Quality analysis of medical
drugs from the vitamins of the aromatic and heterocyclic raws
Aromatic vitamins
•
2-methyl-1,4-naphthoquinone (vitamin
of
Ê group) derivatives belong to the
aromatic vitamin’s raw. They have antihemorragic
action and participate in the formation of
prothrombin.
•
Vitamin Ê1 (phylloquinone) present
in the plants (lucerne , spinach , cabbage), vitamin Ê2 (pharnoquinone)
is in animal products and is produced by intestinal microflora. Vitamin Ê3 (menadione) is called 2-methyl-1,4-naphtoquinone.
• In
medical practice, using a synthetic analogue of vitamin K - vikasol.
Coagulation effect of vitamin K is very specific,
since the small changes in their molecule lead to a significant change in their
activity. The discovery of Ansbaher and Ferngolts (1939) was a great
achievement that the 2-methylnaphthoquinone (it was called vitamin K3) is by
three times more active than vitamin K1. Insolubility in water of
3-methylnaphthoquinone has led to the synthesis of a number of its water-soluble
derivatives (by O.V. Palladin), including vikasol.
Vikasol (Vikasolum)
(Menadione of sodium bisulfite)
Sodium 2,3-dihydro-2-methyl-1,4-naphthoquinone-2-sulfonate threehydrate
•
CHARACTERS. A pale-yellow,
crystalline powder, freely soluble in water, very
slightly soluble in ether, hard soluble in alcohol.
Vikasol obtaining
Precursor for the synthesis of the drug is a β-methylnaphthalene,
which is extracted from the waste coke coal industry. Methylnaphthalene is
oxidized in acetate acid by chromic anhydride to methylnaphthoquinone, which is
heated with an aqueous solution of sodium hydrosulfite:
Identification reaction of vikasol is based on its
lability in alkaline and acid solutions.
Identification of
vikasol
1. It
gives reaction of sodium.
2. At the
interaction with a sodium hydroxide solution there is settled down a yellow
crystalline precipitate of 2-methyl-1 ,4-naphthoquinone, which is extracted by
chloroform, purified from impurities and determine the melting point (104-107 °
C):
Sodium sulfite is determined after the removal of the
excess of alkali solution by a iodine
solution according to the iodine discoloration reaction. Vikasol itself does
not react with iodine.
Na2SO3
+ I2 + H2O → Na2SO4 + 2HI
3. At the
interaction of vikasol with a concentrated sulfuric acid there is sulfurdioxide
small:
4. Substance + ethanol + HCl conc. ® red colour.
5. Aqua
solution of the substance + sodium ethylate ®
Red-brown color, according to
the formation of 2-oxi-3-methyl-naphthoquinone (phtyoxol).
Impurities
•
Sodium bisulfite and
2-methyl-1,4-naphthohydroquinone-3-sulfonate are the specific impurities in
vikasol.
•
Sodium bisulfite NaHSO3
is determined by iodometric titration method (less than 2 %).
•
2-methyl-1,4-naphthohydroquinone-3-sulfonate is
determined by the adding of î-phenanthroline - hould
not form the precipitate (the impurity is not allowed.
Assay
1. Cerimetri. Direct
titration, the indicator is o-phenanthroline. By the interaction with a sodium
hydroxide solution 2-methyl-1 ,4-naphthoquinone is precipitated, which is
extracted with chloroform. After removal of chloroform, it is reduced in an
acidic medium to 2-methyl-1 ,4-dioxinaphthalene, then it is titrated by a
solution of cerium (IV) sulfate until the green color:
2. Gravimetry. (Precipitation
form – 2-methyl-1,4-naphthoquinone).
Storage
• Store protected
from light.
Application
To increase the clotting of blood at various bleedings. Water-soluble
synthetic substitute of K group vitamins, which take part in the formation of
liver prothrombin and promotes the normal blood coagulation. At Haemophilia it
does not act. It acts during 12-18 hours after injection.
Produced: powder, tablets. în 0,015 g, 1% solution
for injection.
•
Per oral: the highest day dose – 60 mg, intra/muscular – 30 mg.
Heterocyclic
row vitamins
Chromane
derivatives
Heterocyclic
vitamins, chromane derivatives (vitamins of Å
group - tocopherols), are in (Corn,
cotton, flax, peanuts, sea buckthorn, etc.) oils, and
in the green parts of plants, especially in the young shoots of
cereals. They are also available in small quantities in milk, butter, egg
yolks, meat, fats.
Source of tocopherols extraction is wheat germ oil, or corn.
In industry, the vitamin E extracted from natural sources or by synthesis.
The
basis of the structure of E vitamin group is a tocol molecule -
6-oxy-2-methyl-2 (4 ', 8', 12'-trimethyltridecyl) chromane:
Different
tocopherols by the number of methyl groups in the core of chromane, there are
seven natural vitamins of E group. The most active-α-tocopherol. In
clinical practice using tocopherol acetate.
Obtaining
of α-tocopherol
Tocopherol
acetate is synthetically extracted by the condensation of
trimethylhydroquiinone with phythilbromide and subsequent acetylation of
α-tocopherol:
Phythilbromide is extracted
from phytol containing in the nettles. From 1 ton of nettles get about
Tocopherol
acetate
(Tocopheroli acetas) Vitamin Å
(±)-2,5,7,8-tetramethyl-2-(4',8',12'-trimethyltridecyl)-6-acetoxichromane
CHARACTERS. Light
yellow, transparent, thick, oily liquid with low odor. Practically insoluble in
water, soluble in 95% alcohol and very easily soluble in ether, acetone,
chloroform, and oils. Under the influence of light tocopherol acetate is
oxidized and darkened.
Identification of
Tocopherol acetate
1. Oxidation
of the fuming nitric acid, at the heating in a water bathe – appearance a red-orange
color (o-tocopherylquinone).
If we
continue the condensation of o-tocopherylquinone with o-phenylenediamine, then
forming a phenazine dye of red-orange color with a yellow-green fluorescence
2. Tocopherol
acetate is hydrolyzed by a solution of potassium hydroxide in absolute alcohol
(at the heating), then to add the concentrated sulfuric acid – feeling the
smell of ethyl acetate.
3. At the
oxidation of tocopherol by a potassium ferricyanide in an alkaline medium there
is formed colored di-α-tocopherol:
Assay
1. Cerimetry. Direct
titration after hydrolysis, indicator – diphenilamine. Å = ½
Ì.m.
Firstly tocopherol is hydrolyzed
by boiling with H2SO4, and then extracted tocopherol is titrated with cerium
(IV) sulfate to the blue-violet color.
2. Photocolorimetry
3. Liquid
chromatography
4. Spectrophotometry.
Storage
Store protected
from light in a cold place.
Application
An
important antioxidant. It participates in the biosynthesis of proteins and
other important metabolic processes in cells. At its insufficient amount
appearance the degenerative changes in nerve cells, skeletal muscle, cardiac
muscle, increased fragility and permeability of capillaries.
Apply for nervous diseases, muscular dystrophy, sclerosis, menstrual
irregularities and the threat of termination of pregnancy, dysfunction of the
sexual men glands, to improve vision, with radiation sickness, etc.
Using 50-100 mg / day (sometimes up to 400 mg) as oil solutions of 5%, 10%, 30%
α-tocopherol;
intra/muscular - 5%, 10%, 30% oil solutions; inside - Capsules 100 , 200, 400
mg.
Heterocyclic
vitamins
Phenylchromane
derivatives (flavan)
Flavans
derivatives are naturally in a free state, or in conjunction with sugars
(glycosides) - flavonoids.
Flavonoids
are a group of Vitamins P. They are able to reduce the fragility and
permeability of capillaries, take part in the ox-red processes and have
specific antioxidant properties.
They
are in green tea, rose hips, citrus fruit, unripe walnuts, mountain ash.
How drugs they are used as - quercetin, routine, and their natural (katergen)
and semisynthetic (troxevasin) analogues.
Routine (Rutinum)
3-Rutinoside
quercetin or 3-ramnoglycosyl-3,5,7,3',4'-pentaoxiflavone
Belongs
to a glycosides class: quercetin aglycone is 3,5,7,3 ', 4'-pentaoxiflavon;
sugar molecule part - routenoza is a disaccharide consisting of D-glucose and
L-rhamnose.
Routine
is found in the leaves and fragrant flowers of rue (Ruta graveolens), buckwheat
(Fagopyrum esculentum).
CHARACTERS
Greenish-yellow finely
crystalline powder, odorless and tasteless. Practically insoluble in water,
slightly soluble in alcohol, it is difficult to dissolve in boiling alcohol,
practically insoluble in acid solution, ether, chloroform, acetone and benzene,
soluble in dilute alkali.
Identification
1. The
reaction wth iron (III) chloride - there is a dark green color (the presence of
phenolic groups).
2. Mineral
acids at the heating hydrolyze rutin with the formation of quercetin, glucose
and rhamnose. Quercetin + H2SO4 → oxonium salt is bright yellow color
with a green fluorescence.
3. Glucose
residue is detected after acidic hydrolysis by the reaction with
copper-tartrate reagent (Feling).
4. When
dissolved a substance in a sodium hydroxide solution appears yellow-orange
color. According to the reaction flavonoid becomes into halcon:
5. The
presence of two absorption maxima in the UV spectrum at 259 and 362.5 nm.
6. Reactions
on the keto group (formation of oxime, phenylhydrazone, semicarbazone).
7. Routine
is reduced by hydrogen in an acidic medium, and forming the perylene salts,
which have red colors (cyanine reaction). For occurring of this
reaction to the alcohol solution of substance to add concentrated hydrochloric
acid and magnesium powder:
Assay
UV-spectrophotometry
Storage
Store protected from light
Application
Vitamin P regulates
vascular permeability, enhances the action of ascorbic acid. Used for the
prevention and treatment of hypo-and avitaminosis of P vitamin, and for the
treatment of diseases associated with the violation of vascular permeability
and capillary lesions.
Produced in
powder and tablets on 20 mg. Included in the Table. "Ascoroutine"
(along with ascorbic acid and glucose) and vikalin (bismuth nitrate basic,
basic magnesium carbonate, sodium bicarbonate, powders of sweet flag (calamus) root
and buckthorn bark, routine and Kelin).
Pyridine
derivatives
the
nicotinic acid, its amide (vitamin PP) and oximethylpyridine vitamins (group Â6 ) belong to the
vitamins of pyridine derivatives.
Nicotinic
or β-pyridinecarboxylic acid was firstly synthetically obtained by Huber
in 1867-1870. Its vitamin properties were found in 1937-
Nicotinic
acid is obtained only synthetically.
Nicotinic acid obtaining
The main source of the obtaining of nicotinic acid - the nicotine alkaloid,
which is a by-product of the tobacco production and the anabasine alkaloid it
is contained in anabasis - wild growing plant in Central Asia. These alkaloids
are easily oxidized by various oxidants to nicotinic acid:
Nicotinic
acid (Acidum nicotinicum), Vitamin ÐÐ, Vitamin Â5, Niacyn (SPhU)
Pyridine-3-carboxylic
acid
CHARACTERS. Crystalline
white powder. Soluble in boiling water and boiling 96% alcohol, moderately
soluble in water, practically insoluble in ether. Dissolves in dilute solutions
of hydroxides and carbonates of alkali metals.
Identification
1. Substance
at the interaction with the cyanobromide (cyanochloride) solution and aniline
solution forms a yellow color:
2. Melting
point, ²R-spectroscopy.
3. Un
pharmacopoeia reaction :
à) Reaction
of pyridine cycle with 2,4-dinitrochlorbenzene (Cink
reaction)
b) formation
of copper nicotinate blue color:
c) With
copper sulfate and ammonium thiocyanide solutions - green
color:
d) At the
heating of the substance with anhydrous sodium carbonate, there is a smell of
pyridine:
Assay
1. Alkalimetry,
direct titration, the indicator - phenolphthalein. Parallel to conduct a blind
test.
Å = Ì.ì
2. In the
injection solutions (except nicotinic acid there is sodium bicarbonate), the
quantitative content of the drug is determined by a coppermetry. In this case,
to the solution of nicotinic acid to add a solution of Copper sulfate, the
precipitate is filtered and in the filtrate there is determined the excess of
CuSO4 by iodometric. Indicator - starch. Parallel to conduct the control test. Å =
3. UV-spectrophotometry
in the injection solution.
Storage
Store protected
from light.
Application
Antipellagric
medicine. Nicotinic acid has vasodilator and hypocholesterolemic action, so it
is prescribed for liver disease, vascular spasm in the limbs, kidneys and
brain, at the infectious diseases.
Side
effects: flushing, feeling a rush of blood to the head.
H.d. –
Producing: tablets
în
amp. 1% - 1,0 ¹10.
It is in the complex tablets “Nicoshpan”
Nicotinamide (Nicotinamidum) (UP)
Pyridine-3-carboxamide
CHARACTERS. Crystalline
white powder or colorless crystals. Easily soluble in water and ethanol. It has
basic properties. It is obtained by the interaction of ammonia and
ethylnicotinate.
Identification
1. Melting
point.
2. IR-spectroscopy.
3. Ammonia
evolving at the heating of the substance with a sodium hydroxide solution:
4. Reaction
of the formation of Schiff bases at the interaction with cyanobromide reagent
and aniline (see nicotinic acid).
5. Unpharmacopoeia
reaction.
à) At the heating with crystalline Na2CO3
– appearance
pyridine small:
b) With CuSO4 and NH4SCN solutions
appearance emerald-green color.
c) With 2,4-dinitrochlorbenzene
and NaOH solution – red-violet color (on
the pyridine cycle).
d) Dragendorff’s reagent (on
the heterocyclic nitrogen atom).
Assay
Acidimetry in
nonaqueous medium of the mixture of anhydrous acetic acid and acetic
anhydride , a direct titration at
the present of mercury (II) acetate, the
indicator - crystal violet (Å=Ì.m). Parallel
to conduct a blind test
Modified
Kjeldahl method (determination of ammonia after alkaline hydrolysis.
Storage
Store
protected from light.
Application
Antipellagric
medicine.
It is
included in the kodegidraz enzymes that transfer hydrogen, take part in ox-red
reactions in the body. Daily requirement -
15 mg.
Assign
at pellagra, liver disease, gastritis with low acidity, chronic colitis.
Nicotinamide has no vasodilatory action.
producing: tab. în 15 mg; amp. 1% - 1,0 ¹10.
It is in polyvitamins.
Oxymethylpyridine vitamins (vitamins of Â6
group)
Vitamins of Â6 group are
represented by the related substances: pyridoxol (pyridoxine), pyridoxal and
pyridoxamine, consistently converted into each other:
Pyridoxine hydrochloride (UP)
(Pyridoxini hydrochloridum) viyamin Â6
(5-hydroxy-6-methylpyridine-3,4-diyl)-dimethanol h/ch îr 3,4-di (oximethyl)-5-oxi-6-methylpyridine h/ch
CHARACTERS. Crystalline
powder of white or nearly white color. Easily soluble in water, slightly
soluble in 96% alcohol. Melts at about 205 ° C with decomposition.
Storage
Store in tightly closed container of a dark glasses, in a cool
place.
Obtaining of Pyridoxine hydrochloride
Contained in the raw grain
cereals, vegetables, meat, fish, cod liver oil and cattle, yeast, egg yolk,
etc.
Now pyridoxine is obtained only by a synthetic way.
Precursor for the synthesis of pyridoxine by the method of M.A. Preobragensky
is monochloracetate acid.
Identification
1. According
to the physico-chemical constants: IR and UV spectroscopy, TLC (as a developer
using 2,6-dichlorquinonechlorimide):
2. It
giver reaction of chlorides.
3. Unpharmacopoeia
reaction :
à) With
silicontungstenic and phosphorustungstenic acids it is formed sediments (on the
presence of pyridine bases).
b)
At the interaction with FeCl3 solution it is formed a red
coloration, which disappears when you add sulfuric acid (reaction to a phenolic
hydroxyl group):
c) Pyridoxine
takes part in the azoconnection reacts with diazonium salts. Formed the azo
dyes yield colored complexes with salts of heavy metals, particularly zinc:
Assay
1. Acidimetry in
non-aqueous medium in a mixture of formic acid and acetic anhydride.
Equivalence point is determined by potentiometric method. E = Ì.m. Conduct
a blind test. (UP, addition 1)
2. Alkalimetry,
direct titration in a mixture of
3.
Alkalimetry, direct titration. Indicator - bromothymol blue. E = A.m. Cl.
Calculations are carried out on the chlorine content, which in terms of dry
matter should be 17,1-17,35%. 4.Acidimetry in
nonaqueous medium, a direct titration at
the present of mercury (II) acetate, the
indicator - crystal violet (Å=Ì.m).
Purity
test
Specific
impurity: methyl ether of pyridoxine. It is determined by the using
of a 2,4-dichlorquinonechlorimide - after binding of pyridoxine by a boric acid
to a complex, which does not give the reaction of the dye:
The
presence of impurities appears a blue color layer of butyl alcohol.
Application
Pyridoxine
is in codecarboxilase. Daily requirement for healthy humans is 2 mg. When
hypo-and avitaminosis there is observed characteristic dermatosis
(erythredema), swelling, degenerative changes in the nervous system, etc.
Applied
in various forms of Parkinson's disease, chorea, acute and chronic hepatitis,
toxicosis during pregnancy, anemia, radiculitis, neuritis, neuralgia and other
nervous diseases.
producing: tab în
You can
not mix in the same syringe Â1 and Â12.
Included
in the medicines of B vitamins: magne-B6, Neyrorubin, Neurobex, Neurovitan,
neuron, multi-tabs B-complex.
Antivitamins
Investigation
of the relationship between chemical structure and vitamin activity allowed to
establish for each vitamin, one or more antivitamin. They tend to differ from
vitamins structure of a single functional group.
In some antivitamin structure differs significantly from the vitamins. For
example, antivitamin naphthoquinones (neodicoumarin, phenyline).
Antivitamin in biocatalytic reactions behave as competitive inhibitors. The
essence of their actions that they form a kind of psevdoenzymes that suppress
the action of these enzymes or displace vitamins from enzymatic systems. This
leads to the using of antivitamin as drugs for the treatment of many diseases.
|
Vitamins |
Antivitamins |
|
L-Ascorbic
acid |
D-Ascorbic
acid |
|
Pantothenic
acid |
ω-methylpantothenic
acid |
|
Naphthoquinones |
Neodicoumarin |
|
Nicitinamide |
Pyridine-β-sulfoacid β-acetopyridine |
|
Pyridoxine |
5-desoxipyridoxal |
|
Thiamin |
oxithiamine |
|
Folic
acid |
Aminopterine |
|
Riboflavin – 6,7-dimethyl-9-(1’-D-ribithyl)-isoaloxasine |
7-methyl-8-chlor-10-(1’-D-ribithyl)-isoaloxasine 7- methyl -8-àmino-10-(1’-D- ribithyl)-isoaloxasine |
|
Cyanocobalamin |
2,5-dimethylbenzimidazole |
Alpha Tocopheryl Acetate Concentrate (Powder Form)
General Notices
(-Tocopheryl Acetate
Concentrate (Powder Form), Ph Eur monograph 0691)
Action and use
Used in prevention and treatment of vitamin E deficiencies.
Ph Eur
DEFINITION
Preparation obtained either by finely dispersing all-rac--Tocopheryl acetate (0439) in a
suitable carrier of suitable quality (for example gelatin, acacia,
carbohydrates, lactoproteins or
a mixture thereof) or by adsorbing all-rac--Tocopheryl acetat e (0439) on
silicic acid of
suitable quality.
Content
90.0 per cent to 115.0 per cent of the -tocopheryl acetate content stated on the label, which
is not less than
CHARACTERS
Appearance
Almost white, yellowish or light brown, small particles.
Solubility
Practically insoluble or swells or forms a dispersion in water,
depending on the formulation.
IDENTIFICATION
Thin-layer chromatography (2.2.27).
Test solutionı To a quantity of the preparation to be examined corresponding to 50 mg
of -
tocopheryl acetate add 5 ml of
Add 5 ml of anhydrous ethanol R and 10 ml of cyclohexane R, shake
for 1 min and
centrifuge for 5 min. Use the upper layer.
Reference solutionı Dissolve 50 mg of -tocopheryl
acetate CRS in cyclohexane R and
dilute to 10 ml with the same solvent.
Plateı TLC
silica gel F 254 plate R .
Mobile phaseı ether R, cyclohexane R (20:80 V/V).
Applicationı 10 μl.
Developmentı Over a path of
Dryingı In
a current of air.
Detectionı Examine
in ultraviolet light at 254 nm.
Resultsı The
principal spot in the chromatogram obtained with the test solution is similar
in
position and size to the principal spot in the chromatogram obtained
with the reference
solution.
TESTS
Related substances
The thresholds indicated under Related substances (Table 2034.-1) in the
general
monograph Substances for pharmaceutical use (2034) do not apply.
ASSAY
Gas chromatography (2.2.28) .
Internal standard solutionı Dissolve
100.0 ml with the same solvent.
Test solutionı Weigh accurately a quantity of the preparation to be examined
corresponding
to about
hydrochloric acid and treat with ultrasound
at
ethanol R and 50.0 ml of the
internal standard solution and thoroughly mix the 2 layers for 30
min. Allow to separate, and use the upper layer.
Reference solutionı Dissolve
solution and dilute to 50.0 ml with the same solution.
Column:
ı— material: silanised glass;
ı— size: l = 2.0-
ı— stationary phase: diatomaceous
earth for gas chromatography R (125-150 μm or 150-
180 μm), silanised with
dimethyldichlorosilane and impregnated with 1-5 per cent m/m of
poly(dimethyl)siloxane R;
ı— plug: silanised glass wool placed
at each end of the column.
Carrier gası nitrogen for chromatography R .
Flow rateı 25-90
ml/min.
Temperature:
ı— column: constant between
ı— injection port and detector:
constant between
Detectionı Flame
ionisation.
Injectionı 1
μl; inject directly onto the column or via an injection port (preferably
glass-lined)
using an automatic injection device or other reproducible injection
method.
System suitabilityı Reference solution:
ı— resolution: minimum 1.4 between
the peaks due to dotriacontane and -tocopheryl
acetate. Set the temperature of the column and the flow rate of the
carrier gas in such a
manner that the required resolution is achieved. Repeat the injection
until the response
factor (R F) determined as described below is constant to within
± 2 per cent.
Interference testı Weigh accurately a quantity of the substance to be examined
corresponding to about
ethanol R and 50 ml of hexane R and
thoroughly mix the 2 layers for 30 min. Allow to
separate. Inject 1 μl of the upper
layer and record the chromatogram, choosing an attenuation
such that the height of the peak due to -tocopheryl acetate is greater than 50 per cent of the
maximum recorder response; during the recording, change the attenuation
so that any peak
appearing with the same retention time as that of the peak due to
dotriacontane is recorded
with a sensitivity at least 8 times greater than for the peak due to -tocopheryl acetate. If a
peak with a height of at least
same retention time as that of dotriacontane, use the corrected peak
area S
D(corr) for the final
calculation.
S
D
=
area of the peak due to dotriacontane in the chromatogram obtained with
the test
solution
S I
=
area of the peak with the same retention time as that of the peak due to
dotriacontane in the chromatogram obtained in the interference test
S
T
=
area of the peak due to -tocopheryl
acetate in the chromatogram obtained with the
test solution
S TI
=
area of the peak due to -tocopheryl
acetate in the chromatogram obtained in the
interference test
f
=
factor by which the attenuation was changed
Record the chromatograms choosing an attenuation such that the peak due
to -tocopheryl
acetate is greater than 50 per cent of the maximum recorder response.
Measure the areas of the peaks due to -tocopheryl acetate CRS (S T) and
to dotriacontane
(S
D) in the chromatogram obtained with the reference solution and the areas
of the peaks
due
to -tocopheryl
acetate (S
T)
and to dotriacontane (S
D)
in the chromatogram obtained
with
the test solution.
Determine
the response factor (RF) for -tocopheryl acetate from the areas of
the peak due
to
-tocopheryl
acetate and the peak due to dotriacontane in the chromatogram obtained with
the
reference solution using the following expression:
Calculate
the percentage content of -tocopheryl acetate using the
following expression:
S D
=
area
of the peak due to dotriacontane in the chromatogram obtained with the
reference
solution
S
D(corr.)
=
corrected
area of the peak due to dotriacontane in the chromatogram obtained
with
the test solution
S T
=
area
of the peak due to -tocopheryl acetate CRS in the chromatogram
obtained
with the reference solution
S
T
=
area
of the peak due to -tocopheryl acetate in the chromatogram obtained with
the
test solution
m D
=
mass
of dotriacontane in the test solution and in the reference solution, in
milligrams
m
T
=
mass
of -tocopheryl
acetate CRS in the reference solution, in milligrams
m
=
mass
of the substance to be examined in the test solution, in milligrams
STORAGE
In
an airtight, well-filled container, protected from light.
LABELLING
The
label states the content of -tocopheryl acetate, expressed in
grams per
concentrate.
Alpha Tocopheryl Hydrogen Succinate
General Notices
(DL--Tocopheryl Hydrogen
Succinate, Ph Eur monograph 1258)
C33H54O5 ıı530.8ıı
Action and use
Used in prevention and treatment of vitamin E deficiencies.
Ph Eur
DEFINITION
(2RS)-2,5,7,8-Tetramethyl-2-[(4RS,8RS)-4,8,12-trimethyltridecyl]-3,4-dihydro-2H-1-
benzopyran-6-yl hydrogen succinate.
Content
96.0 per cent to 102.0 per cent.
CHARACTERS
Appearance
White or almost white, crystalline powder.
Solubility
Practically insoluble in water, very soluble in methylene chloride,
soluble in acetone and in
anhydrous ethanol.
IDENTIFICATION
First identificationı B, D.
Second identificationı A, C, D.
ıA. Absorbance (see Tests).
ıB. Infrared absorption spectrophotometry (2.2.24)
.
Comparisonı RRR--tocopheryl hydrogen
succinate CRS.
ıC. Thin-layer chromatography (2.2.27) .
Test solution (a)ı Dissolve 10 mg of the substance to be examined in 2 ml of cyclohexane
R
.
Test solution (b)ı In a ground-glass-stoppered tube, dissolve 10 mg of the substance to be
examined in 2 ml of
and add 2 ml of water R and 2 ml of cyclohexane R . Shake
for 1 min. Use the upper layer.
Reference solution (a)ı Dissolve 10 mg of RRR--tocopheryl
hydrogen succinate CRS in 2
ml of cyclohexane R .
Reference solution (b)ı Prepare as described for test solution (b), using RRR--tocopheryl
hydrogen succinate CRS instead of the
substance to be examined.
Plateı TLC
silica gel F 254 plate R .
Mobile phaseı glacial acetic acid R, ether R, cyclohexane R (0.2:20:80 V/V/V).
Applicationı 10 μl.
Developmentı Over a path of
Dryingı In
a current of air.
Detection Aı Examine in ultraviolet light at 254 nm.
Results Aı The
principal spot in the chromatogram obtained with test solution (a) is similar
in
position and size to the principal spot in the chromatogram obtained
with reference solution
(a). In the chromatograms obtained with test solution (b) and reference
solution (b), there are
2 spots: the spot with the higher R F value is due to -tocopherol, the spot with the lower R F
value is due to DL--tocopheryl
hydrogen succinate and corresponds to the spot obtained with
reference solution (a). Depending on the degree of hydrolysis, the lower
spot may be weak or
even absent.
Detection Bı Spray with a mixture of 10 volumes of hydrochloric acid R , 40
volumes of a 2.5
g/l solution of ferric chloride R in ethanol (96 per cent) R and
40 volumes of a 10 g/l solution
of phenanthroline hydrochloride R in ethanol (96 per cent) R .
Results Bı In
the chromatograms obtained with test solution (b) and reference solution (b),
the spot due to -tocopherol is orange.
ıD. Optical rotation (see Tests).
TESTS
Optical rotation (2.2.7)
- 0.01° to + 0.01°.
Dissolve
Absorbance (2.2.25) .
Solution Aı Dissolve
solvent.
Test solution (a)ı Dilute 10.0 ml of solution A to 100.0 ml with anhydrous ethanol R .
Test solution (b)ı Dilute 20.0 ml of solution A to 50.0 ml with anhydrous ethanol R .
Absorption maximumı At 284 nm for test solution (a).
Absorption minimumı At 254 nm for test solution (b).
Specific absorbance at the absorption maximumı 35 to 38 for test solution (a).
Specific absorbance at the absorption minimumı 6.0 to 8.0 for test solution (b).
Acid value (2.5.1)
101 to 108, determined on
Free tocopherol
Maximum 1.0 per cent.
Dissolve
0.1 ml of a 2.5 g/l solution of diphenylamine R in sulphuric
acid R . Titrate with
ammonium and cerium sulphate until
a blue colour is obtained that persists for at least 5 s.
Carry out a blank titration.
1 ml of
Related substances
The thresholds indicated under Related substances (Table 2034.-1) in the
general
monograph Substances for pharmaceutical use (2034) do not apply.
Heavy metals (2.4.8)
Maximum 20 ppm.
solution (10 ppm Pb) R.
Sulphated ash (2.4.14)
Maximum 0.1 per cent, determined on
ASSAY
Gas chromatography (2.2.28) .
Internal standard solutionı Dissolve
100.0 ml with the same solvent.
Test solutionı Weigh 30.0 mg of the substance to be examined into a 20 ml vial. Add 2.0
ml
of methanol R , 1.0 ml of dimethoxypropane R and 0.1 ml of
hydrochloric acid R . Cap
tightly and sonicate. Allow to stand in the dark for 1 h ± 5 min. Remove
from the dark, uncap
and evaporate just to dryness on a steam bath with the aid of a stream
of nitrogen. Add 10.0
ml of the internal standard solution. Vortex into solution.
Reference solutionı Weigh 30.0 mg of RRR--tocopheryl
hydrogen succinate CRS into a 20
ml vial. Add 2.0 ml of methanol R , 1.0 ml of dimethoxypropane
R and 0.1 ml of hydrochloric
acid R . Cap tightly and sonicate. Allow to
stand in the dark for 1 h ± 5 min. Remove from the
dark, uncap and evaporate just to dryness on a steam bath with the aid
of a stream of
nitrogen. Add 10.0 ml of the internal standard solution. Vortex into
solution.
Column:
ı— material: fused silica;
ı— size: l =
ı— stationary phase: poly(dimethyl)siloxane
R (film thickness 0.25 μm).
Carrier gası helium for chromatography R .
Flow rateı 3-6
ml/min.
Split ratioı 1:10 to 1:20.
Temperature:
Detectionı Flame
ionisation.
Injectionı 1
μl; inject directly onto the column or via a glass-lined injection port
using an
automatic injection device or some other reproducible injection method.
System suitabilityı Reference solution:
ı— resolution: minimum 12.0 between
the peaks due to dotriacontane and DL--tocopheryl
hydrogen succinate.
Interference testı Dissolve
to 50.0 ml with the same solvent. Inject 1 μl of the solution and record the chromatogram. If a
peak is detected with the same retention time as that of the peak due to
dotriacontane,
calculate the area of this peak relative to the peak area of the
substance to be examined. If
the relative peak area is greater than 0.5 per cent, use the corrected
peak area S
D(corr) for the
final calculation.
S
D
=
area of the peak due to dotriacontane in the chromatogram obtained with
the test
solution
S I
=
area of the peak with the same retention time as that of the peak due to
dotriacontane in the chromatogram obtained in the interference test
S
T
=
area of the peak due to DL--tocopheryl
hydrogen succinate in the chromatogram
obtained with the test solution
S TI
=
area of the peak due to DL--tocopheryl
hydrogen succinate in the chromatogram
obtained in the interference test
Measure the areas of the peaks due to RRR--tocopheryl hydrogen succinate CRS (S
T) and
dotriacontane (S D) in the chromatogram obtained with the
reference solution and the areas of
the peaks due to DL--tocopheryl
hydrogen succinate (S
T) and dotriacontane (S
D) in the
chromatogram obtained with the test solution.
Determine
the response factor (R F) for DL--tocopheryl hydrogen succinate from
the areas of
the
peaks due to RRR--tocopheryl hydrogen succinate CRS and
dotriacontane in the
chromatogram
obtained with the reference solution, using the following expression:
Calculate
the percentage content of dl--tocopheryl hydrogen succinate using
the following
expression:
S D
=
area
of the peak due to dotriacontane in the chromatogram obtained with the
reference
solution
S
D(corr)
=
corrected
area of the peak due to dotriacontane in the chromatogram obtained
with
the test solution
S T
=
area
of the peak due to RRR--toco pheryl hydrogen succinate CRS in
the
chromatogram
obtained with the reference solution
S
T
=
area
of the peak due to DL--tocopheryl hydrogen succinate in the
chromatogram
obtained with the test solution
m D
=
mass
of dotriacontane in the test solution and in the reference solution, in
milligrams
m T
=
mass
of RRR--tocopheryl
hydrogen succinate CRS in the reference solution,
in
milligrams
m
=
mass
of the substance to be examined in the test solution, in milligrams
STORAGE
Protected
from light.
Ph
Eur
Nicotinic Acid
General Notices
(Ph Eur monograph 0459)
C6H5NO2
ıı123.1ıı59-67-6
Action and use
Component of vitamin B.
Preparation
Nicotinic Acid Tablets
Ph Eur
DEFINITION
Nicotinic acid contains not less than 99.5 per cent and not more than
the equivalent of 100.5
per cent of pyridine-3-carboxylic acid, calculated with reference to the
dried substance.
CHARACTERS
A white or almost white, crystalline powder, soluble in boiling water
and in boiling alcohol,
sparingly soluble in water. It dissolves in dilute solutions of the
alkali hydroxides and
carbonates.
IDENTIFICATION
First identificationıA, B.
Second identificationıA, C.
ıA. Melting point (2.2.14):
ıB. Examine by infrared absorption
spectrophotometry (2.2.24), comparing with the spectrum
obtained with nicotinic acid CRS.
ıC. Dissolve about 10 mg in 10 ml of water
R. To 2 ml of the solution add 2 ml of cyanogen
bromide solution R and 3 ml of a 25 g/l
solution of aniline R and shake. A yellow colour
develops.
TESTS
Related substances
Examine by thin-layer chromatography (2.2.27), using silica
gel GF254 R as the coating
substance.
Test solutionıDissolve
necessary, and dilute to 25 ml with the same solvent.
Reference solutionıDilute 0.5 ml of the test solution to 100 ml with water R.
Apply separately to the plate 5 μl
of each solution. Develop over a path of
mixture of 5 volumes of water R, 10 volumes of anhydrous
formic acid R and 85 volumes of
propanol R. Dry the plate at
254 nm. Any spot in the chromatogram obtained with the test solution,
apart from the principal
spot, is not more intense than the spot in the chromatogram obtained
with the reference
solution (0.5 per cent).
Chlorides (2.4.4)
Dissolve
solvent. The solution complies with the limit test for chlorides (200
ppm).
Heavy metals (2.4.8)
lead standard solution (10 ppm Pb) R.
Loss on drying (2.2.32)
Not more than 1.0 per cent, determined on
Sulphated ash (2.4.14)
Not more than 0.1 per cent, determined on
ASSAY
Dissolve
phenolphthalein solution R as indicator,
until a pink colour is obtained. Carry out a blank
titration.
1 ml of
STORAGE
Store protected from light.
Ph Eur
Nicotinamide
General Notices
(Ph Eur monograph 0047)
C6H6N2Oıı122.1ıı98-92-0
Action and use
Component of vitamin B.
Preparations
Nicotinamide Tablets
Vitamins B and C Injection
Ph Eur
DEFINITION
Nicotinamide contains not less than 99.0 per cent and not more than the
equivalent of 101.0
per cent of pyridine-3-carboxamide, calculated with reference to the
dried substance.
CHARACTERS
A white or almost white, crystalline powder or colourless crystals,
freely soluble in water and
in ethanol.
IDENTIFICATION
First identificationıA, B.
Second identificationıA, C, D.
ıA. Melting point (2.2.14): 128 °C
to 131 °C.
ıB. Examine by infrared absorption spectrophotometry
(2.2.24), comparing with the spectrum
obtained with nicotinamide CRS.
ıC. Boil 0.1 g with 1 ml of dilute
sodium hydroxide solution R. Ammonia is evolved which is
recognisable by its odour.
ıD. Dilute 2 ml of solution S (see Tests)
to 100 ml with water R. To 2 ml of the solution, add 2
ml of cyanogen bromide solution R and 3 ml of a 25 g/l solution
of aniline R and shake. A
yellow colour develops.
TESTS
Solution S
Dissolve 2.5 g in carbon dioxide-free water R and dilute to 50 ml
with the same solvent.
Appearance of solution
Solution S is clear (2.2.1) and not more intensely coloured than
reference solution BY7 (2.2.2,
Method II).
pH (2.2.3)
The pH of solution S is 6.0 to 7.5.
Related substances
Examine by thin-layer chromatography (2.2.27), using a TLC
silica gel GF254 plate R.
Test solutionıDissolve 0.4 g of the substance to be examined in a mixture of equal
volumes
of alcohol R and water R and dilute to 5.0 ml with the
same mixture of solvents.
Reference solutionıDilute 0.5 ml of the test solution to 200 ml with a mixture of equal
volumes of alcohol R and water R.
Apply to the plate 5 μl of each
solution. Develop over a path of 10 cm using a mixture of 4
volumes of water R, 45 volumes of ethanol R and 48 volumes
of chloroform R. Allow the plate
to dry and examine in ultraviolet light at 254 nm. Any spot in the
chromatogram obtained with
the test solution, apart from the principal spot, is not more intense
than the spot in the
chromatogram obtained with the reference solution (0.25 per cent).
Heavy metals (2.4.8)
Dilute 12 ml of solution S to 18 ml with water R. 12 ml of the
solution complies with limit test A
for heavy metals (30 ppm). Prepare the standard using lead standard
solution (1 ppm Pb) R.
Loss on drying (2.2.32)
Not more than 0.5 per cent, determined on 1.00 g by drying in vacuo for
18 h.
Sulphated ash (2.4.14)
Not more than 0.1 per cent, determined on 1.0 g.
ASSAY
Dissolve 0.250 g in 20 ml of anhydrous acetic acid R, heating
slightly if necessary, and add 5
ml of acetic anhydride R. Titrate with 0.1 M perchloric acid,
using crystal violet solution R as
indicator until the colour changes to greenish-blue.
1 ml of 0.1 M perchloric acid is equivalent to 12.21 mg of
C6H6N2O.
Ph Eur
Pyridoxine Hydrochloride
General Notices
(Ph Eur monograph 0245)
C8H11NO3,HClıı205.6ıı58-56-0
Action and use
Vitamin B6.
Preparations
Pyridoxine Tablets
Vitamins B and C Injection
When vitamin B6 is prescribed or demanded, Pyridoxine Hydrochloride
shall be dispensed or
supplied.
Ph Eur
DEFINITION
Pyridoxine hydrochloride contains not less than 99.0 per cent and not
more than the
equivalent of 101.0 per cent of
(5-hydroxy-6-methylpyridine-3,4-diyl)dimethanol hydrochloride,
calculated with reference to the dried substance.
CHARACTERS
A white or almost white, crystalline powder, freely soluble in water,
slightly soluble in alcohol.
It melts at about 205 °C, with decomposition.
IDENTIFICATION
First identificationıB, D.
Second identificationıA, C, D.
ıA. Dilute 1.0 ml of solution S (see Tests)
to 50.0 ml with 0.1 M hydrochloric acid (solution A)
. Dilute 1.0 ml of solution A to 100.0 ml with 0.1 M hydrochloric
acid . Examined between
250 nm and 350 nm (2.2.25), the solution shows an absorption
maximum at 288 nm to 296
nm. The specific absorbance at the maximum is 425 to 445. Dilute 1.0 ml
of solution A to
100.0 ml with a mixture of equal volumes of 0.025 M potassium
dihydrogen phosphate
solution and 0.025 M disodium hydrogen
phosphate solution (2.2.3). Examined between
220 nm and 350 nm, the solution shows 2 absorption maxima, at 248 nm to
256 nm and at
320 nm to 327 nm. The specific absorbances at the maxima are 175 to 195
and 345 to 365,
respectively.
ıB. Examine by infrared absorption
spectrophotometry (2.2.24), comparing with the spectrum
obtained with pyridoxine hydrochloride CRS.
ıC. Examine the chromatograms obtained in
the test for related substances. The principal
spot in the chromatogram obtained with test solution (b) is similar in
position, colour and
size to the principal spot in the chromatogram obtained with reference
solution (a).
ıD. Solution S gives reaction (a) of
chlorides (2.3.1).
TESTS
Solution S
Dissolve 2.50 g in carbon dioxide-free water R and dilute to 50.0
ml with the same solvent.
Appearance of solution
Solution S is clear (2.2.1) and not more intensely coloured than
reference solution Y7 (2.2.2,
Method II).
pH (2.2.3)
The pH of solution S is 2.4 to 3.0.
Related substances
Examine by thin-layer chromatography (2.2.27), using a TLC
silica gel G plate R.
Test solution (a)ıDissolve 1.0 g of the substance to be examined in water R and
dilute to 10
ml with the same solvent.
Test solution (b)ıDilute 1 ml of test solution (a) to 10 ml with water R.
Reference solution (a)ıDissolve 0.10 g of pyridoxine hydrochloride CRS in water R and
dilute
to 10 ml with the same solvent.
Reference solution (b)ıDilute 2.5 ml of test solution (a) to 100 ml with water R. Dilute
1 ml of
this solution to 10 ml with water R.
Apply to the plate 2 μl of each
solution. Develop in an unsaturated tank over a path of 15 cm
using a mixture of 9 volumes of concentrated ammonia R, 13
volumes of methylene chloride
R, 13 volumes of tetrahydrofuran R and
65 volumes of acetone R. Allow the plate to dry in air
and spray with a 50 g/l solution of sodium carbonate R in a
mixture of 30 volumes of alcohol
R and 70 volumes of water R. Dry the
plate in a current of air, spray with a 1 g/l solution of
dichloroquinonechlorimide R in
alcohol R and examine the chromatograms immediately. Any
spot in the chromatogram obtained with test solution (a), apart from the
principal spot, is not
more intense than the spot in the chromatogram obtained with reference
solution (b) (0.25 per
cent). Disregard any spots remaining on the starting line.
Heavy metals (2.4.8)
12 ml of solution S complies with limit test A (20 ppm). Prepare the
standard using lead
standard solution (1 ppm Pb) R.
Loss on drying (2.2.32)
Not more than 0.5 per cent, determined on 1.000 g by drying in an oven
at 105 °C.
Sulphated ash (2.4.14)
Not more than 0.1 per cent, determined on
ASSAY
In order to avoid overheating in the reaction medium, mix thoroughly
throughout and stop the
titration immediately after the end-point has been reached.
Dissolve
with
blank titration.
1 ml of
STORAGE
Store protected from light.
IMPURITIES
ıA. 6-methyl-1,3-dihydrofuro[3,4-c]pyridin-7-ol,
ıB.
5-(hydroxymethyl)-2,4-dimethylpyridin-3-ol.
Ph Eur