U.S. patent application number 17/593512 was filed with the patent office on 2022-05-19 for a stable parenteral dosage form of cetrorelix acetate.
The applicant listed for this patent is Sun Pharmaceutical Industries Limited. Invention is credited to Sudeep Agrawal, Subhas Balaram, Jaydip Joshi, Rajamannar Thennati, Rakesh Thummar, Arunkumar Yadav.
Application Number | 20220153802 17/593512 |
Document ID | / |
Family ID | |
Filed Date | 2022-05-19 |
United States Patent
Application |
20220153802 |
Kind Code |
A1 |
Joshi; Jaydip ; et
al. |
May 19, 2022 |
A STABLE PARENTERAL DOSAGE FORM OF CETRORELIX ACETATE
Abstract
The present invention relates to a stable parenteral dosage form
with a ready-to-inject sterile stable aqueous solution of
cetrorelix acetate. The invention also relates to an injection
device prefilled with the ready-to-inject sterile stable aqueous
solution of cetrorelix acetate. The present invention relates a
method of inhibiting premature luteinizing hormone surges in women
undergoing controlled ovarian stimulation comprising a stable
parenteral dosage form with a ready-to-inject sterile stable
aqueous solution of cetrorelix acetate.
Inventors: |
Joshi; Jaydip; (Baroda,
IN) ; Thummar; Rakesh; (Baroda, IN) ; Agrawal;
Sudeep; (Baroda, IN) ; Balaram; Subhas;
(Baroda, IN) ; Yadav; Arunkumar; (Baroda, Gujarat,
IN) ; Thennati; Rajamannar; (Baroda, IN) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Sun Pharmaceutical Industries Limited |
Mumbai |
|
IN |
|
|
Appl. No.: |
17/593512 |
Filed: |
October 23, 2020 |
PCT Filed: |
October 23, 2020 |
PCT NO: |
PCT/IB2020/059988 |
371 Date: |
September 20, 2021 |
International
Class: |
C07K 14/59 20060101
C07K014/59; A61K 9/08 20060101 A61K009/08 |
Foreign Application Data
Date |
Code |
Application Number |
Oct 24, 2019 |
IN |
201921043355 |
Claims
1. A parenteral dosage form comprising a stable aqueous solution
comprising: (i) cetrorelix or a pharmaceutically acceptable salt
thereof; and (ii) an impurity of Formula I in an amount less than
1% w/v of cetrorelix base, ##STR00017##
2. The parenteral dosage form as claimed in claim 1, wherein the
dosage form is a sterile, stable, aqueous solution.
3. The parenteral dosage form as claimed in claim 1, wherein the
dosage form is a sterile, ready-to-infuse dosage form.
4. The parenteral dosage form as claimed in claim 1, wherein the
stable, aqueous solution further comprises an organic acid to
adjust the pH in the range of 3 to 5.
5. The parenteral dosage form as claimed in claim 4, wherein the
stable, aqueous solution further comprises an osmotic agent.
6. A parenteral dosage form according to claim 1, wherein the
amount of cetrorelix or a pharmaceutically acceptable salt thereof
is 0.25 mg/ml.
7. A parenteral dosage form according to claim 5, wherein the
osmotic agent is present in an amount sufficient for osmolality of
the solution in the range of 250 to 375 mOsm/Kg.
8. The parenteral dosage form according to claim 1, wherein the
parenteral dosage form is a ready-to-inject, sterile, stable
aqueous solution present in the reservoir of an injection
device.
9. The parenteral dosage form according to claim 8, wherein the
injection device is a prefilled syringe.
10. The parenteral dosage form according to claim 8, wherein the
injection device is an auto-injector.
11. The parenteral dosage form according to claim 8, wherein the
injection device is a pen auto-injector.
12. The parenteral dosage form according to claim 1, wherein the
stable, aqueous solution is stable for at least 1 month at
25.degree. C. temperature and 60% relative humidity.
13. The parenteral dosage form according to claim 1, wherein the
stable, aqueous solution is stable for at least 3 months at
25.degree. C. temperature and 60% relative humidity.
14. The parenteral dosage form according to claim 1, wherein the
stable, aqueous solution is stable for at least 6 months at
25.degree. C. temperature and 60% relative humidity.
15. The parenteral dosage form according to claim 1, wherein the
parenteral dosage form is suitable for subcutaneous use.
16. The parenteral dosage form according to claim 1, wherein the
parenteral dosage form is suitable for intramuscular use.
17. A pharmaceutical composition of cetrorelix or a
pharmaceutically acceptable salt thereof, comprising a decapeptide
of formula I: ##STR00018##
18. A method of inhibiting premature luteinizing hormone surges in
women undergoing controlled ovarian stimulation comprising: a
parenteral dosage form comprising: a ready-to-inject, sterile,
stable, aqueous solution comprising: (i) cetrorelix or a
pharmaceutically acceptable salt thereof, (ii) Impurity A, a
decapeptide of formula I, in an amount less than 1% w/v of
cetrorelix base, ##STR00019##
19. A decapeptide of formula I ##STR00020##
20. The decapeptide of claim 19, wherein the decapeptide is
identified by HPLC analysis, the process comprising: a) injecting a
diluent comprising water, acetonitrile and formic acid into the
chromatographic system, b) injecting a system suitability solution
comprising cetrorelix acetate, diluent and impurity stock solution
and recording the chromatogram, c) injecting a standard solution
comprising cetrorelix acetate and diluent into the chromatographic
system, d) injecting a sample comprising aqueous solution of
cetrorelix acetate and placebo preparation into the chromatographic
system, and e) determining the relative retention time and relative
response factor of impurities and cetrorelix acetate with respect
to cetrorelix acetate.
21. A process to identify the decapeptide of claim 19 by HPLC
analysis, the process comprising: a) injecting a diluent comprising
water, acetonitrile and formic acid into the chromatographic
system, b) injecting a system suitability solution comprising
cetrorelix acetate, diluent and impurity stock solution and
recording the chromatogram, c) injecting a standard solution
comprising cetrorelix acetate and diluent into the chromatographic
system, d) injecting a sample comprising aqueous solution of
cetrorelix acetate and placebo preparation into the chromatographic
system, and e) determining the relative retention time and relative
response factor of impurities and cetrorelix acetate with respect
to cetrorelix acetate.
22. The process of claim 21, wherein the mobile phase A and B in
the HPLC analysis comprises a buffer, acetonitrile and
tetrahydrofuran, and wherein the relative retention time and
relative response factor for the decapeptide is determined to be
0.57 and 1.0, respectively.
Description
FIELD OF THE INVENTION
[0001] The present invention relates to a stable parenteral dosage
form with a ready-to-inject, sterile, stable, aqueous solution of
cetrorelix acetate. The invention also relates to an injection
device prefilled with the ready-to-inject, sterile, stable, aqueous
solution of cetrorelix acetate. The present invention relates to a
method of inhibiting premature luteinizing hormone surges in women
undergoing controlled ovarian stimulation comprising a stable
parenteral dosage form with a ready-to-inject, sterile, stable,
aqueous solution of cetrorelix acetate.
BACKGROUND OF THE INVENTION
[0002] Cetrorelix is gonadotropin releasing hormone antagonist
(GnRH antagonist)
acetyl-D-3-(2'-naphtyl)-alanine-D-4-chlorophenylalanine-D-3-(3'-pyridyl)--
alanine-L-serine-L-tyrosine-D-citruline-L-leucine-L-arginine-L-proline-D-a-
lanine-amide (C.sub.70H.sub.92ClN.sub.17O.sub.14) having the below
formula. It is a decapeptide with a terminal acid amide group. It
acts by blocking the action of GnRH upon the pituitary, thus
rapidly suppressing the production and action of leutinizing
hormone and follicle stimulating hormone.
##STR00001##
[0003] Aqueous solutions of peptides are required for parenteral
administration. However, aqueous solutions of peptides such as
cetrorelix are susceptible to chemical degradation. They are also
prone to aggregation whereby the turbidity or cloudiness of the
solution increases on storage.
[0004] The first product on the market was Cetrotide.RTM.. It is
available as a lyophilized powder in glass vials containing 0.25 mg
or 3 mg of cetrorelix. A prefilled glass syringe having 1 ml or 3
ml of sterile water for injection is provided separately and the
solution is prepared only prior to injection. Therefore, the first
product solved the problem of degradation in aqueous solution
simply by avoiding preparing a dosage form containing an aqueous
solution that needed to be stored over time. Instead the water was
removed and a lyophilizate was prepared to avoid instability
problems. However, this solution to the problem has clear
disadvantages--(1) expensive and time consuming process; (2)
product is not ready-to-inject and requires reconstitution before
administration; and (3) reconstituted solution is stable only for a
short period of time. Cetrotide.RTM. thus did not fulfil a need for
a ready-to-inject aqueous solution.
[0005] U.S. Pat. No. 7,718,599 discloses that aqueous solutions of
cetrorelix were prone to aggregation. Under a polarized light
microscope, liquid crystalline structures were observed. To
cetrorelix acetate solutions (2.5 mg/ml), gluconic acid was added,
whereby at concentrations of gluconic acid less than 0.07%,
resulting in a pH of 3.7, aggregation was seen within 2 days.
Similar failure was reported when the pH was more than 3.7. When
the concentration of gluconic acid was increased to 0.71%,
resulting in a pH of 3.1, the aggregation was seen in 12 days
indicating that higher concentrations of gluconic acid and thus
lower pH led to improvement. The disadvantage of the method is that
the degree of resolution of the problem of aggregation is dependent
on the gluconic acid concentration and with more gluconic acid the
pH decreases. However, U.S. Pat. No. 7,718,599 did not report the
effect of pH on the chemical stability of cetrorelix. Moreover,
there were no formulations where aggregation was not seen during
long term storage stability studies. US 2013/0303464 discloses a
ready-to-use aqueous preparation of cetrorelix comprising
cetrorelix acetate, glacial acetic acid, a tonicity adjusting agent
and water for injection. A suitable pH was illustrated by working
examples where the pH was about 3. The preferred pH according to
the invention was pH 2.8 to 3.5.
[0006] U.S. Pat. No. 7,214,662 discloses aqueous solutions of
peptides including cetrorelix acetate and suggested solutions to
the problem of aggregation. It taught that carboxylic acids and
especially hydroxycarboxylic acids, preferably gluconic acid, in
combination with a surfactant reduces aggregation. The use of
carboxylic acid according to U.S. Pat. No. 7,214,662 resulted in a
low pH such as pH 2.5 to 3.
DESCRIPTION OF THE INVENTION
[0007] The object of the present invention is to provide a
parenteral dosage form comprising a ready-to-inject sterile stable
aqueous solution of cetrorelix acetate. Another object of the
invention is to provide an injection device pre-filled with the
sterile stable aqueous solution of cetrorelix acetate. The term
"ready-to-inject" as used herein refers to a ready-to-inject,
sterile, stable, aqueous solution of cetrorelix acetate which is
suitable for direct subcutaneous or intramuscular administration,
i.e., it is ready-to-inject and there is no requirement of
reconstitution or dilution before injection. More particularly, it
is another objective that the sterile stable aqueous solution of
cetrorelix acetate dispensed in an injection device be
ready-to-inject, not only be physically stable in terms of control
on aggregation or turbidity development but also be chemically
stable such that impurities remain low while the parenteral dosage
form is stored on the shelf and until it is injected into the
patient subcutaneously or intra-muscularly.
[0008] Degradation of peptides can lead to generation of other
peptides and/or peptide derivatives which may themselves have
pharmacological activity. Therefore the objective more particularly
was to develop an appropriate method to separate individual
impurities and quantify them. The objective was to limit the
concentration of such impurities. The inventors discovered a High
Performance Liquid Chromatographic ("HPLC") method which gave
separate peaks for several impurities which were here before not
reported in the prior art. Whereas the prior art advocated low pH
values to decrease the tendency for agglomeration, the inventors
found with the use of their HPLC method that in the parenteral
dosage form of the present invention, a pH of 3 to 5 was optimal
for chemical stability in terms of increases in level of impurities
over a period of time and also the aqueous solution of cetrorelix
acetate could be prepared at this higher pH without agglomeration
problems.
[0009] A novel impurity discovered by the inventors was Impurity A
represented by the compound of Formula I given below:
##STR00002##
[0010] Impurity B is characterized to have a structure represented
by the compound of Formula II given below:
##STR00003##
[0011] Impurity D is characterized to have a structure represented
by the compound of Formula III given below:
##STR00004##
[0012] Impurity F is characterized to have a structure represented
by the compound of Formula IV given below:
##STR00005##
[0013] The prior art considered low pH of 3.0 to be the optimum pH
for stability; however, the present invention found that at pH
values of 2.5 to 3.0 advocated by the prior art, the level of
Impurity A increases significantly upon storage of the solution at
25.degree. C./60% relative humidity.
[0014] None of the prior art identified the compounds of formula I,
II, III and IV, i.e. Impurities A, B, D and F respectively.
[0015] The present invention found that not only could the stable
aqueous solution of cetrorelix acetate be prepared at a pH 3 to 5
without agglomeration problems but also the level of Impurity A and
total impurities were well controlled and remain at low
concentrations upon storage of the parenteral dosage form at
25.degree. C./60% RH for at least 1 month, at least 2 months, at
least 3 months, or at least 6 months. The parenteral dosage form
could also be stored at 2 to 8.degree. C. with good stability for
at least 24 months.
[0016] In one aspect, the present invention provides a parenteral
dosage form comprising a stable aqueous solution comprising: [0017]
(i) cetrorelix or a pharmaceutically acceptable salt thereof; and
[0018] (ii) an impurity of Formula I in an amount less than 5% w/v
of cetrorelix base,
##STR00006##
[0019] Preferably, the parenteral dosage form comprises impurity of
Formula I in an amount less than 4% w/v of cetrorelix base. More
preferably, the parenteral dosage form comprises impurity of
Formula I in an amount less than 3% w/v of cetrorelix base. More
preferably, the parenteral dosage form comprises impurity of
Formula I in an amount less than 2% w/v of cetrorelix base. More
preferably, the parenteral dosage form comprises impurity of
Formula I in an amount less than 1% w/v of cetrorelix base.
[0020] The parenteral dosage form further comprises an osmotic
agent and water for injection.
[0021] In a preferable aspect, the present invention provides a
parenteral dosage form comprising a stable aqueous solution
comprising: [0022] (i) cetrorelix or a pharmaceutically acceptable
salt thereof; and [0023] (ii) an impurity of Formula I in an amount
less than 1% w/v of cetrorelix base,
##STR00007##
[0024] In another aspect, the present invention provides a
parenteral dosage form comprising a stable, aqueous solution
comprising: [0025] (i) cetrorelix or a pharmaceutically acceptable
salt thereof; and [0026] (ii) an impurity of Formula I in an amount
less than 1% w/v of cetrorelix base,
##STR00008##
[0027] In another aspect, the present invention provides a
parenteral dosage form comprising a ready-to-inject, sterile,
stable, aqueous solution comprising: [0028] (i) cetrorelix or a
pharmaceutically acceptable salt thereof, [0029] (ii) an organic
acid to adjust the pH in the range of 3 to 5, [0030] (iii) Impurity
A, a decapeptide of formula I, in an amount less than 1% w/v of
cetrorelix base
[0030] ##STR00009## [0031] (iv) an osmotic agent; and [0032] (v)
water for injection.
[0033] In one embodiment, the invention provides a parenteral
dosage form comprising a ready-to-inject sterile, stable, aqueous
solution consisting of: [0034] (i) cetrorelix or a pharmaceutically
acceptable salt thereof, [0035] (ii) an organic acid to adjust the
pH in the range of 3 to 5, [0036] (iii) Impurity A, a decapeptide
of formula I, in an amount less than 1% w/v of cetrorelix base
[0036] ##STR00010## [0037] (iv) an osmotic agent, and [0038] (v)
water for injection.
[0039] The parenteral dosage form comprising the ready-to-inject
sterile, stable aqueous solution of cetrorelix according to the
present invention remains physically and chemically stable when
stored at 2 to 8.degree. C. for at least 1 month, at least 3
months, at least 6 months, at least 12 months, at least 18 months,
or at least 24 months; or at room temperature (25.degree. C./60%
RH) for at least 1 month, at least 3 months, or at least 6
months.
[0040] Preferred embodiments of the stable parenteral dosage form
can be labelled with a shelf life at 2 to 8.degree. C. of at least
24 months or of 24 months. More preferred embodiments of the
parenteral dosage form can be labelled with a shelf life of at
least 6 months or of 6 months at room temperature (25.degree.
C./60% RH) storage condition.
[0041] The concentration of decapeptides of formula I (Impurity A)
remains in the range of 0.001% to 1.0%, preferably 0.05 to 0.5% by
weight of cetrorelix base, single maximum unknown impurity remains
less than 0.5% by weight of cetrorelix base and total impurity
remains not more than 3.5% by weight of cetrorelix base upon
storage at 2 to 8.degree. C. for at least 1 month, at least 2
months, at least 3 months, at least 6 months, at least 12 months,
at least 18 months or at least 24 months and/or at room temperature
(25.degree. C./60% RH) for at least 1 month, at least 2 months, at
least 3 months, or at least 6 months.
[0042] The parenteral dosage form comprising the ready-to-inject
sterile aqueous solution of cetrorelix according to the present
invention is physically stable with no aggregation, gel formation
or precipitation of the aqueous solution during the shelf-life. The
aggregation or gel formation can be determined by measuring the
cloudiness or turbidity of the solution. It is measured in FTU unit
(Formazin Turbidity Unit) or NTU unit (Nephelometric Turbidity
Unit).
[0043] The test is performed according to the protocol described in
European Pharmacopoeia 9.0. The solution is said to be free of any
aggregation or gel formation if the cloudiness/turbidity value is
less than or equal to 8 FTU/NTU. The higher the FTU/NTU values the
higher the cloudiness or turbidity in the solution and vice-versa.
The NTU values of the ready-to-inject, parenteral dosage form
according to the present invention remains less than 2 NTU,
preferably less than 1 NTU, more preferably less than 0.5 NTU,
initially and upon long term storage of the dosage form at 2 to
8.degree. C. for at least 1 month, at least 2 months, at least 3
months, at least 6 months, at least 12 months, at least 18 months
or at least 24 months and/or at room temperature (25.degree. C./60%
RH) for at least 6 months. Thus, there occurs no aggregation, gel
formation or precipitation of the aqueous solution during the
shelf-life. Also, there occurs no substantial increase in viscosity
of the solution upon storage.
[0044] The parenteral dosage form comprising the ready-to-inject,
sterile, stable, aqueous solution of cetrorelix according to the
present invention contains cetrorelix acetate at a concentration
ranging from 0.26 mg/ml to 0.28 mg/ml, which amount is equivalent
to 0.25 mg/ml of cetrorelix base. Preferably, cetrorelix acetate is
present in the ready-to-inject sterile, stable aqueous solution at
a concentration equivalent to 0.25 mg/ml of cetrorelix base.
[0045] In one embodiment, the parenteral dosage form comprising the
ready-to-inject sterile, stable aqueous solution of cetrorelix
according to the present invention comprises a pH adjusting agent
at a concentration sufficient to adjust the pH in the range of 3 to
6.
[0046] In a preferred embodiment, the parenteral dosage form
comprising the ready-to-inject, sterile, stable aqueous solution of
cetrorelix according to the present invention comprises an organic
acid as a pH adjusting agent at a concentration sufficient to
adjust the pH in the range of 3 to 5, more preferably in the range
of 4 to 4.5. The pH of the ready-to-inject sterile, stable aqueous
solution according to the present invention may be for example, 3,
3.05, 3.10, 3.15, 3.20, 3.25, 3.30, 3.35, 3.40, 3.45, 3.5, 3.55,
3.60, 3.65, 3.70, 3.75, 3.80, 3.85, 3.90, 3.95, 4.00, 4.05, 4.10,
4.15, 4.20, 4.25, 4.30, 4.35, 4.40, 4.45, 4.50, 4.55, 4.60, 4.65,
4.70, 4.75, 4.80, 4.85, 4.90, 4.95, 5.00, 5.05, 5.10, 5.15, 5.20,
5.25, 5.30, 5.35, 5.40, 5.45, 5.50, 5.55 and 6 or intermediate
ranges thereof.
[0047] The organic acid may be selected from any parenterally
acceptable organic acid soluble in water but is preferably acetic
acid, more preferably lactic acid. For example, lactic acid may be
used in the ready-to-inject sterile aqueous solution according to
the present invention at a concentration ranging from about 0.013
mg/ml to 0.53 mg/ml, preferably in amount ranging from about 0.033
mg/ml to about 0.53 mg/ml; and intermediate ranges thereof.
[0048] Preferably, according to the present invention, the
ready-to-inject sterile, stable aqueous solution of cetrorelix
comprise cetrorelix (base) and organic acid in a weight ratio
ranging from 5 0.47:1 to 19.23:1, preferably in a weight ratio
ranging from about 0.47:1 to 7.57:1, more preferably in a weight
ratio ranging from about 1.56:1 to 7.57:1 and intermediate ranges
thereof.
[0049] The parenteral dosage form comprising the ready-to-inject
sterile, stable aqueous solution of cetrorelix according to the
present invention comprises an osmotic agent or tonicity adjusting
agent, in amounts suitable to adjust the osmolality of the solution
in the range of about 250-375 mOsm/kg, preferably 270-330 mOsm/kg.
The osmotic agent that may be used in the aqueous solution
according to present invention is selected from, but not limited
to, mannitol, glycerol, sorbitol, sodium chloride, potassium
chloride, dextrose, sucrose, and the like and mixtures thereof.
[0050] According to one preferred embodiment, the osmotic agent is
mannitol and it may be used in the aqueous solution in an amount
ranging from about 40.0 mg/ml to 60.0 mg/ml, preferably in an
amount ranging from about 50.0 mg/ml to 58.0 mg/ml. In one
preferred embodiment, the osmotic agent is mannitol and it is used
in the ready-to-inject sterile aqueous solution in an amount of
about 55.0 mg/ml.
[0051] The ready-to-inject, sterile, aqueous solution of the
parenteral dosage form of the present invention does not contain
lactic acid in the form of its derivatives, polymer or copolymers
such as polylactic acid or polylactic-co-glycolic acid. Preferably,
lactic acid is used as a sole pH adjusting agent. In preferred
embodiments, the ready-to-inject sterile, aqueous solution is free
of any surfactant, such as tween 80, polysorbates, poloxamers,
spans and the like. The ready-to-inject sterile, aqueous solution
of the parenteral dosage form avoids use of surfactants, complexing
agents, preservative or anti-oxidants for solubilization or
stabilization. In certain embodiments, the solution is free of
complexing agents like cyclodextrins, free of co-solvents such as
alcohols or glycols and is also free of preservatives and
antioxidants.
[0052] In another aspect, the present invention provides the
sterile, aqueous solution of cetrorelix acetate as above which
remains stable for at least 1 month, preferably for at least 3
months and more preferably for at least 6 months at 25.degree. C.
temperature and 60% relative humidity.
[0053] In yet another aspect, the present invention provides the
sterile, aqueous solution of cetrorelix acetate as above which
remains stable for at least 1 month, preferably for at least 3
months, more preferably for at least 6 months, even more preferably
for at least 12 months or 18 months, and most preferably for at
least 24 months at 2-8.degree. C.
[0054] The stable parenteral dosage form comprising the
ready-to-inject, sterile, stable aqueous solution of cetrorelix
according to the present invention is suitable for administration
by subcutaneous route or intra-muscular route. The ready-to-inject,
sterile, stable aqueous solution is suitable for direct
subcutaneous administration, i.e., it is ready-to-inject or
ready-to-self-administer and there is no requirement of
reconstitution or dilution before use. The ready-to-inject,
sterile, stable aqueous solution according to the present invention
does not involve lyophilization.
[0055] The stable parenteral dosage form of the present invention
is suitable for self-administration and enables the patient to
self-administer a small volume of the aqueous solution
subcutaneously. The volume of the ready-to-inject sterile, aqueous
solution of cetrorelix filled in the reservoir of the injection
device ranges from about 0.5 ml to 10.0 ml, preferably 1.0 ml to
2.0 ml, more preferably 1.0 ml. According to one of the preferred
embodiments, the ready-to-inject, sterile, stable, aqueous solution
of cetrorelix is filled in the reservoir of the injection device in
volume of 1.0 ml. Preferably the parenteral dosage form according
to the present invention is suitable for administering a single
dose of cetrorelix acetate. In one embodiment, the parenteral
dosage form comprises a fill volume of about 1.0 ml of aqueous
solution of cetrorelix acetate suitable for self-administration as
a single dose. In some embodiment, the parenteral dosage form may
comprise aqueous solution of cetrorelix at a fill volume of about
10.0 ml, suitable for multiple dose administration.
[0056] The injection device according to the stable, parenteral,
dosage form of the present invention may be selected from, but not
limited to, prefilled syringes, autoinjectors and the like. In one
preferred embodiment, the injection device is a prefilled syringe.
In another preferred embodiment, the injection device is an
autoinjector such as a pen auto-injector. These pre-filled syringes
or auto-injectors are suitable for self-administration or
auto-injection of the drug solution by the patients in need
thereof, thus providing a user friendly approach.
[0057] In one preferred embodiment, the injection device is a
prefilled syringe. The prefilled syringe comprises the following
components: a reservoir such as, for example, a barrel or a
cartridge, which stores the aqueous solution; a stalked needle
attached at one end of the reservoir; a needle shield or tip cap
that covers the needle and seals the needle tip opening,
optionally, a rigid shield covering the needle shield or tip cap; a
plunger stopper at other end of the reservoir that stoppers and
seals the aqueous solution filled in the reservoir; a plunger rod
that fits into the plunger stopper and is used to push the plunger
stopper along with the solution towards the needle end while
administering the drug.
[0058] In another preferred embodiment, the injection device is an
autoinjector. The auto-injector can have varied designs. In one
preferred design, the autoinjector comprises the following
components: a central assembly or body portion that is suitable to
hold a pre-filled syringe, the syringe comprising a reservoir such
as a barrel or a cartridge which stores the aqueous solution, the
reservoir having a stalked needle at one end and a plunger stopper
at other end. The central body portion may have a clear inspection
window through which the solution in the reservoir is visible. The
autoinjector further comprises a front assembly having a cap
portion that holds a needle shield or tip cap, and it is attachable
to the central assembly covering the stalked needle and sealing the
needle tip opening. The autoinjector further comprises a rear
assembly which comprises a plastic rod with a spring assembly and
an activation button. During self-administration of the aqueous
solution, first, the cap along with needle shield is removed from
the body portion exposing the needle and subsequently after placing
the body portion of the autoinjector at the site of administration
the activation button is pressed, which pushes the plastic rod with
spring assembly towards the plunger stopper which leads to delivery
of the aqueous solution through the needle to the patient.
[0059] The reservoir may be a barrel or a cartridge, such as, for
example, a barrel of a pre-filled syringe or a cartridge of an
auto-injector. It may be made up of a material selected from glass,
plastic or a polymeric material. In some preferred embodiments, the
reservoir is made up of glass, such as USP Type I siliconized glass
or non-pyogenic glass material. In other embodiments, the reservoir
is made up of a non-glass plastic or polymeric material selected
from cycloolefin polymer, cycloolefin copolymer, polyolefins,
styrene-polyolefin based polymers and block co-polymers,
polycarbonates and the like. In one preferred embodiment, the
reservoir is a non-pyogenic glass barrel of a pre-filled syringe or
non-pyogenic glass cartridge of an auto-injector.
[0060] In one or more embodiments, the reservoir may have a stacked
needle at one end. In some other embodiments, the reservoir is
needleless and has a luer tipped lock at one end with provision for
attaching a needle at the leur tip before use. The stalked needle
may be made up of stainless steel. The needle tip is shielded or
covered with a needle shield or tip cap. The reservoir containing
the sterile aqueous solution of drug is further sealed with a
stopper such as a plunger stopper at the other end. These stoppers,
needle shields or tip caps provide a physical and sterility barrier
against exterior environment.
[0061] Preferably, the plunger stopper, the needle shield/tip cap
or the cap of leur lock is made up of a non-glass component. The
non-glass component may be a rubber or elastomeric material such as
for example, bromobutyl rubber, chlorobutyl rubber, USP type II
rubber, natural rubber made up of poly-cis-1,4-isoprene, styrene
butadiene rubber and the like. Other suitable materials include
high density polyethylene or low density polyethylene or other
plastic materials. In preferred embodiments, the plunger stopper is
made up of bromobutyl rubber and the needle shield or tip cap is
made up of natural rubber. The needle shield may further be covered
on an outer side by a rigid shield made up of polypropylene. It
protects the needle shield from damage and enhances removal of
needle shield before injection. The injection device assembly may
have a plunger rod that attaches to the plunger stopper and is used
to push the plunger stopper along with the solution towards the
needle end while administering the drug.
[0062] Preferably, the ready-to-inject, sterile, stable aqueous
solution of cetrorelix is filled in the reservoir of the injection
device and stoppered in such a manner that there is substantially
no headspace air left inside the reservoir. The aqueous solution in
the reservoir always remains in contact with the plunger stopper
made up of elastomeric or rubber material during storage. In the
case of prefilled syringes having a stalked needle made up of
stainless steel, the needle being covered by a needle shield or tip
cap, the aqueous solution remains in contact with the needle and
the needle shield or tip cap during storage.
[0063] The injection device may optionally be packaged or enclosed
in a secondary packaging. The secondary packaging may be a blister
pack or an aluminum pouch and/or an opaque carton. A suitable
oxygen scavenger may optionally be placed inside the secondary
packaging.
[0064] The stability testing of the parenteral dosage form is done
by storing the dosage form at 2-8.degree. C. and at room
temperature (25.degree. C./60% relative humidity). During stability
testing, the ready-to-inject sterile solution of cetrorelix remains
in contact with the plunger stopper and needle shield made up of
elastomeric rubber material as well as with the stacked needle made
up of stainless steel. In preferred embodiments, the parenteral
dosage form comprising the ready-to-inject sterile aqueous solution
of cetrorelix according to the present invention remains physically
and chemically stable for a period of 1 year, preferably 2 years
when stored at 2-8.degree. C. and at least for 6 months at room
temperature (25.degree. C., 60% relative humidity). The
concentration of Impurity A remains less than 1.0% by weight of
cetrorelix base upon storage of the filled injection device at room
temperature (25.degree. C./60% relative humidity) for at least 6
months and at 2-8.degree. C. for at least 24 months. The
extrapolated shelf life of the aqueous solution of cetrorelix
determined by Minitab computation for Impurity A considering levels
of not more than 1%, is found to be 122 months.
[0065] In one aspect, the present invention relates to a method of
inhibiting premature luteinizing hormone surges in women undergoing
controlled ovarian stimulation comprising:
[0066] a parenteral dosage form comprising: a ready-to-inject
sterile, stable aqueous solution comprising: [0067] (i) cetrorelix
or a pharmaceutically acceptable salt thereof; and [0068] (ii) an
impurity of Formula I in an amount less than 5% w/v of cetrorelix
base,
##STR00011##
[0069] Preferably, the stable aqueous solution comprises impurity
of Formula I in an amount less than 4% w/v of cetrorelix base. More
preferably, the stable aqueous solution comprises impurity of
Formula I in an amount less than 3% w/v of cetrorelix base. More
preferably, the stable aqueous solution comprises impurity of
Formula I in an amount less than 2% w/v of cetrorelix base. More
preferably, the stable aqueous solution comprises impurity of
Formula I in an amount less than 1% w/v of cetrorelix base.
[0070] The stable aqueous solution further comprises an osmotic
agent and water for injection.
[0071] In one aspect, the present invention relates to a method of
inhibiting premature luteinizing hormone surges in women undergoing
controlled ovarian stimulation comprising:
[0072] a parenteral dosage form comprising: a ready-to-inject
sterile, stable aqueous solution comprising: [0073] (i) cetrorelix
or a pharmaceutically acceptable salt thereof, [0074] (ii) Impurity
A, a decapeptide of formula I in an amount less than 1% w/v of
cetrorelix base,
##STR00012##
[0075] In one aspect, the present invention relates to a method of
inhibiting premature luteinizing hormone surges in women undergoing
controlled ovarian stimulation comprising: a parenteral dosage form
comprising: a ready-to-inject sterile, stable aqueous solution
comprising: [0076] (i) cetrorelix or a pharmaceutically acceptable
salt thereof, [0077] (ii) Impurity A, a decapeptide of formula I,
in an amount less than 1% w/v of cetrorelix base,
##STR00013##
[0078] In one preferable aspect, the present invention relates to a
method of inhibiting premature luteinizing hormone surges in women
undergoing controlled ovarian stimulation comprising: a parenteral
dosage form comprising: a ready-to-inject, sterile, stable aqueous
solution comprising: [0079] (i) cetrorelix or a pharmaceutically
acceptable salt thereof, [0080] (ii) an organic acid to adjust the
pH in the range of 3 to 5, [0081] (iii) Impurity A, a decapeptide
of formula I, in an amount less than 1% w/v of cetrorelix base,
[0081] ##STR00014## [0082] (iv) an osmotic agent, and [0083] (v)
water for injection.
[0084] In another aspect, this disclosure provides a decapeptide of
formula I
##STR00015##
[0085] This compound is termed "Impurity A" herein, as it is an
impurity of a cetrorelix solution.
[0086] This disclosure also provides a composition comprising a
decapeptide of formula I:
##STR00016##
[0087] In another aspect, the disclosure provides a process to
identify the decapeptide of Formula I by HPLC analysis, the process
comprising: [0088] a) injecting a diluent comprising water,
acetonitrile and formic acid into the chromatographic system,
[0089] b) injecting a system suitability solution comprising
cetrorelix acetate, diluent and impurity stock solution and
recording the chromatogram, [0090] c) injecting a standard solution
comprising cetrorelix acetate and diluent into the chromatographic
system, [0091] d) injecting a sample comprising aqueous solution of
cetrorelix acetate and placebo preparation into the chromatographic
system, and [0092] e) determining the relative retention time and
relative response factor of impurities and cetrorelix acetate with
respect to cetrorelix acetate.
[0093] This disclosure also provides a decapeptide of Formula I,
identified by HPLC analysis, the process comprising: [0094] 1.
injecting a diluent comprising water, acetonitrile and formic acid
into the chromatographic system, [0095] 2. injecting a system
suitability solution comprising cetrorelix acetate, diluent and
impurity stock solution and recording the chromatogram, [0096] 3.
injecting a standard solution comprising cetrorelix acetate and
diluent into the chromatographic system, [0097] 4. injecting a
sample comprising aqueous solution of cetrorelix acetate and
placebo preparation into the chromatographic system, and [0098] 5.
determining the relative retention time and relative response
factor of impurities and cetrorelix acetate with respect to
cetrorelix acetate,
[0099] Hereinafter, the invention will be more specifically
described by way of Examples. The examples are not intended to
limit the scope of the invention and are merely used as
illustrations.
Example 1A Identification of the Degradation Product
[0100] In order to investigate the degradation of cetrorelix,
peptide related substances of cetrorelix were prepared by the known
technique of solid phase peptide synthesis. The synthesis involved
coupling of one amino acid at a time sequentially starting from
c-terminal amino acid on a resin. The synthesis of the peptide
chain was carried out using the Fluorenylmethyloxycarboyl
(Fmoc)/tButyl (Fmoc/tBu) with N,N'-diisopropyl carbodiimide (DIPC)
as the coupling reagent. The Fmoc groups were removed via treatment
with 20% piperidine in dimethylformamide. The peptide formed on
resin was finally cleaved using trifluoroacetic acid to obtain
related substances which were further purified by reverse phase
high performance liquid chromatography (RP-HPLC) on a C18 Silica
column using a gradient of acetonitrile/water containing 0.1%
trifluoroacetic acid. The purified peptide related substances were
lyophilized to obtain pure solid form. The structure of these
related substances were characterized by Proton NMR, Carbon NMR,
Mass spectroscopy and elemental analysis and they were referred to
as Impurity A, B, D and F. [0101] Impurity-A:
Ac-2-D-Nal-4-Cl-D-Phe-3-D-Pal-Ser-Tyr-D-Cit-Leu-Arg-Pro-D-Ala-OH
(detailed structure depicted as the Compound of Formula I), [0102]
Impurity-B:
2-D-Nal-4-Cl-D-Phe-3-D-Pal-Ser-Tyr-D-Cit-leu-Arg-Pro-D-Ala-NH2
(detailed structure depicted as the Compound of Formula II), [0103]
Impurity-D: Ac-2-D-Nal-4-Cl-D-Phe-3-D-Pal-Ser-Tyr-D-Cit-Leu-OH
(detailed structure depicted as the Compound of Formula III), and
[0104] Impurity-F:
Ac-2-D-Nal-4-Cl-D-Phe-3-D-Pal-Ser-Tyr-D-Cit-Leu-Arg-Pro-OH
(detailed structure depicted as the Compound of Formula IV).
[0105] The degradation peaks separated on the HPLC column, were
identified to be these compounds based on their relative retention
time. The details of the HPLC method is provided in Example 1B
below:
Example 1B
[0106] Cetrorelix and the identified impurities namely, Impurity A,
Impurity B, Impurity D and Impurity F from the aqueous solution
samples were separated on a reverse phase (C-18) column using
gradient technique (Column: X-Select CHS C18, (150.times.4.6) mm,
2.5p. (by Waters, Ireland, Part No: 186006729), detected and
quantified by Ultraviolet spectroscopy at 225 nm wavelength. The
mobile phase was run at a flow rate of 0.7 ml/min and 1.0 ml/min.
The run time of the chromatogram was 150 minutes.
Mobile Phase Details:
[0107] Mobile Phase A: A mixture of buffer solution as below, with
acetonitrile and tetrahydrofuran in the ratio of (700:280:20),
degassed by sonication. Mobile Phase B: A mixture of buffer
solution as below, with acetonitrile and tetrahydrofuran in the
ratio of (500:480:20), degassed by sonication. Buffer: 2.5 g of
Ammonium dihydrogen orthophsphate and 0.75 g of 1-Octane sulphonic
acid sodium salt in 1000 ml water with pH adjusted to 8.0.+-.0.05
using triethylamine. Diluent: A mixture of water, acetonitrile and
formic acid in the ratio of (700:300:1).
TABLE-US-00001 TABLE 1 Details of gradient elution Time Flow Mobile
Phase A Mobile Phase B (minutes) Rate (% v/v) (% v/v) 0 0.7 100 0
65 0.7 100 0 75 0.7 0 100 76 1.0 0 100 135 1.0 0 100 136 0.7 100 0
150 0.7 100 0
Preparation of the Stock Solution of Impurities:
[0108] 3.125 mg each of Impurity A; Impurity B, Impurity D and
Impurity F were taken in a 50 ml volumetric flask and dissolved in
about 5 ml of diluent by sonication, followed by making up the
volume using the diluent.
Preparation of System Suitability Solution:
[0109] This was prepared by weighing and transferring about 12.5 mg
of cetrorelix acetate working standard in 100 ml volumetric flask
and dissolving it in about 50 ml of diluent by sonication, followed
by addition of about 2 ml of impurity stock solution and making up
the volume using the diluent.
Preparation of the Standard Solution of Cetrorelix Acetate:
[0110] The standard solution of cetrorelix acetate was prepared by
weighing and transferring 20 mg of cetrorelix acetate working
standard into 250 ml volumetric flask and dissolving it in about 50
ml of diluent by sonication and making up the volume with the
diluent. Two ml of this solution was transferred into 250 ml
volumetric flask and volume made up to the mark using the diluent
with mixing.
Preparation of Test Solution:
[0111] The aqueous solution of cetrorelix acetate from about 10
pre-filled syringes of the sample to be tested (prepared according
to example as described above) was mixed in a container. The
solution comprises cetrorelix acetate, an organic acid, an osmotic
agent and water for injection. Accurately about 5.0 ml of this
solution was transferred in 10 ml volumetric flask and about 3 ml
of the diluent was added and the solution was sonicated for 5
minutes with intermediate shaking. Volume made up using the diluent
with mixing.
[0112] The placebo was prepared by transferring accurately about
5.0 ml of placebo solution in 10 ml volumetric flask, adding about
3 ml diluent and sonicating for 5 minutes with intermediate
shaking. Volume made up using the diluent with mixing 50
microlitres injections in duplicate of diluent as blank were
injected into the chromatographic system. Subsequently, the system
suitability solution was injected and the chromatogram was
recorded. The resolution between Impurity D and Impurity F is not
less than 2.0. Following this, six replicates of standard solution
were injected. Subsequently, the sample and placebo preparation
were injected into the chromatographic system.
[0113] The relative retention time and relative response factor of
cetrorelix acetate and Impurities A, B, D and F with respect to
cetrorelix acetate are presented in Table 2.
TABLE-US-00002 TABLE 2 Name of Retention Time Relative retention
compound (minute) time Cetrorelix 42.3 1.00 Impurity A 23.5 0.55
Impurity B 56.8 1.34 Impurity D 16.9 0.39 Impurity F 20.3 0.48
[0114] The percentage of Impurities A, B, D, F and unknown impurity
was calculated excluding peaks from diluent and placebo. The sum of
all known and unknown impurities provided % total impurities.
[0115] The % of identified impurities (A, B, D, F) was calculated
by following formula:
A .times. .times. 1 AS .times. WS 250 .times. 2 250 .times. 10 V
.times. P LC .times. 1 RRF ##EQU00001##
Where,
[0116] A1=Peak response of each known impurity in the chromatogram
of test preparation AS=Average peak response of cetrorelix in the
chromatogram of standard preparation WS=Weight of cetrorelix
acetate working standard in mg [0117] V=Volume of sample taken in
ml [0118] P=% potency of cetrorelix working standard (on as is
basis) LC=Label claim of cetrorelix in mg per ml (0.25 mg/ml)
RRF=Relative response factor of each Impurity
[0119] The % of Unknown impurity was calculated by following
formula
A .times. .times. 1 AS .times. WS 250 .times. 2 250 .times. 10 V
.times. P LC ##EQU00002##
Where,
[0120] A1=Peak response of each unknown impurity in the
chromatogram of test preparation AS=Average peak response of
cetrorelix in the chromatogram of Standard preparation WS=Weight of
cetrorelix acetate working standard in mg [0121] V=Volume of sample
taken in ml [0122] P=% potency of cetrorelix working standard (on
as is basis) LC=Label claim of cetrorelix in mg per ml (0.25 mg/ml)
[0123] The total impurities (%)=Sum of % known impurities and %
unknown impurities.
TABLE-US-00003 [0123] TABLE 3 Composition Example Examples of the
invention Comparative examples Numbers 1 2 3 4 5 6 7 8 9 10 11 12
13 14 Ingredients Quantity (mg/ml) Cetrorelix 0.25 0.25 0.25 0.25
0.25 0.25 0.25 0.25 0.25 0.25 0.25 0.25 0.25 0.25 acetate expressed
as cetrorelix base Mannitol 54.8 54.8 54.8 54.8 54.8 54.8 54.8 54.8
54.8 54.8 54.8 54.8 54.8 54.8 Lactic acid q.s to adjust pH pH 3 3.1
3.2 3.3 3.4 3.5 4 4.5 5 2.5 2.6 2.7 2.8 2.9 Water for q.s to 1 ml
Injection
Method of Preparation:
[0124] Water for injection was taken at temperature between
2.degree. C. to 8.degree. C. in a vessel. Mannitol was added and
dissolved gradually in water for injection with stirring, until a
clear solution was obtained. To this cetrorelix acetate was added
and dissolved gradually with stirring. The pH of the solution was
checked and was adjusted to the pH as mentioned in Table 3 for each
example of the invention and comparative examples, using specified
amount (volume) of 0.1% w/v lactic acid solution. The volume was
made up with water for injection. The solutions were stirred for
10-15 minutes. The solutions of the Examples were filtered
aseptically through a bed of 0.2 micron membrane filter. The
solution was aseptically filled in the reservoir of injection
device, i.e., in the barrel of 1 ml glass syringe with a fill
volume of 1.1 ml. The stacked needle in the barrel was stoppered by
elastomeric needle shield, covered by a rigid cap before filling.
After filling, the glass syringe (barrel) was stoppered with
plunger stopper by vacuum stoppering in such a manner that there
was substantially no headspace air left inside the syringe. The
aqueous solution remains in contact with the plunger stopper made
up of rubber, stacked needle made up of stainless steel and needle
shield made up of natural rubber upon storage.
[0125] The ready-to-inject, aqueous solution of working examples 1
to 9 and comparative examples 10 to 14 were subjected to chemical
analysis at different stages. Initially, the % assay of cetrorelix
in the solution before and after filtration was analyzed by the
HPLC method described above. The change in the chemical assay %
before and after filtration was determined.
[0126] The solutions of the examples contained in the glass
syringes were then subjected to storage stability testing. The %
assay, the level of degradation products like the compounds of
formula I, II, III and IV and the level of unknown and total
impurities in the filtered solution filled in injection device of
the parenteral dosage form at initial time point and upon storage
at different time points at room temperature (25.degree. C./60%
relative humidity) and at 2 to 8.degree. C. were determined using
the high performance liquid chromatographic method described
above.
[0127] It was found that after 6 months of storage at room
temperature the level of Impurities A, B, single maximum unknown
impurity and the total impurities remained unchanged or the change
was small. Based on this data it is expected that the parenteral
dosage form of the present invention is chemically stable over a
long period of time. It was found that the solutions did not
exhibit any problems of agglomeration or increase in viscosity when
prepared and when filled into the injection device and stored. The
data also demonstrated that there was no absorption or adsorption
of cetrorelix onto or into the components of the device, for
instance, the rubber stopper which was in contact with the solution
during the period of storage.
[0128] The stability results for the stable parenteral dosage form
at 25.degree. C./60% RH and 2-8.degree. C. according to the present
invention are provided in Table 4 and Table 5 below:
TABLE-US-00004 TABLE 4 Observation at different time points upon
storage at (25.degree. C./60% RH) Impurity Impurity Single maximum
unknown Total A (%) B (%) impurity (%) impurity (%) Time points
(months) pH 0 1 3 6 0 1 3 6 0 1 3 6 0 1 3 6 3 BQL 0.20 0.54 1.0
0.055 ND ND BQL 0.113 0.123 0.112 0.431 0.363 0.398 0.748 1.829 3.5
BQL 0.07 0.23 0.40 0.068 ND BQL BQL 0.105 0.148 0.189 0.392 0.335
0.292 0.623 1.059 4 BQL BQL 0.09 0.15 0.039 ND ND ND 0.095 0.162
0.196 0.388 0.308 0.302 0.496 0.792 4.5 ND BQL BQL 0.04 0.058 ND ND
ND BQL 0.159 0.204 0.331 0.308 0.237 0.331 0.563 5 BQL BQL -- -- ND
BQL -- -- 0.119 0.125 0.205 0.208 -- -- ND: Not Detected;
RH--Relative Humidity; BQL: Below Quantifiable limit
TABLE-US-00005 TABLE 5 Observation at different time points upon
storage at (2-8.degree. C.) Impurity Impurity A (%) B (%) Time
points (months) pH 0 1 3 6 12 18 24 0 1 3 6 12 18 24 3 BQL 0.05
0.08 0.18 0.363 0.49 0.545 0.055 ND ND ND BQL BQL BQL 3.5 BQL BQL
BQL 0.06 0.144 0.171 0.238 0.068 BQL ND ND BQL BQL BQL 4 BQL BQL
BQL 0.03 0.055 0.068 0.078 0.039 ND ND ND ND ND BQL 4.5 ND BQL ND
BQL BQL BQL BQL 0.058 ND ND ND ND BQL ND Observation at different
time points upon storage at (2-8.degree. C.) Single maximum unknown
impurity (%) Total impurity (%) Time points (months) pH 0 1 3 6 12
18 24 0 1 3 6 12 18 24 3 0.113 0.079 0.08 0.146 0.109 0.138 0.15
0.363 0.206 0.161 0.333 0.551 0.628 0.695 3.5 0.105 0.087 0.069
0.135 0.108 0.139 0.149 0.335 0.087 0.069 0.197 0.337 0.31 0.387 4
0.095 0.16 0.144 0.138 0.105 0.186 0.15 0.308 0.23 0.144 0.174
0.242 0.398 0.228 4.5 BQL 0.142 0.136 0.136 0.107 0.134 0.15 0.308
0.213 0.136 0.136 0.193 0.202 0.15 ND: Not Detected; RH--Relative
Humidity; BQL: Below Quantifiable limit
TABLE-US-00006 TABLE 6 Assay of Cetrorelix acetate eq. to
Cetrorelix (%) Storage conditions Un- 2-8.degree. C. 25.degree.
C./60% RH pH filtered Initial 1M 2M 3M 6M 12M 18M 24M 1M 2M 3M 6M
2.5 104.05 103.97 103.03 105.51 105.04 104.54 103.7 -- -- 102.76
102.9 102.9 99.97 3 103.56 101.11 101.8 104.9 105.42 104 103.5
104.93 104.77 102.09 104.71 105.08 102.36 3.5 103.86 102.51 101.82
104.88 102.88 104.2 103.1 104.13 104.16 103.65 103.62 102.23 103.68
4 103.76 102.96 104 104.17 104.75 104.84 103.3 104.48 103.61 102.58
103.28 103.72 103.39 4.5 102.52 99.56 103.43 103.97 103.57 103.59
102.6 103.97 103.86 101.66 103.62 102.79 102.77 5 99.48 -- -- -- --
-- 99.02 -- -- --
[0129] The stability results for additional intermediate pH ranges
were studied at different time points upon storage at 25.degree.
C./60% RH and 2-8.degree. C. are given in Table 7 below:
TABLE-US-00007 TABLE 7 Observation at different time points upon
storage Impurity A (%) Time 0M 1M 3M 6M 12M points pH I II III I II
III I II III I II III I II III At 3.1 0.04 NA NA 0.28 0.27 0.27
0.53 0.54 0.53 0.62 0.63 0.62 -- -- -- (25.degree. C. 3.2 BQL NA NA
0.29 0.29 0.30 0.57 0.57 0.57 0.64 0.63 0.64 -- -- -- 60% 3.3 BQL
NA NA 0.17 0.18 0.17 0.37 0.37 0.37 0.42 0.42 0.42 -- -- -- RH) 3.4
BQL NA NA 0.2 0.2 0.20 0.34 0.34 0.34 0.39 0.39 0.39 -- -- -- At
3.1 0.04 NA NA 0.14 0.15 0.14 0.25 0.24 0.24 0.17 0.17 0.18 0.24
0.25 0.24 2-8.degree. C. 3.2 BQL NA NA 0.14 0.15 0.15 0.26 0.27
0.26 0.17 0.17 0.18 0.29 0.29 0.29 3.3 BQL NA NA 0.1 0.09 0.10 0.17
0.18 0.18 0.11 0.11 0.11 0.18 0.18 0.18 3.4 BQL NA NA 0.09 0.10
0.09 -- -- -- -- -- -- -- -- -- Observation at different time
points upon storage Single maximum unknown impurity (%) Time points
(months) Time 0M 1M 3M 6M 12M points pH I II III I II III I II III
I II III I II III At 3.1 0.13 NA NA 0.15 0.124 0.143 0.223 0.211
0.224 0.192 0.153 0.178 -- -- -- (25.degree. C. 3.2 0.129 NA NA
0.136 0.141 0.138 0.214 0.21 0.208 0.18 0.173 0.171 -- -- -- 60%
3.3 0.137 NA NA 0.139 0.153 0.137 0.214 0.213 0.211 0.175 0.184
0.175 -- -- -- RH) 3.4 0.131 NA NA 0.165 0.15 0.12 0.21 0.204 0.203
0.166 0.174 0.167 -- -- -- At 3.1 0.13 NA NA 0.128 0.115 0.123
0.115 0.143 0.129 0.129 0.127 0.134 0.116 0.119 0.121 2-8.degree.
C. 3.2 0.129 NA NA 0.134 0.127 0.127 0.131 0.139 0.126 0.135 0.129
0.134 0.119 0.119 0.123 3.3 0.137 NA NA 0.123 0.126 0.12 0.126 0.12
0.123 0.118 0.129 0.129 0.138 0.135 0.13 3.4 0.131 NA NA 0.123
0.128 0.124 -- -- -- -- -- -- -- -- -- Observation at different
time points upon storage Impurity B (%) Time 0M 1M 3M 6M 12M points
pH I II III I II III I II III I II III I II III At 3.1 ND NA NA ND
ND -- BQL BQL BQL BQL BQL BQL -- -- -- (25.degree. C. 3.2 ND NA NA
BQL BQL BQL BQL BQL BQL BQL BQL BQL -- -- -- 60% 3.3 ND NA NA ND ND
ND BQL BQL BQL BQL BQL BQL -- -- -- RH) 3.4 ND NA NA ND ND ND BQL
BQL BQL BQL BQL BQL -- -- -- At 3.1 ND NA NA ND ND ND BQL BQL BQL
BQL BQL BQL -- -- -- 2-8.degree. C. 3.2 ND NA NA ND ND ND BQL BQL
BQL BQL BQL BQL BQL BQL BQL 3.3 ND NA NA ND ND ND BQL BQL BQL BQL
BQL BQL ND ND ND 3.4 ND NA NA ND ND ND BQL BQL BQL BQL BQL BQL ND
ND ND Observation at different time points upon storage Total
impurity (%) Time points (months) Time 0M 1M 3M 6M 12M points pH I
II III I II III I II III I II III I II III At 3.1 0.178 NA NA 0.567
0.517 0.55 0.865 0.873 0.866 0.934 0.898 0.93 -- -- -- (25.degree.
C. 3.2 0.129 NA NA 0.569 0.57 0.571 0.906 0.896 0.892 1.037 0.932
0.935 -- -- -- 60% 3.3 0.228 NA NA 0.512 0.448 0.429 0.7 0.7 0.586
0.72 0.725 0.719 -- -- -- RH) 3.4 0.201 NA NA 0.523 0.49 0.485
0.667 0.656 0.66 0.678 0.693 0.687 -- -- -- At 3.1 0.178 NA NA
0.381 0.361 0.365 0.365 0.46 0.373 0.299 0.293 0.311 0.358 0.365
0.364 2-8.degree. C. 3.2 0.129 NA NA 0.423 0.436 0.48 0.504 0.581
0.501 0.379 0.303 0.311 0.492 0.405 0.41 3.3 0.228 NA NA 0.315 0.4
0.386 0.419 0.415 0.415 0.294 0.236 0.238 0.321 0.319 0.312 3.4
0.201 NA NA 0.333 0.332 0.327 -- -- -- -- -- -- -- -- --
TABLE-US-00008 TABLE 8 Assay of Cetrorelix acetate eq. to
Cetrorelix (%) Storage conditions 2-8.degree. C. 25.degree. C./60%
RH pH Unfiltered Initial 1M 3M 6M 12M 1M 3M 6M 3.1 99.96 98.67
99.12 99.32 98.98 98.94 98.65 97.65 97.52 3.2 100.89 100.21 99.9
100.89 99.61 101.27 100.06 100.38 98.2 3.3 99.96 99.05 98.58 100.03
99.13 100.29 98.97 99.87 98.13 3.4 100.02 98.54 99.59 -- -- --
99.91 99.97 99.03
TABLE-US-00009 TABLE 9 Stability data of cetrorelix acetate
Injection 0.25 mg/ml, 1 ml PFS at pH 5 Each mL contains cetrorelix
acetate eq. to cetrorelix 0.25 Mg, Mannitol 54.8 mg, Lactic acid
q.s. to pH adjusted 5.0, Water For Injection q.s. to 1 mL Related
Substances Unknown Assay of Impurities Cetrorelix Highest acetate
eq. To Known Impurities Unknown Total Cetrorelix Impurity A
Impurity B Impurity Impurities 95.0% to Not more Not more Not more
Not more Description 105.0% of LC than 1.0% than 1.0% than 0.5%
than 3.5% UNFILTER * 99.59 INITIAL * 99.67 BQL (<0.035%) ND
0.131 0.131 2-8.degree. C. 1M * 98.13 BQL (<0.035%) ND 0.11
0.182 OTS 2M * 98.6 ND ND 0.109 0.208 3M * 99.98 ND ND 0.112 0.198
25.degree. C./60% 1M * 98 BQL (<0.035%) ND 0.106 0.106 RH 2M *
98.24 0.074 ND 0.109 0.369 OTS 3M * 98.18 0.18 ND 0.107 0.353 ND:
Not Detected; RH--Relative Humidity; BQL: Below Quantifiable limit;
* Clear colorless solution filled in 1 ml PFS
TABLE-US-00010 TABLE 10 Observation at different time points upon
storage Impurity A (%) Time 0M 1M 3M 6M 12M points pH I II III I II
III I II III I II III I II III At 2.5 0.08 -- -- 0.82 -- -- 1.97 --
-- 3.38 -- -- -- -- -- (25.degree. C. 2.6 0.08 0.08 0.08 1.28 1.29
1.29 2.20 2.19 2.19 -- -- -- -- -- -- 60% 2.7 0.58 0.59 0.58 0.99
1.00 0.98 1.65 1.65 1.64 1.85 1.84 1.86 -- -- -- RH) 2.8 0.06 0.07
0.07 0.80 0.81 0.80 1.38 1.39 1.39 1.56 1.56 1.56 -- -- -- 2.9 0.06
0.06 0.05 0.67 0.66 0.66 1.12 1.13 1.12 1.30 1.32 1.30 -- -- -- At
2- 2.5 0.08 -- -- 0.20 -- -- 0.35 -- -- 0.63 -- -- 1.33 8.degree.
C. 2.6 0.08 0.08 0.08 0.72 0.73 0.72 1.12 1.13 1.15 -- -- -- -- --
-- 2.7 0.58 0.59 0.58 0.58 ND ND 0.90 0.91 0.91 0.60 0.6 0.59 -- --
-- 2.8 0.06 0.07 0.07 0.48 0.49 0.48 0.74 0.77 0.74 0.46 0.45 0.46
-- -- -- 2.9 0.06 0.06 0.05 0.42 0.42 0.41 0.63 0.63 0.61 0.39 0.39
0.40 -- -- -- Observation at different time points upon storage
Single maximum unknown impurity (%) Time points (months) Time 0M 1M
3M 6M 12M points pH I II III I II III I II III I II III I II III At
2.5 0.105 -- -- 0.159 -- -- 0.178 -- -- 0.417 -- -- -- -- --
(25.degree. C. 2.6 0.138 0.125 0.121 0.155 0.154 0.151 0.18 0.199
0.201 -- -- -- -- -- -- 60% 2.7 0.141 0.153 0.141 0.145 0.148 0.189
0.266 0.237 0.245 0.191 0.2 0.194 -- -- -- RH) 2.8 0.14 0.133 0.145
0.173 0.129 0.133 0.25 0.218 0.247 0.21 0.166 0.165 -- -- -- 2.9
0.142 0.131 0.14 0.137 0.132 0.139 0.23 0.222 0.223 0.19 0.159
0.167 -- -- -- At 2- 2.5 0.105 -- -- 0.173 -- -- 0.131 -- -- 0.139
-- -- 0.11 -- -- 8.degree. C. 2.6 0.138 0.125 0.121 0.107 0.122
0.114 0.14 0.14 0.142 -- -- -- -- -- -- 2.7 0.141 0.153 0.141 0.116
0.109 0.111 0.135 0.146 0.191 0.126 0.132 0.113 -- -- -- 2.8 0.14
0.133 0.145 0.11 0.135 0.135 0.141 0.14 0.125 0.124 0.111 0.11 --
-- -- 2.9 0.142 0.131 0.14 0.126 0.124 0.117 0.137 0.126 0.147
0.112 0.135 0.123 -- -- -- Observation at different time points
upon storage Impurity B (%) Time 0M 1M 3M 6M 12M points pH I II III
I II III I II III I II III I II III At 2.5 0.072 -- -- BQL -- --
0.23 -- -- 0.36 -- -- -- -- -- (25.degree. C. 2.6 ND -- -- ND ND ND
0.23 0.21 0.25 -- -- -- -- -- -- 60% 2.7 ND -- -- ND ND ND 0.21
0.18 BQL 0.182 0.22 0.19 -- -- -- RH) 2.8 ND -- -- ND ND ND BQL
0.183 BQL BQL BQL BQL -- -- -- 2.9 ND -- -- ND ND ND BQL BQL BQL
0.204 0.204 0.194 -- -- -- At 2- 2.5 0.072 -- -- BQL -- -- BQL --
-- BQL -- -- BQL -- -- 8.degree. C. 2.6 ND -- -- BQL ND ND BQL BQL
BQL -- -- -- -- -- -- 2.7 ND -- -- ND ND ND BQL BQL BQL BQL BQL BQL
-- -- -- 2.8 ND -- -- ND ND ND BQL BQL BQL BQL BQL BQL -- -- -- 2.9
ND -- -- ND ND ND BQL BQL BQL BQL BQL BQL -- -- -- Observation at
different time points upon storage Total Impurity (%) Time points
(months) Time 0M 1M 3M 6M 12M points pH I II III I II III I II III
I II III I II III 2.5 0.409 -- -- 1.067 -- -- 2.57 -- -- 4.404 --
-- -- -- -- At 2.6 0.227 0.214 0.21 1.708 1.69 1.721 2.821 2.789
2.896 -- -- -- -- -- -- (25.degree. C. 2.7 0.381 0.393 0.311 1.365
1.344 1.46 2.313 2.269 2.092 2.424 2.486 2.423 -- -- -- 60% 2.8
0.277 0.209 0.299 1.214 1.162 1.149 1.767 1.909 1.831 2.032 2.011
1.914 -- -- -- RH) 2.9 0.272 0.283 0.195 0.939 0.919 1.048 1.496
1.459 1.457 1.902 1.788 1.799 -- -- -- 2.5 0.409 -- -- 0.43 -- --
0.484 -- -- 0.842 -- -- 1.521 -- -- At 2- 2.6 0.227 0.214 0.21
0.923 1.022 0.93 1.353 1.374 1.383 -- -- -- -- -- -- 8.degree. C.
2.7 0.381 0.393 0.311 0.863 0.866 0.786 1.163 1.188 1.373 0.798
0.731 0.779 -- -- -- 2.8 0.277 0.209 0.299 0.679 0.731 0.731 1.077
1.121 0.991 0.655 0.646 0.725 -- -- -- 2.9 0.272 0.283 0.195 0.673
0.664 0.636 0.897 0.884 0.872 0.505 0.525 0.526 -- -- -- ND: Not
Detected; RH--Relative Humidity; BQL: Below Quantifiable limit; NA:
Not available
TABLE-US-00011 TABLE 11 Assay of Cetrorelix acetate eq. to
Cetrorelix (%) Storage conditions 2-8.degree. C. Initial 1M 3 6M pH
Unfiltered I II III I II III I II III I II III 2.6 100.05 100.25
100.04 99.63 98.65 98.32 99.27 98.27 98.22 97.45 2.7 -- 100.75
100.4 100.66 98.69 99.22 98.78 98.94 98.74 99.77 99.87 97.82 99 2.8
-- 100.7 100.93 100.99 99.39 98.76 99.05 98.69 99.33 98.57 99.85
100.18 99.92 2.9 -- 97.55 97.6 97.68 98.64 98.62 98.47 95.37 95.42
95.55 97.75 97.8 98.52 Assay of Cetrorelix acetate eq. to
Cetrorelix (%) Storage conditions 25.degree. C./60% RH 1M 3M 6M pH
Unfiltered I II III I II III I II III 2.6 100.05 97 97.76 97.21
96.58 96.25 96.63 2.7 -- 98.36 98.22 98.55 97.4 98.04 97.55 96.97
97.07 97.09 2.8 -- 97.64 97.62 97.65 97.74 97.65 97.94 98.12 96.51
96.04 2.9 -- 96.92 96.84 96.56 95.19 94.8 94.8 94.23 94.32
95.26
Comparative Example 2
[0130] An aqueous solution of cetrorelix acetate was prepared as
per the disclosure of US 2013/0303464 (Patel et al.). The
composition is illustrated below in Table 12:
TABLE-US-00012 TABLE 12 Ingredients Quantity (mg/ml) Cetrorelix
acetate 0.25 Mannitol 42.0 Glacial Acetic acid q.s to pH 3.0 Water
for injection 1 ml
[0131] Method of Preparation: Water for injection was taken at
temperature between 2.degree. C. to 8.degree. C. in a vessel
Mannitol was added and dissolved gradually in water for injection
with stirring, until a clear solution was obtained. To this
cetrorelix acetate was added and dissolved gradually with stirring.
Glacial acetic acid was then added and the pH of the solution was
adjusted to about 3.0. The volume was made up with water for
injection. The solution was stirred for 10-15 minutes and
subsequently filtered aseptically through a bed of 0.2 .mu.m
membrane filter (optiscale 47 capsule, Polyethersulfone membrane
filter by Millipore). The solution was aseptically filled in the
reservoir of injection device, i.e. in the barrel of 1 ml glass
syringe with a fill volume of 1.1 ml. The stacked needle in the
barrel was stoppered by elastomeric needle shield, covered by a
rigid cap before filling. After filling, the glass syringe (barrel)
was stoppered with plunger stopper by vacuum stoppering in such a
manner that there was substantially no headspace air left inside
the syringe. The aqueous solution remains in contact with the
plunger stopper made up of rubber, stacked needle made up of
stainless steel and needle shield made up of natural rubber upon
storage.
[0132] The solution of this comparative example (comparative
example 2) filled in glass syringe was subjected to storage
stability testing. The level of Impurity A, Impurity B and total
impurity in the solution were analyzed initially and upon storage
at room temperature (25.degree. C./60% relative humidity) by high
performance liquid chromatographic technique. The results are
provided in Table 13 below.
TABLE-US-00013 TABLE 13 Stability results of comparative example 2
Impurity A (%) Impurity B (%) Total impurity (%) (25.degree. C./60%
RH) (25.degree. C./60% RH) (25.degree. C./60% RH) Time Point
(Months) 0 3 6 0 3 6 0 3 6 0.06 0.84 1.77 ND 0.07 0.17 0.99 1.88
2.83 ND. Not detected; RH--Relative Humidity
[0133] It was observed that the solution of cetrorelix acetate of
US 2013/0303464 (comparative) showed significant increase in the
level of Impurity A and total impurity upon storage at room
temperature. Particularly, the level of Impurity A which is a
degradation impurity increases significantly and increases to 1.77%
by weight of cetrorelix in 6 months. Also the level of total
impurity increases to 2.83% by weight of cetrorelix in 6
months.
[0134] In contrast, the parenteral dosage form comprising the
ready-to-inject aqueous solution of cetrorelix acetate of the
present invention remains stable at room temperature for a
prolonged period of time whereby there occurs substantially no
degradation or increase in level of Impurity A, other impurities or
total impurities upon storage and the solution have an extrapolated
shelf life of more than 24 months.
* * * * *