Note: Descriptions are shown in the official language in which they were submitted.
Background o the Invention
1. Field of the Invention
.
The novel acid addition salt a:nd compositions of
the present invention possess the advantageous antitumor
properties of the known free base compound and in addition
have unexpectedly high water-solubility, thus allowing
preparation of useful clinical dosage forms for intravenous
administration.
2 Descri tion of the Prior Art
:1~
The acridine derivative m-~MSA [4'-9-acridinylamino)
methanesulfon-m-anisidide] has been reported by Cain, et al,
in Europ. J. Cancer 10:539-549 (1974) to possess ~ignificant
_
antitumor activity in animal tumor sys~ems, Since then,
this compound has been subjected to clinical evaluation with
very promising initial results.
~ en an antitumor agent such as m-AMSA is employed
for human clinical use, it is recogniæed that solub.ility of
the agent is often the controlling factor in determining
route of administration and dosage forms, For instance, a
water-soluble substance can be generally administered intra-
vanously whereas a water-insoluble material is limited to
other ~orms of parenteral administration such as intra-
muscular and subcutaneous. A therapeutic agent having wateL
solubility also facilitates preparation of oral and non-
intravenous parenteral dosage forms for human administration,
~hus, it i5 decidedly advantageous i~ a therapeutic agent
iY water-soluble, particularly when one considers that the
most direct route ~or achieviny therapeutic blood levels
o~ a drug within the human body is by intravenous administration.
The ~.ree base form o~ m~MSA has very limited
solubility in water and thu~ cannot be used as a dosage form
for inkravenous administration~ ~ttempts ha~e ~een made to
3~
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prepare acid addition salts to overcome thls solubility
problem, but the reported monohydrochloride and monomethane~
sulfonate salts also proved insufficiently water-soluble for
clinical useO The formulation presently in clinical use
consists of two sterile liquids combined just prior to use.
A solution of m-AMSA in anhydrous N,N-dimethylacetamide is
contained in an ampule. A separate vial contains an aqueous
lactic acid solution for use as a diluent. When mixed the
resulting m-AMSA solution is administered by i.v. infusion.
While the present clinical formulation provides
an intravenous dosage form, it suffers from several dis-
advantages. In addition to the obvious dificulties in
preparing and administering the dosage form, it contains
dimethylacetamide as a vehicle. Dimethylacetamide has been
reported to show various toxic symp~oms in animals and may
thus prove to be unacceptable or undesirable as a pharma-
ceutical vehicle.
It is accordingly an object of the present
invention to provide water-soluble, stable, therapeutically
acceptable forms of m-AMS~ which can be administered lntra-
venously (as well as by other routPs) and which do not: con-
tain or require dimethylacetamide as a pharmaceutical vehicle,
This object as well as other eatures and advantages o~ the
invention will be readily apparent to those skilled iIl the
art from the disclosure set out below,
Summary o~ the Invention
_.
In one aspect the present invention provides a
novel water-solublQ acid addition salt o~ m-AMSA which upon
reconstitution wi.th sterile water or a sterile aqueous
~e~icle can be administered intravenously and which does
not have the disadvantages associated with the known intra~
3~
venous forms of this agent. More particularly, there is
provided the crystalline monogluconate salt of m-AMSA.
In another aspect the invention provides a
stable, solid,-water-soluble composition for reconsti~ution
with water or an aqueous vehicle as a s~able solution of
m-AMSA, said composition comprising a mixture of about one
mole of m-AMSA monogluconate salt per one to three moles
of an organic acid (or precursor thereof) selected from
gluconic acid, gluconolactone or mixtures thereof.
Also provided are processes for preparing the
above-describ~d salt and composition.
Description of the Drawings
FIG. 1 shows the infrared absorption spectrum of
the crystalline gluconate salt when pelleted in potassium
bromide.
FIG. 2 shows the infrared absorption spectrum of
a typical water-soluble composition when pelleted in potassium
bromide.
Detailed Descri~ion
Many conventional pharmaceutically acceptab].e
acid addition salts o~ m-AMSA are only slightly soluble in
water and are thus unsuited for intravenous administration
to human patients. This is evident from literature
references to the hydrochloride and methanesulfonate salts
as well a~ from solubility tests carried out by the present
lnventors on salt~ such as -the levulinate, citrate and
lactobionate,
In investigating solubility propexties of m-AMSA
acid addition salts, we have unexpectedly found that one
particular crystalline salt o~ m-AMSA po~sesses significan~ly
high water-solubility at room temperature to provide an
acoeptable intravenous dosage form, Thus, the novel mono
3~
-- 4
gluconate salt of m-AMSA provided by the present invention
has an aqueous solubility at room temperature of about
25 mg/ml. This gluconate salt has also been found to have
acceptable sta~ility, both as a crys~alline solid and as an
aqueous solution upon reconstitution,
Preparation of the crystalline gluconate salt
of m-AMSA is carried out by the steps of
(1) forming a solution of m-~MSA and an organic
acid (or precursor thereof) selected from the group
consisting of gluconic acid (D-gluconic acid),
gluconolactone (D-gluconic acid ~-lactone) and
mixtures thereof in an inert aqueous polar organic
solvent, the molar ratio of organic acid to m-AMSA
being ~rom about 1:1 to about 2:1;
and
(2) crystallizing the desired gluconate salt
from the so-produced solution.
The particular inert polar organic solvent used
to solubilize thè m-~qSA base is not critical and examples of
suitable solvents will be readily apparent to those skilled
in the art. Preferred sol~ents are polar alcohols and
ketones such as methanol, ethanol, n-propanol, isopropanol,
acetone, n-butanol, 2-butanone, n-pentanol, n-hexanol,
diethylene glycol, methyl isobutyl ketone, 3-pentanone, etc.
A particularly convenient solvent is ethanol, The so:Lvent
system should contain a small percentage of water (e.g~
~0.5~) which may either be added to the organic solvent or
pre~erably supplied in the form of aqueous gluconic acid
or gluconolactone solution,
The term "organic acid" as used herein and in the
claims re~ers to gluconic acid ~ se or a precursor thereof
which hydroly2es in aqueous solution to form gluconiG acid,
e.g. gluconolactone. Gluconic acid is dif~icult to produce in
a well-defined crystalline form and thus commercial gluconic
acid i~ supplied as a 50% aqueous solution. Gluconolactone, on
5~
the other hand, is a well-defined crystalline material which
may be easily hydrolyzed in aqueous solu~ion to gluconic
acid. Because of the availability of crystalline glucono-
lactone, it is preferred to use gluconolactone as the source
of gluconic acid in preparing the gluconate salt, The
gluconolactone may be added to an aqueous solution o~ the
polar organic solven~ to generate the gluconic acid or
may ~e added to the organic solvent in the form of an
aqueous solution.
The temperature at which solution is effected is
not critical and may range from the freezing point to the
boiling point of the solvent system. Most advantageously
temperatures of around room temperature or above are used.
It has been found that solubility is maximized if the mix-
ture is brought to reflux ~emperature.
The gluconic acid or gluconolactone may be employed
in molar ratios of about 1 to 2 moles per mole of m-AMSA
base. Best quality product, however, has resulted from
using equimolar quantities of the m~AMSA and organic acid.
After forming a solution of m-AMSA and acid, it
is preferred to carry out a ~iltration step before allowing
crystallization to proceed, Standard crystallization
techniques may then be used to obtain the desired gluconate
salt. Seed crystals of the gluconate salt may be added to
the reaction mixture to induce and/or enhance crystallization.
After recovery the crystalline salt is washed (e,g, with
ethanol) and dried by conventional procedures, Recrystalli-
zation (e,g~ from ethanol) may be used to obtain product in
a highly puri~ied ~orm~
In another aspect the present invention provides
a stable, solid, water-soluble composition suitable upon
reconstitution with water or o~her aqueous vehicle as a
stable solu~ion o m-AMSA, said composikion comprising a
mixture o~ about one mole of m~AMSA monogluconate salt per
~ 6
one to three m~les of an organic acid (or precursor thereof)
selected from the group consisting of gluconic acid, glucono-
lactone and mixtures thereof.
Thus the present invention provides a process for
producing a stable, solid, water-soluble composition for re-
constitution with water or aqueous vehicle as a stable solution
of ~'-(9-acridinylamino)-methanesulfon-m-anisidide which com-
prises the steps of (1) forming an aqueous solution of 4'-(9-
acridinylamino~methanesulfon-m-anisidide and an organic acid
selected from the group consisting of gluconic acid, glucono-
lactone and mixtures thereof, the molar ratio of the organic
acid to 4'-(9 acridinylamino)-methanesulfon-m anisidide being
from about 2:1 to about 4:1; and (2) lyophilizing the so
produced aqueous solutionO
The above-described composition may be employed in the
form of either a dry-fill or lyophilized product, but is
preferably a lyophilized mixture. The composition may be con-
veniently and rapidly reconstituted with sterile water or a
sterile aqueous vehicle to provide at least a 5 mg/ml true
solution of m-AMSA having excellent stability.
- 6a - ~5~3~8
Preparation of the water-soluble composition may
be conveniently accomplished by a conventiona' lyophilization
procedure. Thus, an aqueous olution of m-AMSA and an excess
of gluconic acid or a source of gluconic acid (i.e. an
organic acid which hydrolyzes in water ~o form gluconic acid)
is formed, and the solution is then subjected to a standard
lyophilization process to obtain the desi:red solid composi~ion.
The gluconic acid (or equivalen~) is used in a
molar ratio of about 2-4 moles (most preferably about 2.5
moles) per mole of m-AMSA base. Since as noted above
commercial gluconic acid i5 not available in a well-defined
crystalline form, it is preferred to use crystalline glucono-
lactone as the organic acid. The gluconolactone xapidly
hydrolyzes in water to form gluconic acid. During lyo-
philization gluconic acid is at least partially converted
to gluconolactone. The lyophilized product, therefore, -
comprises a mixture of the monogluconate salt of m-AMSA
with from about one to three moles of excess gluconic acid,
said acid being partly in the gluconic acid form and partly
in the gluconolactone form.
After forming the aqueous solution of m-AMSA and
acid, the reaction mixture is preferably iltered before
lyophilization, Lyophilization may be carried out in
conventional laboratory or industrial lyophilizers. Pre-
ferred lyophilization parameters are as follows:
prefreez_n~ at -55~C.;
freezing at ~50C. for 2 hours;
sublimation at -40C. for about 68 hours at
a pressure of about 4 x 10 2 torr;
dryin~ at +30C. for abou~ 48 hours.
The crystalline gluconate salk and water~soluble
composition provided by the present invention exhibit sub-
stantially the same antitumor proper~ies as the prior art
m-AMSA forms. Because of their high water-solubility,
however, they may be used to prepare clinical dosage forms
for intravenous administration which do not contain an
undesirable pharmaceutical vehicle such as dimethylacetamide.
The salt and composition, moreover, can be used to prepare
a single vial dry-fill or lyophilized product for reconskitution
with sterile water or a sterile aqueous vehicle. A pre- ~~
ferred vehicle for reconstitution of the gluconate salt is
aqueous gluconic acid,
The m~AMSA salt and composition of the present
invention may be used to prepare oral or non-intravenous
parenteral dosage ~orms as well as the preferred intravenous
injectable product. The salt and composition have acceptable
stability, both in solid form and in aqueous solution, and
have suf~icient water-solubility to permit administration of
an effective dose o~ m-AMSA in a relatively small volume of
parenteral soLution ~thus allowing for bolus i.v. injections).
In the treatment o~ mammalian tumor~ the salt and
composit.ion o~ the present invention may be administered
either orally or paxenterally, but pre~erably parenterally,
in dosages (adjuæted for ~mount o~ m AMSA base) and according
to regimens pre~iously disclosed in the literature,
The following examples are ~i~en in illuskraki,on
o~, bu~ no~ in limitation o, the preæent invention.
. .
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Example 1
Preoaration of m-AMSA Monoqluconate Salt
Delta gluconolactone (0,89 g,; 0~005 mole) was
dissolved in 0.5 ml. of water. m-~MSA base (1,95 g,; 0.005
mole) and 100 ml. of ethanol were added, and the mixture
was then refluxed for a short time, iOe. about 5-10 minutes.
The resulting solution was allowed to stand ovexnight
whereupon crystalline material separated from solution.
The product was recrystallized from 100 mlO of ethanol to
give 1.10 g. of crystalline m-AMSA monogluconate salt.
Pro erties of luconate salt:
~ g _ _
m-~MSA content by U,V. = 62O6% (theoretical
conkent i5 66.6~);
gluconic acid content by U,V. = 36,9%;
gluconolactone content by U.V. = 1.1%.
Solubility in water: 30 mg/ml. at S0 60C.;
25 mg/ml. at room temperature.
When dissolved in water at a concentration of
7.1 ~g/ml., the gluconate salt exhibits ultraviolet
absorption peaks at 208 nm (O.D. = 0.527), 247.5 nm
(O.D. = 0.567), 263 nm (O.D. - 0.425) and 412 nm (O.D. =
0.121).
FIG. 1 shows the infrared absorption spectrum
of the ~luconate salt when pelleted in potassium bromide.
3~
g
Example 2
Preparation of m-AMSA Water-Soluble Composition
(for preparation of 75 mg. m-AMSA activity vials)
Formula Per Vial Per Liter Batch
m AMSA base 75 mg. 5 g.
gluconolactone
(gluconic acid ~-lactone) 93~46 mg. 6.23 g.
water for injection q.s. to 15 ml, q.s. to 1 liter
Manufacturing Instructions (for 1 liter batch)
.L) Preparation of a 10% solution of gluconolactone-
- weigh 10 g, of gluconolactone
- with agitation, add the lactone into a glass
container containing 80 ml. water for injection.
Maintain agitation until complete solution is
obtained,
- q.s. to 100 ml. with water for injection
- stir 5 min.
This solution is to be used after 24 hours of
standing at room temperature,
Z) Weigh out 5 g~ of m-AMSA base,
3) Into a suitable glass container containing 600 ml. of
water for injection, add with agitation 25 ml. of the
10% gluconolacto~e solution,
4) ~ith strony agitation add slowly the 5 gv of m~AMSA
base to the gla~s container. Maintain agitation ~or 30
min.
5) Wi~h agltation add 20 ml. o~ the 10~ gluconolactone
solution ~o ~he reaction mixture, Agitate ~or 30 min.
6) Slowly add the remainder of the 10% gluconolaotone solution
(17~3 ml.) to the reaction mixture, Maintain agitation
until complete solution is obtained.
.
3`~3
-- 10 --
7) ~.S. to 1 liter with water for injection.
8) Using nitrogen pressure pass the solution through a
0.22~ filter.
9) Fill the solution into 30-38 ml, flint glass vials
(15 ml. solution per vial). Partially insert red butyl
lyophilization stoppers.
0) Subject vials to freeze drying at fol:iowing parameters:
prefreezing at -55C.;
freezing at 50C. for 2 hours;
sublimation at -40C. for about 68 hours at a
pressure of about 4 x 10 2 torr;
drying at +30C. for about 48 hours.
11) Stopper the vials under vacuum or nitrogen atmosphere
and seal.
12) To reconstitute, use 20 ml. water for injection per
vial.
Pro erties of L o hilized Composition:
P Y P
Reconstitution time with 20 ml. water = 4-5 min.
pH of solution: 3.65
Analysis of lyophilized product:
of 0,172 g. total composition, ~72 mg, m-AMSA,
~93 mg. total gluconic acid (potentiometry) of
which ~40 mg. is ~-gluconolactone (gas chromato-
graphy). Impurities are below detection limits.
% H2O(K.F,) = 0-8
Aqueous stability o~ reconstituted product
satis~actory ak 24 hours. Loss of potency barely
perceptible and no impurities were noted.
When dissolved in water at a concentration of
12.17 ~g~ml., the lyophilized composition ex-
hibits ultraviolet absorption peaks at 209 nm
(O.D. = 0.607), 247.5 nm (O.D. = 0.607), 266 nm
(O.D. = 0.534~, 413 nm (O.D. = 0.145) and
435 nm (O.D. = 0.143).
FIG. 2 shows the inrared absoxption spectrum
of the lyophilized composition when pelleted in
potassium bromide.
'
`; ~' :.
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