PHASE SOLUBILITY ANALYSIS

Presented byB.N.S.SAILAKSHMIM.Pharmacy(pharmaceutics)

SRI PADMAVATHI MAHILA VISWAVIDYALAYAM TIRUPATHI

STANDARD METHOD

GRAPHICAL REPRESENTATION

Solvent charecterstics:

Sufficient volatility

Boiling point b/w 60 – 150 c⁰

Not react with test substance

Not form solvates or salts

Pure in nature

APPARATUS CONSTANT

TEMPERATURE BATH– Contain horizontal

shaft(25rpm)– Temp with in +/- 0.1 c⁰– Vibrator(100-120/sec)

AMPULE

- 15 ml ampules SOLUBILITY FLASK

15ml

Increased amount of sample

5ml solvent

Cool in dry acetone Double jet air gas burner

Weigh all ampoules

PROCEDURESYSTEM COMPOSITION

15 ml 15 ml15 ml 15 ml

15 ml 15 ml 15 ml15 ml

weigh

Calculate the system composition,in mg per g,for each ampule by the formula:-

1000(W 2 –W 1) / (W 3-W 2)

in which W 2 = wt.of ampule plus test substance,

W 1 =wt.of empty ampule,

W 3 =wt.of ampule plus test substance,solvent.

EQUILIBRATION

Varies with Substance Method of mixing Temperature

DETERMINATION OF EQUILIBRATION:

∆ 40⁰ c

SOLUTION COMPOSITION

Content settles

Ampoule(F1)Water bath

Transfer 2ml Solution

Solubility flask(weight F2)

Dry residue(F3)

Open ampule

Evaporate vacuumcool

CALCULATIONS

System composition in mg/gm for each ampoule =1000(w2-w1)/(w3-w2)

Solution composition in mg/gm for each ampoule = 1000(F3-F1)/(F2-F3)

Along DE- saturated with

main compound

Point E- Saturated in both

compound and impurity

The rise of the curve along

the segment DE- Wt of the

impurity per unit wt of the

sample.

%Purity by weight = (1-

Slope of segment DE) * 100%

Point C- Sum of the solubilities

of the substance and the

impurity

Ponit b- solubility of the pure

substance

Solubility of the substance= b/

Solvent Volume

Solubility of the impurity= c-b/

Solvent Volume

Additional

impurities-

Additional

breaks or as

deviation of the

initial slope

from 1.0Insoluble or

volatile

impurity-

Initial slope will

become less

than 1

PURIFICATION TECHNIQUE

Test specimen Non reactive solvent 10% material dissolved seal & shake room temperature,24hr

Mother liquor Residue , Rince,dry

Impurity residue Pure reference

CONCLUSIONSolubility is an important factor in pharmaceutical

process.Phase solubility analysis is an important process for

Detection of impuritiesPreparation of reference substanceSeparation of optical isomers.