUCOUS
MEMBRANES.
• LINCTUSES ALSO BE FORMULATED AS SUGAR-FREE
ALTERNATIVES IN WHICH SUCROSE IS REPLACED BY
SORBITOL AND THE REQUIRED
• CONC. OF SWEETENING AGENT. 52
• A liquid oral preparation used for a demulcent,
expectorant or sedative effect in treatment of cough.
• Linctuses are viscous preparations that contain the
39

53. MOUTHWASHES /GARGLES
53
• Mouth washes/gargles are designed for the treatment of
infections and inflammation of the oral cavity.
• Formulations designed for this purpose employ water as
the vehicle, although a co-solvent, e.g. alcohol, may be
employed to solubilise the active agent.
• The use of alcohol as a co-solvent act to enhance the
antimicrobial properties of the therapeutic agent.
• Other formulation components are frequently required to
enhance the palatability and acceptability of preparation.
• These include preservatives, colours, flavouring agents
and non-cariogenic sweetening agents.
• Oral drops: oral solutions or suspensions administered in
small volumes, using a suitable measuring device.
• E.g.; Abidec® vitamin drops.
40

54. SOLUTIONS FOR ORAL DOSAGE
54
• Containers for dispensed oral solutions
• Plain, amber medicine bottles should be used, with a re-closable
child-resistant closure.
• A 5 mL measuring spoon or an appropriate oral syringe should be
supplied to the patient.
• Advice to store away from children should then be given.
Special labels and advice for dispensed oral solutions:
• An expiry date should appear on the label for the final prepared
sols. Most 'official' mixtures & some oral sols are freshly prepared.
• 'Official' elixirs, linctuses and manufactured products are generally
more stable, unless diluted.
• Diluted products generally have a shorter shelf life than undiluted
preparation.
• Linctuses should sipped & swallowed slowly without addition of water
41