CN114504550A - Eye gel containing metronidazole and preparation method thereof - Google Patents

Abstract

The invention discloses an ophthalmic gel containing metronidazole and a preparation method thereof. The ophthalmic gel comprises the following components: 0.5-1.5 parts of metronidazole, 1.0-5.0 parts of thickening agent, 0.8-1.2 parts of isotonic agent, 0.001-0.02 part of bacteriostatic agent, 0.001-0.005 part of pH regulator, 0.2-1.0 part of humectant, 0.2-1.0 part of seaweed extract and 90-110 parts of deionized water; the pH value of the ophthalmic gel is 6.5-8.0. Experiments show that the ophthalmic gel has good improvement effects on the mite-expelling treatment of ocular demodex infection and the treatment of acanthamoeba keratitis.

Description

Eye gel containing metronidazole and preparation method thereof

Technical Field

The invention relates to the field of pharmaceutical preparations, in particular to an ophthalmic gel containing metronidazole and a preparation method thereof.

Background

Demodex oculi can be classified into follicular demodex and sebaceous demodex, wherein follicular demodex mainly inhabits eyelash follicles, and sebaceous demodex mainly inhabits sebaceous glands and meibomian glands associated with eyelids. Researches report that the demodex infection rate of eye eyelashes microscopic examination is 11% -100%, and the demodex detection rate is positively correlated with age. Demodex has a strong correlation with blepharitis, and can also cause meibomian gland dysfunction, aragonima, blepharospermia-associated keratoconjunctivitis, pterygium and other common ocular surface diseases. With age, the incidence of meibomian gland dysfunction is increasing, and there are data indicating that demodex infestations are the major cause of disease in young and middle-aged patients under the age of 60 years, so demodex treatment is essential. Blepharitis is a common chronic inflammation of eyes, and is usually manifested by terminal duct obstruction, secondary bacterial reproduction, and stimulation of metabolites on the eyelid margin, resulting in abnormal eye membrane, inflammation of the ocular surface, dry eyes, foreign body sensation, redness of eyes and other symptoms.

Acanthamoeba is a free-living acanthamoeba widely present in natural environments such as soil, seawater, fresh water, putrefactive substances, etc., and Acanthamoeba Keratitis (AK) is an infectious keratopathy caused by acanthamoeba protozoa, and cases have been increasing year by year in recent years. Acanthamoeba keratitis is associated with wearing contact lenses, contact with contaminated water sources, and corneal trauma.

The treatment method aiming at the ocular infection caused by demodex and amebiasis comprises surgical treatment and drug treatment, and clinically common treatment modes of antibiotics and artificial tear drugs for dry eye caused by meibomian gland dysfunction can effectively eliminate infection, but have poor mite killing effect, can improve symptoms and have high recurrence rate. The tea tree oil can be used as an acaricide for treating eye diseases caused by demodex in a combined mode, but the price is high. Acanthamoeba keratitis lacks effective treatment drugs, and commercial anti-acanthamoeba drugs available in domestic markets are very limited, so that many acanthamoeba keratitis cannot be effectively treated to cause permanent visual function loss. The clinical application of the novel corneal collagen crosslinking treatment provides a new hope for curing acanthamoeba keratitis, but the cost of the operation treatment is high, great pain is brought, the compliance of part of patients is poor, and part of patients are not suitable for the operation treatment. Therefore, there is a need for an ophthalmic gel that is safe for treating ocular infections caused by mites and Acanthamoeba and that is highly effective and resistant to high temperatures.

Disclosure of Invention

Aiming at the defects in the prior art, the invention provides an ophthalmic gel containing metronidazole and a preparation method thereof.

The invention provides an ophthalmic gel containing metronidazole, which comprises the following components:

0.5-1.5 parts of metronidazole, 1.0-5.0 parts of thickening agent, 0.8-1.2 parts of isotonic agent, 0.001-0.02 part of bacteriostatic agent, 0.001-0.005 part of pH regulator, 0.2-1.0 part of humectant, 0.2-1.0 part of seaweed extract and 90-110 parts of deionized water; the pH value of the ophthalmic gel is 6.5-8.0.

Further, the metronidazole is 1 weight part.

Further, the ophthalmic gel has a pH of 7.0.

Further, the thickening agent is any one or more of carbomer, gelatin, hydrolyzed collagen, cellulose, xanthan gum and sodium alginate. Carbomers are preferred. Carbomer has remarkable maintenance effect, is a key raw material for preparing gel, and can diminish inflammation and sterilize.

Further, the isotonic agent is any one or more of sodium chloride, glucose and boric acid.

Further, the bacteriostatic agent is any one or more of thimerosal, benzalkonium bromide, benzalkonium chloride and paraben.

Further, the pH regulator is one or more of phosphoric acid, hydrochloric acid and sodium hydroxide.

Further, the humectant is any one or more of glycerol, lactic acid, 1, 2-hexanediol, caprylyl glycol, allantoin and sodium hyaluronate.

Further, the seaweed extract is a mixture of a kelp extract, a brown seaweed extract and a kelp extract. The seaweed has excellent moisturizing effect due to the rich seaweed polysaccharide and vitamin E; the seaweed extract adopted in the seaweed moisturizing and repairing gel is a fermentation mixture of various seaweeds, and the rich seaweed polysaccharide can effectively resist the invasion of external harmful substances and increase the efficacy of moisturizing and maintaining stability. The existing formula has strong irritation to eyes, and the addition of seaweed extract greatly reduces the irritation and adapts to special parts of eyes. In addition, the invention discovers that the high-temperature resistant storage of the ophthalmic gel is obviously acted after the seaweed extract is added.

The invention also provides a preparation method of the ophthalmic gel, which comprises the following steps:

s1: weighing the raw materials according to the weight part, dispersing the thickening agent in a proper amount of deionized water, stirring to fully swell, adding a pH regulator to regulate the pH to 6.5-8.0, sterilizing by a damp-heat sterilization method, and cooling to room temperature for later use;

s2: dissolving metronidazole in an appropriate amount of deionized water, adjusting pH to 6.5-8.0, adding thickener, isotonic agent, bacteriostatic agent, humectant and seaweed extract, stirring, mixing, filtering with filter membrane for sterilization, adding into the solution obtained in step S1, adding deionized water, stirring, and aseptically packaging to obtain the ophthalmic gel.

In summary, compared with the prior art, the invention achieves the following technical effects:

1. the metronidazole can be used for non-invasively treating and treating the ocular infection caused by the mites and the Acanthamoeba without operation, and has great treatment significance for patients who cannot be treated by the operation.

2. The ophthalmic gel is mild, non-irritating and capable of diminishing inflammation and sterilizing.

3. The ophthalmic gel has obvious effect on eye infection and high safety.

4. The ophthalmic gel provided by the invention is high-temperature-resistant to storage and is not easy to lose efficacy.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings needed to be used in the embodiments will be briefly described below, it should be understood that the following drawings only illustrate some embodiments of the present invention and therefore should not be considered as limiting the scope, and for those skilled in the art, other related drawings can be obtained according to the drawings without inventive efforts.

FIG. 1 shows the result of fluorescein staining of rabbit keratoconjunctiva before molding;

FIG. 2 shows the results of fluorescein staining of conjunctiva before administration;

FIG. 3 shows the results of the 2d keratoconjunctival fluorescein staining test;

FIG. 4 shows the results of 7d keratoconjunctival fluorescein staining test;

FIG. 5 shows the results of 10d keratoconjunctival fluorescein staining test.

Detailed Description

In order to make the technical solutions of the present invention better understood, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be obtained by a person skilled in the art without any inventive step based on the embodiments of the present invention, shall fall within the scope of protection of the present invention.

The preparation method of the ophthalmic gel comprises the following steps:

s1: weighing 0.5-1.5 parts by weight of metronidazole, 1.0-5.0 parts by weight of thickening agent, 0.8-1.2 parts by weight of isotonic agent, 0.001-0.02 part by weight of bacteriostatic agent, 0.001-0.005 part by weight of pH regulator, 0.2-1.0 part by weight of humectant, 0.2-1.0 part by weight of seaweed extract and 90-110 parts by weight of deionized water; wherein the seaweed extract is a mixture of a kelp extract, a brown algae extract and a kelp extract. Dispersing the thickening agent in a proper amount of deionized water, stirring to fully swell, adding a pH regulator to regulate the pH to 6.5-8.0, sterilizing by a damp-heat sterilization method, and cooling to room temperature for later use;

s2: dissolving metronidazole in an appropriate amount of deionized water, adjusting pH to 6.5-8.0, adding the thickening agent, the isotonic agent, the bacteriostatic agent, the humectant and the seaweed extract, stirring and mixing uniformly, filtering and sterilizing by using a 0.22 mu m microporous filter membrane, adding the solution obtained in the step S1, adding deionized water, stirring uniformly, and carrying out aseptic packaging to obtain the ophthalmic gel.

EXAMPLE 1 preparation of ophthalmic gel

S1: weighing 0.5 part by weight of metronidazole, 1.0 part by weight of a thickening agent (gelatin), 0.8 part by weight of an isotonic agent (glucose), 0.001 part by weight of a bacteriostatic agent (benzalkonium bromide), 0.001 part by weight of a pH regulator (phosphoric acid), 0.2 part by weight of a humectant (sodium hyaluronate), 0.2 part by weight of a seaweed extract and 90 parts by weight of deionized water; dispersing the thickening agent in a proper amount of deionized water, stirring to fully swell, adding a pH regulator to regulate the pH to 6.5, sterilizing by a damp-heat sterilization method, and cooling to room temperature for later use;

s2: dissolving metronidazole in an appropriate amount of deionized water, adjusting pH to 6.5, adding the thickening agent, the isotonic agent, the bacteriostatic agent, the humectant and the seaweed extract, stirring and mixing uniformly, filtering and sterilizing by using a 0.22 mu m microporous filter membrane, adding the filtrate into the solution obtained in the step S1, adding deionized water, stirring uniformly, and carrying out aseptic packaging to obtain the ophthalmic gel.

EXAMPLE 2 preparation of ophthalmic gel

S1: weighing 1.5 parts by weight of metronidazole, 5.0 parts by weight of thickening agent (hydrolyzed collagen), 1.2 parts by weight of isotonic agent (glucose), 0.02 part by weight of bacteriostatic agent (thimerosal), 0.005 part by weight of pH regulator (sodium hydroxide), 1.0 part by weight of humectant (1, 2-hexanediol), 1.0 part by weight of seaweed extract and 110 parts by weight of deionized water; dispersing the thickening agent in a proper amount of deionized water, stirring to fully swell, adding a pH regulator to regulate the pH to 8.0, sterilizing by a damp-heat sterilization method, and cooling to room temperature for later use;

s2: dissolving metronidazole in an appropriate amount of deionized water, adjusting pH to 8.0, adding the thickening agent, the isotonic agent, the bacteriostatic agent, the humectant and the seaweed extract, stirring and mixing uniformly, filtering and sterilizing by using a 0.22 mu m microporous filter membrane, adding the filtrate into the solution obtained in the step S1, adding deionized water, stirring uniformly, and carrying out aseptic packaging to obtain the ophthalmic gel.

EXAMPLE 3 preparation of ophthalmic gel

S1: weighing 1 part by weight of metronidazole, 4 parts by weight of a thickening agent (xanthan gum), 1.1 parts by weight of an isotonic agent (boric acid), 0.015 part by weight of a bacteriostatic agent (p-hydroxybenzoate), 0.004 part by weight of a pH regulator (hydrochloric acid), 0.8 part by weight of a humectant (octylene glycol), 0.8 part by weight of a seaweed extract and 105 parts by weight of deionized water; dispersing the thickening agent in a proper amount of deionized water, stirring to fully swell, adding a pH regulator to regulate the pH to 7.5, sterilizing by a damp-heat sterilization method, and cooling to room temperature for later use;

s2: dissolving metronidazole in an appropriate amount of deionized water, adjusting pH to 7.5, adding the thickening agent, the isotonic agent, the bacteriostatic agent, the humectant and the seaweed extract, stirring and mixing uniformly, filtering and sterilizing by using a 0.22 mu m microporous filter membrane, adding the filtrate into the solution obtained in the step S1, adding deionized water, stirring uniformly, and carrying out aseptic packaging to obtain the ophthalmic gel.

EXAMPLE 4 preparation of ophthalmic gel

S1: weighing 1 part by weight of metronidazole, 3 parts by weight of a thickening agent (carbomer), 1 part by weight of an isotonic agent (sodium chloride), 0.01 part by weight of a bacteriostatic agent (benzalkonium chloride), 0.003 part by weight of a pH regulator (hydrochloric acid), 0.6 part by weight of a humectant (glycerin), 0.6 part by weight of a seaweed extract and 100 parts by weight of deionized water; dispersing the thickening agent in a proper amount of deionized water, stirring to fully swell, adding a pH regulator to regulate the pH to 7, sterilizing by a damp-heat sterilization method, and cooling to room temperature for later use;

s2: dissolving metronidazole in an appropriate amount of deionized water, adjusting pH to 7, adding the thickening agent, the isotonic agent, the bacteriostatic agent, the humectant and the seaweed extract, stirring and mixing uniformly, filtering and sterilizing by using a 0.22 mu m microporous filter membrane, adding the solution obtained in the step S1, adding deionized water, stirring uniformly, and carrying out aseptic packaging to obtain the ophthalmic gel.

Comparative example 1 preparation of ophthalmic gel (without seaweed extract)

S1: weighing 1 part by weight of metronidazole, 3 parts by weight of a thickening agent (carbomer), 1 part by weight of an isotonic agent (sodium chloride), 0.01 part by weight of a bacteriostatic agent (benzalkonium chloride), 0.003 part by weight of a pH regulator (hydrochloric acid), 0.6 part by weight of a humectant (glycerin) and 100 parts by weight of deionized water; dispersing the thickening agent in a proper amount of deionized water, stirring to fully swell, adding a pH regulator to regulate the pH to 7, sterilizing by a damp-heat sterilization method, and cooling to room temperature for later use;

s2: dissolving metronidazole in an appropriate amount of deionized water, adjusting pH to 7, adding the thickening agent, the isotonic agent, the bacteriostatic agent and the humectant, stirring and mixing uniformly, filtering and sterilizing by using a 0.22 mu m microporous filter membrane, adding the solution obtained in the step S1, adding deionized water, stirring uniformly, and carrying out aseptic packaging to obtain the ophthalmic gel.

Example 5 animal experiments to verify the efficacy of ophthalmic gels of the invention

The normal corneal surface is covered with a layer of tear film, which plays an important role in maintaining the physiological function of the ocular surface. Normal tear film has a 3-layer structure: the bottom is a mucin layer which is mainly formed by conjunctival goblet cells in a secretion manner, the middle is an aqueous liquid layer which is mainly formed by conjunctival glandular layer in a secretion manner during basal secretion and is generated by lacrimal glands in a reflex secretion manner; the surface is a lipid layer, which is mainly formed by meibomian gland secretion, and any structural and functional abnormality of the layer can cause the occurrence of dry eye. In order to verify the dry eye disease caused by meibomian gland dysfunction caused by the metronidazole-containing ophthalmic gel of the present invention, the rabbit dry eye disease model caused by alkali burn was selected in the present example. The ocular symptoms caused by this model are similar to those caused by mites and amoebae. The alkali burn model mainly destroys conjunctival goblet cells and conjunctival surface tissues by strong alkali, reduces the goblet cells, changes mucus layers and finally causes the stability of tear film to be reduced, tears are evaporated too fast, and dry eyes are caused to animals.

The test method comprises the following steps:

1. test drug

Ophthalmic gel prepared in example 4

2. Test grouping

9 New Zealand rabbits are female and male. A new Zealand rabbit left eye dry eye model induced by 1mol/L NaOH solution. The right eye served as a self-normal control. The test was divided into 1% ophthalmic gel treatment group, model control group and blank vehicle ophthalmic gel control group, 3 of each group.

3. Molding method

Each New Zealand rabbit was anesthetized by 10% chloral hydrate by ear-edge intravenous injection (2.5 ml/kg), and after the animals were kept stable under anesthesia, the animals were topically anesthetized by instillation of tetracaine ophthalmic gel on both eyes. Then, 1 piece of filter paper of about 10X 5 mm size was dipped in 1mol/L NaOH solution and placed on the bulbar conjunctiva about 2mm above the corneal limbus of the left eye, and 90 s later, the ocular surface and conjunctival sac were repeatedly washed with about 50ml of 0.9% sodium chloride injection.

4. Administration route, administration method, administration dose, administration frequency, administration period

1% ophthalmic gel and blank solvent ophthalmic gel, which are administered by eyes, 100 mul/eye/time, 4 times/day, the administration interval is about 3h, and the administration is continuously carried out for 10 days. The model control group was not administered.

5. Detection method

(1) Keratoconjunctiva fluorescein staining: and (3) dripping 2 mul of 0.5% fluorescein sodium solution into the right eye conjunctival sac of the New Zealand rabbit by using a pipette, flushing redundant fluorescein by using 0.9% sodium chloride injection after 5s, and observing conjunctival staining conditions by cobalt blue diffusion under a slit lamp microscope.

(2) Amount of lacrimal secretion: secretion of tears from New Zealand rabbits was measured using the Schirmer I experiment (Schirmer I test). The eye forceps are used for clamping the phenol red cotton thread, the phenol red cotton thread is placed at the outer canthus of a New Zealand rabbit, and the phenol red cotton thread is taken out after 30 seconds to measure the wet length (cm) of the phenol red cotton thread. Test results table 1 shows that the ophthalmic gel prepared in example 4 has a significant improvement effect on a model of alkali burn induced rabbit dry eye.

TABLE 1 Effect of ophthalmic gels on tear secretion in New Zealand Rabbit Dry eye model due to alkali burn (n =6, Mean + -SD)

Note: compared with the negative control eye, the eye contrast ratio,^#represents P<0.05，^##Represents P<0.01; represents P in comparison with model control group<0.05, indicates P<0.01; and (3) comparing before molding: denotes P<0.05, represents P<0.01。

The detection result of the amount of the lacrimal secretion shows that: the lacrimal secretion amount of each group before molding has no statistical difference, and the lacrimal secretion amount of each group 1d after molding is obviously lower than that before molding. The lacrimal secretion amount of the administration group is increased to be close to the level before the model building when the administration group is administered for 10 days. The tear secretion was still significantly lower than the level before molding in the model and blank groups to the administration of 10 d. In conclusion, according to the research results, the ophthalmic gel containing metronidazole provided by the invention has an obvious effect of resisting dry eye diseases.

The results of fluorescein staining detection of the keratoconjunctiva are shown in fig. 1-5, and the results show that the left and right keratoconjunctivas of the tested animal before molding are not stained with fluorescein. After 1mol/L NaOH induces and molds for 1d, a large fluorescein coloring area is seen in the upper bulbar conjunctiva, after the ophthalmic gel is administrated for 2d, the fluorescein coloring area of the bulbar conjunctiva is obviously reduced and weakened, and the bulbar conjunctiva is seen to be basically free of fluorescein coloring after the ophthalmic gel is administrated for 10 d. The result indicates that the ophthalmic gel of the invention can effectively treat the inflammation of the bulbar conjunctiva of the new zealand rabbit caused by alkali burn.

Example 6 verification of analytical methods for ophthalmic gels of the invention

Validation Using ophthalmic gel prepared in example 4

1. System applicability

In the chromatogram of the control solution, the number of theoretical plates is 8680 which is larger than 2000 calculated according to the metronidazole peak, and the separation degree between the metronidazole peak and the metronidazole impurity I peak is 3.6 which is larger than 2.0. In the sensitivity solution chromatogram, the signal-to-noise ratio of the peak height of the main component is more than 10. Indicating that the system is well suited.

2. Specificity

The blank solvent/negative sample has no interference to the measurement of metronidazole and metronidazole impurity I; the method is proved to have good specificity.

3. Forced degradation test

The product can not generate new impurities due to acid, alkali and high-temperature damage, the product can generate new impurities due to oxygen and illumination damage, the newly generated impurities can be well separated from the main peak, and the purity of each peak meets the requirement.

4. Linearity and range

The concentration of metronidazole is in the range of 0.04208-0.8068 mug/ml, the linear relation of the concentration and the peak area is shown, the linear equation is y =51.78x +1.4, the correlation coefficient r =0.9999 > 0.998, and the sum of the squares of the residuals is 0.01. The concentration of the impurity I is in the range of 0.03108-4.662 mug/ml, the concentration is in a linear relation with the peak area, the linear equation is y =51.41x +3.483, the correlation coefficient r =0.9997 > 0.998, and the sum of the squares of the residuals is 0.01.

5. Detection limit and quantification limit

The detection limit of metronidazole is 0.2104ng, and the quantification limit is 0.4208 ng. The detection limit of the impurity I is 0.1554ng, and the quantitative limit is 0.6312 ng.

6. Precision of the instrument

Continuously injecting an impurity I reference substance solution for 6 times, wherein the retention time RSD of the impurity I is 0.1% < 1.0%; the peak area RSD of the impurity A is 0.9% <2.0%, and the precision of the instrument is good.

7. Repeatability of

The average content of impurities I in 6 parts of standard sample solution is 0.16%, and the content RSD =1.0% < 10%; total miscellaneous RSD =3.0% <5.0%, good reproducibility.

7. Intermediate precision

The impurity I in the intermediate precision solution of 6 parts of intermediate sample is 0.15 percent, and the content RSD =1.4 percent and is less than 10 percent; the total impurity detection quantity RSD =3.0% <5%, and the intermediate precision result is good; calculating by adding 6 parts of repeated test samples, wherein the average content of the impurity I in 12 parts of standard test samples and the intermediate precision solution is 0.15 percent, and the content RSD =2.1 percent and is less than 15 percent; total assay of impurities RSD =3.1% <7.5%, indicating good reproducibility and intermediate precision.

8. Stability of solution

And (3) continuously injecting 10 samples of the sample solution at room temperature for 24h, wherein the absolute difference value between the impurity I and the total impurity content is less than 0.1%, and the absolute difference value between the total impurity content is less than 0.1%, which indicates that the sample solution is stable when placed at room temperature for 24 h.

9. Durability

The durability is better, when the temperature and the flow rate of the chromatographic column and the column are slightly changed, the requirement of the system applicability can be met, and the influence on the measurement result is less.

Example 7 validation of benzalkonium chloride content determination methodology

Validation Using ophthalmic gel prepared in example 4

1. System applicability

The retention time of benzalkonium chloride peaks in the system applicability solution and the test sample solution is consistent with that of a benzalkonium chloride control solution; the number of theoretical plate numbers 17096 of benzalkonium chloride in the system applicability solution is more than 2000 according to the peak of n-C12H25 homologue; the tailing factor of benzalkonium chloride in the solution according to the n-C12H25 homolog peak is 1.23<2.0, and the system applicability requirement is met.

2. Specificity

The blank auxiliary materials have no interference on the peaks of the benzalkonium chloride n-C12H25 homologues, and the peaks of the benzalkonium chloride n-C12H25 homologues can be well separated from other peaks, so that the method has good specificity.

3. Linearity and range

The peak of the benzalkonium chloride n-C12H25 homolog is in the range of 3.0234 mu g/ml to 8.0624 mu g/ml, the concentration and the peak area are in a linear relation, the linear equation is y =65.64x +1.75, the correlation coefficient r =0.9999 > 0.990, and the sum of the squares of the residuals is 0.0016.

4. Accuracy of

The peak of the n-C12H25 homologue of benzalkonium chloride has recovery rate of 99.72% -100.59% at the concentration level of 80% -120% of the concentration of the test sample, the average recovery rate is 99.97%, and the relative standard deviation RSD =0.3% <4.0% in 9 recovery data between 85% -110%.

5. Precision of the instrument

The peak retention time RSD of benzalkonium chloride n-C12H25 homolog in 6-needle benzalkonium chloride control solution was 0.2% < 4.0%; the peak area RSD of benzalkonium chloride n-C12H25 homolog in 6-needle benzalkonium chloride control solution is 0.1% <4.0%, and the precision is good.

6. Repeatability

The 6 parts of test solution has the average peak content of the benzalkonium chloride n-C12H25 homolog of 0.0488mg/ml, RSD =0.5% <4.0%, meets the requirement, and has good repeatability.

7. Intermediate precision

The average concentration of benzalkonium chloride n-C12H25 homolog is 0.0485mg/ml, and the content RSD =1.0% <2.0% when 6 intermediate precision solutions are prepared by another experimenter; meets the requirements. The average concentration of benzalkonium chloride n-C12H25 homolog is 0.0487mg/ml, and the content RSD =1.0% < 8.0%, which is measured by two experimenters to prepare 12 repeated sample solutions/intermediate precision solutions in different instruments; meets the requirement and has good intermediate precision.

8. Stability of solution

The test solution is placed at room temperature for 24h, the peak area of benzalkonium chloride is equivalent to 98.29% -98.68% of the peak area of 0h, the peak areas are all in the range of 98.0% -102.0%, and RSD =1.0%, which indicates that the test solution is stable when placed at room temperature for 24 h; the benzalkonium chloride control solution is equivalent to 98.76% -99.60% of the 0h peak area within 24h at room temperature, and is in the range of 98.0% -102.0%, and RSD =1.0% indicates that the benzalkonium chloride control solution is stable within 24h at room temperature.

9. Durability

The durability is better, when the temperature and the flow rate of the chromatographic column and the column are slightly changed, the requirement of the system applicability can be met, and the influence on the measurement result is less.

Example 8 assay test methodology validation results

Validation Using ophthalmic gel prepared in example 4

1. System applicability

The separation degree between the metronidazole peak and the metronidazole impurity I peak is 3.6 and is more than 2.0. The system has good applicability.

2. Specificity

And (3) taking the reference substance solution, the test substance solution and the metronidazole-deficient negative sample solution of the content determination items to perform determination by the same method, wherein the result shows that the retention time of the main peak in the test substance solution is the same as that of the main peak in the metronidazole reference substance solution, and the negative sample has no same characteristic peak and shows that the negative sample has no interference.

3. Linearity and range

Under the condition of the chromatogram, the concentration of metronidazole is in the range of 0.06162mg/ml-0.16432mg/ml, the linear equation is y =50665x +103.12, the correlation coefficient r =0.9997, and the residual square sum is 0.000004.

4. Accuracy of

Samples were treated at three concentrations of 80%, 100%, and 120% relative to the measured concentration, respectively, and the recovery rates were measured, resulting in an average recovery rate of 99.15% and RSD = 0.2%.

5. Precision of the instrument

The reference substance solution under the content determination item is continuously determined for 6 times, the peak area and the retention time RSD are respectively 0.2 percent and 0.1 percent, and the precision is good.

6. Repeatability

Taking 6 parts of test sample solution under content measurement, wherein the average content is 101.5%, and the content RSD =0.2% < 4.0%; the repeatability is good.

7. Intermediate precision

The average content of metronidazole is 101.6 percent, the content RSD =0.3 percent and less than 2.0 percent, which is measured by different instruments, wherein 12 parts of repetitive test sample solution/intermediate precision solution are prepared by two experimenters; meets the requirements. The average content of metronidazole is 101.7 percent, the content RSD =0.3 percent and less than 2.0 percent, which is measured by preparing 6 parts of intermediate precision solution by another experimenter; meets the requirements.

8. Stability of solution

Taking the reference solution and the sample solution under the content determination item, placing the reference solution and the sample solution at room temperature, and determining the peak areas of the reference solution and the sample solution in 0, 4, 8, 12, 18 and 24 hours respectively, wherein the RSD is 0.3 percent and 0.2 percent respectively, and the solution stability is good.

9. Durability

The durability is better, when the temperature and the flow rate of the chromatographic column and the column are slightly changed, the requirement of the system applicability can be met, and the influence on the measurement result is less.

EXAMPLE 9 quality standards for Metronidazole-containing ophthalmic gels of the invention

The ophthalmic gel prepared in example 4 was used for verification, the criteria are shown in table 2.

TABLE 2

EXAMPLE 10 Effect of Metronidazole-containing ophthalmic gels of the invention

Validation Using ophthalmic gel prepared in example 4

Examination conditions were as follows: high temperature: 60 ℃; illumination: the fluorescent lamp was continuously irradiated, and the results are shown in Table 3.

TABLE 3

The ophthalmic gel prepared in comparative example 1 without the seaweed extract was verified and the test method was the same as above, and the results are shown in Table 4.

TABLE 4

Influence factor results show that: the ophthalmic gel disclosed by the invention can resist high temperature, but is sensitive to illumination, impurities exceed the standard after 10 days of illumination, the content of metronidazole is also reduced, and the ophthalmic gel is stored in a dark place. The ophthalmic gel prepared in comparative example 1, to which no seaweed extract was added, failed to maintain the gel characteristics from yellowish to colorless clear and viscous colloid from day 10, and the impurities and visible foreign substances were not in accordance with the regulations, thus indicating the great contribution of seaweed extract to the high temperature resistance and stable storage of the ophthalmic gel of the present invention.

EXAMPLE 11 accelerated stability test results for Metronidazole-containing ophthalmic gels of the invention

Verification was carried out using the ophthalmic gel prepared in example 4, investigating the conditions: temperature: at 40 +/-2 ℃; relative humidity: 75% +/-5%.

The results are shown in Table 5.

TABLE 5

The accelerated test result shows that all quality indexes have no obvious change.

EXAMPLE 12 Long-term stability test results of Metronidazole-containing ophthalmic gels of the invention

Validation Using ophthalmic gel prepared in example 4

Examination conditions were as follows: temperature: 25 +/-2 ℃; relative humidity: 60% +/-5% and the results are shown in Table 6.

TABLE 6

Long-term test results show that all quality indexes have no obvious change, and the prescription process is stable.

By combining the above embodiments, the present invention discloses an ophthalmic gel containing metronidazole and a method for preparing the same. The ophthalmic gel comprises the following components: 0.5-1.5 parts of metronidazole, 1.0-5.0 parts of thickening agent, 0.8-1.2 parts of isotonic agent, 0.001-0.02 part of bacteriostatic agent, 0.001-0.005 part of pH regulator, 0.2-1.0 part of humectant, 0.2-1.0 part of seaweed extract and 90-110 parts of deionized water; the pH value of the ophthalmic gel is 6.5-8.0. Experiments show that the ophthalmic gel has good improvement effects on the mite-expelling treatment of ocular demodex infection and the treatment of acanthamoeba keratitis. The ophthalmic gel of the present invention may therefore be used in the treatment of ocular infections caused by mites and Acanthamoeba. The seaweed extract is a fermentation mixture of various seaweeds, and the rich seaweed polysaccharide can effectively resist the invasion of external harmful substances, increase the efficacy of moisturizing and maintaining stability, greatly reduce the irritation of gel, and adapt to special parts of eyes. In addition, the invention discovers that the high-temperature resistant storage of the ophthalmic gel is obviously acted after the seaweed extract is added. Therefore, the ophthalmic gel has remarkable curative effect on eye infection, high safety and high-temperature storage resistance.

The above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the invention, and any modifications, equivalents, improvements and the like that fall within the spirit and principle of the present invention are intended to be included therein.

Claims (10)

1. An ophthalmic gel comprising metronidazole, characterised in that it comprises the following components:

0.5-1.5 parts of metronidazole, 1.0-5.0 parts of thickening agent, 0.8-1.2 parts of isotonic agent, 0.001-0.02 part of bacteriostatic agent, 0.001-0.005 part of pH regulator, 0.2-1.0 part of humectant, 0.2-1.0 part of seaweed extract and 90-110 parts of deionized water; the pH value of the ophthalmic gel is 6.5-8.0.

2. The ophthalmic gel of claim 1, wherein said metronidazole is present in 1 part by weight.

3. The ophthalmic gel of claim 1, wherein the ophthalmic gel has a pH of 7.0.

4. The ophthalmic gel of claim 1, wherein said thickener is any one or more of carbomer, gelatin, hydrolyzed collagen, cellulose, xanthan gum, sodium alginate.

5. The ophthalmic gel of claim 1, wherein the isotonicity agent is any one or more of sodium chloride, dextrose, and boric acid.

6. The ophthalmic gel of claim 1, wherein the bacteriostatic agent is any one or more of thimerosal, benzalkonium bromide, benzalkonium chloride, and parabens.

7. The ophthalmic gel of claim 1, wherein the pH regulator is any one or more of phosphoric acid, hydrochloric acid, and sodium hydroxide.

8. The ophthalmic gel of claim 1, wherein the humectant is any one or more of glycerin, lactic acid, 1, 2-hexanediol, caprylyl glycol, allantoin, sodium hyaluronate.

9. The ophthalmic gel of claim 1, wherein the seaweed extract is a mixture of a kelp extract, a brown seaweed extract, and a kelp extract.

10. A process for the preparation of an ophthalmic gel as claimed in any one of claims 1 to 9, characterized in that it comprises the following steps:

s1: weighing the raw materials according to the weight part, dispersing the thickening agent in a proper amount of deionized water, stirring to fully swell, adding a pH regulator to regulate the pH to 6.5-8.0, sterilizing by a damp-heat sterilization method, and cooling to room temperature for later use;

s2: dissolving metronidazole in an appropriate amount of deionized water, adjusting pH to 6.5-8.0, adding thickener, isotonic agent, bacteriostatic agent, humectant and seaweed extract, stirring, mixing, filtering with filter membrane for sterilization, adding into the solution obtained in step S1, adding deionized water, stirring, and aseptically packaging to obtain the ophthalmic gel.

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