NationalLibraryOfScotland/medical-history-of-british-india huggingface dataset:
9
It was considered desirable to determine whether the Quinine in these
mixtures of blood-serum and Quinine salt solutions was present (1) in solution
in the supernatant fluid, (2) in the suspended precipitate, or (3) in the
deposit.
The tube containing the mixture of blood-serum and Quinine bi-sulphate
1 in 80 was taken and its contents filtered. The clear filtrate gave an
intense emerald green colour on the addition of chlorine water and ammonia,
so that the filtrate contained Quinine in solution. The deposit was examined
next. It was thoroughly washed with water till the washings no longer
gave any colour re-action with these reagents, and then treated with weak
sulphuric acid. The deposit was not dissolved, but some of the supernatant
fluid was placed in a clean test-tube and the reagents, chlorine water and
ammonia, added. An intense deep-blue colour resulted. This blue solution was
divided between two test-tubes, one of which was heated and the other kept at
laboratory temperature. The solution in the tube that was heated turned green
in a couple of minutes; the solution in the tube left at laboratory temperature
turned green in three days: These results suggest that Quinine was present in
the deposit but in an altered form, and probably as an oxidised product.
A quantitative estimation of the Quinine in solution and in suspension
was carried out as follows:
—
A mixture of serum and Quinine hydrochloride solution was specially pre-
pared by dissolving .1 gramme Quinine hydrochloride in two cubic centimetres
of boiling water which on cooling was added to two cubic centimetres of ox
blood-serum. After half-an-hour this mixture was filtered through cotton wool
with the aid of a water-suction pump. The filtrate was made strongly alkaline
with liquor potassæ, when a heavy white precipitate of Quinine alkaloid took
place. This milky suspension was then extracted three times with ethyl æther
and the æthereal extracts filtered. The æther was evaporated from the filtrate
and the residue dissolved in alcohol. The alcoholic solution was then filtered
and the filter-paper washed with a little alcohol, the filtrate and washings
being received into a weighed porcelain capsule. The alcohol was evaporated
on a water-bath and the residue dried at 120° C., when the capsule and residue
were weighed. The calculation was as follows:—
Capsule + dried extract
.
.
. .
.
=
1 2 . 4 8 4 gm.
Capsule
.
.
.
.
.
=
1 2 . 4 4 0 "
[ I L L ]
d r i e d e x t r a c t .
.
.
.
.
. =
0 . 0 4 4 gm.
The dried extract is, of course, anhydrous Quinine base. Now, Quinine
hydrochloride contains 82 per cent . anhydrous base; therefore 0.044 gramme
10
anhydrous base corresponds with 0.0536 gramme Quinine hydrochloride. It
follows therefore that 0.0536 gramme Quinine hydrochloride was in solution in
the mixture.
Next a similar mixture—.1 gramme Quinine hydrochloride dissolved in two
cubic centimetres of boiling water which after cooling was added to two cubic
centimetres of ox blood-serum—was prepared and allowed to stand till the deposit
had settled. The supernatant fluid was pipetted off and (in order to lose as
little as possible) the residue was filtered through fine meshed cloth, a thick
yellow creamy deposit being left behind on the cloth. The fluid pipetted off
and that filtered through the cloth were mixed and made strongly alkaline with
liquor potassæ. The resulting suspension was thrice ætherised; the æther
extracts filtered; the æther evaporated; the residue dissolved in alcohol; the
solution filtered and the filtrate and washings evaporated in a weighed capsule
on a water-bath; and the residue, dried at 120° C., weighed—in the manner
already described. The results were as follows:—
Capsule + dried extract
.
.
.
.
. = 12.0435 gm.
Capsule
.
.
.
.
.
= 11.995
„
[ I L L ] d r i e d e x t r a c t
.
.
.
.
.
= 0.0485 gm.
Now, 0.0485 gramme anhydrous Quinine base corresponds with 0.0591
gramme Quinine hydrochloride; so that the amount of Quinine hydrochloride in
solution and in suspension in the mixture amounts to 0.0591 gramme.
It is evident therefore that in such a mixture as that prepared above, out
of .1 gramme Quinine hydrochloride contained in it, there was (1) in solution,
. 0 5 3 6 g r a m m e , ( 2 ) i n t h e s u s p e n d e d p r e c i p i t a t e , ( . 0 5 9 1 — . 0 5 3 6 ) g r a m m e , i . e . ,
. 0 0 5 5 g r a m m e a n d ( 3 ) i n t h e d e p o s i t , ( . 1 — . 0 5 9 1 ) g r a m m e , i . e . , . 0 4 0 9 g r a m m e o f
Quinine hydrochloride respectively. In other words slightly over half the
Quinine was in solution and slightly under half was contained in the deposit—
probably transformed (oxidised), combined with proteids and therapeutically
useless. The importance of this observation in connection with the hypodermic
administration of Quinine salts is obvious. In this particular instance the
strength of the Quinine salt solution that had been added to the blood-serum
was about 1 in 20, which is much more dilute than the solutions generally
used for hypodermic injection. It will be evident, on referring to the table
giving miscibility of Quinine salt solutions with ox blood-serum, that the
greater the dilution of the Quinine salt solution the less is the deposit that
forms, and therefore presumably, the greater is the proportion of Quinine in
solution until finally in extreme dilution no deposit takes place and all the
Quinine is in solution.
11
The action of Quinine salt solutions on blood-serum reminds one strongly
of that of alcohol, which in greater concentration than 33 per cent. is quite
incompatible with blood-serum but in greater dilution perfectly miscible.
Solubility of Quinine Alkaloid in Ox Blood=Serum.
With 25 cubic centimetres of ox blood-serum, fresh and centrifuged, .1
gramme crystalline Quinine alkaloid was shaken up in a flask and incubated
at 37° C. for two hours, during which time the flask was frequently shaken.
After these two hours, the flask and its contents were allowed to cool at
laboratory temperature (12° C.), and then the contents were filtered through
cotton wool with the aid of a water-suction pump. The amount of alkaloid in
solution in the clear filtrate was determined as follows:—
The filtrate was made distinctly alkaline with liquor potassæ and the
resulting suspension thrice shaken up with ethyl æther. The æther extracts
were then filtered and the æther evaporated. The residue was dissolved in 60
per cent. alcohol and this solution filtered into a weighed porcelain capsule.
The filtrate and washings were evaporated on a water-bath, avoiding boiling,
and the residue dried at 120° C. and weighed. The following figures were
obtained:—
Capsule + dried residue= 12.474 gm.
Capsule= 12.440 „
[ I L L ] d r i e d r e s i d u e = 0 . 0 3 4 g m . ( a n h y d r o u s Q u i n i n e b a s e ) .
Now, crystalline Quinine alkaloid contains 85.7 per cent. anhydrous Qui-
nine base; therefore, 0.034 gramme anhydrous Quinine base corresponds with
.0397 gramme crystalline Quinine alkaloid. Thus .0397 gramme crystalline
Quinine alkaloid was dissolved in 25 cubic centimetres of ox blood-serum,—i.e.,
practically 4 parts in 2,500 parts of serum or 1 in 625. Crystalline Quinine
alkaloid is therefore nearly three times as soluble in ox blood-serum as in water.
Solubility of Quinine Alkaloid in Ox Bile,
Malanin1 i n 1 8 6 8 d e m o n s t r a t e d t h e i n s o l u b i l i t y o f t h e c o m p o u n d s f o r m e d
by the union of Quinine and bile acids and assumed from this that the intestines
took little or no part in the absorption of Quinine. A similar action was
attributed to bile acids by Kerner. 2 L a u d e r B r u n t o n ,
3 w h i l e a c k n o w l e d g i n g
the sparingly soluble character of the precipitate obtained by adding Quinine
to bile acids, refers to its solubility in an excess of bile. The opinion expressed
by Dixon7 i s t h a t a f t e r e n t e r i n g t h e d u o d e n u m Q u i n i n e i s u n d e r o r d i n a r y
circumstances absorbed rapidly ; but if there is excess of alkali in the
duodenum Quinine is precipitated, forming with the bile acids insoluble salts
which are passed unchanged in the fæces. It is, however, pointed out by
12
Marshall6 t h a t t h e p r e c i p i t a t e o f Q u i n i n e g l y c o c h o l a t e w h i c h i s o b t a i n e d b y
adding a solution of Quinine to bile, although very insoluble, is easily decom-
posed by carbonic acid and alkaline carbonates, and under ordinary circum-
stances probably plays little part in the absorption of Quinine.
The solubility of crystalline Quinine alkaloid in fresh ox bile was deter-
mined by me in the following manner:
—
With 15 cubic centimetres of fresh ox bile (the re-action of which tested
with red litmus paper, was faintly alkaline) .2 gramme crystalline
Quinine alkaloid was shaken up in a flask. To ensure small division
of the Quinine the alkaloid was first triturated in a test-tube with a
little of the bile by means of a glass rod. The flask after being well
shaken was incubated at 37°C. for three hours, and shaken frequently
during this period. The flask and its contents were then cooled at
laboratory temperature (12°C.). The contents of the flask were fil-
tered through cotton wool with the aid of a water-suction pump, the
residue on the cotton wool being washed with a small amount of cold
water and the washings added to the filtrate. The clear filtrate was
made distinctly alkaline with liquor potassæ. The resulting suspen-
sion was shaken up three times with ethyl æther. The æther extract
was filtered and the æther evaporated from the filtrate in a stream of
hot air (80°C.). The residue was dissolved in 96 per cent. alcohol and
this solution filtered. The filtrate and washings were evaporated to
dryness on a water-bath. The residue was then dissolved in weak
sulphuric acid and the resulting solution filtered, the filter being
washed with a little of the sulphuric acid. The filtrate and washings
were made distinctly alkaline with liquor potassæ and the resulting
emulsion thrice shaken up with æther. The æther extract was fil-
tered into a weighed porcelain capsule and the æther evaporated in a
stream of hot air (80°C). The extract was then further dried at 120°C.
and weighed—with the following results:—
Capsule + dried extract=12 .065 gm.
Capsule= 11 .9 9 6 ”
[ i l l ] d r i e d e x t r a c t = 0
.
0 6 9 g m . ( a n h y d r o u s Q u i n i n e b a s e ) .
As crystalline Quinine alkaloid contains 85.7 per cent. anhydrous Quinine
base, .069 gramme anhydrous Quinine base corresponds with .082 gramme
crystalline Quinine, alkaloid. Therefore, 15 cubic centimetres of ox bile
dissolved .082 gramme crystalline Quinine alkaloid; i.e., 15,000 cubic centi-
metres of ox bile can dissolve 82 grammes of crystalline Quinine alkaloid; i.e.,
13
183 cubic centimetres of ox bile can dissolve one gramme crystalline Quinine
alkaloid. Crystalline Quinine alkaloid is therefore about nine times as soluble
in ox bile as in water. This result differs considerably from that of Giemsa and
Schaumann5 who, using amorphous Quinine alkaloid instead of the crystalline
form used by me, give the amazing solubility of 1 in 83;—i . e
. , Q u i n i n e a l k a l o i d
(amorphous) is twenty times as soluble in ox bile as in water. The amorphous
form would certainly dissolve more quickly than the crystalline, so the solubility
may be under-estimated in my experiments. It is worthy of note also, in this
connection, that the Quinine alkaloid that is precipitated on Quinine salts
coming in contact with alkali in the duodenum must be of the amorphous
variety.
Absorption of Quinine.
Hitherto, experimenters have taken the amount of Quinine eliminated in
the urine as a measure of the amount that has been absorbed and entered the-
circulation. It is, therefore, necessary to examine the reliability of this gauge.
Until the beginning of the last decade the views held regarding the elimi-
nation of Quinine appear to have been quite erroneous; there was a lack of
harmony in the results obtained by different investigators not only regarding the
proportion of Quinine eliminated but also regarding the chemical characters of
the Quinine or its derivatives that were eliminated. According to Kerner 2
and Merkel1 9
m o s t o f t h e Q u i n i n e w a s e l i m i n a t e d u n c h a n g e d i n t h e u r i n e , t h e
remaining part being excreted in the form of transformed products. Personne,20
however, affirmed that only about half the Quinine administered is eliminated
unchanged in the urine and that the other half is destroyed in the body and not
excreted as transformed products. Schmitz 21 and also Giemsa and Schaumann 5
have confirmed Personne's observation that only unchanged Quinine is elimi-
nated in the urine; and they maintain that there is no Quinine derivative with
alkaloidal characters present in detectable amount in the urine after Quinine
administration.
Practically speaking, only traces of Quinine are eliminated by channels
other than the kidneys. Mariani 1 3
w a s a b l e t o d e t e c t t r a c e s i n t h e m i l k o f
nursing mothers and in sweat, in the latter only after the secretion had been
concentrated by evaporation. From the bitter taste experienced for a long
time after taking Quinine in wafers, Giemsa and Schaumann 5 are of opinion
that probably a very little is excreted in saliva. In the fæces, under ordinary
circumstances, very little is eliminated: after administration by the mouth,
Kerner2 could find traces only; Merkel1 9
c o u l d f i n d n o Q u i n i n e ; K l e i n e ,2
2
. 3
p e r
cent. at most; Flamini,2 3
u s i n g t h e i n s o l u b l e t a n n a t e o f Q u i n i n e , 8 — 1 5p
e r c e n t . ,
Schmitz21 traces only; and Giemsa and Schaumann, 5 even after the adminis-
tration of the insoluble alkaloid itself, traces only—amounts so small that they
D 2
14
could not be weighed. So far therefore as elimination by other channels is con-
cerned, Quinine excretion in the urine is quite a feasible gauge of absorption.
Regarding the rate and amount of elimination of Quinine in the urine
there is commendable harmony in the results of recent investigators. After
medium doses ( e.g. one gramme) of Quinine administered by the mouth while
fasting, the average amount eliminated in the first 24 hours has been given by
Kleine22 as 21.9 per cent., by Mariani1 3
a s 2 4 . 7
p e r c e n t . ,
b y F l a m i n i
2 3
a s 2 4 . 6
per cent., by Schmitz21 as 19.5 per cent., and by Giemsa and Schaumann5 as
25.8 per cent., and under the same conditions the average total elimination ( i.e.,
the amount eliminated during the two or three days Quinine excretion lasted)
according to the same authorities is about 40 per cent. It would appear there-
fore that under these circumstances about 60 per cent. of Quinine is destroyed
in the body. That the amount of Quinine eliminated in the urine should
vary, as a rule, between fairly narrow limits when the mode of administration
and other conditions are similar is what one would expect. But even, under
such conditions, Giemsa and Schaumann, 5 who regard the amount of Quinine
elimination in the urine as the best practical measure of the amount absorbed,
acknowledge that in particular individuals there are considerable variations
from the normal, and that even in the same individual there might be striking
variations on different days even when examination of the fæces showed that
absorption was similar on all the days. Further, even granting that under
similar conditions as regards mode of administration, state of gastro-intestinal
tract, etc., the amount of Quinine eliminated in the urine is fairly constant, it
cannot be assumed that under altered conditions the relative amounts of Quinine
eliminated in the urine will be proportional to the corresponding amounts of
Quinine absorbed. To show that such an assumption would be wrong it is only
necessary to compare the average amounts of Quinine eliminated in the urine
after intravenous administration on the one hand and intramuscular or oral on
the other. Mariani 13 gives the following averages:—
Table III.
Intravenous injection. Intramuscular injection. Oral administration (fasting).
1st day
.
.
20.54%
18.47%
24.70%
2nd day
.
.
6.33%
9.60%
?
3rd day
.
.
1.07%
4.91%
?
4th day
.
. —
2.45%
?
TOTAL
.
27.94%
35.43%
40.88%
15
These figures show that after intravenous injection less Quinine (totals)
is eliminated in the urine than after either intramuscular injection or oral
administration. As with intravenous injection there can be no doubt about
the Quinine entering the circulation, it is evident that Quinine elimination
in the urine cannot be directly proportional to the amount of Quinine that has
entered the blood. Further, on referring to the amounts of Quinine eliminated
during the first day, it is quite obvious that there is no direct relationship
between the amount of Quinine that has entered the circulation and the
amount that has been excreted: if it be said that elimination varies directly
with absorption, then more Quinine entered the blood after oral administration
than after intravenous; if it be said that elimination varies inversely with
absorption, then more Quinine entered the blood after intramuscular injection
than after intravenous.
In reality, the amount of Quinine absorbed must be equal to the amount
of Quinine eliminated in the urine plus the amount that has undergone cleavage
in the body. The determination of the amount of Quinine eliminated in the
urine cannot possibly give us any idea of the amount absorbed unless we are
able to determine at the same time the amount that has undergone cleavage
or to satisfy ourselves that the amount that has undergone cleavage is constant.
Under different conditions of Quinine administration, each of these three
factors varies; and as there is no means of estimating the amount of Quinine
that has undergone cleavage in the body the amount of Quinine eliminated in
the urine is quite fallacious as a universal gauge of the amount of Quinine that
has entered the circulation.
There is, however, another method, namely, that of determining the mini-
mum-lethal dose—which hitherto seems to have escaped notice—which is cap-
able of giving us a rough estimate of the amount of absorption, especially when
comparing different methods of administration of Quinine. The toxicity or
lethality of a substance must be proportional to the rapidity and thoroughness of
its absoption, no matter by what channel or under what conditions the substance
is administered. And, as in calculating the minimum-lethal dose, death must
occur within twenty-four hours, rapidity may be taken as a constant, so
lethality varies directly with thoroughness of absorption.
Oral Administration.
As already noted, many assume without any definite proof that Quinine
is absorbed chiefly from the stomach. In their opinion Quinine, in whatever
form administered, is converted to some extent into the soluble hydrochlorides
16
in the stomach, and almost all the Quinine that passes into the duodenum is
immediately and permanently rendered inert by the bile acids and alkaline
fluids, the alkaloid precipitated by the alkaline juices being very insoluble
in water .
For determining the seat of absorption, the following points have to be
considered:—(1) the time interval between administration and the first appear-
tance of Quinine in the urine; (2) the period of maximal limination in the
urine; (3) the period during which subjective symptoms, e.g. tinnitus, are
at their worst; and (4) the period of manifestation of symptoms in cases of
poisoning (suicidal in man and experimental in animals).
As regards the stomach, it must be conceded that Quinine is very soluble in
gastric juice; but gastric juice is likely to be present in a stomach only dur
ing digestion, when little of it can be spared for Quinine. In fact, recent in-
vestigators are in harmony regarding the retardation of Quinine absorption
when administered with or soon after a meal. According to Mariani, 13 the maxi-
mal elimination of Quinine, given while food is in the stomach, takes place
between the sixth and twelfth hours after administration; but, given when no
food is in the stomach, between the third and sixth hours. As food does not, under
normal circumstances, remain in the stomach more than five hours, it follows
that most of the Quinine given with food is absorbed from the small intestine.
Subjective symptoms moreover, just like the maximal elimination of Quinine
in the urine, are at their height between the third and sixth hours when
Quinine is given while fasting and between the sixth and twelfth hours when
given with a meal. That some absorption may take place from the stomach
cannot be denied, for the following reasons, but such absorption is probably
very insignificant. Kerner 2 f o u n d t r a c e s o f Q u i n i n e i n t h e u r i n e 1 5 m i n u t e s
after administering Quinine hydrochloride by the mouth; Lewin 2 4
h a s c o n f i r m e d
this, giving the time as 13 to 17 minutes; Giemsa and Schaumann 5 found
traces in the urine 25 to 30 minutes after giving the sparingly soluble Quinine
alkaloid by the mouth.
In the small intestine, the alkaline secretions of the liver, pancreas and
intestine itself in all probability precipitate the alkaloid. Reference has
previously been made to the insolubility of Quinine glycocholate, and Lauder
Brunton's3 advice to clear out the liver by administering an emetic and a
cholagogue purgative before giving Quinine. That such measures as Lauder
Brunton recommends are useful in enhancing the therapeutic value of Quinine
in obstinate cases of malarial fever is well recognised by experienced physicians.
This beneficial result, however, is probably obtained, not by preventing bile
from coming in contact with the Quinine, but by actually favouring contact of
as much bile as possible with the Quinine. It has been shown above that, accord-