TX Q&A

Titanium cages for the spine are primarily used for vertebral replacement or spinal fusion. Common types include titanium cage vertebral replacement implants and titanium cage vertebral implants, which should be categorized into different registration units. Products made from different materials (including material grades) should be divided into different registration units. Based on the commonly used materials for titanium cages, they can be divided into registration units such as TA3 pure titanium, TC4 titanium alloy, TC4 ELI titanium alloy, etc.

The primary packaging materials for soft corneal contact lens products may risk extracting leachable substances that could affect the performance and safety of the contact lenses. Therefore, when selecting or changing primary packaging materials, attention should be paid to: 1. Verifying the performance of the primary packaging materials, including their physicochemical properties, with a recommendation for a biological evaluation; 2. The suitability for sterilization and the validation of the sterilization process; 3. Conducting stability tests in accordance with "GB/T 11417.8-2012 Ophthalmic optics - Contact lenses - Part 8: Determination of shelf life", which should include assessments of lens performance, packaging integrity, and sterility, with a recommendation for research on the performance of the preservation solution; 4. Validating the stability during transportation; 5. If the product includes two or more types of packaging, conducting full performance testing and biological evaluation on the final product separately; 6. If using primary packaging materials that have never been used in similar products, it's recommended to thoroughly evaluate and validate solutions that may contain leachables during stability testing, including but not limited to biological evaluations.

The detection system for in vitro diagnostic reagents is a combination made up of products for sample processing, test reagents, calibrators, quality control materials, and suitable instruments. The whole detection system undergoes thorough safety and effectiveness evaluation and gets approved. During the product registration process for in vitro diagnostic reagents, regardless of whether they include other products for completing the test, the accompanying products should be clearly stated in the instructions to ensure the testing process is carried out according to the detection system composed of all the accompanying products. For instance, for nucleic acid testing reagents that do not include extraction reagents, the extraction reagents specified in the instructions should be used during performance evaluation and clinical evaluation. Likewise, if the declaration materials involve comparative reagents, the operations should be carried out according to their approved detection system. If nucleic acids are extracted using extraction reagents not specified in the comparative reagent instructions and then tested, the obtained test results, if not thoroughly validated and confirmed, cannot be used as a basis for evaluating and assessing the reagent.

According to the "Announcement on the Publication of the Requirements for the Registration Application Materials and the Format of Approval Certificates for In Vitro Diagnostic Reagents" (Announcement No. 44 of 2014 by the former China Food and Drug Administration), the annex of the clinical trial report includes: (1) Basic information of other test methods or diagnostic reagent products used in the clinical trial, such as test methods, sources of diagnostic reagent products, product instructions, and registration approval status. (2) All test data from the clinical trial (to be signed by the clinical trial operators, reviewers, and stamped on the first page and across the binding by the clinical trial institution). (3) Main references. (4) Resumes of principal investigators. (5) Other circumstances that the applicant needs to explain. These documents should be submitted as annexes to the clinical trial report and confirmed by the signature of the clinical trial institution. Item (1) should include instructions for the comparative reagent and third-party reagent (if involved), and if a clinical reference method/gold standard is used, the specific method's operating procedures and criteria should be submitted. The data tables in item (2) should at least contain sample numbers, basic information (such as gender, age, sample type), results from various tests, and clinical background information. The clinical background information should come from the clinical case information of the subjects and meet the inclusion criteria of the protocol. Item (4) should include the resumes of the principal investigators, and other participants do not need to submit theirs. Items (3) and (5), if involved, should also be submitted together.

If a light-curing device must be equipped with a light guide during clinical use, it should be tested with the light guide to assess whether it meets the requirements of radiation clause 7.2 in YY 0055.1-2009 or YY 0055.2-2009. The type or model of light guide chosen for the test should cover all the light guides included in the declared product composition or all the light guides that are clearly stated in the accompanying documents as compatible for use. The test report should reflect the type or model of the light guide. Light-curing devices that do not require a light guide during clinical use should be tested under normal usage conditions.

The performance study of PMMA bone cement for spinal use should not only focus on the performance of the powder and liquid components but also on the performance of the final product formed after mixing the powder and liquid. The study should at least focus on the following aspects: 1. The components and ratios of the powder and liquid, the morphology, and particle size distribution of the powder components; 2. Molecular weight, such as viscosity-average molecular weight, number-average molecular weight/weight-average molecular weight; 3. Polymer structure, such as grafting, linear, or copolymer; 4. Physical properties, such as shrinkage rate, water absorption, etc.; 5. Stability of the components, such as liquid absorption and aging caused by polymerization, changes in liquid viscosity after heating, changes (aging) in the level of benzoyl peroxide; 6. Residual evaluation of the monomers in the polymer, such as the amount of monomer released during and after polymerization, residual amount of monomer after polymerization, and on this basis, safety evaluation of the residual toxicity of the monomers; 7. Combined with the intended application site, relevant dynamic and static mechanical performance studies; 8. Study of the polymerization reaction process of mixing bone cement powder and liquid under the expected mode of use.

Test reports do not have an expiration date. If the product has not undergone any changes, the original test report can be submitted.

For products coated with PVP, when the coating material leads to abnormal test results for reducing substances, it is recommended to test products without the coating to confirm whether their chemical performance test results are affected by the coating. At the same time, taking into account the clinical application history of the coating material and biocompatibility data, a comprehensive evaluation is advised, and it is not necessary to establish requirements for reducing substances in the product technical specifications.

Reusable accessories must be disinfected or sterilized before use. The manual should specify the exact disinfection/sterilization methods (such as the disinfectants used, disinfection or sterilization equipment), and the critical parameters of the disinfection/sterilization cycle (such as time, temperature, and pressure). Research materials should provide the basis for determining the disinfection/sterilization methods, data confirming the effectiveness of disinfection/sterilization, and studies on the tolerance of the recommended disinfection/sterilization methods.

The connection methods between implants and abutments mainly fall into two categories: external and internal connections, which can be further classified by geometric shapes into internal square connections, external hex connections, external octagon connections, spline connections, Morse taper connections, etc. The connection method between the implant and the abutment is an essential aspect of the product structure and composition that should be specified. Different connection methods should undergo respective studies on system compatibility verification, including the fit of the internal connection taper, the gap between the implant and the abutment, torsional resistance, tightening torque, and fatigue limit.