TX Q&A

Metal cables and cable systems are used for internal fixation of limb fractures, with the structure detailed in YY/T 0812. Products with different constituent materials (including material grades) are categorized into separate registration units. Based on the commonly used metal materials for the main components of cables and cable systems, registration units can include TC4 titanium alloy, TC4ELI titanium alloy, TC20 titanium alloy, 00Cr18Ni14Mo3 stainless steel, cobalt-chromium-tungsten-nickel alloy, and others. Metal components used in conjunction with metal cables and cable systems, such as locks, can be categorized under the same registration unit if the constituent materials differ but are used as an integrated assembly or combination. Metal cables, cable systems, and flexible metal wires fall under different registration units.

1. Pay attention to the final ion concentration of the dialysate, the components and proportions of the chemical raw materials in the AB agent, the status of the dialysis concentrate provision, and the ratio of concentrate to dialysis water. If there is any difference in the above four aspects, a comprehensive registration testing report should be provided for each. 2. If the product is provided in concentrated liquid form, provide a full-item registration test report that complies with the YY 0572 standard for dialysis water used in production. 3. When applying for online use of B powder according to the instructions for use on applicable machine types, provide registration test reports in different packaging forms based on clinical usage. This should include at least four time points (at the start of dialysis, at three equally spaced clinical usage time points, and at the end of dialysis) and registration test reports related to the dialysate formation with the A agent.

First, it should be confirmed whether the additional model applied for can be considered as the same registration unit as the original model. If they can be considered as the same registration unit, you can apply for permit changes to add models. In cases not involving new standards, the determination should follow the principle of typical model representation. If the original model can represent the new model, there is no need to repeat the testing. If new standards are involved, a testing report for the new model against the new standards should be provided. If some items in the testing report of the original model can represent the testing of the new model, there is no need to repeat testing for those specific items.

Although the risk of quality changes during the storage period decreases when the shelf life of the product is shortened, it is advisable for the registrant to provide a reasonable explanation and necessary supportive materials when applying for permit changes. For instance, if it is discovered after conducting real-time stability testing that the shelf life of the product should be shortened, it is recommended to provide verification data from this real-time stability testing.

Accelerated stability testing involves subjecting a product to external stress to assess material degradation under stress conditions. By using known acceleration factors and degradation rates, the test infers the material degradation under normal storage conditions. Therefore, storage conditions are directly related to shelf life, and it is necessary to specify the product's storage conditions.

A core algorithm refers to the algorithms necessary to implement the core functions of software (functions necessary for the software to achieve its intended purpose in the expected usage environment), including but not limited to imaging algorithms, post-processing algorithms, and artificial intelligence algorithms.

When selecting a clinical trial institution for in vitro diagnostic reagents, in addition to regulatory qualifications, attention should also be paid to whether the institution has the conditions and capabilities to conduct clinical trials. Firstly, the institution should have the capability to conduct the relevant testing projects, be familiar with the testing projects for the products to be evaluated, and routinely carry out the corresponding tests. If it involves new products or markers, institutions should also choose those familiar with the relevant methods or similar tests and regularly conduct related disease diagnosis and treatment work to conduct the trials. Evaluation of the institution's testing capabilities should include laboratory conditions and personnel. Secondly, the selected institution should be able to recruit a sufficient number of eligible participants for the trial and choose institutions with specific disciplinary advantages for the product's specific indications. Additionally, the clinical trial institution should be able to ensure cooperation in the registration declaration process, including conducting necessary supplementary tests, and assisting with clinical trial audit.

When conducting in vitro degradation studies on absorbable hemostatic products, it is recommended to simulate in vivo conditions (such as the environment at 37°C, proteolysis, etc.) to study the time required for the product to be completely absorbed and degraded, as well as all degradation products. It is advisable to establish reasonable in vitro degradation study methods based on the product characteristics and clinical applications. It is recommended to refer to existing standard methods and compare them with similar products that are already on the market. The suggested observation indicators for in vitro degradation studies include product solubility, degradation cycle, conditions required for degradation, the relationship between degradation speed and conditions, the main degradation products and their quantities, and morphological changes (disintegration process, whether there are fragments falling off, fragment swelling, etc.).

The sample type should be consistent with what is claimed in the instructions. For situations covering different sample types, if the product's claimed different sample types are comparable, such as serum or plasma, one type of sample should be primarily used. The sample quantity should meet the "Technical Guidelines for Clinical Trials of In Vitro Diagnostic Reagents" for clinical trials, with additional clinical trials comparing other types of samples to the aforementioned samples. The number of comparison samples should meet the requirement of at least 200 cases for Class III products and at least 100 cases for Class II products, conducted in at least two (including two) clinical trial institutions. If different sample types are not comparable, one type of sample volume should meet the "Technical Guidelines for Clinical Trials of In Vitro Diagnostic Reagents," with the remaining sample types compared to the control reagent, increasing each sample type as appropriate compared to the aforementioned situation.

For in vitro diagnostic reagent products used for rare disease detection, the number of clinical positive samples can be appropriately reduced, but the total number of clinical positive samples should be statistically significant.