TX Q&A

When considering the compatibility of metal powders with printing parameters, it is essential to take into account the powder production process and the key process parameters of the printing equipment. Taking laser selective melting as an example, it is necessary to submit the key process principles and the basis for selection, such as electrode induction melting gas atomization, plasma inert gas atomization, vacuum induction melting gas atomization, and plasma rotating electrode atomization. Verification data for key process parameters should also be submitted, including gas pressure, flow rate, temperature, inner diameter and spray angle of the atomization nozzle, pressure and oxygen content in the atomization tower, current, and rotation speed of the rotating electrode atomization process. Compatibility with the key process parameters of the printing equipment should consider factors such as laser power, spot diameter, scanning speed, scanning distance, powder layer thickness, printing direction, atmospheric protection, support structures, and the temperature of the forming chamber.

Yes, applicants can change the grade of the main raw materials of approved products through the modification registration procedure, provided that the product's performance indicators are not reduced after verification and confirmation. Additionally, it is encouraged to record the primary documents of implant materials such as polyetheretherketone (PEEK), alumina-zirconia composite ceramics, and highly cross-linked ultra-high molecular weight polyethylene to avoid redundant verification.

Given the unique physicochemical properties of silicone hydrogel contact lenses compared to regular hydrogel lenses, the following special precautions are necessary: 1. Compatibility Testing: According to YY 0719.5 "Ophthalmic optics - Contact lens care products - Part 5: Determination of physical compatibility with contact lenses," it is required to conduct separate compatibility tests for the care products with silicone hydrogel contact lenses. 2. Representative Lens Selection: In the compatibility testing, select representative, commercially available silicone hydrogel contact lenses for the study and provide verification data. 3. Technical Requirements: The technical specifications of the product must clearly indicate that silicone hydrogel contact lenses have been tested. Submit either a self-inspection report or an inspection report issued by a qualified medical device inspection agency as supporting documentation.

(1) If the product documentation, labels, or other materials of the intravascular catheter mention a nominal flow rate, relevant flow study data must be provided. (2) For catheters used for infusing medication into the body, such as central venous catheters, it is necessary to specify the flow rate/speed, and requirements for flow rate/speed should be set in the technical specifications. (3) Flow testing methods can refer to YY0285.1 "Intravascular catheters - Sterile and single-use catheters - Part 1: General requirements." If the declared product's infusion pressure exceeds 10 kPa, the applicant may establish an applicable test method.

(1) If the material design, weaving process, or other factors cause the patch's tensile strength to be anisotropic, separate standards for longitudinal and transverse tensile strength should be established. (2) It is recommended to establish the elongation at break under the maximum abdominal wall tension that may be encountered under physiological conditions in the human body. The acceptance criteria for elongation at break should be formulated based on the natural elongation rate of the human abdominal wall and the actual measured data of the patch.

(1) The main factors affecting biocompatibility risk include: the chemical composition of the product's materials (including the proportions of each component material), the physical structure of the product, surface characteristics, manufacturing processes, sterilization methods, raw material suppliers, and technical specifications, and for liquid products or products preserved in a wet state, the internal packaging materials must also be considered. (2) If there are inconsistencies between the test item and the declared product regarding the factors listed above that may affect biocompatibility risk, sufficient rationale and evidence must be provided to support the applicability of the submitted test report to the declared product. When necessary, additional biological evaluation data should be supplemented, such as leachable analysis and toxicological risk assessment data, and supplementary tests for related biological test items.

Quantitative evaluation of cytotoxicity can objectively measure cell numbers, total protein content, enzyme release, release of vital dyes, reduction of vital dyes, or other measurable parameters. It is less susceptible to the subjective bias of the tester, offers relatively high sensitivity, and provides clear determination limits. Currently, the MTT assay is a widely used quantitative method in China. In contrast, qualitative evaluation of cytotoxicity involves more subjectivity on the part of the evaluator and is more suitable for screening purposes.

When a registrant applies to amend a registration to add a product model, it is first necessary to confirm whether the new model can be considered part of the same registration unit as the existing models. If they are part of the same unit, an amendment to add the model can be applied for. If there are no new mandatory standards involved, the decision should be made based on the principles of typical model determination. If the existing models can represent the new model, then there is no need to test the new model again; if the test report of the existing model can represent some aspects of the new model, then those aspects do not need to be retested, but a test report for the new model is required for any aspects not covered. If new mandatory standards are involved, a test report must be provided showing that the new model complies with these standards, or a report proving that the existing models meet the new standards can also be submitted.

For product components that are not managed as medical devices, they cannot be registered separately but can be included as part of a medical device. If an applicant declares these components as part of a medical device, they should be evaluated as part of the whole. Therefore, these components should undergo the necessary validation and verification (including testing) along with the entire device. If they meet the requirements, they can be included in the structure and composition section of the product registration certificate. If the applicant does not declare these components as part of the product, or does not validate and verify them along with the entire device, they cannot be reflected as part of the product composition.

Generally, when selecting typical models for testing within the same registration unit of medical endoscopes, the following factors should be considered: If there is a difference in the direction of view, the model with the largest viewing angle should be selected; if there is a difference in the field of view, the models with the largest and smallest field of view should be chosen; for variations in inner diameter, outer diameter, and working length, the model with the smallest diameter and the highest slenderness ratio (i.e., the ratio of length to diameter) should be selected. For products with a working channel, the diameter considered here should be the outer diameter of the insertion part minus the inner diameter of the working channel; if there are differences in optical performance indicators like angular resolution, the model with the highest requirements should be selected.