MXPA01006176A - Bis-amido polybiguanides and the use thereof to disinfect contact lenses and preserve pharmaceutical compositions - Google Patents

Abstract

Bis-amido polybiguanides and their use as antimicrobial agents in pharmaceutical compositions are disclosed. A method of synthesis of bis-amido polybiguanides is also disclosed. The bis-amido polybiguanides are useful in the preservation of pharmaceutical compositions, particularly ophthalmic and otic pharmaceutical compositions and compositions for treating contact lenses. The compounds are especially useful for disinfecting/cleaning contact lenses.

Description

BIS-AMIDOPOLIBIGUANIPAS AND THE USE OF THEM TO DISINFECT CONTACT LENSES AND PRESERVE PHARMACEUTICAL COMPOSITIONS BACKGROUND OF THE INVENTION The present invention relates to novel polymeric biguanides having potent antimicrobial activity and little, if any, toxicity relative to human tissues. The amidopolybiguanides described herein have many industrial applications, but are especially useful as antimicrobial preservatives in pharmaceutical compositions. The invention particularly relates to the use of these compounds in compositions and methods for disinfecting contact lenses, and to the preservation of different types of ophthalmic products. Contact lenses are exposed to a broad spectrum of microbes during normal use and get dirty relatively quickly. Therefore, routine cleaning and disinfection of the lenses is required. Although the frequency of cleaning and disinfection may vary slightly between different types of lenses and regulations for lens care, daily cleaning and disinfection is usually required. The lack of cleaning and disinfecting the lenses properly can lead to a variety of problems ranging from simple discomfort when the lenses are used to serious eye infections. Eye infections caused by particularly virulent microbes, such as Pseudomonas aeruginosa, can lead to the loss of the infected eye (s) if it is left untreated, or if it is allowed to reach an advanced stage before it is start the treatment. Therefore, it is extremely important that patients disinfect their contact lenses according to the treatment prescribed by their optometrist or ophthalmologist. Unfortunately, patients often do not follow the prescribed treatments. Many patients find the treatments difficult to understand and / or complicated, and as a result they do not comply with one or more aspects of the treatment. Other patients may have a negative experience with the treatment, such as ocular discomfort attributable to the disinfecting agent, and as a result they do not routinely disinfect their lenses or otherwise deviate from the prescribed treatment. In any case, the risk of eye infections is aggravated. Despite the availability of different types of contact lens disinfection systems, such as heat, hydrogen peroxide, and other chemical agents, there is still a need for improved systems which: 1) are easy to use, 2) are active potent antimicrobial, and 3) are non-toxic (ie, do not cause eye irritation as a result of binding to the lens material). Conventional contact lens cleaners with potent antimicrobial activity also have rather high toxicity. Therefore, there is a particular need in the fields of disinfection of contact lenses and preservation of ophthalmic composition, of safe and effective chemical agents with high antimicrobial activity and low toxicity. The use of polymeric biguanide compounds as disinfecting agents is known. The commercially available polybiguanides are hexamethylene biguanide polymers having end groups consisting of a cyanoguanidine group and an amino group, respectively. The widely used polybiguanide Cosmocil CQ (polyhexamethylene biguanide or "PHMB") has strong antimicrobial activity, but also high toxicity. A primary objective of the present invention is to provide polymeric biguanides that retain the antimicrobial activity compared to PHMB, but which are less toxic to human tissue than PHMB. As explained below, this objective has been achieved by means of a unique modification of the terminal amino groups of PHMB. The present invention relates to the satisfaction of the aforementioned needs and objectives.

BRIEF DESCRIPTION OF THE INVENTION The present invention relates to polybiguanides having an amido portion in the terminal groups. These compounds have antimicrobial activity compared to PHMB, but are generally less toxic than PHMB. The invention also relates to contact lens disinfectant compositions which contain the subject compounds, and to different ophthalmic compositions (eg, pharmaceuticals, artificial tears and resting drops) and other types of pharmaceutical compositions containing the compounds for the purposes of preserve the compositions against microbial contamination. Modification of the bis-amino portions of known polybiguanides to bis-amido moieties containing the substituents described herein results in good antimicrobial activity and reduced toxicity over the prior art compounds. In addition, the addition of specific substituents to the PHMB polymer changes its physicochemical and biochemical properties to provide a compound whose toxicity profile is lower than that of PHMB, and maintains the antimicrobial activity of PHMB. As discussed above, Cosmocil CQ is a widely used, commercially available polyhexamethylene biguanide biguanide ("PHMB") disinfectant containing a terminal amino group. PHMB has strong antimicrobial activity, but instead, high toxicity. A key difference between the compounds of the present invention and conventional PHMB is the modification of the two terminal amino groups of PHMB to form bis-amido groups. This modification has resulted in the production of a new class of compounds that have properties that are superior to those of PHMB. This invention also involves a modification of the PHMB polymer to include other substituents that change their physical, chemical and biochemical properties to provide compounds whose toxicity profiles are inferior to those of PHMB, while maintaining the potent antimicrobial activity of PHMB.

DESCRIPTION OF THE PREFERRED MODALITY The compounds of the present invention are polybiguanides in which the end groups are amido portions. The compounds have the following formula: RC (= O) NH-X- [NHC (= NH) NHC (= NH) NH-X-] nNHC (= 0) R (I) wherein: n is an integer in the scale from 1 to 100; X is alkyl, saturated or unsaturated cycloalkyl, alkyl substituted with cycloalkyl, aryl, or aralkyl, with the proviso that the X groups contain from 1 to 40 carbon atoms (Ci to C o) and are substituted or unsubstituted with any number of N, O, S, P, B, F, Cl, Br, or I; and R is a saturated or unsaturated alkyl (Ci to C50), cycloalkyl (C3 to C5o), alkyl substituted with cycloalkyl, polyethylene oxide having a molecular weight of 50 to 10,000 (MW 50-10,000), polypropylene oxide which has a molecular weight of 50 to 10,000 (MW 50-10,000), any combination of the above groups, unsubstituted aralkyl, aralkyl substituted with any number of N, O, S, P, B, F, Cl, Br, or I , unsubstituted aryl, or aryl substituted with any number of N, O, S, P, B, F, Cl, Br, or I.

The substituent R in compounds of formula I optionally includes amide, urea or other functional groups of covalent bond. As used herein, the term "alkyl" includes straight or branched chain hydrocarbon groups. The alkyl groups may be substituted with other groups, such as halogen, hydroxyl or alkoxy. Preferred compounds are those in which n is 4 to 16, X is alkyl or aralkyl and R is polyethylene oxide (P.M. 100 to 2,000) or alkyl ether of polyethylene oxide (P.M. 100 to 2,000). The following compounds are particularly preferred: Compound n X R A 10 hexamethylene Alkyl chain of C? 3H2 B 18 hexamethylene Succinimidyl methyl ether of polyethylene oxide (P.M. 550) C 13 hexamethylene C12H25 (OCH2CH2) 10NHC (= O) CH2CH23 (RLM-100) Compound B is the most preferred. The synthesis of the bis-amido polybiguanide compounds of formula I is illustrated in Scheme I below:SCHEME 1 General synthesis of Bis-amidopolibiguanides Na + 2 HCl H2N- -X-NH.

OR R ONHS H H H H H wherein n, X and R are as defined above. The synthesis is carried out by reacting a diamine (II) of the formula NH2-X-NH2 with sodium dicyanamide to produce a cyanoguanidine (III) of the formula NCNHC (= NH) NH-X-NHC (= NH) NHCN.

The resulting cyanoguanidine reacts with the same diamine (II) to produce a bis-aminopolibiguanide (IV) of the formula: NH2- [X-NHC (= NH) NHC (= NH) NH] n-X-NH2. The bis-amidopolyguiguanide (I) is obtained by reacting the bis-aminopolibiguanide (IV) with an activated ester (V) of the formula: RC (= 0) ONHS, where NHS can be N-hydroxysuccinimide or another activation group . The general synthesis of bis-aminopolibiguanide (IV) is carried out by reacting a compound of a, β-diamino-2HCl (II) with sodium dicyanamide in a suitable solvent, preferably n-butanol at 140 ° C for 5 hours. The resulting dicyanoguanidine compound (II!) Is then reacted with a slight excess (1.2-1.5 molar ratio) of an α, β-diamino 2 HCI compound at 160 ° C for 3-6 hours to obtain a polymeric biguanide compound (IV) ending at both ends with terminal amino groups. The synthesis of bis-aminopolibiguanide (IV) is further demonstrated by the procedures described in Example 1 below. The synthesis of the activated ester (V) is further explained in scheme 2 and scheme 3 below.

SCHEME 2 General synthesis of esters of N-hydroxysuccinimide THF at room temperature 4-16 hrs.

In general, the N-hydroxysuccinimide esters are synthesized by the reaction of the suitable carboxylic acid-containing compound with N-hydroxysuccinimide in the presence of dicyclohexylcarbodiimide or other suitable carbodiimide compound in THF or other suitable solvent at ambient temperatures for 3-16 hours under a dry atmosphere such as argon or nitrogen. The compounds of the present invention wherein R is a polyethylene oxide can be prepared by the method illustrated in Scheme 3 below: SCHEME 3 Reaction reaction for succinimidyl succinate of PEO PM 550 (compound 5) Compound 3 gpmpuestp 2 succinic anhydride diisopropylethylamine chloroform, reflux, 4 hrs.

Compound 4 Synthesis of compound 1 50 ml of a chloroform solution of 11.0 g (0.02 mole) of poly (ethylene glycol) methyl ether (polyethylene oxide, PEO) PM 550 (Aldrich lot # 05022ET) and 1.6 g (0.02 mole) of pyridine was added dropwise under an N2 atmosphere to 75 ml of a chloroform solution of 3.09 g (0.026 mole) of thionyl chloride. After addition, the reaction mixture was heated to reflux (70 ° C) under constant stirring for 2.5 hours. The organic layer was washed with 3 x 50 ml of aqueous sodium chloride and sodium carbonate followed by 2 x 60 ml of aqueous sodium chloride, dried (sodium sulfate), filtered and concentrated in vacuo to obtain 11.14 g (0.0196). moles, 98.0%) of compound 1. The structure was confirmed with NMR by observing the change in chemical shift from a methylene adjacent to the terminal hydroxyl group (3.69, t, 2H) to a methylene adjacent to the terminal chlorine group (d 3.77, t , 2H).

Synthesis of compound 2 2.85 g (0.005 mole) of compound 1 and 1.21 g (0.0065 mole) of potassium phthalimide were mixed in 10 ml of dimethylformamide (D F) and heated to 120 ° C under constant stirring for 4 hours. The DMF was removed in vacuo and the remaining residue was dissolved in 20 ml of chloroform, filtered and concentrated in vacuo to yield 3.4 g (0.005 mol, 100%) of compound 2. The structure was confirmed with NMR by observing the appearance of peaks. of aromatic phthalimide (d 7.70 and 7.85, m, 4H) and change in chemical displacement of a methylene adjacent to the terminal chlorine group (d 3.77, t, 2H) to a methylene adjacent to the terminal phthalamide group (d 3.90, t, 2H) .

Synthesis of compound 3 3.4 g (0.005 mole) of compound 2 and 1 g (0.011 mole) of hydrazine (35% w / w in water) were dissolved in 130 ml of ethanol and heated to reflux (80 ° C) overnight . The solution produced copious precipitation which was filtered after heating. The residue was dissolved in ethyl acetate and refrigerated overnight to induce precipitation of phthalhydrazide. The solution was filtered and redissolved in chloroform and refrigerated overnight. The solution was then filtered again and concentrated in vacuo to yield 2.08 g (0.0038 moles., 75.6%) of compound 3. The structure was confirmed with NMR by observing the disappearance of phthalimide peaks and appearance of a methylene adjacent to the terminal primary amine group (d 2.86, t, 2H).

Synthesis of compound 4. 7.75 g (0.014 mol) of compound 3, 1.75 g (0.0175 mol) of succinic anhydride and 2.59 g (0.02 mol) of N, N-diisopropylethylamine were dissolved in 100 ml of chloroform and heated to reflux (70 ° C). C) for 4 hours. The reaction mixture was then diluted to 150 ml and washed with 3x50 ml of aqueous sodium chloride and 1 N HCl followed by 2x50 ml of aqueous sodium chloride. Then the solution was dried (sodium sulfate), filtered and concentrated in vacuo to yield 7.11 g (0.011 mol, 78.2%) of compound 4. The structure was confirmed with NMR by observing the appearance of succinylmethylene groups (d 2.55 and 2.65, m, 4H) and change in chemical shift from a methylene adjacent to an amine (d 2.86, t, 2H) to a methylene adjacent to an amide (d 3.44, t, 2H).

Synthesis of compound 5 2.85 g (0.0044 mole) of compound 4 and 0.51 g (0.0044 mole) of N-hydroxysuccinimide were dissolved in 40 ml of tetrahydrofuran and stirred for 20 minutes. Then 0.91 g (0.0044 mole) of 1,3-dicyclohexylcarbodiimide (DCC) was added and the reaction mixture was stirred overnight. 8 drops of glacial acetic acid were added to convert the DCC residue to DCU (dicyclohexylurea). This was monitored by IR observing the disappearance of the diimide peak (2100 cm "1), then the mixture was concentrated in vacuo, dissolved in ethyl acetate (40 ml) and cooled to induce DCU crystallization. concentrated in vacuo to yield 3.28 g (0.0044 mol, 100%) of succinimidylsuccinimide methyl ether of PEO PM 550. The product was confirmed with NMR by observing the appearance of the N-hydroxysuccinimidamethylene groups (d 2.84, s, 4H) and shift in displacement of succinylmethylene groups (d 2.55 and 2.65, m, 4H) to succinimidylsuccinimidamethylene groups (d 2.99 and 2.61, t, 4H) The compounds of the present invention wherein R is a dodecyl ether of polyethylene oxide, can be prepared by of the same procedure described above in scheme 3, except that PEO 10 dodecyl ether is used instead of PEO PM 550 methyl ether. The compounds of the present invention display a strong activity profile. antimicrobiality, as discussed above, which is similar to unmodified polyhexamethylene biguanide ("PHMB"), but has significantly less toxicity than unmodified PHMB. 1 The compounds discussed herein may be used individually or in combination with other disinfectants or preservatives. The amount of each compound used will depend on the purpose of use, for example, disinfection of contact lenses or preservation of pharmaceutical products, and the absence or inclusion of other antimicrobial agents. The concentration determined to be necessary for the aforementioned purposes can be functionally described as "an effective amount to disinfect" and "an effective amount to conserve", or "effective amounts of microbiocidal form", or variations thereof. The concentrations used for disinfection will generally be in the range of about 0.00001 to about 0.01% by weight based on the total weight of the composition ("% by weight"). The concentrations used for preservation will generally be in the range of about 0.00001 to about 0.001% by weight. The compositions of the current inventions can be aqueous or non-aqueous, but will generally be aqueous. As will be appreciated by those skilled in the art, the compositions may contain a wide variety of ingredients, such as tonicity agents (e.g., sodium chloride or mannitol), surfactants (e.g., polyvinylpyrrolidone and polyoxyethylene / polyoxypropylene copolymers) , viscosity adjusting agents (for example, hydroxypropylmethylcellulose and other cellulose derivatives) and pH regulating agents (for example, borates, citrates, phosphates and carbonates). The ability of the compounds of the present invention to retain their antimicrobial activity in the presence of such agents is an important advantage of the present invention. The pharmaceutical compositions of the present invention will be formulated to be compatible with human tissues that will be treated with the compositions (e.g., tissues of the eye or ear), or contact lenses that will be treated. Formulations that meet these basic requirements are referred to herein as "pharmaceutically acceptable carriers" for the compounds of the present invention or, in the case of compositions for treating the eye or contact lenses, "ophthalmically acceptable carriers". As will be apparent to those skilled in the art, ophthalmic compositions that have the purpose of direct application to the eye will be formulated to have a pH and tonicity which are compatible with the eye. This will usually require a pH regulator to maintain the pH of the composition at or near physiological pH (i.e., 7.4) and may require a tonicity agent to bring the osmolality of the composition to a level at or about 280 to 320 milliosmoles per kilogram of water ("mOsm / kg) The formulation of compositions for disinfecting and / or cleaning contact bodies will involve similar considerations, as well as considerations regarding the physical effect of the compositions on contact lens materials and the potential of the contact lens. lens to join or absorb the components of the composition.

The disinfecting compositions for contact lenses of the present invention will preferably be formulated as aqueous solutions, but can also be formulated as non-aqueous solutions, as well as suspensions, gels, etc. The compositions may contain a variety of tonicity agents, surfactants, viscosity adjusting agents, and pH regulating agents, as described above. The compositions described above can be used to disinfect contact lenses according to procedures known to those skilled in the art. More specifically, the lenses will first be removed from the eyes of the patients, and then immersed in the compositions for a sufficient time to disinfect the lenses. Immersion will typically be done by immersing the lenses in a solution overnight (ie, approximately 6 to 8 hours). The lenses will then be rinsed and placed in the eye. Before immersion in the disinfectant compositions, preferably the lenses will also be cleaned and rinsed. The compositions and methods of the present invention can be used in conjunction with different types of contact lenses, including both generally classified as "hard" lenses, and lenses generally classified as "soft" lenses. The compounds of the present invention can also be included in different types of pharmaceutical compositions as preservatives, to avoid microbial contamination of the compositions.

The types of compositions which can be preserved by the compounds of the present invention include: ophthalmic pharmaceutical compositions, such as topical compositions used in the treatment of glaucoma, infections, allergies or inflammation; otic pharmaceutical compositions, such as topical compositions gradually introduced into the ear for treatment of inflammation or infection; compositions for treating contact lenses, such as disinfectant solutions, cleaning products and products for improving the ocular comfort of patients wearing contact lenses; other types of ophthalmic compositions, such as ocular lubricant products, artificial tears, astringents, etc; dermatological compositions, such as anti-inflammatory compositions, as well as shampoos and other cosmetic compositions; and other different types of pharmaceutical compositions. The present invention is not limited with respect to the types of ophthalmic compositions in which the compounds of the present invention can be used as preservatives. The following examples are presented to further illustrate different aspects of the present invention.

EXAMPLE 1 Synthesis of bis-amino polvhexamethylene biguanide . 0 g (0.132 mol) of 1,6-hexamethylenediamine 2HCl (Aldrich batch # 03625BT) and 25.9 g (0.291 mol) of sodium dicyanamide (Aldrich 02811 HZ) were mixed with 200 ml of n-butanol and heated to 145 ° C. under constant stirring for 5 hours. The organic layer was concentrated in vacuo and 150 ml of 1 N HCl was added to the precipitate and stirred. The solution was filtered and washed with 3x100 ml of water to remove excess HCl to yield 26.01 g (0.104 moles, 78.8%) of 1,6-hexamethylenedium guanidine. The structure was confirmed with NMR observing the chemical shift of the methylene group exchange adjacent to the amine (d 2.9, 4H) in the methylene group adjacent to the cyanoguanidine (3.0, 4H). 1.0 g (0.0053 mmol) of 1,6-hexamethylenediamine 2 HCl and 1.1 g (0.0044 mol) of 1,6-hexamethylenediuceroguanidine were added to a 3-necked flask and heated for 3.5 hours at 160 ° C with constant stirring under argon. 0.25 ml of water was added to aid agitation. IR did not indicate nitric peak (2160 cm "1) after the reaction.The solvent was removed in vacuo and the compound was dissolved in 4 ml of water and precipitated with isopropanol to remove excess diamine.The supernatant layer was decanted, and the precipitate was dissolved in water (5 ml) and concentrated in vacuo until the remaining isopropanol was removed. It was then redissolved in water and lyophilized to yield 1.23 g (0.0006 mol, 59%) of bis-amine polyhexamethylenebiguanide (bis-NH2 PHMB) with an average of 8-9 biguanide repeating units. The structure was confirmed with NMR and elemental analysis. The number of biguanide repeating units was determined with NMR by comparing the integration peaks between the methylene groups adjacent to the biguanide units and the methylene groups adjacent to the terminal amine groups. Elemental analysis calculated for C74H? 7? N4 .5C o.5 (MW 2056.73, 8-9 repeat units): C, 43.21; H, 8.38; N, 30.31; Cl, 18.10 Found C, 43.01; H, 8.37; N, 29.90; Cl, 17.96. 1 H NMR (200 MHz, D 2 O): 3.15 (t, 34 H, CH 2 NHC (= NH) NHC (= NH) NHCH 2), 2.95 (t, 4 H), NH 2 CH 2), 1.52 (broad peak, 34 H, NHC (= NH). NHCH2CIH2), 1.32 (broad peak, 34H, NHC (= NH) NHCH2CH2CJH2).

EXAMPLE 2 Synthesis of compound B 0. 50 g (0.24 mmoles) of bis-amino polyhexamethylene biguanide with an average of 8-9 repeating units and 0.18 g (1.4 mmoles) of diisopropylethylamine were dissolved in 2.5 ml of dimethyl sulfoxide (DMSO) and stirred for 30 minutes at room temperature. environment under an argon atmosphere. Then 0.46 (0.62 mmol) of PEO PM 550 succinimidylsuccinatomonomethyl ether in 1 ml of DMSO was added and the reaction mixture was stirred overnight. The reaction was precipitated with acetone. The precipitate was dissolved in 1 ml of methanol and precipitated with acetone. This was repeated twice to remove all the remaining PEO starting material. The compound was then dissolved in water, concentrated in vacuo to remove the remaining acetone, redissolved in 5 ml of water and lyophilized to obtain 0.42 g of AL-12336A (18 units of biguanide repeat). NMR and elemental analysis confirmed the structure. The number of repeating units was determined with NMR by comparison of integration peaks of the methylene groups adjacent to the biguanide units and the PEO methylene groups. Elemental analysis helped confirm this discovery. Elemental analysis calculated for C2o8H45oN9 Cl? 8028 + 3 CH3OH (MW 5450.75): C, 46.49; H, 8.54; N, 24.16; Cl, 11.71. Found C, 47.05; H, 8.33; N, 24.26; Cl, 11.55. 1 H NMR (200 MHz, D 2 O): 3.66 (broad peak, 96H, OCI ^ CÜO), 3.3 (s, 6H, CH 3 O and CH 3 OH), 3.1 (t, 76H, and ChÍ2NHC (= 0)); 2.5 (t, 8H, C (= O) CH2CH2C (= O)), 1.5 (broad peak, 72H, NHC (= NH) NHCH2CH2), 1.3 (broad peak, 72H, NHC (= NH) NHCH2CH2CH2).

EXAMPLE 3 Synthesis of compound A 0. 5 g (0.00029 mole) of bis-NH2PHMB (7 repeat units) and 0.18 g (0.0014 mole) of diisopropylethylamine were dissolved in 2.5 ml of DMSO and stirred for 30 minutes. Then 0.21 g (0.00064 moles) NHS of myristic acid ester (synthesized by coupling myristic acid with N-hydroxysuccinimide in the presence of DCC) was added and the reaction mixture was stirred overnight. Then the reaction mixture was precipitated with acetone and the acetone layer was decanted. The precipitate was dissolved in 2 ml of water and 0.5 ml of methanol (necessary to dissolve the precipitate) and precipitated with acetone. This precipitation procedure was repeated two more times using 1.5 ml of water each time. Then the supernatant was removed, water was added and the compound was concentrated in vacuo to remove the remaining acetone and methanol. It was then redissolved in water and lyophilized overnight to yield 0.3 g (0.00011 mol, 50%) AL-12345A containing 10 biguanide repeating units. The structure was confirmed with NMR and elemental analysis. The number of biguanide repeating units was determined with NMR by comparing the integration peaks of the methylene groups adjacent to the biguanide units and the terminal methyl groups on the alkyl chain substituents. Elemental analysis calculated for C114H248N52CI10O2 + 2.5 H2O (PM 2779.14, 10 repetition units): C, 49.27; H, 9.18; N, 26.21; Cl, 12.76 Found C, 49.32; H, 8.94; N, 26.64; Cl, 12.26. 1 H NMR (200 MHz, D 2 O): 3.14 (broad t, 40 H, CH 2 NHC (= NH) NHC (= NHCH 2), 2.2 (t, 4 H, CIH 2 C (= O) NH), 1.50 (broad peak, 40H, NHC (= NH) NHCH2CjH2), 1.30 (broad peak, 40H, NHC (= NH) NHCH2CH2Cid2), 1.22 (broad s, 22H, CHs ± n), 0.8 (t, 6H, CHJÍCHJ H).

EXAMPLE 4 Synthesis of compound C 0. 40 g (0.00016 mole) of bis-NH2 PHMB (11 units of biguanide repeat) and 0.10 g (0.00077 mole) of diisopropylethylamine were dissolved in 20 ml of DMSO and stirred under argon atmosphere for 30 minutes. Then 0.42 g (0.00051 mole) of succinimidylsilycinatedodecyl ether of PEO 10 was added and the reaction mixture was stirred for 3 hours. 0.10 g (0.00012 mole) of additional PEO 10 succinimidylsuccinatododecyl ether was added and the reaction mixture was stirred overnight. The DMSO was removed in vacuo and acetone was added to the residue to remove excess succinate. Then the residue was dissolved in 1 ml of water and then acetone was used to precipitate the compound. The material was dissolved in water and concentrated in vacuo in order to remove the remaining acetone. The compound was then dried to yield 0.4 g (0.00009 moles, 57%) AL-12572A (13 units of biguanide repeat). The structure was confirmed by NMR and elemental analysis. The number of biguanide repeating units was determined with NMR by comparison of the methylene groups of the repeating units of polyethylene oxide and the methylene groups adjacent to the biguanide units. Elemental analysis calculated for Ci82H388N69? 24 (MW 4388.42, 13 repeat units): C, 49.81; H 8.91; N, 22.02; Cl, 10.50 Found C, 50.12; H, 8.76; N, 22.16; Cl, 11.05. 1H NMR (200 MHz, D2O): 3.69 (broad s, 80H, OCH2CH2O), 3.09 (broad, t, 52H, CM2NHC (= NH) NHC (= NH) NHCjH2l 2.5 (broad s, 8H, C (= 0) CiH2CH2C (= 0) NH), 1.56 (broad peak, 52H, NHC (= NH) NHCH2CH2), 1.36 (broad peak, 52H, 1.26 (broad peak, 40H, CH3 (CH2) 1oCH2O), 0.9 (t, 6H, CH ^ CH ^ -,).

EXAMPLE 5 The following formulation is provided to further illustrate the compositions of the present invention, particularly compositions used to disinfect contact lenses.

Amount (% by weight) Inherent Compound 0.00001 to 0.01 Boric acid 0.58 Sodium borate 0.18 Sodium chloride 0.49 Sodium edetate 0.05 NaOH / HCl q.s. pH 7.0 In this formulation, the term "compound" refers to any of the compounds of the present invention, particularly those of the formula (I) above.

EXAMPLE 6 The antimicrobial activity of the compounds of the present invention is demonstrated by the microbiological data provided in the table below. Three compounds of the present invention (ie, Compound A, Compound B and Compound C) were tested at concentrations of 0.0005% by weight. The compounds were tested using water or the formulation of Example 5 as the carrier for the compounds. (The formulation of Example 5 is referred to in the table below as "FID 84509"). After the box, a description of the testing procedures is provided. a The underlined number indicates that no survivors were recovered (< 10 CFU / mL).

The bacteria Serratia marcescens ATCC 13880 and Staphylococcus aureus ATCC 6538 were grown in inclined tubes of agar for soybean casein digestion (SCDA). The yeast Candida albicans ATCC 10231 was grown in inclined tubes of Sabouraud Dextrose Agar. Surface growth of the three microorganisms was cultured with phosphate buffered saline containing Polysorbate 80. The microbial suspensions were spectrophotometrically adjusted to a concentration of approximately 1.0 x 108 colony forming units / mL (CFU / mL). The test compounds were separated into target concentrations in selected vehicles. Ten mL of test solution was inoculated with 0.1 mL of the appropriate microbial suspension so that the test solution contained approximately 1.0 x 10 6 CFU / mL. The tubes were thoroughly mixed and kept at room temperature during the test. At six and 24 hours after the inoculation of test solution, an aliquot of 1.0 mL of each test sample was transferred for each attack organism to 9.0 mL of Dey Engley Neutralizing Broth preforms. The samples were serially diluted in the neutralizing broth and flow plates were prepared from suitable dilutions with neutralizers containing SCDA. Petri dishes were incubated for 48-72 hours and the number of survivors visible as separate colony forming units was determined according to standard microbiological methods. The invention has been described as reference to certain preferred embodiments; however, it will be understood that it can be modalized in other forms or specific variations of the same without departing from its spirit or essential characteristics. Therefore, the modalities described above are considered illustrative in all respects and not restrictive, indicating the scope of the invention through the appended claims, rather than the foregoing description.

Claims (1)

NOVELTY OF THE INVENTION CLAIMS 1. A compound comprising a bis-amido polybiguanide wherein a first terminal group is an amido moiety and a second terminal moiety is an amido moiety. 2.- A compound of the following formula: RC (= O) NH-X- [NHC (= NH) NHC (= NH) NH-X-] nNHC (= O) R where: n is an integer in the scale from 1 to 100; X is alkyl, saturated or unsaturated cycloalkyl, alkyl substituted with cycloalkyl, aryl, or aralkyl, with the proviso that the X groups contain from 1 to 40 carbon atoms (Ci to C40) and are substituted or unsubstituted with any number of N, O, S, P, B, F, Cl, Br, or I; and R is a saturated or unsaturated alkyl (Ci to C50), cycloalkyl (C3 to C5u), alkyl substituted with cycloalkyl, polyethylene oxide having a molecular weight of 50 to 10,000, polypropylene oxide having a molecular weight of 50 to 10,000, any combination of the above groups, unsubstituted aralkyl, aralkyl substituted with any number of N, O, S, P, B, F, Cl, Br, or I, unsubstituted aryl, or aryl substituted with any number of N , O, S, P, B, F, Cl, Br, or I, optionally including one or more amide, urea or other functional groups of covalent bond. 3. The compound according to claim 2, further characterized in that R is polyethylene oxide. 4. - A pharmaceutical composition comprising an effective microbiocidal amount of the compound of claim 2. 5. An ophthalmic composition for disinfecting contact lenses, comprising: a compound of the following formula in an amount effective to disinfect contact lenses: RC (= O) NH-X- [NHC (= NH) NHC (= NH) NH-X-] nNHC (= 0) R where: n is an integer on the scale from 1 to 100; X is alkyl, saturated or unsaturated cycloalkyl, alkyl substituted with cycloalkyl, aryl, or aralkyl, with the proviso that the X groups contain from 1 to 40 carbon atoms (C-i to C40) and are substituted or unsubstituted with any number of N, O, S, P, B, F, Cl, Br, or I; and R is a saturated or unsaturated alkyl (Ci to C5o), cycloalkyl (C3 to C50), alkyl substituted with cycloalkyl, polyethylene oxide having a molecular weight of 50 to 10,000 (MW 50-10,000), polypropylene oxide having a molecular weight of 50 to 10,000 (MW 50-10,000), any combination of the above groups, unsubstituted aralkyl, aralkyl substituted with any number of N, O, S, P, B, F, Cl, Br, or I, unsubstituted aryl, or aryl substituted with any number of N, O, S, P, B, F, Cl, Br, or I, optionally including one or more amide, urea or other functional groups of covalent bond; and an ophthalmically acceptable vehicle for said compound. 6. A method for disinfecting a contact lens which comprises immersing the lens in the composition of claim 5 for a sufficient time to disinfect the lens.

1. - A method for protecting a pharmaceutical composition from microbial contamination which comprises including in the composition an effective amount of preservative of a compound of the following formula: RC (= 0) NH-X- [NHC (= NH) NHC (= NH ) NH-X-] nNHC (= O) R where: n is an integer on the scale from 1 to 100; X is alkyl, saturated or unsaturated cycloalkyl, alkyl substituted with cycloalkyl, aryl, or aralkyl, with the proviso that the X groups contain from 1 to 40 carbon atoms (Ci to C40) and are substituted or unsubstituted with any number of N, O, S, P, B, F, Cl, Br, or I; and R is a saturated or unsaturated alkyl (C1 to C50), cycloalkyl (C3 to C50), alkyl substituted with cycloalkyl, polyethylene oxide having a molecular weight of 50 to 10,000 (MW 50-10,000), polypropylene oxide which has a molecular weight of 50 to 10,000 (MW 50-10,000), any combination of the above groups, unsubstituted aralkyl, aralkyl substituted with any number of N, O, S, P, B, F, Cl, Br, or I , unsubstituted aryl, or aryl substituted with any number of N, O, S, P, B, F, Cl, Br, or I, optionally including one or more amide, urea or other functional groups of covalent bond. 8. The method according to claim 7, further characterized in that the composition is an ophthalmic pharmaceutical composition. 9. The method according to claim 7, further characterized in that the composition is an otic pharmaceutical composition.