TX Q&A

During clinical treatment, some purified blood may return to the entrance of the extracorporeal circulation circuit, meaning the blood flows in reverse from the venous end to the arterial end, constituting recirculation of the purified blood. The recirculation of the vascular access not only affects the dialysis efficiency but also interferes with the assessment of dialysis adequacy. The measurement, evaluation, and application of vascular access recirculation can guide clinicians in tailoring personalized prescriptions for different dialysis patients and assessing vascular dysfunction to enhance dialysis efficacy, providing essential guidance.

Absorbable bone plate trauma products are primarily used in low-load-bearing areas, with common types including absorbable limb bone plate fixation systems and absorbable craniofacial bone plate fixation systems, which should be categorized into separate registration units. If the composition materials of the products differ (including aspects like chemical composition, molecular weight, specific rotation, crystallinity, etc.), they should be classified into distinct registration units. Based on common absorbable polymer materials, they can be categorized into registration units such as poly-L-lactic acid, poly-d,l-lactic acid, and copolymers of lactic acid and glycolic acid.

During comparison, the applicant should provide a detailed description of all software differences, analyzing whether these differences affect the safety and effectiveness of the product. If necessary, clinical/non-clinical data of the declared product should be submitted to demonstrate that these differences have not had any adverse effects on safety and effectiveness.

Orthodontic brackets are medical devices bonded to the surface of the tooth crown, used in orthodontic treatment to bear and transfer corrective forces. Typically made of metal, ceramic, or polymer materials, they usually have slots, tie wings, and some may have traction hooks. Orthodontic bracket products with different materials should be classified into different registration units, such as ceramic brackets and metal brackets should be classified as different registration units; products with different structural compositions should be classified into different registration units, such as self-ligating brackets and non-self-ligating brackets should be classified as different registration units; products with different design principles should be classified into different registration units, such as lingual brackets and labial brackets should be classified as different registration units; products that must be used together to achieve the intended purpose can be considered as the same registration unit.

Referring to YY/T 0962-2014 "Cross-linked Sodium Hyaluronate Gel for Plastic Surgery," for injectable sodium hyaluronate gel used in plastic surgery, it is recommended to establish requirements for in vitro degradation testing in the product technical requirements. This serves as a quality control measure for the degradation performance of sodium hyaluronate gel. It is suggested to set multiple observation time points, observe until the complete degradation of the sodium hyaluronate gel, and specify upper and lower limit requirements for the degree of degradation at different time points. In vitro testing can accelerate degradation by adjusting experimental conditions such as the concentration of degrading enzymes.

If the radiotherapy planning system is a general planning system that can be used with multiple radiotherapy devices, it should be declared separately. However, if it is a dedicated planning system for a specific radiotherapy device, it can be declared together with that radiotherapy equipment.

Changes to the content of the instructions for in vitro diagnostic reagent products fall into two categories: textual changes to informational content and other content changes. 1. Textual Changes to Informational Content: According to the "Notice on Textual Changes to Instructions for In Vitro Diagnostic Reagents" (SFDA Medical Device Office [2016] No. 117), applicants can make textual changes to informational content on their own. Specifically, changes may include: - Changes in basic information such as contact details of the registrant or manufacturer of in vitro diagnostic reagents, the name and contact details of the after-sales service unit, changes in the production license number or production filing certificate number, and changes in the contact details of the agent for imported in vitro diagnostic reagents. Changes to the production license number or production filing certificate number should be made after the corresponding provincial food and drug supervision department has issued the production license or production filing certificate. - Changes in the Medical Device Registration Certificate number/Product Technical Requirements number should be made by the registrant after the corresponding food and drug supervision department has issued the medical device registration certificate. - Changes in the interpretation of labels should be made by the registrant if it enhances the explanation of corresponding labels in the instructions according to the YY/T 0466 series standards, without involving other changes that require permission. 2. Other Content Changes: The content of the instructions for in vitro diagnostic reagents should be considered as part of the registration certificate. Apart from the aforementioned informational content changes, other content changes should be modified through an application for permission to change. Notification of changes to the instructions does not apply to in vitro diagnostic reagents.

The stability verification of concentrates is recommended to reference the "Guiding Principles for Stability Testing of Raw Materials and Preparations" in the Chinese Pharmacopoeia. Submit verification data for long-term testing of drug formulations and determine the product's shelf life based on the results. Observe the stability of concentrates for all models and package sizes at different assessment time points under the selected storage conditions of temperature and humidity corresponding to southern or northern regions during actual storage and transportation. Observation parameters should include clauses in the technical requirements and analysis of chemical contaminants. As per the technical requirements, provide inspection results for solute concentration, insoluble particles, microbial limits (or sterility), endotoxins, etc., at different assessment time points for concentrates. For dry powder, include comparative results for dissolution time. For online use of B-type dry powder products, provide test results for ion concentration and pH values of at least four time points (at the start of dialysis, at three equal intervals during clinical use, and at the end of dialysis). Chemical contaminant analysis at different assessment time points should refer to the detection indicators in YY 0572 "Water for Hemodialysis and Related Therapies," and chemical ions already present in the raw materials of the formulation do not need to be tested.

After the reagents intended for registration have passed inspection, they can be used for clinical trials with either inspection batches or non-inspection batches. The reagent batch numbers used by each institution should be clearly stated in the clinical trial report. If the clinical trial duration is long, multiple batches can be used based on actual circumstances. However, it is important to note that the reagents used in clinical trials, registration inspections, and preclinical studies of in vitro diagnostic reagents should be produced under conditions that comply with the medical device quality management system, and the production quantity of the batch should be sufficient. For domestic products, if the batches used in clinical trials, registration inspections, and preclinical studies are different, the reasons and specific details of the production batches should be explained.

In addition to establishing corresponding physical and chemical requirements based on the product characteristics in the technical requirements, the applicant should simulate the actual clinical use conditions to verify the special performance of the product. The verification tests should consider aspects such as product design, intended use, methods of use, and duration of use, and suitable test methods should be developed based on the product characteristics. When developing the test plan, the following should be considered at least: 1) The test steps should be consistent with actual clinical operations; 2) The selection of test conditions should cover possible clinical scenarios; 3) The sample size for testing should reflect scientific rigor; 4) The number of verifications should not be less than the claimed number of uses of the product; 5) Other relevant guidance documents, etc.