This document discusses different types of drugs and their sources, manufacturing processes, storage conditions, and decomposition. It also covers limit tests, which are used to identify and quantify impurities. Specific limit tests are described for iron, arsenic, and sodium nitrite. Non-aqueous titrations are discussed as a method to titrate weak acids and bases using solvents like acetic acid. Beer's law and its use in UV-Vis spectrometry to determine analyte concentration is also summarized.
2. Definition
Drug is a chemical substance used to treat, cure,
prevent, or diagnose a disease or to promote well-
being
3. Anti hyperlipidemic
Anti hypertensive
Anti hyperuricemic agents
Anti malarial agents
Anti metabolites
Anti migraine agents
Anti neoplastic
Anti platelet agents
Antipsychotics
Anti rheumatics
Anti septic and germicides
Anti thyroid agents
6. Raw material employed in Manufacturing
Method or the process employed in Manufacturing
Chemical Process and Plant materials employed in the
process
Storage Condition
Decomposition
7. Limit test is defined as semi quantitative test designed to identify
and control small quantities of impurity which is likely to be
present in the substance.
Limit test is generally carried out to determine the inorganic
impurities present in compound.
In short, limit test is nothing but to identify the impurities present
in the substance and compare it with standard.
Importance of Limit tests:
To find out the harmful amount of impurities
To find out the avoidable/unavoidable amount of impurities
8. 25 ml test solution
Maintain pH 3-4
by Acetic acid
10 ml H2S Solution
25 ml Standard solution
(20 ppm)
Maintain pH 3-4
by Acetic acid
10 ml H2S Solution
9. The limit test for Iron is based on the reaction between
iron and Thiogycolic acid in ammonical solution to
form pink to deep reddish purple coloured complex of
iron thioglycollate.
2Fe
3+
+ 2HS.CH 2COOH HOOC.CH 2SSCH 2.COOH + 2H
+
Ferric Thioglycolic Acid
Fe
2+
2HS.CH 2COOH
Fe
O.COHSH 2C
CO.O HS.CH 2
Ferrous Thioglycolic Acid Ferrous Thioglycolate
complex
10. 10 ml Test solution
2 ml Citric Acid
0.1 ml Thiogycolic acid
Ammonia till alkaline
10 ml Standard solution
(20 ppm)
2 ml Citric Acid
0.1 ml Thiogycolic acid
Ammonia till alkaline
11. The limit test for Arsenic is based on the conversion
of Arsenic to Arsine gas (AsH3) which when passed
over mercuric chloride test paper which produces
yellow stain.
Step I Arsenic is converted Arsenic acid
Step II Arsenic acid is reduced by different reducing
agents like potassium iodide, stannous chloride etc.
H2AsO4 H3AsO3
Arsenic acid Arsenious Acid
KI
Limit Test for Arsenic
12. Step III The nascent hydrogen produced during the
reaction converts arsenious acid to Arsine gas which
reacts with mercuric chloride paper and produces yellow
stain.
H3AsO3 + 3H2 AsH3 3H2O+
16. Advantages
It is suitable for titration of very weak acids and bases
It also provides a solvent in which organic compounds
are soluble.
OH2 H
+
H3O
+
+
+NH2R H
+
NH3
+
R
OH2 + +X OH
-
XH
+
+ROH + X RO
-
HX
+
Competition of water with weak acids and bases for protons
17. Types of solvents used in Non aqueous
titrations
Protogenic solvents
Protophilic
Amphiprotic
CH3COOH CH3COO
-
H
+
+
+
HClO 4 H
+
ClO 4
-
+
CH3COOH H
+
CH3COOH 2
+
19. Sodium Nitrite titrations are also known as
Diazotization Titration
Substances containing primary aromatic amino group
are assayed by these type of titration
NH2 SO2NH2 N SO2NH2NCl + NaCl 2H2O+
HNO2
From
NaNO2+ HCl
20. A demonstration of Beer's Law. A aqueous solution
of rhodamine (a fluorescent dye) is illuminated with a
green laser pointer. Note how far the green light travels
before it is fully absorbed (the length of the yellow-green
line).
The same green laser illuminating
an aqueous rhodamine solution of lower concentration.
Note the laser light is visible to a greater depth than
observed in the photo above, because the less concentrated
solution absorbs the light less efficiently (i.e., the more
dilute solution has lower c).
UV and Visible Spectrometry
Methods
The amount of energy absorbed or transmitted by a
solution is proportional to the
solution's molar absorptivity and the concentration
of solute.
