IL45741A - Water-soluble derivative of 6-deoxytetracycline and proceswater-soluble derivative of 6-deoxy-tetracycline and process for the preparation thereof s for the preparation thereof - Google Patents

Description

»j»p»SRiee*»opi«»'r«i€ © o*03 nooan iVin nnaanV i»Vani A water-soluble derivative of 6-deoxy-tetracycli&eft and process or the preparation thereof The present invention has for subject matter a novel antibiotic product having the general formula; its pharmaceutically acceptable soluble salts of organic or inorganic acids and its pharmaceutically acceptable soluble mono- or poly-valent metal salts.

In U.S. Patent 3,637,471 and Belgian Patent !)615425 there are described aminoacid methylene derivatives of tetracycline. In British Patent 1,098,566 there is described methio- derivatives nineamide methyl adduoto of tetracycline and in the article whose abstract appears in CA 55, 21074e there is disclosed r' derivfttiv.fis N-methioninomethyl adducfe or tetracycline, however, none of said publications teach or suggest the present doxycycline or the advantageous properties thereof as described hereinafter.

The new derivative forming subject matter of the invention is characterized by great solubility in water at neutral pH, and it can therefore be administered both per os and intramuscularly or intravenously and, in addition, preserves unaltered the antibiotic activity of deoxycycline.

The new derivative has improved patient-toleration, stability and higher blood levels as compared with both the 6-deoxy-tetracyclines and with their water soluble derivatives; furthermore, its toxicity is lower while it maintains The product having the general formula I can be prepared by placing doxycycline into contact with an eguimolecular quantity of methionine, in the presence of formaldehyde, in a polar solvent, at the temperatures and for the periods of time necessary to obtain a complete reaction.

The formaldehyde should for preference be added in the proportion of one mole per mole of starting doxycycline and can be in the form of aqueous solution, gas or even in solid form. - la - Suitable solvents are mono- or poly-bydroxylated alcohols containing from 1 to 4 C atoms, water, dioxane, tetrahydrofurane, ^ methylisobutylketone, Ν,Ν' dimeth lformamide.

The reaction temperatures are comprised between 10° and 80°C , o but the most favourable range is 3 -40 C.

The reaction times vary from 20 minutes to 240 minutes.

The product is isolated by means of precipitation from the same solvent in which its formation takes place, or it can be precipitated with a second solvent in which it is insoluble, or it can be obtained by freeze-drying.

The product can be utilized as is or in the form of one of its pharmaceutically acceptable soluble salts of organic or Inorganic acids or in the form of one of its pharmaceutically acceptable soluble mono- or poly-valent salts.

While the invention will now be described in connection with certain preferred embodiments in the following examples it will be understood that these examples are illustrative and not restrictive and that e.g., equivalent salts other than those exemplified can also readily be produced and used.

Example 1 At 65°C, 4.44 g of doxyoycllne anhydrous base was dissolved under agitation in 140 ml of absolute ethanol. o At 35 C, addition was made of 1 .5 g of methionine dissolved with 1 .2 ml of 3 # NaOH and 1 .1 ml of 3 # formic aldehyde.

The agitation was continued for 30 minutes at 35°C and for a further o 30 minutes at 3 C, filtration was performed on the product obtained and washing performed with ethanol. o After vacuum drying at 40 C, there was obtained 4.85 g of product o in the form of a light yellow powder, m.p. 208 C.

The pH of a 5% aqueous solution was 7»! .

The solubility of the product was more than 1 g per ml „ Compositions Co0H N 0 S (mol. wt „ 605 - 6) , 2o 3 5 3 10 Calculated values s Cs 55*5%; Hs 5o%%; 0% 26*4%; Ss 5 .3 ; N's 7.0%, Values founds Cs 54 ° 6$ ; Hs 5.9%; Os 27 · 156 Ss 5. 456; s 6 . 5$ » There are now given the results of a few pharmacological, chemical and chemotherapeutic tests in order to illustrate the principal properties and characteristics of the product of the Example I„ A) - The product is soluble in water at pH values close to neutrality; 1 g of derivative will dissolve in 0 <, 7 ml of water „ B) - The stability of the product in aqueous solution is equal or superior to that of doxycycline in analogous conditions. This is confirmed by the spectrophotometric tests „ C) The Minimal Inhibitory Concentration (MIC) of the compound of the Example I, as compared with that of doxycycline, in respect of standard bacterial strains as listed hereunder demonstrates that, the content of doxycycline being equal, the activity of the derivative is almost identical _ M„I-C, • Compound Doxycycline of Ex „ I aureus 209P 0.2 0.25 s. aureus 171G 0.05 0.07 s. pyrogenes ATCC 8663 0,05 O.O7 s. fa ecalis ATCC 8043 Ο.25 0,35 B, a culans ATCC 9961 0,05 O.04 B, subtilis ATCC 6633 0.05 O.04 S. lutea ATCC 10054 0,05 O.07 D. pneumoniae 0,01 0,02 E. coli 11.3-3 1.5 2,0 E. coli 266 0.75 1.0 E, coli ATCC 8739 2,0 2.75 E. coli ATCC 10530 1.25 1.75 K. pneumoniae 132 1.5 2,25 P. vulgaris ATCC 9920 >50 50 P. ettgerii ATCC 9250 1.75 2.5 P. mirabilis ATCC 9921 9> 100 100 D) - Chemotherapeutic activity of the compound of the Example I expressed as mi°e infected with various bacterial strains.

Compound of Doxy- Infection ' Route (a) Dose (b) S. aureus (d) oral S. intravenous S, 7.11 78.6 subcutaneous M, 1,67 16.2 2,21 S, pyrogenes 8668 oral S. 7.55 - 5.74 S. pyrogenes 8668 intravenous S, 5.41 71.6 S, pyrogenes (d) oral S. 0,64 - 0.51 intravenous S, 0.47 73.3 Infection Route (a) Dos PD50 Doxy- \ mg/kg cycline Eo.coli 266 oral 52 o l 38.Ο intravenous 36. 7 70.4 E, coli (d) oral 20,4 16 , 2 intravenous 14.6 71 = 5 K, pneumoniae subcutaneous 1 .32 intravenous l o03 78.Ο a) = Route of administrations oral, intravenous, subcutaneous b) = Doses s single (S) or multiple (M) c) = decrease in percentage of oral PD, 50 d) = Strains of clinical origin e) = Decrease in percentage of subcutaneous PD( 50 E) - The blood level of the product of the Example I in mice, rats and rabbits after a single oral dose of 12.5 mg/kg is equal or superior, in the various time intervals, to the blood level of doxycycline in the same conditions „ F) - Acute toxicity (LD^) of the compound of the Example 1 in mice and rats „ Data compared with data for Doxycycline (in brackets) Animal species Route LD mg/kg Mouse oral 2000* ( -» 2000)* intravenous 394 ( 257) 67Ο ( 425) Rat oral 3000·* (ss-3000)* 582 (370) *) Tests limited to a maximum dose of 2.0 g/kg or 3 -0 g/kg, thereafter suspended inasmuch as not of great significance „ The following are some specific Examples of the preparation of formulations suitable for pharmaceutical use.

Example II Injectable preparation, ISO mg, of the compound prepared in the Example I, equivalent to 100 mg of doxycycline base, are admixed with 20 mg of solid NaCl, From this mixture a $% dextrose solution for slow intravenous perfusion is prepared.

Example III Capsules for oral administration Compound of Example I 150 mg Mg stea ate 3 mg Lactose 50 Talc 5 mg Corn starch, q„s, to 300 mg .

Example IV Powder for extemporaneous solution for oral administration.

Compound of Example I 1.5 g (equivalent to 1,0 g of doxycycline base) Na benzoate 0„06 g Na carboxymethyl cellulose 0.l6 g Sugar 35 g Strawberry spirit 0,05 g Colorant E 127 0.005 g.

Claims (8)

1. 45741/2 A novel antibiotic product having the general formula: its pharmaceutically acceptable soluble salts of organic or inorganic acids and ite pharmaceutically acceptable soluble mono- or poly-valent metal salts. ' . . ( ■

2. A process for the preparation of the product of claim 1 , wherein doxycycllne is placed into contact with an equimolecular quantity of methionine in the presence of formaldehyde in a polar solvent at .a o temperature of 10 to 80 C. J.

3. Process according to claim 2, characterized by that the polar solvent is selected in the group consisting of mono or polyhydroxylated alcohols containing from 1 to

4. C atoms, water, dioxane, tetrahydrofurane, methyl-isobutylketone and Ν,Ν' dimethylformamide. 4..: . Process according to. claim 2, characterized by that, the reaction o o temperature is comprised between 30 C and 40 C.

5. Process according to claim 2, characterized in that the reaction times are comprised between 20 minutes and 240 minutes, preferably between 30 and 120 minutes. 45741/2

6. Process for the preparation of a water soluble derivative of doxycycline according to the Example 1.

7. Novel antibiotic product according to claim 1 , associated with a therapeutically acceptable vehicle according to the Example 2, 3 and 4·

8. Novel antibiotic product according to claim 1 in water soluble form adapted for oral, intravenous, parenteral administration. Attorney for Applicants - 8 -