Contents
• Introduction

• Classification of Monophasic liquid

• Formulation Consideration

• Manufacturing Consideration

• Recent advance in monophasic liquid

• Recent approach in monophasic liquid formulation

• Conclusion

• Recommendation

Introduction
• Monophasic dosage form refers to liquid preparation containing two

or more components in one phase system, it is represent by true
solution.

• A true solution is a clear homogenous mixture that is prepared by
dissolving solute in a suitable solvent.

• The component of the solution which is present in a large quantity is
known as “SOLVENT” where as the component present in small
quantity is termed as “SOLUTE”.

Advantage
• It is easier to swallow, therefore easier for children and old age people.

• Facilitate absorption of drug faster than solid dosage form as drug is

already in solution form.

• It is homogenous therefore give uniform dose than suspension or

emulsion which need shaking.

• Simple and fast to formulate

• It can be administered by various routes :

Oral, Parenteral (injection),enema for rectal use, otic(ear), nasal and

ophthalmic preparation.

Disadvantage
• They are bulky, so difficult to transport and store.

• Water is commonly use vehicle, which is prone to microbial growth.

So addition of preservative is needed.

• When expose to direct sunlight it may undergo hydrolysis, so need to

store in cool and dark place.

• Drug stability reduce by hydrolysis or oxidation. So, they have shorter

expire date than solid dosage form.

• Other major sign of drug instability are color change, Precipitation,

microbial growth etc.

Classification

Liquids meant for internal administrations

• Syrup : Aqueous preparations of 60% to 85% sucrose with or without

flavoring agents and medicinal substances. e.g. Chlorpheniramine

maleate syrup, Chloral hydrate .

• Elixirs : Clear, aromatic, sweetened hydro alcoholic solutions with or

without medicinal substances, intended for oral use. Eg:

Dexamethasone elixir .

• Linctuses : Viscous, liquid and oral preparations that are generally

prescribed for the relief of cough. Eg: Codeine Linctus.

Market available Syrup/Elixir/ Linctus

Liquids meant for external administration

Liquids used in the mouth
• Gargles :Aqueous solutions containing antiseptics or antibiotics used to

treat throat infections. Available in concentrated form with direction for

dilution with warm water before use. eg: Povidone Iodine gargle.

• Mouthwash: Aqueous solution with a pleasant taste and odor used to

clean and deodorize the buccal cavity. Have antiseptic and astringent

activity.eg: Antiseptics-phenol derivatives.

• Throat paints : Viscous liquid preparation used for mouth and throat

infections. Eg: Phenol glycerine, Compound Iodine.

Market available Gargle, Mouthwash
and Throat paints

Liquids meant for external administration
Liquids instill into body cavity

• Eye drops: Sterile, aqueous/oily solutions intended for instillation in

eye. Eg: Timolol maleate eye drops.

• Nasal drops Administered through the nose to obtain local effect. Used

during nasal congestion and upper-respiratory tract problem. Eg:

Oxymetazolin Hydrochloride nasal drops.

• Enemas: Aqueous or oily solution that is introduced into the rectum and

colon via the anus for cleansing, therapeutic or diagnostic purposes.

Market available Eye drop, Nasal drop
and Enemas

Liquids meant for external administration

Liquid meant for skin

• Liniments : Oily liquid preparations, intended for external application

with rubbing action to the affected area. Use to relief pain and stiffness,

such as from muscles spasm and arthritis.

• Lotions : Topical preparation with a low to medium viscosity. Use to

moisturize dry skin. Eg: Calamine Lotion, baby lotion

• Paints : Solutions used to sterilize the skin. Eg. Betadine antiseptic

paint, Magenta paint

Market available Liniment, Lotion and
Paint

Consideration
Formulation Consideration Manufacturing Consideration

• Solubility • Raw Materials

• Stability
• Equipments

• Preservatives
• Manufacturing Procedure

• Pharmaceutical elegance

 Viscosity modifiers

 Sweetening agents

 Flavouring agents

 Colouring agents

Approaches to increase the solubility of the drug
 pH adjustment : By addition of buffer to the formulation .
 Co-solvency: By addition of water miscible solvent in which drug

has good solubility. The solvent known as co-solvent.
Micelle solubilization : At high concentration surfactant s are
forced into water to form colloidal aggregate known as micelle.
Drugs get adsorbed into micelle that increase drug solubility. Micelle
form only at critical micelle concentration.

Complexation: Drug-complexing agent complexation formed when
complexing agent is added to solution. It increase solubility of drug on
the basis of Le Chatelier’s principle or “ The equilibrium law”.

Micronization:

The process involve size reduction of drug particle 1 to 10microns
either by spray drying or fluid energy mill.

Hydrotrophy : Drug dissolve in the cluster of hydrotropic agent. Also
there is drug- hydrotrophy agent complexation formation to increase
drug solubility.

Preservative

Preservatives must have following criteria:

• Effective against broad spectrum of microorganisms.

• Physically, chemicaly and microbiologically stable for lifetime of the product.

• Non toxic, non sensitizing, soluble, compatible and with acceptable taste and
odour.

Types of Preservatives

• Acidic : phenol, benzoic acid, sorbic acid

• Neutral preservatives : chlorobutanol, benzyl alcohol

• Quarternary ammonium compounds : Benzalkonium chloride

Stability
Chemical Stability Physical Stability

Chemical stability of a formulation  A stable formulation retains its


is affected by: viscosity, color, clarity, taste,

pH and odour throughout its shelf


 Temperature life

 Ionic Strength
 Solvent effects Objective

bjective evaluation
 Light evaluation Su

gen  Colour can be measured
 Oxy  Taste and odour can be

spectrophotometrically. determined either by
Instability can be prevented by  Clarity can be

 pharmaceutical
use of: determined by investigator or by a panel
o Buffering agents measurement of its of unbiased, taste sensitive
o Antioxidants turbidity or light individuals.
o Proper packaging scattering equipment.

(eg: use of amber bottle for light  Viscosity can be

sensitive products) measured by use of
viscometers.

Pharmaceutical Elegance
Viscosity modifiers Enhance viscosity. Eg: Povidone, hydroxyethylcellulose

Sweetening agents To enhance palatability and mask the taste of the
drugs. Eg : Sucrose, saccharin, aspartame

Flavouring agents

Taste Sensation Recommended flavour

Salt Butter scotch, maple, apricot, peach, vanilla,

Bitter Wild cherry, walnut, chocolate, mint.

Sweet Fruit and berry, vanilla.

Sour Citrus flavours, liquorice, raspberry.

To enhance the appearance of the vehicle; which
matches well with the flavor employed in the

Colouring agents
preparation .Eg: green with mint, brown with
chocolate flavor etc.

Manufacturing Consideration
Raw Materials : Incoming raw materials should be tested as per specifications
that is identity, purity, uniformity and microbial contamination .

Equipments :

The following types of equipments may be used in the manufacture of
liquid formulations:-

1. Mixing tanks (SS 316 Stainless Steel) equipped with an agitator.

2. Measuring devices for large and small amount of solids and liquids.

3. A filtration system e.g. filter press

Cleaning of equipments
 All equipments must be thoroughly cleaned and sanitized before use.
Disinfectants used: Dilute solutions of H2O2, phenol derivatives.
Sterilized by: Alcohol, boiling water, autoclaving, steam or dry heat.

Manufacturing of Monophasic Liquid

Recent Advance in Monophasic Liquid

• Recently developed method for the enhancement
of solubility of drugs.
– Nanocrystal
– Nanomorph
– Sonocrystallization
– Supercritical Fluid Process

• Recent advances for the delivery of liquid dosage
form
– Novel Parenteral drug delivery
– Novel ophthalmic drug delivery