In-use tests

As with evaluation of preservative challenge tests, manufacturers are at liberty to set their own evaluation criteria for such tests. When evaluating user-tests, it is reasonable to expect the presence of micro-organisms in the product immediately after use. Analogous to the preservation challenge test one would expect a reduction in microbe number over a pre-specified time. Returned product samples with 10 cfu/g suggest product preservation is insufficient. Lower microbe numbers should be reduced over an acceptable time period to 100 cfu/g. 

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Therefore the problem of development of express, inexpensive and simple in use test-methods for determination of volatile amines is of present day interest. 

Performance rests for local venrilatlon systems are classified in the following three ways type, commissioning, and in-use tests. 

The commissioning tests are typically performed before a local ventilation system is put into use the purpose is to confirm that the design conditions have been achieved. Hence, commissioning tests apply to methods used in type testing, but in a simple and modified way. In-use tests concentrate on the exposure effects of a local ventilation system. 

In-use tests deal with the concentration measurements in the worker s breathing zone for various hood applications. The performance tests presented here are typically in-use tests, where normal work procedures are ongoing. 

The efficacy of an antimicrobial agent must be investigated by appropriate capacity, challenge and in-use tests to ensure that a standard is obtained which is appropriate to the intended use (Chapter 11). In practice, it is not usually possible to know which organisms are present on the articles being treated. Thus, it is necessary to categorize chemicals according to their antimicrobial capabilities and for the user to have an awareness of what level of antimicrobial action is required in a particular situation (Table 10.1). 

The wide range of micro-organisms found in emulsion paints dictates the use of broad spectrum products. However, many biocides are less active against fungi than bacteria (or vice versa) and it is therefore important to ensure that biocide manufacturers claims are backed up by results of realistic in-use tests. 

Where a large pack size is provided, it might be necessary to undertake more extensive in-use testing and/ or to restrict the in-use shelf life once the container has been opened. In addition to preservative efficacy testing the chemical stability of antimicrobial preservatives should also be investigated over the unopened and in-use shelf lives of the product. 

Aubry, A.F., Sebastian, D., Hobson, T., Xu, J.Q., Rabel, S., Xie, M., and Gray, V., In-use testing of extemporaneously prepared suspension of second generation non-nucleoside reversed transcriptase inhibitors in support of Phase I clinical studies, /. Pharm. Biomed. Anal., 23,535,2000. 

In order that a wax be accepted for use as a desensitizer in an expl compn, it must not only meet the requirements of Specification Ml L-W-20553, it must also be found acceptable in use tests. Such tests include characterization of a wax in the specific expl compn for incorpora-bility, possibility, sensitivity, physical compatibility, flow properties, cast shrinkage, etc. Examples of Army qualificationworkis contained in Refs 63,87,92 99. The qualification test procedures required by the Navy are spelled out in Ref 95. Specification MIL-W-20553D, paragraph 6.4.2 cites NWS TR-1 and TR-2 for qualification of waxes for Composition B and H-6 and D-2, respectively, and WS 13574, OD 45295 and WS 13564, OD45001 for qualification of Compn A-3... 

Valve delivery (spray weights), 40 Meter chamber size, in-use test,... 

In use tests represent a very valuable tool in the assessment armory. Many personal care products are designed for frequent skin contact, often with very sensitive areas of skin (e.g., the face or underarm). Materials such as face creams and deodorants, etc. must therefore be evaluated for their irritation potential to ensure that they are safe for normal use. A use or exaggerated use test provides data on which a safety assessment can be made. A test material is compared with a control, usually a material of similar formulation that is already marketed, and has an acceptable market history. The frequency of exposure may be exaggerated to maximize the sensitivity of the test. For the duration of the test, panellists are provided with test and control materials and a treatment card to record the daily use of each material. The materials issued at the start of the test are weighed before and after the test, so that the amount of material used can be calculated. 

The guideline does not include the design of in-use test, nor does it cover abridged applications (in all regions), clinical trial materials, or generic products. In-use considerations can be complicated and need to be addressed in the future. 

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

Studies have reported success in using test specimens attached to dentures [40—42] or intraoral appliances [43-45], and, in a small number of examples, test specimens were cemented to natural teeth [46] or inserted into crowns or crown facings [47, 48],... 

The design of in-use tests such as the stability of reconstituted lyophilized products, or products administered through an intravenous drip, is excluded from the ICH Guideline but should be based on the same principles and considerations as the formal product test. When high-volume infusion products are administered, they may be exposed to ambient light conditions for some hours and this could include exposure to glass-filtered sunlight. 

One should ensure that in use testing, patient acceptability and possible abuse and misuse aspects are adequately covered and interpreted, since most formal shelf-life testing does not involve any use of product and pack. It is possible that the product—pack may have a restricted shelf life once the pack is opened and is in use, i.e. it may occasionally be necessary to have two shelf-life periods, e.g. for reconstituted and/or overwrapped products ... 

In-use tests with patients. May be part of clinical evaluation or an extension to it. Most important with devices or where pack acts as an administration aid. 

In-use tests, etc. (i.e. checking possible misuse, abuse by patient or user). 

A stability program not only covers registration studies, but also includes studies that are set up to provide supporting data to other programs such as bulk storage, in-process testing, in-use testing, or excursions. This chapter offers details of studies to support these purposes. 

Generally required as part of in-use testing. Would be required for products in semi-permeable containers on stability. 

In-use testing should be performed on two batches, at least one of which should be near end of shelf-life or at the final time-point of the submitted stability studies [34, 35]. Thus if a product is to be used within 3 months after removal of the protective packaging (according to the Instructions For Use (IFU)), the product should be removed from the protective packaging 3 months before the end of the shelf-life, and... 

Samples to be removed for in-use testing, if appropriate as determined by when the data are to be filed and the shelf life being requested. 

Daniels GF, Ashurst 1C, Malley TR, Walker S, Noble R, Gillet B. Simulated patient in-use testing at extreme environmental conditions of a dry powder inhaler device containing a combination of salmeterol and fluticasone propionate (abstr). Eur J Respir 1999 14 (suppl 30) 2284. 

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