Note: Descriptions are shown in the official language in which they were submitted.
WO 90/14094 2 0 ~ 6 ~ ~ 5 PCI`/US90/03063
INJECTABLE CLARITHROI~!YCIN COMPOSITION
This is a continuation-in-part of U.S.
Application No. 07/358,283, filed on May 26, 1989 and
now pending.
T~CHNICAL FI~LD
This invention relates to injectable
compositions of clarithromycin.
BACKGROUND ART
Lipophilic drugs such as erythromycin and
clarithromycin are not administered by intramuscular
injection or intravenously because these drugs cause
severe pain at the injection site. A variety of
approaches have been taken to address this problem,
including attempts to derivatize the lipophilic drugs
themselves. Nevertheless, there is a continuing need
for injectable compositions of lipophilic drugs that do
not cause severe pain.
It has been found that erythromycin fat
emulsions are locally non-irritative. The antibiotic
clarithromycin, however, has a low solubility in fat
emulsions even in the presence of oils, and will
precipitate out of such emulsions. It has heretofore
not been possible to solubilize clarithromycin so as to
achieve stable injectable compositions at concentrations
which are high enough for therapeutically effective
pharmaceutical purposes. For example, Japanese patent
application No. 61291~20 (published December 22, 1986)
suggests the addition of benzyl benzoate to increase the
concentration of erythromycin in vegetable oils.
However, when clarithromycin is prepared as suggested by
the Japanese patent, therapeutically acceptable
wO9o/14094 ~ 4 4 5 PCT/US90/03063
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concentrations (for example, s mg/ml) are not achieved.
Therefore, administration of the desired total daily
dose of clarithromycin would require the administration
of either larger individual injections or more numerous
injections. Accordingly, there is a continuing need for
stable injectable compositions of clarithromycin at
therapeutically acceptable concentrations that do not
cause severe pain at the injection site.
SUMMARY OF THE INVENTION
The present invention relates to
pharmaceutical compositions of clarithromycin for
injection. The composition can be delivered by
intramuscular or central or peripheral venous routes.
More particularly, the present invention
relates to an injectable fat emulsion having a
therapeutically effective concentration of
clarithromycin which includes a triglyceride oil and a
stabilizing agent.
DETAILED DESCRIPTION OF THE INVENTION
The pharmaceutical compositions of the present
invention include compositions comprising an injectable
fat emulsion having a therapeutically effective
concentration of clarithromycin, a triglyceride oil and
a stabilizing agent. The invention also includes
compositions which additionally comprise an emulsifier,
as well as those containing a tonicity-adjusting agent.
The compositions of the invention are
specifically those containing the antibiotic
clarithromycin. By "clarithromycin" as used herein is
WO90/14094 2 0 5 6 '1 A ~ PCT/US90/03063
meant 6-O-methyl-erythromycin (see U.S. 4,331,803) and
semisynthetic derivatives of clarithromycin known to the
art as well as their pharmaceutically acceptable salts
and esters. By "pharmaceutically acceptable salts and
esters" as used herein is meant those salts and esters
which are, within the scope of sound medical judgment,
suitable for use in contact with the tissues of humans
and lower animals without undue toxicity, irritation,
allergic response, and the like, commensurate with a
reasonable benefittrisk ratio, and effective for their
intended use in the chemotherapy and prophylaxis of
antimicrobial infections. Among the more common
pharmaceutically acceptable salts and esters of
macrolide antibiotics are the acetate, estolate (lauryl
sulfate salt of the propionate ester), ethyl succinate,
gluceptate (glucoheptonate), lactobionate, stearate, and
hydrochloride forms. Other acid salts used in the
pharmaceutical arts are the following: adipate,
alginate, aspartate, benzoate, benzene-sulfonate,
bisulfate, butyrate, citrate, camphorate,
camphorsulfonate, cyclopentanepropionate, digluconate,
dodecylsulfate, ethanesulfonate, fumarate, gluconate,
glycerophosphate, hemisulfate, heptonate, hexanoate,
hydrobromide, hydroiodide, 2-hydroxy-ethanesulfonate,
lactate, maleate, methanesulfonate, 2-naphthalene-
sulfonate, nicotinate, oxalate, pamoate, pantothenate,
pectinate, persulfate, 3-phenylpropionate, picrate,
pivalate, propionate, succinate, tartrate, thiocyanate,
tosylate, and undecanoate. Basi~ nitrogen-containing
groups can be quaternized with such agents as lower
alkyl halides, such as methyl, ethyl, propyl and butyl
chloride, bromides and iodides; dialkyl sulfates like
dimethyl, diethyl, dibutyl, and diamyl sulfates; long
woso/14~4 ~ 4 4 ~ PCT/US90/0~K3
--4--
chain halides such as decyl, lauryl, myristyl and
stearyl chlorides, bromides and iodides; aralkyl halides
like benzyl and phenethyl bromides and others. ~ater or
oil-soluble or dispersible products are thereby obtained.
Because the compositions of the invention
offer improved solubilization of clarithromycin, higher
concentrations are achieved than have previously been
attainable. By "therapeutically effective
concentration" as used herein is meant the concentration
of clarithromycin that is effective to treat or prevent
susceptible bacterial or other microbial infections, at
a reasonable benefit/risk ratio applicable to any
medical treatment, for example s mg/ml. Of course, the
total daily dose of the compositions herein will be
decided by the attending physician within the scope of
sound medical judgment. The specific total daily dose
level for any particular patient will depend upon a
variety of factors including age, body weight, general
health, sex, diet, time of administration, route of
administration (i.e., intramuscular or central or
peripheral venous routes), rate of excretion, the
severity of the particular disease undergoing therapy,
and like factors well known in the medical arts. The
preferred therapeutically effective concentration of
clarithromycin is from about 2.5 mg/ml to about 10
mg/ml. The most preferred concentration is about 5
mg/ml.
The lipid phase of the injectable emulsious of
the invention is provided by a triglyceride oil. By
"triglyceride oil" as used herein is meant a
triglyceride composition which is liquid at room
t~u~erature (22 C), and which consists primarily of
triglycerides of C6 to C18 fatty acids. The
WO9o/140~4 2 0 ~ PCT/US90/0~K3
triglyceride oil can be short chain (C6 to Cl2) or
long chain (Cl4 to Cl8) and preferably C6 to Cl2
aliphatic fatty acids. These triglyceride oils are
generally present in a range of from about 2 to about
40~.
One preferred class of triglyceride oils of
short chain fatty acids is represented by those oils
which consist predominantly of glycerol triesters of
C6 to Cl0 fatty acids. Such oils can be prepared
synthetically by well known techniques, or can be
obtained from natural sources by known techniques of
thermal or solvent fractionation of suitable natural
oils, such as palm oil, to yield fractions rich in the
desired low-melting triglycerides. A preferred
low-melting, low molecular weight triglyceride oil is a
low molecular weight fraction of palm oil which is rich
in mixed esters of caprylic (octanoic) and capric
(decanoic) acids. Such an oil is commercially available
as Neobee~ M-s oil from PVO International, Inc., of
Boonton, New Jersey. Other low-melting cuts of palm oil
are also suitable.
Another preferred class of triglyceride oil
consists of triglyceride oils having a high percentage
of glycerol triesters of unsaturated or polyunsaturated
C6 to Cl8 fatty acids. A preferred example of such
an oil is safflower oil, which typically has a fatty
acid composition of over 90~ oleic and linoleic acids.
Triglycerides of these acids are liquid at 20C, while
the corresponding saturated triglyceride tristearin is a
waxy solid at room temperature and melts at about
72C. A further preferred example of such an oil is
soybean oil. Other low-melting vegetable oils or
low-melting fractions of oils, which can be obtained by
wo9o/l4os4 PCT/US90/0~K3
20564~5
conventional thermal or solvent fractionation, are also
suitable. While such unsaturated or polyunsaturated
vegetable oils may offer a cost advantage in formulating
compositions according to this invention, they also
exhibit a greater tendency to oxidative deterioration,
and may require the addition of oil soluble
antioxidants, such as tocopherols.
Also preferred are intravenous fat emulsions
which are generally prepared from either soybean or
safflower oil and provide a mixture of neutral
triglycerides containing predominantly unsaturated fatty
acids. An example of such an emulsion is Liposyn
II, a commercially available triglyceride oil and water
emulsion. The major component fatty acids are linoleic,
oleic, palmitic, stearic, and linolenic acids. In
addition, these products can contain egg yolk
phospholipids as an emulsifier, and glycerol to adjust
tonicity. The emulsified fat particles are generally
0.33 to 0.5 microns in diameter, similar to naturally
occurring chylomicrons.
In some compositions according to this
invention, the triglyceride oil may contain small
amounts of mono- and/or diglycerides to enhance
solubility of the components or to enhance
emulsification. In other compositions of this
invention, it will be preferable that the oil have a low
polarity. In such a case, the preferred triglyceride
oils will be low in the content of mono- and
diglycerides, as well as phospholipids, all of which
have significant polarity.
The compositions of the present invention also
include at least one stabilizing agent. By "stabilizing
agent" as used herein is meant an additive that
WO 90/14~94 2 ~ 5 6 ~ ~ 5 PCT/US90/03~3
increases the solubility of the clarithromycin in ~he
triglyceride oil phase such that a therapeutically
acceptable concentration of clarithromycin can be
achieved. Stabilizing agents include fatty acids (C6
to C12 saturated fatty acids, or unsaturated C16 to
C18 fatty acids), N-methyl pyrrolidone (NMP), and
benzyl alcohol. Preferred fatty acids are oleic,
decanoic, octanoic and hexanoic acids. Methylene
chloride can be utilized, but it must be evaporated off
to achieve the final product. It has been found that,
in the absence of the stabilizer, the emulsion is not
stable and the clarithromycin tends to precipitate out
of the emulsion within a short period of time, i.e.,
within one month. The stabilizing agent acts to
increase the stability of the emulsion and maintain the
suspension for at least six months.
The present invention also includes
compositions containing an amulsifier. By "emulsifier"
as used herein is meant a compound which prevents the
separation of the injectable emulsion into individual
lipid and aqueous phases. Suitable emulsifiers include,
but are not restricted to, egg yolk phospholipids
(approximately 0.5 to 5%); glycodeoxycholic or
glycocholic acids or a combination thereof; and
non-ionic surfactants (as for example polysorbate,
sorbitan monostearate and combinations thereof).
The compositions of the present invention may
also contain minor additives such as compounds to adjust
tonicity, as for example glycerol (1-5%) and propylene
glycol (1-10~).
The following examples are intended to
illustrate the inventiGn without limiting the practice
thereof.
WO90/140~4 PCT/US~/0~K3
20~4~
EXAMPLE 1
A representative composition of the present invention
was prepared as follows:
ComPound Amount
clarithromycin solution
in NMP 167 mg/ml x 3 ml
Liposyn~ II 20% 100 ml
Clarithromycin base (500 mg, available from Abbott
Laboratories, Illinois) was dissolved in 3 ml NMP (N-methyl
pyrrolidone, available from GAF Corp., Wayne N.J.). This
solution was then added to 97 ml of Liposyn II 20% (20%
oil~80% water emulsion) and the mixture shaken. The
clarithromycin concentration was calculated to be
approximately 5 mg/ml.
EXAMPLE 2
The compositions of EXAMPLE 2 can generally contain
the following relative amounts of ingredients.
Com~ound Amount*
Neobee~ oil 10-40%
decanoic acid 0.5-3%
clarithromycin base 0.5-3~
egg phosphatide 0.5-3%
glycerol 1-4%
water q.s.**
= percent of composition
** q.s. = adjust volume to desired value
Solution A was prepared by adding 2.5 gm
clarithromycin and 5.6 gm decanoic acid to 100 gm of
Neobee oil (a medium chain triglyceride). The solution
was then stirred with heating (approximately 40C) until
dissolved.
w090/l4~4 PCT/US90/0~K3
20~6445
Solution B was prepared by stirring 6 gm egg
phosphatide and 12 gm glycerol into 200 ml of water.
Solution 8 was passed through a Microfluidizer
M-110 (Microfluidics Corp.) 3 times. Solution A was then
added via a syringe pump at 1 ml/min while the mixture was
passed through the microfluidizer. After the addition was
completed, the mixture was passed 5 more times ~hrough the
microfluidizer, adjusted to pH 7.5 with NaOH and diluted to
500 ml with water. The clarithromycin concentration was
calculated to be approximately 5 mg/ml.
EXAMPLE 3
A methylene chloride-containing example of the
compositions of the present invention was prepared as
follows:
Compound Amount
clarithromycin base 1-20 mg/ml final
concentration
egg phosphatide in methylene 0.5-3
chloride
Neobee~ oil 10-40%
water q.s.
Clarithromycin (2.5 gm) and 6 gm egg phosphatide
were dissolved in 150 ml methylene chloride. The solution
was evaporated to dryness in a rotary evaporator and the
residue thin film was taken up, with vortexing, into 200 ml
of water. Neobee oil (100 gm) was then added via a
syringe pump and microfluidizer to the drug-phosphatide
mixture as in EXAMPLE 2. The final emulsion was adjusted to
pH 7.5 with NaOH and diluted to 500 ml with water.
EXAMæLE 4
EX~MPLE 2 can be repeated using the solubilizer
WO90/14~4 2 0 S 6 4 4 ~ PCT/US90/03~3
--10--
octanoic acid. Solution A is prepared by adding 2.5 gm
clarithromycin base and 4.7 gm octanoic acid to 100 gm of
Neobee oil. The solution is then stirred with heating
until dissolved.
Solution B is prepared by stirring 6 gm egg
phosphatide and 12 gm glycerol into 200 ml of water.
Solution B is passed through a microfluidizer 3
times. Solution A is then added via a syringe pump while
the mixture is passed through the microfluidizer; After the
addition is completed, the mixture is passed 5 more times
through the microfluidizer, adjusted to pH 7.5 with NaOH and
diluted to 500 ml with water. The clarithromycin
concentration is calculated to be approximately 5 mg/ml.
EXAMPLE 5
A further example of the compositions of the
present invention was prepared as follows: Clarithromycin
base (5 gm) and soybean oil (20 gm) were mixed to a smooth
suspension. Oleic and hexanoic acids (6 gm and 3gm,
respectively) were added while stirring and the oil phase
mixture heated to 45C or until clear.
Separately, egg lecithin (50 gm) was dissolved in
preheated water (500 ml) and the solution stirred without
heat as 12.2 gm NaOH is 50 ml water was added. Glycerin
(25 gm) was then stirred in and the mixture circulated
without cooling (approx. 10-15 min.) through a Gaulin M-15
homogenizer until 60-65~C and semi-transparent. After
transfer of the dispersion to a beaker, and while cooling if
necessary to less than 40C, the above oil phase was
gradually blended in using a Silverson mixer at the highest
speed possible. Keeping the temperature below 40C, the
mixture was blended an additional 30 minutes.
WO90/14094 2 0 5 6 '~ 4 5 PCT~US90/03063
The resulting mixture was then homogenized (30
passes at 6000-7000 p.s.i. at 35-40C) and the homogenizer
rinsed with 450 ml water, the rinse being stirred into the
emulsion. After adjusting the pH to 7.7-7.9 with 7% NaOH,
the volume was adjusted to l liter with water and the
emulsion filtered through a 0.2 micron nylon membrane under
N2 gas at about 30 p.s.i.
SCRATCH TEST
A scratch test was conducted in mice to measure
the response to the sensation of irritation, i.e., the pain
associated with an injection. A composition containing
clarithromycin, NMP, and Liposyn II (see EXAMPLE l) was
administered subcutaneously at a dose of 5 ml/kg to groups
of mice (l0/group) weighing 16 to 30 g each. A second
inventive composition containing the oleic acid/hexanoic
acid system of EXAMP1E 5 and a clarithromycin lactobionate
standard were similarly tested. The number of times that
each mouse scratched the injection site was then counted for
exactly five minutes. The results indicate a low scratch
response associated with the compounds of the present
invention and are summarized in Table l below.
wo ~/14~4 PCT/US90/03063
2056445
-12-
TABLE 1
Composition No. of Scratches
Mean S.D
1. 0.9% Saline Solution 2.6 1.6
2. clarithromycin base (2mg/ml) 7.0 4.3
in Liposyn II plus NMP
3. clarithromycin base (5mg/ml) 9.7 4.2
in Liposyn II plus NMP
4. clarithromycin base (5mg/ml) 11.1 --
in oleic/hexanoic system
5. clarithromycin lactobionate 52.0~* --
(5mg/ml)
S.D. = standard deviation
~ = extrapolated from 1-4 mg/ml
VEIN IRRITATION TEST
Clarithromycin in Liposyn II (5 mg/ml) was
evaluated for acute vein irritation in rabbits. The
test composition was infused into two male and two
female rabbits at a rate of 1 ml/minute via the marginal
ear vein at a dose volume of 8 ml/kg. The rabbits were
observed frequently during and after treatment for signs
of local irritation. The injection site appearance at 1
hour, 3 hours and 21 hours was normal with no apparent
redness, thus indicating that the composition did not
cause local irritation.
ANTIBACTERIAL ACTIVITY
The antibacterial activity of 5mg/ml
compositions of clarithromycin base in Liposyn II for
intravenous administration (composition A) was compared
WOg0/14094 PCT/US90/03~3
2~6 14~
-13-
to the activity of clarithromycin base lactobionate
(composition B) in mouse protection tests. Mice were
infected intraperitoneally with 100 LD50 doses of
StaphYlococcus aureus, StrePtococcus pYoqenes, or
Streptococcus pneumoniae (Groups 1, 2 and 3,
respectively) and treated one hour after infection by
injecting either (A) or (B) intravenously via the tail
vein. ED50 was calculated from cumulative mortalities
on the sixth day after infection. The results indicate
that the composition has antibacterial activity as shown
in Table 2 below.
TABLE 2
ED50 ~mq/kq/daY)
CompositionGroup l* Group 2** Group 3***
A 16.8 2.5 0.6
B 40.0 2.1 1.3
* = innoculum size 5.01 x 1o6 colony-forming units
(CEIJ' s)
** = innoculum size lg95 CFU's
*** = innoculum size 6310 CFU's
Similar mouse protection tests comparing the
oleic/hexanoic system of EXAMæLE 5 with clarithromycin
lactobionate showed no significant differences in
antibacterial activity.
PHARMACOKINETIC ACTIVITY
Six beagle dogs were allowed to fast
overnight, The dogs were administered an intravenous
infusion of clarithromycin (100 mg) in 20% Liposyn II (5
mg/ml). Blood samples were obtained periodically for 24
hours and the concentration of clarithromycin in the
Wo ~l4094 PCT/US~/03063
;6~4~
-14-
plasma samples was determined using a high-performance
liquid chromatographic assay with electrochemical
detection. The results indicate good plasma levels of
clarithromycin and are shown in Table 3 below.
Table 3
Dog No. 24-hr AUC
(hrs x ug/ml)
-
l 38.59
2 l9.62
3 42.04
4 36.64
32.40
6 21.04
AUC = area under curve
Mean 3l.72
Standard Deviation 9.37
S.E.M. 3.82
A separate pharmacokinetic study likewise
confirmed that plasma levels obtained using the
oleic/hexanoic system of EXAMPLE 5 are comparable to
those obtained with clarithromycin lactobionate. Four
beagle dogs were treated as before with these
compositions; blood samples were drawn and analyzed
using standard microassay techniques. The results,
shown in Table 4 below, demonstrate the bioavailability
of the compounds of the present invention.
WO ~/140942 0 5 6 ~ 4 5 PCT/US90/03~3
TABLE 4
Composition 24-hr AUC Cmax Tmax
(hrs x ug/ml) (ug/ml) (hr)
Oleic/hexanoic system 41.07 5.36 1.33
Clarithromycin37.16 3.84 1.67
lactobionate
This invention has been described in terms of
specific embodiments set forth in detail. It should be
understood, however, that these embodiments are
presented by way of illustration only, and that the
invention is not necessarily limited thereto. It is
contemplated that equivalent lipophilic drugs are those
drugs which have solubility parameters similar to
clarithromycin, such as roxithromycin. Modifications
and variations within the spirit and scope of the claims
that follow will be readily apparent from this
disclosure, as those skilled in the art will appreciate.
