This document provides an overview of self-emulsifying drug delivery systems (SEDDS). SEDDS are isotropic mixtures that form fine oil-in-water emulsions upon dilution in the gastrointestinal tract, avoiding the dissolution step that limits absorption of hydrophobic drugs. The document discusses the methodology, evaluation parameters, marketed products, and conclusion of SEDDS. It summarizes the composition, preparation, advantages, and applications of SEDDS for improving oral drug bioavailability.

1. PRESENTED BY: VIBHA
SELF-EMULSIFYING DRUG
DELIVERY SYSTEM (SEDDS)

2. CONTENT
 Need for new approach
 Introduction
 Methodology
 Evaluation parameters
 Marketed products of SEDDS
 Conclusion
 Reference

3. NEED FOR NEW APPROACH
 BCS Class II DRUGS (Low solubility-High permeability)
dissolution is rate limiting step for absorption.
 Oral route is the easiest and most convenient route for
non invasive administration.

4. INTRODUCTION
 SEDDS are isotropic mixtures of drug, oil/lipid, surfactant and/or co-
surfactant, which form fine emulsion/lipid droplets on dilution with
physiological fluid. The drug therefore remains in solution in the gut,
avoiding the dissolution step that frequently limits the absorption rate
of hydrophobic drugs from the crystalline state.
 Upon mild agitation followed by dilution in aqueous media, such as GI
fluids, these systems can form fine oil−in−water (o/w) emulsions.
 Self-emulsifying formulations spread readily in the GI tract, and the
digestive motility of the stomach and the intestine provide the agitation
necessary for self-emulsification.
 SEDDS typically produce emulsions with a droplet size between 100
and 300 nm.

5. MECHANISM OF SEDDS
 Self-emulsification takes place when the entropy change
favouring dispersion is greater than the energy required to
increase the surface area of the dispersion.
 The free energy of a conventional emulsion formulation is a
direct function of the energy required to create a new surface
between the oil and water phases.

7.  The two phases of the emulsion tend to separate with time to
reduce the interfacial area and thus the free energy of the
systems.
 Free energy in the micro-emulsion formation is directly
proportional to the energy required to create new surface
between the two phases, and is given by the equation-

8.  ∆G= ∑ N∏ rsqσ
Where,
ΔG=Free energy associated with the process.
N=No. of droplets of radius r.
σ=Represents interfacial energy.

9. Advantages and Disadvantages
Advantages Disadvantages
 Improvement in oral
bioavailability.
 Ability to deliver peptides that
are prone to enzymatic
hydrolysis in GIT.
 Inter-subject and intra-subject
variability and food effects are
reduced.
 Ease of manufacture and scale-
up
 No influence of lipid digestion
process.
 Increased drug loading
 Lack of good in vitro models
for assessment of the
formulations for SEDDS.
 The traditional dissolution
methods does not work,
because these formulations
potentially are dependent on
digestion prior to release of the
drug.

10. DRUG. TRADE NAME/
COMPANY.
TYPE OF
FORMULATION.
INDICATION.
CyclosporinA Neoral,Sandimmu
ne (Novartis)
Soft gelatin
capsule
Immuno-
suppressant
Ritonavir Norvir(Abbott) Soft gelatin
capsule
HIVAntiviral
Sanquinavir Fortovase(Roche) Soft gelatin
capsule
HIVAntiviral
Valproic acid Convulex
(Pharmacia)
Soft gelatin
capsule
Anti-epileptic
MARKETED ORAL SOLID SEDDS.

11. COMPOSITION OF SEDDS:-
DRUG
 The drugs with poor aqueous solubility and high permeability are
classified as class II drug by Biopharmaceutical classification system
(BCS). These drugs are use to formulate SEDDS.
Class IV Class I
Low Solubility
Low Permeability
High Solubility
High Permeability
Class III
High Solubility
Low Permeability
Class II
Low Solubility
High Permeability

12. OIL
 Oils are the most important excipient.
 Both long-chain triglyceride and medium-chain
triglyceride oils with different degrees of saturation
have been used for the formulation of SEDDSs.

13. Excipient name
(commercial name)
Examples of commercial products
in which it has been used
Corn oil Sandimmune soft gelatin capsule,
Depakene capsule
Olive oil Sandimmune oral solution
Oleic acid Ritonavir soft gelatin capsule,
Norvir soft gelatin capsule
Sesame oil Marinol soft gelatin capsule
Hydrogenated soybean
oil
Accutane soft gelatin capsule,
Vesanoid soft gelatin capsule
DL-α-Tocopherol Neoral oral solution, Fortovase soft
gelatin capsule
Beeswax Vesanoid soft gelatin capsule
Peanut oil Prometrium soft gelatin capsule

14. SURFACTANTS
❖ Natural surfactants have limited ability to emulsify.
❖Non ionic surfactants are less toxic when compared to ionic surfactants.
❖The usual surfactant strength ranges between 30–60% w/w of the
formulation in order to form a stable SEDDS.
❖Non-ionic surfactants with high hydrophilic–lipophilic balance (HLB)
values are used in formulation of SEDDS.
❖Surfactants are amphiphilic in nature and they can dissolve or solubilize
relatively high amounts of hydrophobic drug compounds

15. Excipient name
( commercial name)
Examples of commercial
products in which it has been
used
Polysorbate 20 (Tween 20) Targretin soft gelatin capsule
Polysorbate 80 (Tween 80) Gengraf hard gelatin capsule
Sorbitan monooleate (Span
80)
Gengraf hard gelatin capsule
Polyoxyl-35-castor oil
(Cremophor EL)
Gengraf hard gelatin capsule,
Ritonavir soft gelatin capsule
Polyoxyethylated glycerides
(Labrafil M 2125Cs)
Sandimmune soft gelatin
capsules
D-α-Tocopheryl polyethylene
glycol 1000 succinate (TPGS)
Agenerase soft gelatin capsule,
Agenerase
oral solution

16. COSOLVENTS/ COSURFACTANTS-
✓Cosolvents may help to dissolve large amounts of
hydrophilic surfactants or the hydrophobic drug in the lipid
base.
✓These solvents sometimes play the role as co-surfactant in
the microemulsion systems.
✓Alcohol is not included in SEDDS/SMEDDS due to
it’s migration.
✓Drug release is increased with increasing concentration
of cosurfactant in formulation.

17. PREPARATION OF SEDDS
 SolidificationTechniques for transforming liquid/ solids.
 Spraydrying
 Melt granulation
 Melt Extrusion Spheronization

18. Solidification Techniques for
Transforming liquid/ solid
 Capsule filling with liquid and semisolid self-
emulsifying formulations:
Four-step process:
A)Heating of the semisolid excipient to at least 20˚C
above its melting point.
B) Incorporation of the active substances (with stirring).

19. C) Capsule filling with the molt cooling to room
temperature. For liquid formulations, it involves a
two-step process.
D) Filling of the formulation into the capsules followed
by sealing of the body and cap of the capsule, either
by banding or by micro spray sealing.

20. Spray drying
➢Technique involves the preparation of a formulation
by mixing lipids, surfactants, drug, solid carriers, and
solubilization of the mixture before spray drying.
➢The solubilized liquid formulation is then atomized
into a spray of droplets.
➢The droplets are introduced into a drying chamber,
where the volatile phase (e.g. the water contained in an
emulsion) evaporates, forming dry particles under
controlled temperature and airflow conditions.

21.  Melt granulation : Melt granulation is a process in
which powder agglomeration is obtained through the
addition of a binder that melts or softens at relatively
low temperatures.
 Melt Extrusion Spheronization : Melt extrusion is a
solvent-free process that allows high drug loading
(60%), as well as content uniformity.
 Extrusion is a procedure of product of uniform shape
and density, by forcing it through a die under
controlled temperature, product flow, and pressure
conditions.

22. DOSAGE
FORMS
OF SEDDS
PARENTRA
L DELIVERY
ORAL
OCULARY &
PULMONARY
DELIVERY
TOPICAL

23. Evaluation Parameters
1. Thermodynamic Stability Studies
2. Dispersibility test
3. Turbidimetric Evaluation
4. Viscosity Determination
5. Droplet Size Analysis and Particle Size
 Measurements
6. Refractive Index and Percent Transmittance
7. Electro Conductivity Study
8. In vitro Diffusion Study
9. Drug Content

24. Thermodynamic Stability Studies
Heating cooling cycle
• Six cycles between refrigerator temperature 4⁰C and
45⁰C with storage at each temperature of not less than
48 h is studied.
• Those formulations, which are stable
at these temperatures, are subjected to
centrifugation test.

25.  Centrifugation: Passed formulations are
centrifuged at room temperature at 3500 rpm for 30
min. Those formulations that does not show any phase
separation are taken for the freeze thaw stress test.
 Freeze thaw cycle: Freeze was employed to evaluate the
stability of formulation.
 Thermodynamic stability was evaluated at difference
temp. To check the effect of temp. the formulation was
subjected to freeze thaw cycle(-20ºC) for 2-3 days.
 Those formulations passed this test showed good stability
with no phase separation, creaming, or cracking.

26. Dispersibility test
 The efficiency of self-emulsification of oral nano or micro
emulsion is evaluated by using a standard USP XXII dissolution
apparatus for dispersibility test.
➢Solution Tested: 1ml
➢Medium: 500 ml water
➢Temperature: 37 ± 1 ⁰C.
➢Paddle speed : 50 rpm
Grade A: Rapidly forming (within 1 min) nano-emulsion, having
a clear or bluish appearance.
Grade B : Rapidly forming slightly less clear emulsion having a
bluish white appearance.

27.  Grade C: Fine milky emulsion that formed within 2 min.
 Grade D: Dull, grayish white emulsion having slightly
oily
 appearance that is slow to emulsify (longer than 2 min).
 Grade E: Formulation, exhibiting either poor or minimal
emulsification with large oil globules present on the surface.
 Grade A and Grade B formulation will remain as nano-
emulsion when dispersed in GIT. While formulation falling
in Grade C could be recommended for SEDDS formulation.

28. Turbidimetric Evaluation
Fixed quantity of Self emulsifying system is added to
fixed quantity of suitable medium (0.1N hydrochloric
acid) under continuous stirring (50rpm) on magnetic
hot plate at appropriate temperature and the increase in
turbidity is measured y using a turidimeter.
However, since the time required for complete
emulsification is too short, it is not possible to monitor
the rate of change of turbidity (rate of emulsification)

29. Viscosity Determination
 The rheological properties of the micro emulsion are
evaluated by Brookfield viscometer.
 The viscosities determination conform whether the
system is w/o or o/w.
 If the system has low viscosity then it is o/w type of
the system If the system has high viscosity then it is
w/o type of the system.

30. Droplet Size Analysis
 The droplet size of the emulsions is determined by photon
correlation spectroscopy (which analyses the fluctuations in
light scattering due to Brownian motion of the particles)
using a Zetasizer able to measure sizes between 10 and 5000
nm.

31. Refractive index and %transmittance
 Refractive index and percent transmittance prove the
transparency of formulation.
 The refractive index of the system is measured by
refractometer by putting a drop of solution on slide and
comparing it with water (1.333).

32.  The percent transmittance of the system is measured at
particular wavelength using UV spectrophotometer by
using distilled water as blank.
 If refractive index of system is similar to the refractive
index of water (1.333) and formulation have percent
transmittance > 99 percent, then formulation have
transparent nature.

33. Electro Conductivity Study
 This test is performed for measurement of the electro
conductive nature of system.
 The electro conductivity of resultant system is
measured by electro conductometer.
 In conventional SEDDSs, the charge on an oil droplet
is negative due to presence of free fatty acids.

34. In-vivo Diffusion Study
 In vitro diffusion studies are carried out to study the
drug release behaviour of formulation from liquid
crystalline phase around the droplet using dialysis
technique.
 Drug content: Drug from pre-weighed SEDDS is
extracted by dissolving in suitable solvent. Drug
content in the solvent extract was analyzed by
suitable analytical method against the
standard solvent solution of drug.

35. Application
✓Improvement in Solubility and bioavailability:
✓Protection against Biodegradation:
✓Controlling the release of drug

36. CONCLUSION.
 Self-emulsifying drug delivery systems are a promising
approach for the formulation of drug compounds with poor
aqueous solubility.
 The oral delivery of hydrophobic drugs can be made possible
by SEDDSs, which have been shown to substantially improve
oral bioavailability.

37. References
❖Nigade P.M., Patil S. I., Tiwari S.S. (2012). “Self
Emulsifying Drug Delivery System (SEDDS)”: A
Review. IJPBS. 2(2), 42-52.
❖Sarpal K., Pawar Y. B., and . Bansal A.K .(2010)”Self
Emulsifying Drug Delivery System (SEDDS) A Strategy
To Improve Oral Bioavailability”, (CRIPS). 11(3), 42-49.
❖Mistry R .B., Sheth N .S.,(2011) A review: “Self
Emulsifying Drug Delivery System”. IJPPS. 3(2), 23-28

38. ❖Mahapatra A K., Murthy P N., Swadeep B, Swain R
P.(2014). ”Self-Emulsifying Drug Delivery Systems
(SEDDS): An Update from Formulation
Development to Therapeutic Strategies”. IJPTR 6(2),
546-568
❖Taksande J. B., Trivedi R., Mahore J. G., Wadher K
J.(2011) “Self-Emulsifying Drug Delivery System:
Hitherto and Resent advances”. IJRAP 2011, 2(4)
1087-1095