Simulated use tests

In fact, there is a recognition that a range of different test data may be required to support label claims. An applicant for authorisation of a biocidal product can confirm their efficacy claim with the provision of data from simple laboratory studies, laboratory simulated-use tests, pilot system studies or field studies according to either standard and/or non-standard test methods. 

Assays for potency, preservative effectiveness, compatibility with primary container-closure system, off-torque, simulated use testing, etc., should be handled in a manner similar to that used for conventional liquid solutions, with the provision that the container is well-mixed prior to sampling. 

Apart from suspension tests, in-use testing of used medical devices, and simulated use tests involving instruments or surfaces deliberately contaminated... 

Simulated use tests involve deliberate contamination of instruments, inanimate surfaces, or even skin surfaces, with a microbial suspension. This may either be under clean conditions or may utilize a diluent containing organic (e.g. albumin) material—dirty condition. After being left to dry, the contaminated surface is exposed to the test disinfectant for an appropriate time interval. The microbes are then removed (e.g. by rubbing with a sterile swab), resuspended in suitable neutralizing medium, and assessed for viability as for suspension tests. New products are often compared with a known comparator compound (e.g. 1 minute application of 60% v/v 2-propanol for hand disinfection products— see EN1500) to show increased efficacy of the novel product. 

It is also useful to conduct a simulated use test in which the product is opened each day and drops administered according to the dosing instructions for 28 days. The remaining formulation should pass the preservative efficacy test at the end of this period. 

Interaction between closure and pack (e.g. the black slurry which may occur with aluminium collapsible tubes), and possible adhesion between closure and pack (e.g. as may occur with sugar- or syrup-based products), are typical of what could occur if usage tests were omitted. Simulated use tests are particularly important with aerosols, pump systems, etc., which combine the closure with a dispensing system. 

E1837-96. Standard test method to determine efficacy of disinfection processes for reusable medical devices (simulated use test). 

Tests Simulating Use Conditions. Several simulation tests involving wear and use testing have been developed. The first and only one to be adopted as a standard in the United States is AATCC Test Method 134-1975 for measuring the electrostatic propensity of carpets (60). In this test a person wearing standard neoprene and leather sole shoes and carrying a probe connected to an electrometer walks on a carpet for 30 to 60 s until the measured body voltage builds up to a maximum. 

It has also been shown by various testing laboratories that the in-vivo failures can be simulated using in-vitro simulators without the presence of a corrosive medium and provided that a torsional component of load is applied to the prosthesis. 

In the case of reservoir systems that rely on the cohesivity of the blend due to interparticle interactions, studies are required on vibrational stability in simulated storage, transport, and use tests, including determination of the effects of elevated temperature and humidity. 

Timm, Gilbert, Ko, and Simmons O) presented a dynamic model for an isothermal, continuous, well-mixed polystyrene reactor. This model was in turn based upon the kinetic model developed by Timm and co-workers (2-4) based on steady state data. The process was simulated using the model and a simple steady state optimization and decoupling algorithm was tested. The results showed that steady state decoupling was adequate for molecular weight control, but not for the control of production rate. In the latter case the transient fluctuations were excessive. 

Anyhow, the result of any flow simulation should be grid independent, i.e., the flow field should not be different if a finer grid is used for the simulation. This test is to be carried out always and everywhere, and may really be described as a conditio sine qua non. 

In co-operation with a German chemical company, a recipe-driven batch process was modelled and simulated using PPSiM. In the simulation study, different pipeless plant scenarios were tested and evaluated. The plant under consideration produces a set of consumer care products. 

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