The term solid dispersion refers to a group of solid products consisting of a hydrophilic matrix and a hydrophobic drug frequently prepared by fusion solvent method. The matrix can be amorphous or crystalline in nature .

1. “Solid Dispersion-A Better Aproach To
Enhancement Of Drug Solubility”
Presented
By:Shubhangi
V. Ambat.
Guided By:Mr
Avinash
Hatkar Sir.

2. Introduction
EVALUATION
CONCLUSION
FUTURE SCOPE
Contents
1
3
4
5
6
REFERENCE7
2 REVIEW LITERATURE
METHOD

3.  Definition of solid dispersion
The term solid dispersion refers to a group of solid
products consisting of a hydrophilic matrix and a
hydrophobic drug frequently prepared by fusion solvent
method. The matrix can be amorphous or crystalline in
nature .
 Defination of Solubility
 The term solubility can be defined as the maximum amount
of solute that can be dissolved in a given amount of solvent.
1.Introduction

4. Methods of solubility enhancement
Salt
Formation
Solubilization
Particle size
Reduction
Solid
Dispersions

5. Salts Formation
 It is a method of converting a drug into its salt form by
virtue of its solubility, dissolution & thereby absorbtion
increses to many folds comparitively.
eg- salt of weak acid –It increses the ph of the diffusion
layer, which promotes the solubility & dissolution of a weak
acid & absorbtion is bound to be rapid.

6. Particle size Reduction
 It increses the dissolution rate of drugs through
incresed surface area.
 Solubilization: The prosses of solubilization involves
the breaking of inter –ionic or intermolicular bonds in the
solute, the separation of the molecules of the solvent to
provide space in the solvent for the solute,interaction
between the solvent & the solute molecular or ion.

7. DIFFERENT TYPES
 Eutectic mixtures – It consist of two or more compounds which are
completely miscible in the liquid state but only to a very limited extent
in the solid state, at the lowest melting point.
 Solid solution – Consisting of just one phase irrespective of the no. of
Components.The drugs particle size has been reduced to its absolute
minimum viz.
 Continuous solid solutions
 Discontinuous solid solutions
 Substitutional solid solutions
 Interstitial solid solutions
 Glass Suspensions – Are the homogeneous glassy system in which
solute dissolve in glass carrier. & these mixtures in which precipitated
particles are suspended in Glass Solvent.

8. ADVANTAGES
o Generally ,solid dispersions is mainly used--
o To reduced particle size.
 To improve wettability.
 To improve porosity of drug.
 To decrease the crystalline structure of drug in to
amorphous form .
 To improve dissolvability in water of a poorly water
soluble drugs .

9. DISADVANTAGES
 Moreover, most of the polymers used in solid
dispersions can absorb moisture, which may result in
phase separation, crystal growth or conversion from
the amorphous to the crystalline state or from a
metastable crystalline form to a more stable structure
during storage.
 This may result in decreased solubility and dissolution
rate
 Drawback of solid dispersions is their poor scale-up for
the purposes of manufacturing.

10. PHARMACUETICAL APPLICATIONS OF SOLID
DISPERSION
To increase the solubility of poorly soluble drugs thereby
enhance the dissolutions rate, absorptions of
bioavailability .
To obtain a homogeneous distribution of a small amount
of drug in solid state .
To stabilize unstable drugs and protects againts
decomposition by process such as hydrolysis ,oxidation ,
racemization photo oxidation etc.
To avoid undesirable incompatiblities.
To formulate a fast release priming dose in a sustained
release dosage forms.
Masking of drugs & reduced side effect of drugs.

11. 2.LITERATURE REVIEW
 Sekiguchi and Obi 1961 first demonstrated the unique approach of solid
dispersion to reduce the particle size and increase dissolution and absorption
rate. They proposed the formation of eutectic mixture of poorly soluble drug
such as sulfathiazole with physiologically inert, easily water-soluble carrier
such as urea. The eutectic mixture was prepared by melting the physical
mixture of drug and carrier, followed by a rapid solidification process.
 Goldberg et al. 1965-66, presented a detailed experimental and theoretical
discussion on advantages of solid solution over the eutectic mixture.
Tachibana and Nakamaru reported a novel method for preparing aqueous
colloidal dispersions of β-carotene by using water-soluble polymers such as
polyvinyl pyrrolidone. They dissolved the drug and the carrier in a common
solvent and then evaporated the solvent completely. A colloidal dispersion
was obtained when the co-precipitate was exposed to water.
 Chiou and Riegelman 1960 advocated the application of glass solution to
increase dissolution rate. They used PEG 6000 as a dispersion carrier. It is
demonstrated that the pharmaceutical technique of solid dispersion can play
an important role in increasing dissolution, absorption and therapeutic
efficacy of drugs in future.

12. 3.METHOD OF PREPARATION
Fusion Method
Solvent Method
Solvent Evaporation Method3
1
2

13. Melting/Fusion Method
The melting or fusion method ,it involves the
preparation of physical mixture of a drug and a inert
water soluble carrier and heating it directly until it
melted.
The melted mixture is then solidified rapidly in an ice-
bath under vigorous stirring.
The final solid mass is crushed and sieved.

14. SOLVENT METHOD
In this method ,the physical mix of the drug and
carrier is dissolved in a common solvent ,which is
evaporated until a clear ,solvent free film is left.
The film further dried to constant weight .
ADVANTAGE
The main advantage of solvent method is thermal
decomposition of drugs or carrier s can be prevented
because for the evaporation of organic solvents

15. SOLVENT EVAPORATION METHOD
It involves preparation of solid dispersions by
dissolving the drug in a suitable liquid solvent and
then incorporating the solution directing into the melt
of polyethylene glycol ,which is then evaporated until a
clear ,solvent free film is left.
The is further dried to constant weight.

16. 4.EVALUATION
 Thin Layer Chromatography:
 Thin Layer Chromatography (TLC) was employed for primary
assessment of drug-polymer incompatibility and degradation
[155]. The study was carried out using chromatographic grade
silica gel-G stationary phase and benzene: methanol (9:1) as
optimized mobile phase
 Drug Content:
 Solid dispersion & equivalent to 10mg of GLZ were weighed
accurately & dissolved in 50 ml of 0.1N HCL & stirr well with
magnetic stirrer. The drug content was determined at 228.8nm
by Specrophotometric Analysis after suitable Dilutions.

17. 5.CONCLUSION
Solubility enhancement of poorly water soluble drugs
remains one of most challenging aspects of drug
development .
The solid dispersion method is one of the effective
approaches to achieve a goal of solubility
enhancement of poorly water soluble drugs .
Various techniques ,are successfully used for the
preparation of solid dispersion in the lab scale and can
be used at industrial scale also .

18. 6.Future prospects
o Despite many advantages of solid dispersion, issues
related to preparation, reproducibility, formulation,
scale up and stability has limited its use in commercial
dosage forms for poorly water-soluble drugs.
o Successful development of solid dispersion systems for
preclinical, clinical and commercial use has been
feasible in recent years due to the availability of surface
active and self-emulsifying carriers with relatively low
melting points.

19. 7.Reference
 [1] Goldberg AH, Galbaldi M, Kaning KL. Increasing in resolution rates
and gastrointestinal via solid solution and eutectic mixture
experimental evaluation of griseofulvin-succinic acid solution. JPharm
sci 1966; 55: 4870-492.
 [2] Chiou, W.L. and Riegelman, S. Pharmaceutical applications of solid
dispersion systems. J. Pharm. Sci., 1971. 60(9): p. 1281-302.
 [3] Sekiguchi, K. and Obi, N., .Studies on Absorption of Eutectic
Mixture. I. A comparison of the behavior of eutectic mixture of
sulfathiazole and that of ordinary sulfathiazole in man. Chem. Pharm.
Bull., 1961. 9: p. 866-872.
 [4] Mullins, J.D. and Macek, T.J. Some pharmaceutical properties of
novobiocin. J. Am. Pharm. Assoc. Sci. Ed., 1960. 49: p. 245-8.
 [5] A.Arunachalam, M.Karthikeyan, Kishore Konam, Pottabathula hari
Prasad, S.Sethuraman. Solid Dispersions: A Review. Current Pharma
Research Vol. 1, 2010; Issue 1.