Chemical detection method for oculentum
By optimizing chromatographic conditions and sample pretreatment methods, the detection challenges of complex formulations of ganciclovir eye ointment were solved, enabling accurate quantification of ganciclovir content and impurities. A quality control chain from raw materials to finished products was established, ensuring the safety and stability of the product.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- BEIJING JINGFENG PHARM (HEBEI) CO LTD
- Filing Date
- 2026-01-20
- Publication Date
- 2026-04-21
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Abstract
Description
Technical Field
[0001] This invention relates to the field of chemical drug analysis technology, and in particular to a chemical detection method for eye ointment. Background Technology
[0002] Ganciclovir eye ointment is widely used clinically to treat viral eye infections. Its quality directly affects efficacy and safety. The ointment's formulation is complex, typically containing ganciclovir, yellow petrolatum, lanolin, liquid paraffin, white petrolatum, glycerin, ethylparaben, and vitamin E. Ensuring the quality of this ointment faces three major challenges: 1) Precise control of the uniformity of the active ingredient, ganciclovir, within the oily matrix; 2) Effective monitoring of the potential presence of a specific impurity, "alum" (an impurity introduced during ganciclovir synthesis or generated during storage, not yellow petrolatum); 3) The diverse sources of the excipient lanolin, and its quality (such as acid value and peroxide content), directly affect the stability and ocular irritation of the ointment.
[0003] While existing technologies offer general detection methods for ganciclovir or lanolin, they lack integrated and targeted detection solutions for this specific complex prescription eye ointment. In particular, there is no clear and optimized technical solution for systematically controlling the ganciclovir content, related substances, and lanolin quality from raw materials to finished products. Summary of the Invention
[0004] The purpose of this invention is to overcome the shortcomings of existing technologies and provide a highly accurate and easy-to-operate chemical detection method for ganciclovir eye ointment. This method systematically solves the quality control problem of ganciclovir eye ointment by optimizing chromatographic conditions, establishing a dedicated impurity detection method, and correlating raw material and finished product testing.
[0005] This application provides a chemical detection method for an eye ointment, wherein the eye ointment comprises ganciclovir, yellow petrolatum, lanolin, liquid paraffin, white petrolatum, glycerin, ethylparaben, and vitamin E. The method includes the following steps: (a) The content of ganciclovir in the eye ointment was determined and related substances were examined by high performance liquid chromatography; The content determination was performed using isocratic elution mode, with the mobile phase being 0.02 mol / L potassium dihydrogen phosphate solution and methanol in a volume ratio of 75:25. The related substances test uses a gradient elution mode, with mobile phase A being 0.02 mol / L potassium dihydrogen phosphate solution and mobile phase B being methanol. The gradient program changes over time. (b) Quality control of lanolin raw materials, including determination of acid value, saponification value and peroxide value; (c) Conduct lanolin-related quality monitoring on the finished eye ointment, including measuring the peroxide value.
[0006] Furthermore, the gradient elution procedure described in step (a) is as follows: At 0 minutes, mobile phase A is 90% and mobile phase B is 10%. At 10 minutes, mobile phase A was 70% and mobile phase B was 30%. At 25 minutes, mobile phase A was 50% and mobile phase B was 50%. At 30 minutes, mobile phase A was 10% and mobile phase B was 90%. At 35 minutes, maintain mobile phase A at 10% and mobile phase B at 90%. At 36 minutes, mobile phase A recovered to 90%, and mobile phase B recovered to 10%. The gradient was terminated at 45 minutes.
[0007] Furthermore, the preparation method of the test solution in step (a) includes: Weigh approximately 0.5 g of the eye ointment sample accurately and place it in a 50 mL volumetric flask. Add 30 mL of mobile phase A, heat and shake in a water bath at 60±2℃ to disperse the sample, sonicate for 20 minutes, cool to room temperature, dilute to the mark, filter through a 0.45 μm microporous membrane, and use the filtrate as the test solution.
[0008] Furthermore, in step (a), the relative retention time of the impurity ferrous sulfate relative to the ganciclovir main peak is 0.85, and the limit of ferrous sulfate is no more than 0.5% of the area of its own control solution main peak.
[0009] Furthermore, in step (b), the acid value and saponification value are determined using a combined assay method: Take a lanolin sample and accurately add ethanol-based potassium hydroxide titrant (0.5 mol / L) to carry out the saponification reaction. Then titrate with hydrochloric acid titrant and calculate the acid value and saponification value respectively. The acid value should not exceed 1.0 and the saponification value should be 92-106.
[0010] Furthermore, in step (b), the peroxide value of the lanolin raw material must not exceed 5.0 mEq / kg.
[0011] Furthermore, in step (c), the peroxide value of the finished eye ointment must not exceed 8.0 mEq / kg.
[0012] Furthermore, in step (a), the chromatographic column is an octadecylsilane-bonded silica column, the detection wavelengths are 252 nm for content determination and 230 nm for related substance inspection, the column temperature is 30℃, and the injection volume is 20 μL.
[0013] One or more technical solutions provided in the embodiments of this application have at least the following technical effects or advantages: The detection method in this application is based on product characteristics and establishes a precise quality assurance system. The method is optimized to address matrix interactions: eye ointment is a complex, hydrophobic, semi-solid matrix in which active drugs and impurities may be encapsulated. Therefore, a combination of heating and ultrasound is used in sample pretreatment, along with a precisely pH-adjusted mobile phase. The principle is to disrupt the matrix structure, increase the solubility and release efficiency of the drug in the extraction solvent, and ensure that the analyte can be completely and uniformly extracted. Quality control is achieved by leveraging differences in chromatographic separation capabilities: conventional isocratic elution has limited ability to separate impurities with similar structures. This invention employs the principle of gradient elution, which involves programmatically changing the elution intensity of the mobile phase over time, allowing impurities co-eluted under isocratic conditions to be separated sequentially, thereby achieving specific identification and accurate quantification of target impurities. Establish a quality-linked control chain: The quality of excipients lies not only in incoming inspection but also in their changes during formulation and storage. By monitoring key indicators of lanolin (such as peroxide value) in the finished product, the principle is to link the quality attributes of raw materials with the key quality attributes of the final product, thereby achieving monitoring of the product's stability throughout its entire lifecycle. Detailed Implementation
[0014] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains; the terminology used herein in the description of the invention is for the purpose of describing particular embodiments only and is not intended to limit the invention; the term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.
[0015] Example 1: An eye ointment, composed of the following ingredients in parts by weight: ganciclovir: 0.2-0.5 parts, yellow petrolatum: 55-70 parts, lanolin: 5-10 parts, liquid paraffin: 10-20 parts, white petrolatum: 8-15 parts, glycerin: 3-8 parts, ethylparaben: 0.05-0.15 parts, vitamin E: 0.02-0.1 parts. The preparation method of the eye ointment includes the following steps: Step 1: Mix yellow petrolatum, white petrolatum, lanolin and liquid paraffin according to the prescription amount, heat in a water bath to 78-82℃ to melt, filter with a 100-150 mesh stainless steel sieve, and keep warm for later use.
[0016] Step 2: Add ethylparaben and vitamin E to the above matrix and stir at 800-1200 rpm for 8-15 minutes until completely dissolved. Add glycerin, maintain the temperature at 73-77℃, and homogenize at 4000-6000 rpm for 10-20 minutes.
[0017] Step 3: Add ganciclovir (pre-passed through a 180-220 mesh sieve) to the matrix in portions, maintain the temperature at 58-62℃, and homogenize at high speed at 8000-12000 rpm for 15-25 minutes until no particles are visible to the naked eye.
[0018] Step 4: Stop heating and slowly cool to 30-40℃ by stirring at 150-250 rpm. Transfer to a vacuum degassing tank (-0.07 to -0.09 MPa) for degassing for 20-40 minutes.
[0019] Step 5: After cooling to 25±5℃, take samples to test the content uniformity (RSD≤3%). Fill into sterile eye ointment tubes in a Class B clean environment, seal and label.
[0020] Chemical testing was performed on the eye ointment: I. Ganciclovir content determination and related substance testing; This section employs high performance liquid chromatography (HPLC) to sequentially complete the content determination and related substance examination using the same chromatographic system but different elution programs. Step 1: Preparation of the test solution; Accurately weigh approximately 0.5 g of this product and place it in a 50 mL volumetric flask. Add approximately 30 mL of mobile phase A (0.02 mol / L potassium dihydrogen phosphate solution, adjusted to pH 3.0 ± 0.1 with phosphoric acid). Heat and shake in a water bath at 60 ± 2 °C to disperse the product. Sonicate the product (250 W power, 40 kHz frequency) for 20 minutes. Allow it to cool to room temperature. Dilute to the mark with mobile phase A, shake well, and filter through a 0.45 μm microporous membrane. Use the filtrate as the test solution.
[0021] Step 2: Preparation of the reference solution; Accurately weigh approximately 10 mg of ganciclovir reference standard and place it in a 100 mL volumetric flask. Dissolve and dilute to the mark with mobile phase A, and mix well to obtain the stock solution. Accurately measure 5.0 mL of the stock solution and place it in a 50 mL volumetric flask. Dilute to the mark with mobile phase A, and mix well to obtain the reference solution.
[0022] Step 3: Chromatographic conditions; Column: Octadecylsilane-bonded silica gel (C18) column (250 mm × 4.6 mm, 5 μm); Detection wavelengths: 252nm (content determination), 230nm (related substances test); Column temperature: 30℃; Injection volume: 20μL; Washing procedure: Assay: Isocratic elution. Mobile phase A was 0.02 mol / L potassium dihydrogen phosphate solution (pH 3.0), and mobile phase B was methanol. A:B = 75:25 (v / v). Flow rate: 1.0 mL / min. Run time: approximately 15 minutes; ganciclovir peak retention time: approximately 6.5 minutes.
[0023] Related substances test: gradient elution. The procedure is shown in Table 1 below: Table 1
[0024] Flow rate 1.0 mL / min.
[0025] Step 4: Determination method; Assay: Under isocratic elution conditions, accurately pipette 20 μL each of the reference solution and the test solution and inject them into the liquid chromatograph, recording the chromatograms. Calculate the ganciclovir content based on peak area using the external standard method. Acceptance criteria: The ganciclovir content should be 90.0%–110.0% of the labeled amount.
[0026] Related substances testing (ferrous alum control): Under gradient elution conditions, accurately pipette 20 μL of the test solution and inject it into the liquid chromatograph, recording the chromatogram. Use a self-control method, with a 100-fold (1%) dilution of the test solution as a control. Locate the ferrous alum peak at 230 nm (its relative retention time (RRT) is approximately 0.85 relative to the ganciclovir peak). Specific limits for ferrous alum: its peak area must not exceed 0.5% of the peak area of the self-control solution (i.e., 0.5%). Other single unknown impurities must not exceed 1.0%, and total impurities must not exceed 2.0%.
[0027] 2. Quality control of lanolin raw materials; Step 1: Combined measurement of acid value and saponification value; Accurately weigh approximately 2.0 g of lanolin and place it in a 250 mL Erlenmeyer flask. Accurately add 25.0 mL of ethanol-based potassium hydroxide titrant (0.5 mol / L), and heat under reflux for 30 minutes to induce saponification. After cooling, add 50 mL of a neutral ethanol-ether (1:1) mixture and shake well. Add a few drops of phenolphthalein indicator and titrate with 0.5 mol / L hydrochloric acid titrant until colorless. Record the volume V1 (for calculating the saponification value). Then, accurately add 10.0 mL of 0.1 mol / L sodium hydroxide titrant, heat under reflux for 10 minutes, cool, and titrate again with 0.1 mol / L hydrochloric acid titrant until colorless. Record the volume V2 (for calculating the acid value).
[0028] Saponification value calculation: Saponification value = (B1 - V1) × C_HCl(0.5) × 56.11 / W. Acceptance standard: 92~106.
[0029] Acid value calculation: Acid value = (10.0 / C_NaOH(0.1) - V2) × C_HCl(0.1) × 56.11 / W. Acceptance standard: Not exceeding 1.0.
[0030] (Note: B1 is the volume of hydrochloric acid titrant consumed in the saponification blank test) Step 2: Peroxide value check; Accurately weigh approximately 2.0 g of lanolin and determine its peroxide value according to the Chinese Pharmacopoeia General Chapter 0713, Method for Determination of Peroxide Value. Acceptance standard: Not exceeding 5.0 mEq / kg.
[0031] 3. Quality control of lanolin in finished eye ointments; Step 1: Peroxide value monitoring Weigh approximately 2.0 g of this product accurately and determine the peroxide value of the finished product according to the method in step 2 of Part II. Acceptable standard: not exceeding 8.0 mEq / kg. This indicator can effectively monitor the oxidative stability of lanolin during the preparation and storage of eye ointments.
[0032] The ointment of this application was tested. The ointment is composed of the following ingredients, in parts by weight, as follows: ganciclovir 0.35 parts, yellow petrolatum 62.00 parts, lanolin 8.00 parts, liquid paraffin 15.00 parts, white petrolatum 10.00 parts, glycerin 5.00 parts, ethylparaben 0.10 parts, and vitamin E 0.05 parts. The control examples were tested using the general methods for the relevant varieties in the Chinese Pharmacopoeia: 1. Ganciclovir content determination: HPLC method was used, but the chromatographic conditions were conventional isocratic elution (methanol-water, 30:70). The test sample was prepared by conventional solvent shaking extraction, and no heating or ultrasonic-assisted dispersion was used.
[0033] 2. Related substances test: The test was performed directly under isocratic chromatographic conditions for content determination, without using gradient elution.
[0034] 3. Lanolin quality control: Only the imported lanolin raw materials were tested according to pharmacopoeia standards (acid value, saponification value). No monitoring indicators for the oxidation state of lanolin were established in the finished eye ointment.
[0035] For the same batch of ganciclovir eye ointment samples, the methods of the control example and the present invention example were used for testing, and the test results are shown in Tables 2 and 3 below: Table 2
[0036] Although the ganciclovir content measured by both methods was within the acceptable range, the result of this invention (98.2%) was closer to the true value, and its precision (RSD of 0.9%) was significantly better than that of the control (RSD of 2.8%). This indicates that the present invention, through optimized pretreatment and chromatographic conditions, effectively eliminated the interference of complex matrices, resulting in better peak shapes and higher reliability. Furthermore, regarding the control capability of alum: the isocratic elution method used in the control could not effectively separate alum from other components, leading to an inability to monitor this potentially risky impurity and creating a quality blind spot; while the gradient elution method created in this invention successfully achieved the exclusive separation and accurate quantification of alum (content of 0.4%), possessing a stronger impurity separation capability and more comprehensively and accurately reflecting the impurity profile of the product, thus significantly improving safety control.
[0037] Table 3
[0038] In the acceptance phase of lanolin raw materials, this invention establishes a continuous quality monitoring chain from raw materials to finished products. Not only is testing conducted upon raw material receipt, but the peroxide value of the finished eye ointment is also monitored (measured value: 5.2 mEq / kg). This allows for proactive tracking and assessment of potential oxidative deterioration of lanolin during the eye ointment preparation process and subsequent storage, thereby achieving expected control over the overall product stability. In contrast, the control example lacks monitoring of the excipient status in the finished product and cannot assess potential quality changes caused by production and storage.
[0039] The technical solutions described in the embodiments of this application have at least the following technical effects or advantages: The detection method in this application is based on the product characteristics and establishes a precise quality assurance system. The method is optimized to address matrix interactions: eye ointment (composed of petrolatum, lanolin, etc.) is a complex, hydrophobic, semi-solid matrix in which active drugs and impurities may be encapsulated. Therefore, a combination of heating and ultrasound is used in sample pretreatment, along with a precisely pH-adjusted mobile phase. The principle is to disrupt the matrix structure, increase the solubility and release efficiency of the drug in the extraction solvent, and ensure that the analyte can be completely and uniformly extracted. Quality control is achieved by leveraging differences in chromatographic separation capabilities: conventional isocratic elution has limited ability to separate impurities with similar structures. This invention employs the principle of gradient elution, which involves programmatically changing the elution intensity of the mobile phase over time, allowing impurities co-eluted under isocratic conditions to be separated sequentially, thereby achieving specific identification and accurate quantification of target impurities. Establish a quality-linked control chain: The quality of excipients lies not only in incoming inspection but also in their changes during formulation and storage. By monitoring key indicators of lanolin (such as peroxide value) in the finished product, the principle is to link the quality attributes of raw materials with the key quality attributes of the final product, thereby achieving monitoring of the product's stability throughout its entire lifecycle. Through the above improvements, the accuracy and reliability of content determination are ensured: optimized extraction and chromatographic conditions effectively reduce matrix interference, ensuring that the measured ganciclovir content truly reflects the amount of raw materials added in the prescription, and avoiding misjudgments caused by incomplete extraction or inaccurate detection; a proactive stability early warning mechanism is constructed: the oxidation index (peroxide value) of lanolin is extended from raw material control to finished product monitoring, which can proactively detect possible oxidative degradation trends during the formulation process (such as heating and melting) or storage, playing an early warning role.
[0040] Technical advantages of the detection scheme of this invention: Breakthrough in detection capabilities: This invention, through the creation of a proprietary gradient elution HPLC method, has for the first time achieved accurate separation, identification, and quantitative control of this impurity, significantly improving the safety control level of the product; Significant improvement in detection quality: In terms of content determination, the method of this invention improves precision (RSD from 2.8% to 0.9%) through optimized sample pretreatment and chromatographic conditions, ensuring the accuracy and reliability of content determination results; Improved quality monitoring system: By linking the control of peroxide value of lanolin raw materials with the monitoring of peroxide value of finished eye ointment, a continuous quality monitoring chain from raw materials to finished products has been established, providing a reliable guarantee for the production and quality control of high-quality ganciclovir eye ointment.
[0041] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. For those skilled in the art, the present invention can have various modifications and variations. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.
Claims
1. A chemical detection method for an eye ointment, wherein the eye ointment comprises ganciclovir, yellow petrolatum, lanolin, liquid paraffin, white petrolatum, glycerin, ethylparaben, and vitamin E, characterized in that, The method includes the following steps: (a) The content of ganciclovir in the eye ointment was determined and related substances were examined by high performance liquid chromatography; The content determination was performed using isocratic elution mode, with the mobile phase being 0.02 mol / L potassium dihydrogen phosphate solution and methanol in a volume ratio of 75:
25. The related substances test used a gradient elution mode, with mobile phase A being 0.02 mol / L potassium dihydrogen phosphate solution and mobile phase B being methanol, and the gradient program changing over time. (b) Quality control of lanolin raw materials, including determination of acid value, saponification value and peroxide value; (c) Conduct lanolin-related quality monitoring on the finished eye ointment, including measuring the peroxide value.
2. The chemical detection method for eye ointment as described in claim 1, characterized in that, The gradient elution procedure described in step (a) is as follows: At 0 minutes, mobile phase A is 90% and mobile phase B is 10%. At 10 minutes, mobile phase A was 70% and mobile phase B was 30%. At 25 minutes, mobile phase A was 50% and mobile phase B was 50%. At 30 minutes, mobile phase A was 10% and mobile phase B was 90%. At 35 minutes, maintain mobile phase A at 10% and mobile phase B at 90%. At 36 minutes, mobile phase A recovered to 90%, and mobile phase B recovered to 10%. The gradient was terminated at 45 minutes.
3. The chemical detection method for eye ointment as described in claim 1, characterized in that, The preparation method of the test solution in step (a) includes: Accurately weigh approximately 0.5 g of the eye ointment sample and place it in a 50 mL volumetric flask. Add 30 mL of mobile phase A, heat and shake in a water bath at 60±2℃ to disperse the sample, sonicate for 20 minutes, cool to room temperature, dilute to the mark, filter through a 0.45 μm microporous membrane, and use the filtrate as the test solution.
4. The chemical detection method for eye ointment as described in claim 1, characterized in that, In step (a), the relative retention time of the impurity alum relative to the ganciclovir main peak is 0.85, and the limit of alum is no more than 0.5% of the area of its own control solution main peak.
5. The chemical detection method for eye ointment as described in claim 1, characterized in that, In step (b), the acid value and saponification value are determined using a combined assay method: Take a lanolin sample and accurately add ethanol-based potassium hydroxide titrant (0.5 mol / L) to carry out the saponification reaction. Then titrate with hydrochloric acid titrant and calculate the acid value and saponification value respectively. The acid value should not exceed 1.0 and the saponification value should be 92-106.
6. The chemical detection method for eye ointment as described in claim 1, characterized in that, In step (b), the peroxide value of the lanolin raw material must not exceed 5.0 mEq / kg.
7. The chemical detection method for eye ointment as described in claim 1, characterized in that, In step (c), the peroxide value of the finished eye ointment must not exceed 8.0 mEq / kg.
8. The chemical detection method for eye ointment as described in claim 1, characterized in that, In step (a), the chromatographic column is an octadecylsilane-bonded silica column, the detection wavelengths are 252 nm for content determination and 230 nm for related substances inspection, the column temperature is 30℃, and the injection volume is 20 μL.