The document details a pre-formulation study of prepared diazepam granules, highlighting objectives including the study of organoleptic properties, melting point, identification tests, calibration curve, and solubility determination. Various analytical methods such as UV-spectrophotometry were used, yielding results that confirm the authenticity and purity of the diazepam sample. The study concluded with a calibration curve for diazepam in methanol and solubility results indicating high solubility in methanol compared to other solvents.

1. Aim: To demonstrate the fundamental pre-
formulation study for prepared granules.
Subject: Formulative Pharmacy
BP-506 P
By: Ms. Uditi Handa (Asst. Prof.)
M.Pharma (Ph.D)
GGSCOP, Yamunanagar

2. References
• Handa, U.; Saroha, K. “Research and
development of diazepam solid dispersion
powder using natural polymers”, International
Journal of Applied Pharmaceutics, volume 10,
2018, 220-225.
• http//:www.arcjournals.org

3. Objectives:
• Requirements: sample,
weighing balance, capillary
tube, melting point
apparatus, thermometer,
butter paper, volumetric
flask (100ml, 10ml),
pipette, UV- spectrometer.
• Procedures: as per
objectives
• Results: as per objectives
a. To study organoleptic
properties,
b. Melting point by
capillary tube
method,
c. Identification test by
Ʌmax.,
d. Calibration curve,
e. Solubility
determination,

4. a) To study organoleptic properties
• Procedure: : Taste, odour & colour of the drug
was determined.
DRUG TEST OBSERVATION
Diazepam (DZM)
Colour White
Odour Odourless
Taste Slightly bitter taste

5. b) To study Melting point by capillary tube
method.
• Procedure: Melting point of drug was
analysed by capillary method using melting
point apparatus.
METHOD USED DEMONSTTRATED
EXPERIMENTAL VALUE (°C)
LITERATURE VALUE (°C)
Capillary
method
131 131-135
Result: Observed melting point of obtained
sample is approx. near to reported data
which confirm the authenticity of obtained
sample.

6. c) To study Identification test by Ʌmax.
• Procedure: Ʌmax. Scanning helps in identifying the drug purity. The scanned graph
was according to reported literature and hence confirmed that the obtained drug
sample was Diazepam. 10mg Diazepam was accurately weighted and dissolved in
100 ml of Methanol to produce a solution 0.1 mg/ml.
Ʌmax.
DEMOSTRATED EXPERIMENTAL VALUE
(nm)
LITERATURE VALUE (nm)
Diazepam 238 245
(methanol solution)
Result: Spectrum of Diazepam was
obtained in methanol solution, observed
wavelength maxima was 238 nm and the
%purity was found to be 97.14%.
% Purity = Absorbance of Sample X 100
Absorbance of Std. Value
% Purity = 238 nm X 100
245 nm
% Purity = 97.14 %

7. d) To study the Calibration curve
• Procedure: Preparation of standard curve:
1. 10mg Diazepam was accurately weighted and dissolved in 100 ml of
Methanol to produce a solution 0.1 mg/ml.
2. 20ml of the solution was transferred in a volumetric flask and volume
was made up to 100ml with distilled water.
3. 1, 2, 3, 4, 5, 6, 7, 8, 9 & 10 ml of this solution was taken in 10ml
volumetric flasks and distilled water was added to adjust the volume
up to the mark to prepare standard solutions.
4. These serial dilutions were carried out to get different Diazepam
concentrations.
5. Standard solutions were then analysed by UV spectrophotometer at
238 nm and absorbance was noted.
6. Then the absorbance values were plotted against drug concentration
and standard curve of Diazepam was produced.

8. Concentration
(µg/ml)
Absorbance
(nm)
1 0.21
2 0.384
3 0.522
4 0.644
5 0.776
6 0.905
7 1.051
8 1.179
9 1.244
10 1.418
R² = 0.9967
y = 0.130x + 0.115
0
0.2
0.4
0.6
0.8
1
1.2
1.4
1.6
0 2 4 6 8 10 12
Absorbance
concentration (µg/ml)
Standard curve of Diazepam in Methanol
DZM
Linear (DZM)
Result: The calibration curve of DZM was prepared in methanol solution at 238
nm and the absorbance values at different concentrations of DZM in methanol
soln are shown in table and graphically represented in figure. Values of R2
(regression coefficient) was found to be 0.996.

9. e) To study the Solubility determination by shake flask
method through UV-spectrometer.
• Procedure:
1. The solubility of diazepam was determined in different solvents.
2. Granules in excess quantity were placed in flask’s containing 10 ml of each
solvent.
3. The samples were placed in an incubator shaker at 37°c & 50 rpm for 24 hrs.
4. The solutions were analysed by UV-spectrophotometer.
5. By using straight line equation calculate the concentration by obtained
absorbance.
SOLVENTS SOLUBILITY
Water Slightly soluble
Chloroform Soluble
Methanol Soluble
Calculations: for water, Y= 0.130 x + 0.115
0.374 – 0.115 = 0.130 x
X = 0.259/0.130 = 0.001 µg/ml
Result: Very high solubility of Diazepam was observed in methanol as the concentration was
found ………………
SOLVENTS CONCENTRATION (µg /
ml)
Absorbance (nm)
Water 0.001 0.374
Chloroform 0.592
Methanol 0.845

10. Thank You