Pharmaceutical compositions containing a corticosteroid substance

Pharmaceutical compositions containing a corticosteroid and an ester of L-arginine with an aliphatic alcohol exhibit a synergistic effect in the protection against shock. The corticosteroid may be 6-.alpha.-methylprednisolone-21-hemisuccinate sodium salt and the L-arginine ester may be the methyl ester in the form of the hydrochloride salt.

The present invention relates to natural corticosuprarenal hormones and 
their synthetic derivatives. It is well known that these hormones exhibit 
a very high therapeutic activity, but the bioloigical activity of these 
compounds unfortunately lack in specificity and this lack in specificity 
of activity is probably responsible for several side effects which are 
observed during treatment with cortisone and cortisone type compounds. 
Obviously, it has been desirable to fine compositions which include 
cortisone and cortisone-type compounds and derivatives of cortison-type 
compounds and which are more specific in therapeutic activity, so that the 
treatment may be effective even at a lower dosage. Clearly, if the object 
of improving the specificity of cortisone and cortisone-type compounds is 
achieved, it will be possible to decrease the side effects and to achieve 
effective treatment at a lower dosage. 
The crux of the present invention resides in the finding that the 
therapeutic activity of 6-.alpha.-methyl-prednisolone-21-hemisuccinate, 
which is considered as a typical case of corticosteroid substances, is 
substantially increased in a pharmaceutical preparation which contains, in 
addition to the corticosteroid, also an ester of L-arginine with an 
aliphatic alcohol. The amount of the L-arginine ester which is necessary 
to cause the synergistic effect may vary over a wide range, but molar 
ratio of the two substances of 1:1 may be used. 
In patent application filled in Italy, Patent Application No. 28416 A/79, 
filed on Dec. 28, 1979, the therapeutic activity of arginine esters with 
aliphatic alcohols has been described, the arginine ester having the 
general formula: 
##STR1## 
in which X.sup.- is an organic or inorganic pharmaceutically acceptable 
anion and R is an alkyl group. In the same Italian Patent Application 
mentioned hereinabove, it has been stated that the pharmaceutical 
compositions are obtained by dissolving the individual compounds in water 
at a pH preferably between 5.5 and 8.5, or by using a corresponding salt 
formed from an organic or inorganic acid. 
It has now been found that pharmaceutical preparations which contain, for 
instance 6-.alpha.-methyl-prednisolone-21-hemisuccinate in the form of its 
sodium salt or an equivalent salt together with an ester of L-arginine 
with an aliphatic alcohol, in the form of a salt, for instance the 
hydrochloride salt, exhibit an activity substantially greater in the 
protection from shock caused by endotoxins and anaphylactic shock, which 
activity is substantially greater than the activity resulting from some of 
the individual components, used separately. More specifically, with an 
equal dose, the effect of protection achieved in accordance with the 
present invention is substantially greater than what may be foreseen on 
the basis of the activity of the compounds used separately. It is, 
therefore, obvious that the combination of the corticosteroid and the 
arginine ester results in a synergism of the therapeutical effects.

The tests reported hereinbelow domenstrate the therapeutic activity of the 
pharmaceutical composition in accordance with the present invention. 
Increase of the protective effect of 
6-.alpha.-methyl-prednisolone-21-hemisuccinate sodium salt with respect to 
shock caused by endotoxins 
The endotoxin shock has been induced in accordance with the method reported 
by A. Bertelli and L. Donati "The Influence of Some Enzymes and Enzymes 
Inhibitors in Shock", "SHOCK Biochemical, Pharmaceutical and Clinical 
Aspects", A. Bertelli and N. Back Editors, Advances in Experimental 
Medicine and Biology, Volume 9--Plenum Press, New York--London (1970) page 
215. 
There are used for the test male Wistar rats of 120.+-.10 grams by weight, 
previously stabilized for a period of ten days at a temperature of 
21.degree..+-.1.degree. C. under conditions of controlled diet and water 
"ad libitum". Twenty-four hours prior to the test, the animals are divided 
into groups of ten, for the purpose of achieving randomization. Each dose 
has been tested on six groups of animals. 
Lipopolysaccharide B from S. Enteritidis (Difco Labs.) has been used as the 
endotoxin which has been administered to the animals by the endoperitoneal 
route in a dose of 10 mg/kg. The administration has been carried out one 
hour after the administration by the parenteral route of the substance 
being tested or one hour after the administration of physiological saline 
solution in equal volume per kilogram of body weight of the animal, in the 
animals being used as control. 
The percentage of mortality has been determined in the animals being 
treated with reference to the animals being used as control after 
twenty-four hours. The results are reported hereinbelow in Table No. 1. 
TABLE 1 
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COMPOUND DOSE, mg/kg % MORTALITY 
______________________________________ 
6-.alpha.-M-P* 2.5 43.3 
6-.alpha.-M-P 5 20.0 
6-.alpha.-M-P 15 0.0 
6-.alpha.-M-P + L-A.M.** 
2.5 + 1.3 21.0 
6-.alpha.-M-P + L-A.M.** 
5 + 2.6 13.3 
6-.alpha.-M-P + L-A.M.** 
2.5 + 6.3 0.0 
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*6-M-P = 6methylprednisolone-21-hemisuccinate, sodium salt 
**LA.M. = Larginine methylester hydrochloride 
Amoumt of Administration: 0.12 ml/rat 
Increase of the effect of 6-.alpha.-methyl-prednisolone-21-hemisuccinate 
sodium salt against anaphylactic shock 
The anaphylactic shock has been caused according to the method of S. M. 
Feimberg, J. Pharmacol. Exp. Therap., 99, 195 (1950). There are used for 
the test male albino guinea pigs of average weight 350.+-.20 grams, 
previously stabilized for a period of ten days at a temperature of 
21.degree..+-.1.degree. C., under conditions of controlled diet and water 
"ad libitum". Three days prior to the beginning of the test, the animals 
were divided in groups of ten for the purpose of achieving randomization. 
Each does has been tested on three groups of animals. 
The sensitization has been achieved by administration of whole horse serum, 
that is horse serum not treated with preservatives, through the endovenous 
route in the amount of 1 ml/guinea pig, the horse serum having been 
diluted with physiological saline solution in the ratio of 1:10. After 14 
days, there are administered the solutions of the substances in the test 
and physiological solution to the animals kept as control through the 
parenteral route. Simultaneously, through the intravenous route, 1 
ml/guinea pig of undiluted horse serum has been administered as the agent 
which prompts the anaphylaxis. The percentage of mortality is determined 
after 12 hours. The results are reported herinbelow in Table 2. 
TABLE 2 
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COMPOUND DOSE,mg/kg % MORTALITY 
______________________________________ 
Physiological Solution 
-- 80 
6-.alpha.-M-P 2.5 75 
6-.alpha.-M-P 5 71 
6-.alpha.-M-P 10 65 
6-.alpha.-M-P 15 57 
6-.alpha.-M-P + L-A.M. 
2.5 + 1.3 53 
6-.alpha.-M-P + L-A.M. 
5 + 2.6 38 
6-.alpha.-M-P + L-A.M. 
10 + 3.9 21 
6-.alpha.-M-P + L-A.M. 
15 + 10 12 
______________________________________ 
The meaning of the symbols and abbreviations are explained under Table 1.