Preparation and clinical application of hydroxypropyl methylcellulose ophthalmic viscoelastic agent

Abstract: Objective: To develop 2% hydroxypropyl methylcellulose according to the non-standard preparation technical requirements of military medical units. Method: The prescription composition, preparation process, quality control and clinical application of the preparation were tested and summarized. Results: The formula and preparation process of the preparation are reasonable, the quality control method is feasible, it can meet the clinical requirements of ophthalmic surgery, and the use is good. Conclusion: 2% hydroxypropyl methylcellulose is a safe and effective ophthalmic viscoelastic agent.

Key words:hydroxypropyl methylcellulose; preparation; clinical application

Hydroxypropyl methylcellulose (hyoloxy propyl methlcellulose, HPMC) is a high-purity, highly water-absorbing polysaccharide polymer with good cohesiveness and lubricity. Its 2% sterile colloidal The solution is a commonly used ophthalmic viscoelastic. Because HPMC is cheap, easy to prepare, and effective in use, it is widely used in ophthalmic microsurgery, and it cannot be completely replaced by sodium hyaluronate at present. Our hospital has self-made 2% HPMC ophthalmic viscoelastic agent for many years, and its preparation process and quality control methods have been continuously improved and perfected, and standardized research has been carried out in accordance with the technical requirements of non-standard preparations in military medical units, and thousands of operations have been performed in ophthalmology clinics. In the application, the use effect is good. Now report as follows.

1. Prescription and preparation

Prescription: HPMC 20g, sodium chloride 9g, water for injection to 1000ml.

Preparation: Weigh sodium chloride and dissolve it in an appropriate amount of water for injection, sprinkle HPMC on the surface of the above solution, add water for injection to the full amount, refrigerate and dissolve at 2~8°C, and after complete peptization, depressurize with G2 vertical melting funnel Filter, seal, and sterilize with circulating steam at 100°C for 400 minutes, and set aside. Dispense it into 1ml syringes by aseptic operation, and obtain it.

2. Quality control

2.1 Traits

This product is a colorless clear, viscous colloidal liquid.

2.2 Identification

The identification reaction of this product is sodium salt and chloride. The method refers to the general identification test item of "Chinese Pharmacopoeia (Part II)" in the 2000 edition; HPMC produces turbidity when heated, and the turbidity disappears when cooled.

2.3 Inspection

PH value: should be 5.5~7.0.

Sterility test: It should comply with the relevant regulations under the sterility test method of the 2000 edition of "Chinese Pharmacopoeia (Part Two)".

Others: It should meet the provisions of eye drops for corneal trauma and surgery under the eye drops of the 2000 edition of "Chinese Pharmacopoeia (Part II)".

2.4 Content determination

2.4.1 Sodium chloride

Precisely measure 5ml of this product with an internal volume pipette, put it in a conical flask, wash the inner wall of the pipette with about 50ml of water, put the washing solution into the conical flask, add 5ml of 2% dextrin solution and fluorescent yellow Take 5-8 drops of indicator solution and titrate with silver nitrate titration solution (0.1 mol/l). Every 1ml of silver nitrate titration solution (0.1 mol/l) is equivalent to 5.844mg of NaCl.

2.4.2 HPMC

Since this product has no pharmacological effect, the clinical use effect has a great relationship with the viscosity, so the viscosity measurement can be used as its quality standard. Methods Referring to the viscosity determination method in the appendix of "Chinese Pharmacopoeia (Part II)" in 2000, the dynamic viscosity was measured with a rotary viscometer. The viscosity range was 190-350 Pa·s at room temperature [(25±2)]°C.

3. Clinical application

2% ophthalmic viscoelastic agent is suitable for a variety of ophthalmic operations, including penetrating keratoplasty, intraocular lens implantation, vitreoretinal surgery, cataract extraction, cataract phacoemulsification, anterior segment reconstruction, etc. agents, fillers and protective viscoelastic liners. Filling the anterior chamber and posterior chamber with this product can maintain the surgical space, facilitate intraoperative operation, and lubricate surgical instruments and intraocular lenses, prevent intraoperative mechanical abrasions, protect corneal endothelial cells, and prevent postoperative tissue adhesion and lubrication Sutures etc. In the application of tens of thousands of operations in the ophthalmology department of our hospital, the use effect is good, and it can meet the needs of clinical operations. Only a small number of patients experience transient intraocular pressure elevation during use, and symptomatic treatment (such as oral acetazolamide) can prevent intraocular pressure elevation and recover quickly. No other adverse reactions were found.

4. Discussion

4.1 Quality requirements

The clinical quality requirements for ophthalmic viscoelastics are: colorless and transparent, with a good surgical field of vision; highly viscoelastic, able to maintain a long-term surgical space; Foreign body reaction; no chemical reaction occurs in the eye; its osmotic pressure, pH value, etc. are consistent with the anterior chamber. The 2% HPMC prepared by our hospital can basically meet the above conditions. In order to ensure the quality of the preparation, the author continuously improved the preparation process and perfected the operating procedures; and improved the product packaging according to clinical needs, using syringe packaging, and equipped with special needles for ophthalmic surgery, which is convenient for doctors to operate; the outer packaging adopts blister film and plastic bags Double-layer structure to prevent the liquid medicine from being polluted.

4.2 Safety performance

The Department of Ophthalmology of our hospital has conducted experimental research on the effects of 2% HPMC, ophthalmic balanced saline and imported 1% sodium hyaluronate on the intraocular pressure and corneal endothelium of rabbits. 1% sodium hyaluronate has basically the same effect on intraocular pressure and corneal endothelium, and can be safely used in ophthalmic surgery.

4.3 Usage

Years of clinical application have proved that 2% HPMC can effectively prevent corneal endothelial damage, reduce postoperative complications, and has no toxicity and foreign body reactions, and is easy to dilute and flush out of the anterior chamber. It is a safe, effective, cheap and easy-to-obtain ophthalmic adhesive Ammunition.