Aqueous-based metronidazole gel formulations

1. An intravaginal aqueous based gel composition comprising:

a) metronidazole in a concentration of about 1.3% to about 1.5% by weight of the aqueous based gel composition;

b) about 1% to about 3% by weight of the aqueous based gel composition of one or more mucoadhesive gelling polymers;

c) about 30% to about 60% of water by weight of the aqueous based gel composition; and

d) a ternary solvent system in a concentration of about 30% to about 60% by weight of the aqueous based gel composition, wherein the ternary solvent system comprises:

i) one or more lower aromatic alcohols selected from the group consisting of benzyl alcohol, 2-methylbenzyl alcohol, phenoxyethanol, and mixtures thereof;

ii) one or more lower alkylene diols selected from the group consisting of ethane-1,2-diol (ethylene glycol), propane-1,2-diol (propylene glycol), and mixtures thereof; and

iii) one or more polyoxyalkylenes selected from the group consisting of polyoxyethylene (polyethylene glycol), polyoxypropylene, (polypropylene glycol) and mixtures thereof;

said aqueous based gel composition exhibiting a viscosity ranging from about 200,000 mPa·s to about 400,000 mPa·s, measured at 25° C. using the controlled shear rate method, a Bohlin CVO 100 rheometer and the rheometer settings of Table 11 and having an aqueous phase with a pH ranging from about 3.0 to about 5.0.

2. The gel composition of claim 1 wherein the one or more mucoadhesive gelling polymers are selected from the group consisting of hydroxyethylcellulose, a carbomer, a polycarbophil, and mixtures thereof.

3. A method of treating a subject with bacterial vaginosis, comprising applying intravaginally to the subject a single administration of the aqueous-based gel composition of claim 1 .

4. A method of treating a subject with bacterial vaginosis, comprising administering intravaginally to the subject a single dose aqueous based metronidazole gel composition wherein the single dose aqueous based metronidazole gel composition is administered once a day for one, two or three days, and the single dose aqueous based metronidazole gel composition comprises:

i) 60-70 mg of metronidazole in a concentration of about 1.3% to about 1.5% by weight of the aqueous based metronidazole gel composition;

ii) about 30% to about 60% of water by weight of the single dose aqueous based metronidazole gel composition;

iii) about 1% to about 3% by weight of the single dose aqueous based metronidazole gel composition of at least one mucoadhesive gelling polymer; and

iv) about 30% to about 60% of a ternary solvent system by weight of the single dose aqueous based metronidazole gel composition, the ternary solvent system comprising:

1) one or more lower aromatic alcohols selected from the group consisting of benzyl alcohol, 2-methylbenzyl alcohol, phenoxyethanol, and mixtures thereof;

2) one or more lower alkylene diols selected from the group consisting of ethane-1,2-diol (ethylene glycol), propane-1,2-diol (propylene glycol), and mixtures thereof; and

3) one or more polyoxyalkylenes selected from the group consisting of polyoxyethylene (polyethylene glycol), polyoxypropylene, (polypropylene glycol) and mixtures thereof;

wherein the single dose aqueous based metronidazole gel exhibits:

a) a pH ranging from about 3.0 to about 5.0; and

b) a viscosity of about 200,000 mPa·s to about 400,000 mPa·s at 25° C. using a controlled shear rate ramp method, a Bohlin CVO 100 rheometer and the rheometer settings of Table 11.

5. The method of claim 4 wherein the one or more mucoadhesive gelling polymers are selected from the group consisting of hydroxyethylcellulose, a carbomer, a polycarbophil, and mixtures thereof.

6. The intravaginal aqueous based gel composition of claim 1 wherein the one or more lower aromatic alcohols comprises about 1% to about 5% of weight of the ternary solvent system.

7. The method of claim 4 wherein the one or more lower aromatic alcohols comprises about 1% to about 5% by weight of the ternary solvent system.

8. An intravaginal aqueous based gel composition comprising:

a) metronidazole in a concentration of about 1.3% to about 1.5% by weight of the aqueous based gel composition;

b) about 1% to about 3% by weight of the aqueous based gel composition of one or more mucoadhesive gelling polymers selected from the group consisting of hydroxyethylcellulose, a polycarbophil, and mixtures thereof;

c) about 30% to about 60% of water by weight of the aqueous based gel composition; and

d) a ternary solvent system in a concentration of about 30% to about 60% by weight of the aqueous based gel composition, wherein the ternary solvent system consists of:

i) about 1.3% to about 2.5% by weight of the aqueous based gel composition of one or more lower aromatic alcohols selected from the group consisting of benzyl alcohol, 2-methylbenzyl alcohol, phenoxyethanol, and mixtures thereof;

ii) about 3% to about 20% by weight of the aqueous based gel composition of one or more lower alkylene diols selected from the group consisting of ethane-1,2-diol (ethylene glycol), propane-1,2-diol (propylene glycol), and mixtures thereof; and

iii) about 10% to about 50% by weight of the aqueous based gel composition of one or more polyoxyalkylenes selected from the group consisting of polyoxyethylene (polyethylene glycol), polyoxypropylene, (polypropylene glycol) and mixtures thereof;

said aqueous based gel composition exhibiting a viscosity ranging from about 200,000 mPa·s to about 400,000 mPa·s, measured at 25° C. using a controlled shear rate method, a Bohlin CVO 100 rheometer and the rheometer settings of Table 11 and having an aqueous phase with a pH ranging from about 3.0 to about 5.0.

9. The intravaginal aqueous based gel composition of claim 8 wherein the one or more mucoadhesive gelling polymers is a polycarbophil and the ternary solvent system consists of:

i) about 1.3% to about 2.5% by weight of the aqueous based gel composition of benzyl alcohol;

ii) about 3% to about 20% by weight of the aqueous based gel composition of propylene glycol; and

iii) about 10% to about 50% by weight of the aqueous based gel composition of polyethylene glycol.