Recent innovation in liquid dosage form 1by sachin
A SEMINAR ON
Recent Innovations in
Roll No. : 15
NOOTAN PHARMACY COLLEGE,VISNAGAR
Suspension as oral
Emulsion as oral
This is a general term used to describe a solution, suspension or emulsion
in which the active ingredient is dissolved or dispersed in a suitable
“A solution is a liquid-preparation that contains one or more soluble
chemical substances dissolved in a specified solvent.”
Immediately available for absorption.
Administration convenient, particularly for infants, psychotic patients.
Easy to color, flavor & sweeten.
Liquids are easier to swallow than solids and are therefore particularly
acceptable for pediatric patient.
A solution is an homogeneous system and therefore the drug will be
uniformly distributed throughout the preparation.
Some drugs like aspirin, KCl can irritate gastric mucosa if used orally as a
solid dosage forms. But this effect can be reduce by solution system.
Bulky than tablets or capsule, so difficult to carry transport.
Less stable in aqueous system. Incompatibility is faster in
solution than solid dosage form.
Patients have no accurate measuring device.
Accident breakage of container results in complete loss.
Solution often provide suitable media for the growth of
The taste of a drug, which is often unpleasant, is always
more pronounced when in solution than in a solid form.
Classification of liquids
External use Parenteral Special use
Used in other
than oral cavity
SUSPENSION AS ORAL
Mixture of two substances, one of which is finely divided and
dispersed in the other.
L-S (OR S-L),
Colloidal suspension 1 nm to 0.5 µm
Coarse suspension 1 to 100 µm
A suspension of liquid droplets or fine solid particles in a gas is
called an aerosol.
Blood is an example of suspensions
Suspensions are useful for administering insoluble or poorly
soluble drugs or in situations when the presence of a finely
divided for the material in the GI tract is required.
The Difference Between Solution & Suspensions
When the 2 substances totally mix it is called a solution.
E.g. Solute + Solvent = Solution
(sugar) + (water) = Solution
Then, We can say sugar is soluble in water, it has dissolved.
Sometimes when we mix substances they stay in
clusters. We therefore say it is insoluble in water.
E.g. Chalk + Water = Suspension
Eventually the particles sink to the bottom to form
More than 40% of drugs are poorly soluble in water, so they show problems in
formulating them in conventional dosage forms.
For class II drugs (e.g.-Itraconazole & carbamazepine), WHICH ARE
POORELY SOLUBLE IN AQUEOUS AND ORGANIC MEDIA, THE
PROBLEM IS MORE COMPLEX.
Various approaches to resolve problems of low solubility and low
- Micronization, co-solvancy, oily solution, salt formation
- SOME OTHER TECHNIQUES ARE LIPOSOMES, EMULSIONS,
MICROEMULSION, SOLID DISPERSION, ß- CYCLODEXTRIN
INCLUSION COMPLEX etc.
Many of these techniques are not universally applicable to all drugs or are not
applicable to drugs which are not soluble in both aqueous & organic media.
A different but simple approach is needed to tackle the formulation problem
to improve their efficacy and to optimize the therapy with respect to
A pharmaceutical nanosuspension is defined as very finely
dispersed solid drug particles in an aqueous or organic vehicle
for either oral and topical use or parenteral and pulmonary
The particle size distribution of the solid particles in
nanosuspensions is usually less than one micron with an
average particle size ranging between 200 and 600 nm.
Nanosuspensions differ from nanoparticles.
Nanoparticles are commonly polymeric colloidal carriers of
drugs whereas solid lipid nanoparticles are lipidic carriers of
drugs. In nanosuspension technology, the drug is maintained in
the required crystalline state with reduced particle size, leading
to an increased dissolution rate and therefore improved
HPH in water
HPH in non
Main advantage is the use of simple and low cost equipments.
Basic challenge is that during the precipitation procedure
growing of the crystals need to be controlled by addition of
surfactant to avoid formation of microparticles.
Limitation of this precipitation technique is that the drug
needs to be soluble in at least one solvent and the solvent
needs to be miscible with non-solvent.
It is not applicable to the drugs, which are poorly soluble in
both aqueous and non-aqueous media.
The nanosuspensions are prepared by using high shear media
mills. The milling chamber charged with milling media,
water,drug & stabilizer is rotated at very high shear rate under
controlled temp. for 2-7 days.
The major concern with this method is the residues of milling
media remaining in the finished product could be problematic for
The high energy and shear forces generated as a result of the
impaction of the milling media with the drug provide the energy
input to break the micro particulate drug into nano-sized
The milling medium is composed of glass, zirconium oxide or
highly cross-linked polystyrene resin.
ADVANTAGES OF MEDIA MILLING
1. applicable to the drugs that are poorly soluble in both aqueous and
2. Very dilute as well as highly concentrated nanosuspensions can be
prepared by handling 1mg/ml to 400mg/ml drug quantity.
DISADVANTAGES OF MEDIA MILLING
1. Nanosuspensions contaminated with materials eroded from balls
may be problematic when it is used for long therapy.
2. The media milling technique is time consuming.
3. Some fractions of particles are in the micrometer range.
4. Scale up is not easy due to mill size and weight.
The instrument can be operated at pressure varying from 100
– 1500 bars (2800 –21300psi) and up to 2000 bars with
volume capacity of 40ml (for laboratory scale).
Have to be started with micronized drug particle size less than
25μ to prevent blocking of homogenization gap.
So it is essential to prepare a presuspension of the micronized
drug in a surfactant solution using high speed stirrer.
High pressure homogenizer
-Cavitation, High shear forces and
collision of particles against each other
-The drug suspension, contained in a
cylinder of diameter about 3 mm, passes
suddenly through a very narrow
homogenization gap of 25 μm, which leads
to a high streaming velocity.
-In the homogenization gap, according to
Bernoulli’s equation, the dynamic pressure
of the fluid increases with the
simultaneous decrease in static pressure
below the boiling point of water at room
- water starts boiling at room temperature, leading to the
formation of gas bubbles, which implode when the
suspension leaves the gap (called Cavitation) and
normal air pressure is reached again.
- The implosion forces are sufficiently high to break
down the drug microparticles into nanoparticles.
- Additionally, the collision of the particles at high speed
helps to achieve the nano-sizing of the drug.
• Drugs that are poorly soluble in both aqueous and organic
media can be easily formulated into nanosuspensions.
• Ease of scale-up and little batch-to-batch variation.
• Narrow size distribution of the nanoparticulate drug present in
the final product.
• Allows aseptic production of nanosuspensions for parenteral
• Flexibility in handling the drug quantity, ranging from 1 to
400mg/mL, thus enabling formulation of very dilute as well as
highly concentrated nanosuspensions.
• Prerequisite of micronized drug particles.
• Prerequisite of suspension formation using high-speed mixers
before subjecting it to homogenization.
The drugs that are chemically labile can be processed in
such non-aqueous media or water-miscible liquids like
polyethyleneglycol-400 (PEG), PEG1000 etc. The
homogenization can be done at room temperature, 0o C and
below freezing point (-20o C).
So the precipitated particle suspension is subsequently
homogenized which preserve the particle size obtained
after the precipitation step.
Evaluation of Nanosuspensions
-Particle size & Size Distribution
-Particle Charge (Zeta potential)
-Crystalline state & Morphology
-Saturation Solubility & Dissolution Velocity
In- Vivo Evaluation
-Interaction with Body Protein
size and size
Particle Charge ( zeta potential)
Gives idea about physical stability of the Nanosuspension
“Potential difference between the ions in the tightly bound layer
and the electroneutral region, referred to as zeta potential.”
Crystalline State and Particle Morphology
X- Ray Diffraction
Change in physical state and
extent of amorphous drug.
SCANNING ELECTRON MICROSCOPY
Saturation solubility & Dissolution Velocity
Help to anticipate In-vivo performance
Microsuspension® is a registered trademark used for Aqueous Solutions
Sold As a Component of Veterinary Pharmaceutical Preparations For Use In
the Treatment of Respiratory Disease In Livestock and owned by G. C.
Hanford Manufacturing Company.
Drug is in micro size range.
No significant advantages over the macrosuspension or Nanosuspension.
Same methods of preparation as the Nanosuspension.
An emulsion is a mixture of two or more liquids that are
normally immiscible (nonmixable or unblendable).
In an emulsion, one liquid (the dispersed phase) is dispersed in
the other (the continuous phase).
Examples of emulsions include vinaigrettes, milk, and some
cutting fluids for metal working.
The word "emulsion" comes from the Latin word for "to
milk", as milk is (among other things) an emulsion of milk fat
“Microemulsions are dispersions of nanometer-
sized droplets of an immiscible liquid within
another liquid. Droplet formation is facilitated by
the addition of surfactants and often also co
Microemulsions can have characteristic properties such
as ultralow interfacial tension, large interfacial area and
capacity to solubilize both aqueous and oil-soluble
• Microemulsions are clear, stable, liquid mixtures of oil,
water and surfactant, frequently in combination with a co
surfactant like short chain alcohol or amine.
• Diameter of the droplets in a microemulsion is in the range
of 0.1 to 10 µm.
• The two basic types of microemulsions are
(1) o/w (oil dispersed in water) and
(2) w/o (water dispersed in oil).
Difference between Ordinary emulsion and Microemulsion:
Ordinary emulsion Microemulsion
Size of globule: 0.5-50 µm 0.1-10 µm
Appearance: Turbid Clear
Thermodynamically: Stable but coalesce
Viscosity: - Less compared to other
Preparation: It require high shear
By simple mixing of the
component and do not
require high shear
Surfactant concentration: 2-3 %Waight 6-8 %Waight
Phases: 2 1
Types of microemulsion systems
According to Winsor, there are four types of microemulsion
phases exists in equilibria , these phases are referred as Winsor
phases. They are,
Winsor I: With two phases, the lower (o/w)
Microemulsion phases in equilibrium with the upper excess oil.
Winsor II: With two phases, the upper (w/o)
Microemulsion phase in equilibrium with lower excess water.
Winsor III: With three phases, middle
Microemulsion phase (o/w plus w/o, called bi continous) in equilibrium
with upper excess oil and lower excess water.
Winsor IV: In single phase, with oil, water and
Surfactant homogenously mixed.
Advantages Of Microemulsion Over Other Dosage Forms
• Increase the rate of absorption.
• Eliminates variability in absorption.
• Helps solublize lipophilic drug.
• Provides a aqueous dosage form for water insoluble drugs.
• Increases bioavailability.
• Various routes like tropical, oral and intravenous can be used to
deliver the product.
• Rapid and efficient penetration of the drug moiety.
• Helpful in taste masking.
• Provides protection from hydrolysis and oxidation as drug in oil
phase in O/W microemulsion is not exposed to attack by water and
• Liquid dosage form increases patient compliance.
• Less amount of energy requirement.
A large number of oils and surfactant are available but their use in the
microemulsion formulation is restricted due to their toxicity, irritation
potential and unclear mechanism of action.
Oils and surfactant which will be used for the formulation of microemulsion
should be biocompatible, non-toxic, clinically acceptable, and use emulsifiers
in an appropriate concentration range that will result in mild and non-
The emphasis is, excipients should be generally regarded as safe.
Component of Microemulsion System
1. Oil phase
3. Aqueous Component
If a cosurfactant is used, it may sometimes be represented at a fixed ratio
to surfactant as a single component, and treated as a single "pseudo-
The relative amounts of these three components can be represented in a
ternary phase diagram.
Gibbs phase diagrams can be used to show the influence of changes in the
volume fractions of the different phases on the phase behavior of the
Main three components
In case turbidity appears followed by a phase
separation, the samples shall be considered as
In case monophasic, clear and transparent
mixtures are visualized after stirring; the samples
shall be marked as points in the phase diagram.
The area covered by these points is considered as
the microemulsion region of existence.
The oil component influences curvature by its ability to
penetrate and swell the tail group region of the surfactant
Following are the different oil are mainly used for the
formulation of microemulsion:
Saturated fatty acid-lauric acid, myristic acid,capric acid
Unsaturated fatty acid-oleic acid, linoleic acid,linolenic acid
Fatty acid ester-ethyl or methyl esters of lauric, myristic and
The main criterion for the selection of oil is that the drug
should have high solubility in it.
This will minimize the volume of the formulation to deliver
the therapeutic dose of the drug in an encapsulated form.
The role of surfactant in the formulation of microemulsion is to
lower the interfacial tension.
The surfactant should have appropriate lipophilic character to
provide the correct curvature at the interfacial region.
Generally, low HLB surfactants are suitable for w/o microemulsion,
whereas high HLB (>12) are suitable for o/w microemulsion.
Following are the different surfactants are mainly used for
Polysorbate (Tween 80 and Tween 20), Lecithins, Decyl
polyglucoside (Labrafil M 1944 LS), Polyglyceryl-6-dioleate
(Plurol Oleique), Dioctyl sodium sulfosuccinate (Aersol OT),
PEG-8 caprylic /capril glyceride (Labrasol).
Cosurfactants are mainly used in microemulsion formulation for
They allow the interfacial film sufficient flexible to take up different
curvatures required to form microemulsion over a wide range of
1. Short to medium chain length alcohols (C3-C8) reduce the
interfacial tension and increase the fluidity of the interface.
2. Surfactant having HLB greater than 20 often require the presence
of cosurfactant to reduce their effective HLB to a value within the
range required for microemulsion formulation.
Following are the different co surfactant mainly used for
sorbitan monoleate, sorbitan monosterate, propylene glycol,
propylene glycol monocaprylate (Capryol 90), 2-(2-
ethoxyethoxy)ethanol (Transcutol) and ethanol.
Preparation of Microemulsion
Following are the different methods are used
for the preparation of microemulsion:
1. Phase titration method
2. Phase inversion method
Microemulsions are thermodynamically stable, so they
can prepared simply by blending oil, water, surfactant
and cosurfactant with mild agitation or mild heat.
Titrating the mixer of surfactant ,cosurfactant,and oil
against the water till the clear solution is obtained.
If solution is still slight turbid then add some more
amount of cosurfactant to get the clear solution.
Phase inversion method
Phase inversion of microemulsion is carried out upon addition of
excess of the dispersed phase or in response to temperature.
During phase inversion drastic physical changes occur including
changes in particle size that can ultimately affect drug release
both in vitro and in vivo.
For non-ionic surfactants, this can be achieved by changing the
temperature of the system,
forcing a transition from an o/w microemulsion at low
temperature to a w/o microemulsion at higher temperatures
(transitional phase inversion).
During cooling, the system crosses a point zero spontaneous
curvature and minimal surface tension, promoting the formation
of finely dispersed oil droplets.
Apart from temperature, salt concentration or pH value may
also be considered.
A transition in the radius of curvature can be obtained by
changing the water volume fraction.
Initially water droplets are formed in a continuous oil phase by
successively adding water into oil. Increasing the water volume
fraction changes the spontaneous curvature of the surfactant
from initially stabilizing a w/o microemulsion to an o/w
microemulsion at the inversion.
Many examples of microemulsion based formulations
are now on the market ;
Among them, the performances of microemulsions
are well demonstrated in the reformulation of
Cyclosporin A by Novartis into a microemulsion
based formulation marketed under the trade mark
Characterization Of Microemulsion
1. The droplet size,
5. refractive index,
6. phase separation and
7. pH measurements shall be performed to
characterize the microemulsion.
The droplet size
The droplet size distribution of microemulsion vesicles can be
determined by either light scattering technique or electron
This technique has been advocated as the best method for
predicting microemulsion stability.
Dynamic light-scattering measurements.
The DLS measurements are taken at 90 in a dynamic
light-scattering spectrophotometer which uses a neon
laser of wavelength 632 nm. The data processing is done
in the built-in computer with the instrument.
Phase analysis and viscosity measurement
Studied using Abbe refractometer.
The viscosity of microemulsions of several compositions can be
measured at different shear rates at different temperatures using
Brookfield type rotary viscometer.
The sample room of the instrument must be maintained at 37
0.2 C by a thermobath, and the samples for the measurement are
to be immersed in it before testing.
Bulb glows with O/W Bulb doesn’t glow with W/O
To determine the type of microemulsion that has formed, the
phase system (o/w or w/o) of the microemulsions is determined by
measuring the electrical conductivity using a conductometer.
The physical stability of the microemulsion must be determined
under different storage conditions (4 C, 25 C and 40 C) during
Depending on different regulatory agency requirement it’ll vary
according to them.
Fresh preparations as well as those that have been kept under
various stress conditions for extended period of time is subjected
to droplet size distribution analysis.
Effect of surfactant and their concentration on size of droplet is
also be studied.
Application of microemulsion in delivery of drug
Microemulsions have the potential to enhance the solubilization
of poorly soluble drugs (particularly BCS class II or class IV)
and overcome the dissolution related bioavailability
These systems have been protecting the incorporated drugs
against oxidation, enzymatic degradation and enhance
Presently, Sandimmune Neoral(R) (Cyclosporine A),
Fortovase(R) (Saquinavir), Norvir(R) (Ritonavir) etc. are the
commercially available microemulsion formulations.
Microemulsion formulation can be potentially useful to improve
the oral bioavailability of poorly water soluble drugs by
enhancing their solubility in gastrointestinal fluid. 65
Topical administration of drugs can have advantages over other
methods for several reasons, one of which is the avoidance of hepatic
first-pass metabolism of the drug and related toxicity effects.
Another is the direct delivery and target ability of the drug to affected
areas of the skin or eyes.
Now a day, there have been a number of studies in the area of drug
penetration into the skin.
They are able to incorporate both hydrophilic (5-flurouracil,
apomorphine hydrochloride, diphenhydramine hydrochloride,
tetracaine hydrochloride, methotrexate) and lipophilic drugs
(estradiol, finasteride, ketoprofen, meloxicam, felodipine, triptolide)
and enhance their permeation.
Evaluation of Microemulsion
Transparency of microemulsion formulation was determined by
measuring percentage transmittance through U.V. Spectrophotometer.
2)Droplet Size Analysis:
By microscopic method
The optimized ME was stored at three different temperature ranges
for 6 months i.e., refrigerating condition (20C – 80C), room
temperature and elevated temperature (50 20C) and shelf life of the
stored microemulsion system was evaluated by visual inspection
(phase separation), % transmittance, Particle size and % Assay.
Drug Name Route Purpose/Result
Flurbiprofen Parenteral Increased the solubility
Apormorphine HCl Transdermal Increased the permeability
Ketoprofen Transdermal Enhancement of permeability
Prilocainne-HCL Transdermal Increased the solubility
Estradiol Transdermal Improvement in solubilization
Aceclofenac Dermatological Increased the solubility
Piroxicam Oral Increased the solubility
Diclofenac Transdermal Permeability enhancement
Dexamethasone Topical Ocular Enhanced the Bioavailability
Chloramphenicol Ocular Increased the solubility
Ibuprofen Parenteral Increased the solubility
Sumatriptan Intranasal Enhanced the Bioavailability
Ibuprofen Topical Increasing the solubility
Research Work carried out on Microemulsions
• Nanoscale emulsion having size less than 100nm.
• Due to their small droplet size, nano-emulsions may appear
transparent, and Brownian motion prevents sedimentation or
creaming, hence offering increased stability.
• In contrast to microemulsions, nanoemulsions are
metastable and can be diluted with water without changing
the droplet size distribution.
• Nanoemulsion are thermodynamically stable system in
which the two immisible liquid (water and oil)are mix to
form a single phase by means of appropriate surfactant .
Method of preparation
1)High pressure homoginization:
• By high pressure homoginizer or piston homoginizer which
produce NEs of exrtemly low particle size upto 1 nm.
• This make use of microfluidizer.
• This device use high pressure positive displacement
pump(500-20000 psi) which force the product through the
interaction chamber which consist of small micro channel.
• Product flow throgh the micro channel on to the impigment
resulting in the formation of nano size droplet.
CHARACTERIZATION OF NANOPARTICALS
• Nano-emulsions are not thermodynamically stable, and because of
that, their characteristics will depend on preparation method. Here
some parameters are discussed which should be analysed at the
time of preparation of nanoemulsion.
• Phase Behavior Study
This study is necessary in characterization and optimization of
ingredients. This is used in case of NE formulation prepared by
phase inversion temperature method and self-emulsification
• Particle Size Analysis
Generally Dynamic Light Scattering(DLS) method are used.
• Surface Charge Measurement
Surface zeta potential of NE droplets should be measured with the
help of mini electrode to predict the surface properties of NEs. .72
• Transmission Electron Microscopy
TEM is used to observe the morphology in Nano-emulsion.
Viscosity should be measured to ensure the better delivery of
• Morphology & structure
Morphology and structure of nanoemulsion can be studied
using TEM. The study of globule shape and surface can be
observed by TEM. To perform TEM observations, a drop of
the nanoemulsion is deposited on the holey film grid and
observed after drying.
Advantages of nanoemulsion
• Reduction of globules: Increase surface area,
Enhance solubility, Increase bioavailability
• They do not show the problems of flocculation,
coalescence and sedimentation.
• They are non-toxic ,non-irritant
Limitations Of Nanoemulsions
• The manufacturing of nanoemulsion formulation is an expensive
process because size reduction of droplets is very difficult as it
required a special kind of instruments and process methods.
• For example, homogenizer (instruments required for the
nanoemulsion formulation) arrangements is an expensive process.
Again microfluidization and ultrasonication (manufacturing
process) required high amount of financial support.
• Stability of nanoemulsion is quite unacceptable and creates a big
problem during the storage of formulation for longer time of
period. Ostwald ripening is the main factor associated with
unacceptability of nanoemulsion formulations. This is due to high
rate of curvature of small droplets show greater solubility as
compared to large drop with a low radius of curvature.
APPLICATIONS OF NANO-EMULSIONS
The compositional flexibility of nanoemulsions offers a wide range of
The incorporation of fluorescent dyes and other molecules into nanoemulsions
makes the interesting probes for exploring properties of living cells and for
Nanoemulsion vaccine could inactivate and kill the virus and then
subsequently induce immunity to the virus that includes cellular immunity,
antibody immunity and mucosal immunity.
The deformable and liquid nature of the droplets may lead to discoveries of
new pathways for cellular uptake and dispersal. Both oil-soluble and water-
soluble drug molecules can be incorporated into the nanodroplets of direct and
inverse nanoemulsions for potential pharmaceutical uses.
In the printing and data storage industries, one may imagine the resolution of
In the personal care and food industries, nanoemulsions may
provide interesting alternatives as pleasantly transparent and soft
solids that possess plastic-like rheological properties. While being
appealing from an optical and rheological point of view,
nanoemulsion also can deliver moisturizers to the skin quite
efficiently and also block ultraviolet light without leaving a white
The small size of the nano droplets will likely increase transport
efficiency of any active drugs or other molecules inside the
droplets across biological membranes, including the skin. Thus,
nanoemulsions may have significant applications in medical
High-throughput production methodologies make nanoemulsions a
realistic commercial-scale alternative for diverse areas, including
lotions and pharmaceuticals.
Drug Brand Manufacturer Indication
Propofol Diprivan Astra zeneca Anesthatic
Dexamethazone Limethasonn Mitsubishi
Flubriprofen axetil Ropion Kaken
Vitamines A,D,E,K Vitalipid Fresenius
Multiple emulsion systems are novel developments in the field of
emulsion technology and are more complex type of dispersed
These are the emulsion systems in which the dispersed phase
contain smaller droplets that have the same compositon as the
These made possible by the double emulsification hence the
systems are also called as “double emulsion”.
Diameter of the droplets in a Multiple emulsion is in the range of
0.5 to 3µm.
Multiple emulsions are defined as emulsions in which both
types of emulsions, i.e. water-in-oil (w/o) and oil-in-water
(o/w) exist simultaneously.
They combine the properties of both w/o and o/w emulsions
These two liquids forming a system are characterized by their
low thermodynamic stability .
Like simple emulsion multiple emulsion are
classified into two type.
The immiscible phase ,which separates the two
miscible phase is known as “liquid membrane” and
act as a diffusion barrier and semipermeable
membrane for drugs or moities entrapped in the
internal aqueous phase.
Multiple emulsions, either W/O/W or O/W/O emulsions, are
generally prepared using a 2-step procedure.
For W/O/W emulsions, the primary emulsion (W/O) is first
prepared using water and a low-HLB surfactant solution in oil.
In the second step, the primary emulsion (W/O) is re-emulsified
in an aqueous solution of a high-HLB surfactant to produce a
W/O/W multiple emulsion.
The first step is usually carried out in a high-shear device to
produce very fine droplets. The second emulsification step is
carried out in a low-shear device to avoid rupturing the multiple
Multiple emulsion (w/o/w or o/w/o), Prepared by two step procedure
First step (o/w)
Second step (o/w/o)
Oil + Aqueous phase Low HLB surfactant + Oil
Blend and heat up to
Formation of very fine droplets
Heat and blend with
Blend with low shear
Test for sterility
Particle size distribution
EVALUATION OF MULTIPLE EMULSION
Controlled and sustained drug delivery.
As a preparative tool for microencapsulation
Absorption enhancement through GIT.
A novel oral dosage formulation of insulin consisting of a surfactant, a
vegetable oil, and a pH-responsive polymer has been developed. First, a
solid-in-oil (S/O) suspension containing a surfactant–insulin complex was
Solid-in-oil-in-water (S/O/W) emulsions were obtained by homogenizing the
S/O suspension and the aqueous solution of hydroxy propyl methyl cellulose
A micro-particulate solid emulsion formulation was successfully prepared
from the S/O/W emulsions by extruding them to an acidic aqueous solution,
followed by lyophilization.
The insulin release from the resultant dry emulsion responded to the change
in external environment simulated by gastrointestinal conditions, suggesting
that the new enteric coated dry emulsion formulation is potentially applicable
for the oral delivery of peptide and protein drugs.
Homogenization and membrane emulsification
Dropwise extrusion through a syringe
Recovery and lyophilization.
Nanosuspension Technology for Drug Delivery,
Walailak J Sci & Tech 2007; 4(2): 139-153.
V. B. Patravale, Abhijit A. Date and R. M. Kulkarni,
Nanosuspensions: a promising drug delivery strategy
JPP 2004, 56: 827–840
Water-Insoluble Drug Formulation
Second Edition, page no. 122-123
Nanoparticle Technology for Drug Delivery,
edited by Ram B. Gupta and Uday B. Kompella
Advances in controlled and novel drug delivery.
Targeted and controlled drug delivery
By S.P.Vyas and R.K.Khar
Nano emulsion: A pharmaceuticle review.
Review Article :Microemulsions: a novel drug carrier
system.International Journal of Drug Delivery Technology
2009; 1(2): 39-41 www.ijddt.com
TOPICAL REVIEW: nanoemulsions:
Formation, structure, and physical properties. Journal of
physics: condensed matter 18 (2006) r635–r666