Intermediate state of mesophases & halfway between isotropic liquid &solid crystal. In solid crystal, basic unit display translational long range order, with center of molecule located on crystal lattice &display orientational order. In isotropic liquid, basic unit do not preset positional or orientational long rang order.

1. Mr. Sagar Kishor SavaleMr. Sagar Kishor Savale
[Department of Pharmaceutics][Department of Pharmaceutics]
avengersagar16@gmail.comavengersagar16@gmail.com
2015-20162015-2016
Mr. Sagar Kishor SavaleMr. Sagar Kishor Savale
[Department of Pharmaceutics][Department of Pharmaceutics]
avengersagar16@gmail.comavengersagar16@gmail.com
2015-20162015-2016

2. CONTENT
1. Introduction
2 .What is Liquid crystal ?
3. Classification of Liquid crystal
4.Method of characterization of LCs
5.Application of Liquid Crystal
6.Referances
2
04/21/16Sagar Kishor Savale

3.  Intermediate state of mesophases & halfway
between isotropic liquid &solid crystal.
 In solid crystal, basic unit display translational
long range order, with center of molecule
located on crystal lattice &display orientational
order.
 In isotropic liquid, basic unit do not preset
positional or orientational long rang order.
3
04/21/16Sagar Kishor Savale

4.  In plastic crystal ,located on lattice but without
any orientational order.
 In LCs,basic unit display orientational order &
even positional order along same direction.
 LCs,phases represent intermediate stages
called mesophases. Molecule that form
mesophases called mesogen.
4
04/21/16Sagar Kishor Savale

5.  Solid Phase
 Molecules with both orientation and positional
orders, and are held to each other strongly
 Liquid Phase
 Molecules with no orientation and positional orders,
but are held together by weak intermolecular forces
 Gas Phase
 No ordering, no intermolecular attraction
5
04/21/16Sagar Kishor Savale

6.  A fluid phase in which a liquid crystal flows and
will take the shape of its container. It differs from
liquid that there are still some orientational order
possessed by the molecules.
6
04/21/16Sagar Kishor Savale

7. Liquid Crystalline
Systems
Liquid Crystalline
Systems
ThermotropicThermotropic LyotropicLyotropic
NematicNematic SmecticSmectic CholestericCholesteric
IntrinsicIntrinsic ExtrinsicExtrinsic
CLASSIFICATION:
7
04/21/16Sagar Kishor Savale

8. 1.THERMOTROPIC:
 Phase transition depend on temperature
 Temp increases, first LCs phase is smectic A
&layer like arrangement & rotational motion of
molecule.
 Further increase temp lead to nematic phase ,
molecule rapidly diffuse out of initial lattice
structure & form layer like arrangement .
 At highest Temp, material become isotropic
liquid where motion of molecule changes
again.
8
04/21/16Sagar Kishor Savale

9. A)Nematic phase:
 Long range orientation order
but no positional order.
 Preferred direction
is known as director.
 Phase Structure change in number way e.g..
electric or magnetic field or treatment of
surface of sample container.
9
04/21/16Sagar Kishor Savale

10. B) Cholesteric/chiral nematic LCs :
 first LC through polarizing microscope is
cholesteryl benzoate.eg cholesteric LC at 147°
c & isotropic 186° c.
 It great potential uses following drug delivery,
sensors, Thermometer, fashion fabrics that
change color with Temp, display devices
 In cholesteric phase, there is orientation
order & no positional order, but director is in
helical order.
10
04/21/16Sagar Kishor Savale

11.  Structure of this LC depend on pitch, which is
distance over director makes one complete
turn. one pitch comprises several hundred
nanometer.
 pitch affected by following :Temp, pressure,
electric & magnetic field.
11
04/21/16Sagar Kishor Savale

12. The director rotates about a horizontal
axis. The distance for one full rotation is
called a pitch.
12
04/21/16Sagar Kishor Savale

13. Types of cholesteric LCs:
I. Intrinsic cholesteric:
 obtained by adding a chiral amphiphilic
molecule to nematic lyotropic LC.
 Molecule take part in micellar structure as
nonchiral amphiphile.
13
04/21/16Sagar Kishor Savale

14. al. Extrinsic cholesteric
 obtained by adding a chiral nonamphiphilic
molecule to nematic lyotropic.
 Depending on electrostatic characteristics of
molecule , it can accommodated either in
inner or outer part of micelle.
14
04/21/16Sagar Kishor Savale

15. C) SMECTIC PHASE:
 Occurs at temp below nematic or cholesteric
phase.
 Not positional order are destroyed when crystal
melts to form a smectic LC & these are useful in
drug delivery.
 Different smectic distinguished on basis of
arrangements with varying temp.
15
04/21/16Sagar Kishor Savale

16.  Phase transitions occurs with increasing temp
e.g.. crystalline to smectic C to smectic A to
nematic to isotropic or crystalline to nematic to
isotropic.
example of phase changes:
 Solid 74˚c Smectic C 94˚c. Nematic 124˚c
isotropic
16
04/21/16Sagar Kishor Savale

17. Smectic A phase:
Director perpendicular
to the plane
Smectic C phase:
director makes an
angle with the plane
17
04/21/16Sagar Kishor Savale

18. 2)LYOTROPIC LIQUID CRYSTAL:
 Phase transition depend on Temp and Conc.
 When two different substances are mixed together,
the mixture can exhibit different phases not only as
the temperature is changed, but also as the
concentration of one component of the mixture is
varied.
 Example: a molecule that has end groups with
different properties (one is hydrophobic and the
other is hydrophilic).
18
04/21/16Sagar Kishor Savale

19.  Lyotropic liquid crystal differ from
thermotropic LCs, form by mesogen and by
associate hydrate and solvate molecule.
 Hydration, solvation are rod shaped molecule
result in different geometries such as cone and
cylinder.
 Cylindrical arrange in layer, result in laminar
phase by altering polar, non polar layer.
19
04/21/16Sagar Kishor Savale

20. 20
04/21/16Sagar Kishor Savale

21. 21
04/21/16Sagar Kishor Savale

22. Fig. 1)Cubic Lyotropic LCs 2) Lamellar Lyotropic LCs
22
04/21/16Sagar Kishor Savale

23. 23
04/21/16Sagar Kishor Savale

24.  Disc-like molecules
 The axis perpendicular to the molecules tends to
orient along a specific direction
nematic
Columar discotic
(smectic discotic)
The molecules tend to position
themselves in column
24
04/21/16Sagar Kishor Savale

25.  The molecule must be elongated in shape-
length should be significantly greater than its
width.
 Molecule must have some rigidity in its central
region.
 The ends of the molecule are somewhat
flexible.
25
04/21/16Sagar Kishor Savale

26. 1.TRANMISSION ELECTRON MICROSCOPY:
 Due to high magnification power electron
microscope , microstructure of LCs can be
visualized.
 Aqueous sample do not survive high vacuum of
electron microscope with out loss of water &
their microstructure changes.
 Therefore special techniques of sample
preparation necessary which is freeze fracture.
26
04/21/16Sagar Kishor Savale

27. •
2. X RAY SCATTERING:
 Interfererences pattern arises due to
distances of Interlayer spacing “d”.
Braggs equation ,d calculate :d=n( /2)sin
 Where d =wavelength of x ray.
n=integer & denotes under of
Interference.
=angle under which interference
occurs.
λ
27
θ
θ
04/21/16Sagar Kishor Savale

28.  Large ‘d’ in region of long range order are
register by small angle x ray diffraction tech.
 Small ‘d’ in region of short range order
register by wide angle x ray diffraction tech.
 SAXD important for exact ‘d’ determination.
28
04/21/16Sagar Kishor Savale

29. 3. RHEOLOGY:
 Different LCs are rheological prop. Which
increase in microstructure LCs, it’s consistency
increases & flow become more viscous.
 Low flow ability of lyotropic LCs such cubic,
hexagonal due to 3&2 dimensional order.
 Lamellar mesophases are one dimensional
long range has high flowability due to gel
character , cubic & hexagonal mesophases
exhibit stress until flow occur .
29
04/21/16Sagar Kishor Savale

30. 4.DETECTION OF VESICLE SIZE BY LASER LIGHT
SCATTERING:
 Quick method ,applied for particle >1m.
 Rayleigh's theory hold for particles <200nm , which
consider scattering intensity to proportional to
sixth potency of particle diameter.
 Scattering intensity depends on scattering angle,
absorption & size of particle as well as refractive
indices of both particle & dispersion medium.
30
04/21/16Sagar Kishor Savale

31. 1) Liquid crystalline formulation for topical use:
Amphilic excipient form lyotropic LCs,
surfactant use as emulsifier which form
micelles after dissolved in solvent ,conc.
Increases form LCs.
2) Surfactant gel:
 Monophasic system of lyotropic LCs are used
limited to gel.
 High surfactant conc. form density packed &
identified as cubic LCs.
31
04/21/16Sagar Kishor Savale

32.  Gel agitated mechanically , elastic prop. Evident ,
because of resonance effect in audible range
called as ‘ringing gels’.
 Ringing gel used in topical NSAID formation.
3)Ointment & cream:
 Surfactant conc. In this lower than in gel.
 Ointment non a.q preparation & cream are
ointment in water added. microstructure of both
consist of LCs & its network or matrix formed by
amphiphilic molecule.
32
04/21/16Sagar Kishor Savale

33. 4) Liposome dispersions for installation into lung:
 Liposomal formation consist of surfactant, which
coats mucosa of bronchi & prevents collapse of
alveolar of lung , has developed for patient suffer
from infant respiratory distress syndrome.
5) Transdermal patch:
 Patch contain drug substance in reservoir form
which drug release controlled manner.
 This patch disadvantage are dose dumping occur
in membrane damage during handling.
33
04/21/16Sagar Kishor Savale

34.  LCs vehicle with lamellar structure used
reservoir due to high solubilization capacity.
6) Sustained release form solid,semisolis and
liquid formulation :
 Sustained formulation it have developed
reduce application frequency.
 LCs excipient appropriate candidate because
in LCs vehicle drug diffusion is reduced by
factor of 10-1000 in comparison with liquid
vehicle such as a solution
34
04/21/16Sagar Kishor Savale

35.  Semisolid formulation :
o Solubilization of drug substance LCs vehicles
results in semisolid formulation which is used
for topical application.
 Solid formulation:
o For the sustained drug release may contain
mesogenic polymer as excipient which form
matrix, which usually compressed into tablet.
35
04/21/16Sagar Kishor Savale

36. 7) LCs in Cosmetics:
 LCs used for decorative purpose in cosmetic
 Cholesteric LCs suitable because of there
iridescent color effect and find application for
nail varnishes, eye shadow and lipstick.
36
04/21/16Sagar Kishor Savale

37.  Encyclopedia of pharnmaceutical technology,
second edition Volume three, Edited by James
Swarbrick, James C. Boylan page no. 834-851
 Physical pharmacy fourth edition edited by
Alfred Martin, Pilar Bustamante, page 36-37.
 Bentelyes textbook of pharmaceutics forth
edition edited by E.A.Rawlins page no.59-69.
37
04/21/16Sagar Kishor Savale

38. The Cooper and Gunn’s “Dispensing Pharmacy”,
6th
edition ,CBS publisher and distributors NEW
DELHI,page no.126.
38
04/21/16Sagar Kishor Savale

39. 39
04/21/16Sagar Kishor Savale