FR2594334A1 - INJECTABLE PHARMACEUTICAL COMPOSITION BASED ON AMOXICILLIN - Google Patents

Abstract

The present invention relates to an injectable pharmaceutical composition based on amoxicillin. According to the invention, this composition comprises amoxicillin trihydrate suspended in an appropriate vehicle or liquid medium. The invention finds application in particular in the pharmaceutical industry, in particular as an antibiotic.

Description

The present invention relates to a novel

  injectable preparation based on amoxicillin.

  Amoxicillin is an antibiotic of the family betalactamines, whose therapeutic interest has been known for a long time. Amoxicillin-based pharmaceutical compositions for oral administration can be readily prepared in any of the usual forms such as, for example, gelules, tablets or the like.

  compositions for oral absorption.

  In contrast to this, injectable preparations of such compositions require the use of soluble derivatives of amoxicillin and a suitable solvent, which may be water. Also, soluble salts of amoxicillin, such as in particular sodium salt have been used until now for the realization of

injectable preparations.

  However, such solutions have limited stability and are therefore difficult to prepare industrially with satisfactory purity because the

salts are degradable.

  In addition, the intramuscular injection of the preparations in aqueous solution is painful and irritating to the tissue. It has therefore proved necessary to add anesthetic to these solutions. However, the choice of a local anesthetic to be used to make the injection tolerable is very limited, in particular because of the incompatibility of the amoxicillin salts with

certain types of anesthetics.

  Thus, there is known an injectable preparation containing amoxicillin containing benzyl alcohol as local anesthetic. This preparation must be injected immediately after reconstitution. However, this product has a low titre and the overall content of decomposition products and impurities is high, and can reach 10%. In addition, multiple antibiotic injections per day are required to maintain the necessary serum concentrations. In addition, benzyl alcohol, although effective against pain, nevertheless causes during the injection

  intramuscular local irritation.

  Because of the difficulties encountered with known injectable solutions, in particular based on sodium salt of amoxicillin, it was therefore necessary to envisage a

alternative formula.

  The present invention aims to solve the aforementioned problems by providing a pharmaceutical composition which is easy to inject, which has good purity and stability over time and which effectively fights against local pain during injection

without causing irritation.

  The solution proposed by the present invention to solve this problem consists of an injectable pharmaceutical composition based on amoxicillin, characterized in that it comprises amoxicillin trihydrate suspended in a vehicle or medium

appropriate liquid.

  Surprisingly, it has been found that the local tolerance to the injection of a suspension of amoxicillin trihydrate was better than that of an aqueous solution of sodium salt of amoxicillin. Parenteral administration of suspensions meets a priori unfavorable opinion and is generally reserved for products that can not be solubilized in conventional vehicles, the objection relating to

  on the poor local tolerance to injection.

  Therefore, until now, only soluble derivatives of amoxicillin have been used, and there was no need for those skilled in the art to refer to amoxicillin derivatives, such as trihydrate, suspended in a liquid medium. According to a particular characteristic of the invention, the particle size of the amoxicillin trihydrate in the suspension is chosen so as to allow the injection of the composition. Advantageously, this size is between about 1 and 25 microns and

  is preferably of the order of 5 microns.

  According to another particular characteristic, the concentration of amoxicillin trihydrate in the suspension is between about 100 mg / ml activity and 700 mg / ml activity and is preferably between 200

and 500 mg activity / ml.

  According to yet another characteristic of the invention, the amoxicillin trihydrate is in micronized form in the solvent. Micronization is particularly advantageous because the conformation of the particles obtained is entirely compatible with

the constraints of the injection.

  The invention will be better illustrated by reading

  the explanatory description which will follow, made in

  reference to the experiments and observations given below

only as an example.

  The local pain after subplant injection in the rat, the local tolerance to intramuscular injection in rabbits and the bioavailability in dogs of an aqueous suspension of micronized amoxicillin trihydrate, according to the invention, were studied by comparison. with an aqueous solution of sodium salt of amoxicillin. The vehicle chosen for comparison is water, which is the simplest liquid medium, and also the least expensive. However, any other suitable customary liquid medium can be used without departing from the scope of the invention. The amoxicillin trihydrate was micronized by passage on a Christo Jet Mill apparatus under strictly defined and reproducible conditions. This known technique is described for example by G. BOULLAY

(APGI Conference Dec. 1984).

  Particle size analysis of the resulting powder reveals the following particle size distribution: about 80% of the particles are less than 5 microns in size; about 10% of the particles have a size of between 5 and 10 microns; about 10% of the particles have a size

between 10 and 20 microns.

  As mentioned above, the micronization of amoxicillin trihydrate is advantageous because it makes it possible to overcome most of the constraints of the injection of the suspension according to the invention. However, it is understood that other techniques can be used, such as microbrushing or

prolonged grinding.

  The integrity of the active ingredient, after this treatment, has been verified, in a conventional manner, by assay and search for impurities. The powder obtained was suspended in water by simple stirring. The resulting suspension is homogeneous and easily administered

by a syringe.

  Two distinct suspensions were prepared, at concentrations of 200 mg activity / ml and 500 mg activity / ml, respectively, expressed in terms of amoxicillin under

anhydrous free acid form.

  Experiment 1: Alcohol injection.

  Injection ALgie has been studied in female OFA strain rats using the technique of E. CELOZZI, V.J. LOTTI, EO STAPLAY and AK MILLER described in J. of Pharmaceutical Methods 1980, Volume 4, pages 285 to 289. Batches of rats weighing 60 to 80 g received the following four preparations: amoxicillin trihydrate / water for injection (500 mg activity / ml); amoxicillin trihydrate / water for injection (200 mg activity / ml); - sodium salt of amoxicillin / water for injection (500 mg activity / ml); - sodium salt of amoxicillin / benzyl alcohol to

3% (500 mg activity / ml).

  Benzyl alcohol is used here as

local anesthetic.

  0.1 ml of each of the above solutions and suspensions is injected into the subplantar tissue of the paw. The pain caused by the injection is evaluated by the licking reflex test of the rat's paw. The number of licks of the paw, consecutive to the injection, is counted in intervals of 3 minutes over a period of minutes. The licking of the leg is defined as follows: licking followed by diversion of the head or 5 seconds of uninterrupted licking. The results obtained are presented

in table 1.

Table 1.

  Local Algie after subplantar injection in the rat N Average number of lechages during 3 minute intervals 0-3 3-6 6-9 9-12 12-15 0-15 2Amoxicillin Na g 25 15.3 7.6 1.4 1.2 0.7 26.2 2 ml distilled water Amoxicillin Na I 9 + 2 ml benzyl alcohol 9 0 0.1 0 0 0 0.1 3% Amoxicillin micronizedel + 2 ml distilled water 10 0.2 0.1 0 0 0 0.3

Micronized Amoxycillin 1.

  + 5 distilled water 5 0.2 0.2 0 0 0.4 + 5 ml water. The results obtained show that the injection of the sodium salt of amoxicillin in aqueous solution is painful, in particular during the first three minutes. The pain then subsides. In contrast, the injection of amoxicillin trihydrate suspended in water is painless regardless of its concentration and the score obtained is quite comparable to that obtained

with a local anesthetic.

  Experiment 2: Tolerance to intramuscular injection These experiments aim to study the muscular irritation caused at the injection site and

  the evolution over time of the observed lesions.

  The test is performed in 12 rabbits

  New Zealand adults (Froxfield Farms Hampshire breeding).

  These rabbits are divided into 3 lots of 4; the thoracolumbar region is shaved, and they each undergo 6 simultaneous intramuscular injections in the sacrospiral muscles of a volume of 0.5 ml, the following compositions: - water for injection (E) - benzyl alcohol 3% (B ) - Sodium amoxicillin / 3% benzyl alcohol (C + B) (concentration of 200 mg activity / ml) - amoxicillin trihydrate / water (200 mg activity / ml) (A + E) - amoxicillin trihydrate / benzyl alcohol 3%

(A + B) (200 mg activity / ml).

  The three groups of rabbits are sacrificed

  respectively 2.5 and 14 days after the injections.

  The injection sites are then examined macroscopically. The lesions are measured and given a score according to their intensity defined as follows: 0: no change 1: very mild impairment 2: moderate impairment

3: marked attack.

  The individual results of this macros-

  copics are reported in Table 2.

  Representative samples from each injection site are then taken, included in paraffin, cut to 5 micrometers, stained with hemalunphloxine-saffron and are subjected to a usual histological examination, the results of which are given below in table

comparative 3.

Table 2.

48 hours 5 days 14 days

I I.

  Intensity size Intensity size Intensity size lesion lesions lesion lesions lesions lesions _____ _ (mm (mm) - (mm) '' _ Compositionlapin 1 rabbit 5 rabbit 9 death D + 4

A + E 3 X 3 I 15 X 10 3 10 X 5 1

A + B 20 X 5 1 12 X 5 3 0 0

C + B 0 0 10 X 5 36 X 5 2

B 20 X 10 3 10 X 5 0 0

E 8 X 4 1 15 X 8 2 15 X 10 1

rabbit 2. rabbit 6 rabbit 10

A + E 8 X 8 1 3 X 2 I 17 X 8 2

  A + B 12 X 7 2 not measurable 1 not measurable '1

C + B 20 X 15 2 18 X 15 2 6 X 3 1

B 20 X 15 3 12 X 5 2 10 X 5 2

E 0 0 8 X 5 2 10 X 5 1

Rabbit 3 Rabbit Rabbit 11

A + E 10X 5 1 0 0 0

A + B 25 X 5 2 10 X 4 1 0 0

C + B 20 X 12 3 12 X 6 2 22 X 4 '2

B 15 X 3 '1 15 X 4' 2 18 X 2, 1

E1X I1 0 0 0 '0

  Rabbit 4 Rabbit 8 Rabbit 12 min. 1 .1 - 7 A + E 9 X4 21 6X3 0 1 min. 2

A + B 20 X 5 3 12 X 10 I 1 25 X 3 2

C + B 15 X9 3 8 X 2 '2 10 X 5' 2

B 13 X 4 2 15 X 13 2 15 X 5 2

E 10 X 1 1 3 X 2 1 I 5 X 4 1

l .. ,. Co-O-L4 Lq-el.

Table 3.

  HISTOLOGICAL EXAMINATION - Compared Results Degeneration

Fibers musk.

  Regeneration Infiltrat Fibers musk. Cell Fibrosis Hemorrhage Total Amoxicillin micronized + water ppi (for injection) (i) (ii) (iii)

  D + 2 4/4 (2-3) 0/4 4/4 (1-2) 0/4 0/4

  D + 5 3/5 (2-4) 2/5 (1-2) 3/5 (2-3) 0/5 1/5 (1)

  D + 14 2/3 (3) 2/3 (1-2) 2/3 (3) 2/3 (2-3) 0/3

  Total 9/12 4/12 9/12 2/12 1/12 Micronized Amoxicillin + Benzyl Alcohol

  J + 2 3/4 (3-4) 0/4 3/4 (2) 0/4 3/4 (1)

  D + 5 4/5 (3-4) 3/5 (2) 4/5 (3) 0/5 0/5

  D + 14 1/3 (3) 1/3 (2) 1/3 (3) 1/3 0/3

  Total 8/12 4/12 8/12 1/12 3/12 24 Sodium salt + benzyl alcohol

  D + 2 3/4 (3-4) 0/4 3/4 (1-2) 0/4 2/4 (2-3)

  D + 5 5/5 (3-4) 5/5 (1-3) 5/5 (2-3) 0/5 2/5 (1-2)

  J + 14 3/3 (2-4) 3/3 (2) 3/3 (3-4) 1/3 (3) 0/3

  Total 11/12 8/12 11/12 1/12 4/12 35 Benzyl alcohol

  D + 2 4/4 (3-4) 1/4 (1) 4/4 (2) 0/4 3/4 (1-3)

  D + 5 4/5 (3-4) 3/5 (1-3) 4/5 (2-3) 0/5 1/5 (2)

  D + 14 2/3 (3) 2/3 (2) 2/3 (3) 2/3 (1-3) 0/3

  Total 10/12 6/12 10/12 2/12 4/12 32 Water ppi

  D + 2 2/4 (1-2) 0/4 2/4 (1-3) 0/4 1/4 (3)

  D + 5 1/5 (3) 1/5 (3) 1/5 (3) 0/5 1/5 (2)

D + 14 1/3 (1) 1/3 (1) 0/3 0/3 0/3

  Total 4/12 2/12 3/12 0/12 2/12 11 (i) Number of rabbits with lesion (ii) Number of rabbits examined (iii) Intensity of injury II Tables 3 and 3 allowed classification the preparations from the most irritating to the best tolerated. This classification is as follows: - sodium amoxicillin / benzyl alcohol 3% - benzyl alcohol 3% - micronized amoxicillin trihydrate / water for injection and amoxicillin micronized trihydrate / benzyl alcohol

- water for injection.

  Table 3 shows in particular the poor results of benzyl alcohol - used alone, or as a local anesthetic with a sodium amoxicillin solution. Experiment 3: Bioavailability The bioavailability of an aqueous suspension of micronized amoxicillin trihydrate in comparison with a solution was studied using standard tests.

  aqueous sodium salt amoxicillin.

  The study was conducted in 2C dogs using sodium amoxicillin reron substituted with 3% benzyl alcohol as the solvent, and secondly the trihydrate form suspended in the suspension.

water for injection.

  6 Beagle dogs (3 males - 3 females) weighing between 10.8 kg and 14.5 kg received intramuscularly (at a dose of 50 mg / kg) the two following preparations: - sodium salt of amoxicillin / 3% benzyl alcohol - amoxicillin trihydrate / water for preparation

injectable.

  Serum levels and urinary excretion were determined microbiologically by the disk method (strain Sarcina Lutea ATCC 9341) Blood samples were taken at the following times: 30 min, lh, lh 30, 2h, 4h, 6h, 8h , 10am,

  12h, 2Ah, 32h 48h after the injection.

  The urine was collected from 0 to 6h, from 6 to 12h, from 12 to 24h. Table 4 gives for each of the compositions

  studied, values of serum levels over time.

  Table 5 gives for each composition studied the urinary excretion values in the

time.

  Table 6 gives for each studied composition the areas under the curve of evolution of the rates

serum in time.

  These results show that the serum peaks are higher and earlier for the preparation of sodium amoxicillin in solution, while there is persistence of serum levels in the composition.

micronized. (see Table 4).

  An inhibitory concentration threshold has been defined arbitrarily but, depending on the usual inhibitory concentrations of amoxicillin,

minimum at 5 mcg / ml.

  Table 4 shows that the decrease in serum levels below the threshold of 5 mcg / ml is reached in 5 hours for the sodium salt of amoxicillin, and in 10 hours

  after administration for the micronized preparation.

  Areas under the serum concentration curve (Table 5) are not statistically significant

  different for both preparations.

  Urinary elimination (Table 6) in 24 hours is not statistically different for both preparations; during the six hours following antibiotic administration, it is significantly higher for sodium salt, whereas between the sixth and the twenty-fourth hours it is significantly higher for amoxicillin trihydrate. However, the significant elimination of the antibiotic in the 12-24 hours interval observed for the micronized trihydrate makes it possible to predict the persistence of urinary levels well beyond

twenty-four hours.

Table 4.

  Dose: 50 mg / kg Animal Serum levels mcg / ml Composition No. Sex Weight 0.5 1 1.5 2 4 6 8 10 12 24 32 48 (Time in - (kg) hours) Sodium salt

of amoxicil-

line

I M 14.5

2 M 13.1

3 M 14.5

4 F 12.9

F 12.7

6 F 10.8

  88.0 102.0 83.0 102.0 83.0 92.0, 0 78.0 88.0 88.0, 0 57.0, 0, 0 53.0, 0 46.0 31.0 36 , 4 33.3 34.6 37.6, 1 17.9

7.0 2.3 0.7

7.0 1.8 0.5

7.0 1.8 0.6

9.7 2.1 0.6

, 0 1.1 0.4

2,2 0,5 0,2

91.6 74.3 47.5 30.8 6.3 1.6 0.5

trihydrate

of amoxicil-

micronized line

1 M 14.5

2 M 13.1

3 M 14.5

4 F 12.9

F 12.7

6 F 10, 8

Average

  7.21 10.23 12.20 13.7311.73 8.98 6.20 5.00 3.41 1.83 0.43 0.10

  Average 6.2 7.5 7.3 8.8 7.3 6.2 7.6 13.0 12.0 12.0 9.2 7.6 7.9 13.6, 4, 5 11.5 9.3 9.4, 4, 4 16.6 13.6 12.0 8.7 12.8 12.8 14.7 11.2, 2 6.7 8.3 8.3 11.8 9, 4 9.4

4.3 4.2

6.2 5.6

, 9 4.9

8.2 6.4

6.4 4.2

6.2 4.7

  3.3 4.1 4.0 3.5 2.6 3.0 2.0 1.6 2.2 2.0 1.6 1.6 0.6 0.3 0.4 0.6 0, 4 0.3 0, 0.09 o, 12 <0.10 <0.10 <0.10% 0 L4

Table 6.

  Dose: 50 mg / kg Composition Dog 0-6 h 6 -12h 12-24 h 0-24 h mg / excretion% mg / excretion% mg / excretion% mg / excretion% Sodium Amoxicillin '

1,408.0

2,394.0

3 21.8

4,355.7

317.4

6,267.1

average 294.0

, 67 75.6 11.06

, 75 1.68

380.36 58.23

  Average micronized amoxicillin trihydrate 67.0 10.71 144.86 22.79

96.2 15.28

  308.08 48.78, and L: 56.28, 3.01, 49.98 49.46 48.0 23, () 259, 2.01, 41.9, 37.8, 77 3.51, 75 7.75 6.60 7.00, 6 1.2 39.2 2.9 4.1 1.5 2.15 0, 18, 41 0.45 0.65 0.28 465 , 4 418.2 320.2 408.6 363.4 306.4 64.19 63.81 44, 16 63.34 57.23 56.74 66.5 54.9 53.9 63.4 71.4 92.0 9.17 8.38 8.62 9.83 11, 24 17.04 142.6 174,? , 1li, 4 166.5 129.5 cn 19.64 26.67 16.90 23.32 26.22 23.98 68.4 81.8 183.6 78.4 83.1 82.0 9.43 12.49 29.36 12.16 13.09, 19 277, 3 311.4 343.1 292.2 321.0 303.5 38.24 47.54 54.89, 30, 55 56.20

Table 5.

  Areas under the curves mg / ml x h No animal Products administered sodium salt trihydrate

1,168.80 120.89

2,174.72 151.11

3,173.45 156.15

4,193.70 172.79

140.97 129.19

6,117.97 127.54

  Mean 161.60 194.94 The above results therefore make it possible to think that the pharmaceutical composition according to the invention

  can also be administered in humans successfully.

  In this regard, the pharmacological properties of such a suspension need not be described here, since they are those of amoxicillin trihydrate which is a compound whose effects are in themselves known for a long time.

2594334-

Claims (6)

  l. Injectable pharmaceutical composition based on amoxicillin, characterized in that it comprises amoxicillin trihydrate suspended in a vehicle or appropriate liquid medium.   2. Pharmaceutical composition according to claim 1, characterized in that the particle size of the amoxicillin trihydrate in the suspension is chosen so as to allow the injection of said composition. 3. Composition according to claim 2, characterized in that the particle size of the amoxicillin trihydrate is between about 1 and p and is preferably of the order of 5 P. 4. Pharmaceutical composition according to one of   Claims 1 to 3, characterized in that the   amoxicillin trihydrate concentration in suspension is between 100 mg activity / ml and 700 mg activity / ml, and preferably between 200 mg activity / ml and 500 mg activity / ml.   5. Pharmaceutical composition according to one of   Claims 1 to 4, characterized in that the trihydrate   amoxicillin is in a micronized form in the   vehicle or liquid medium mentioned above.   6. Pharmaceutical composition according to one of   claims i to 5, characterized in that the vehicle aforementioned is water.