Experimental start date

Experimental starting date Experimental completion date Studyinitjalion date Study completion date... 

Experimental start date" means the first date the test substance is applied to the test system. 

To determine the stability and, when relevant to the conduct of the experiment, the solubility of the test, control, or reference substance in the mixture before the experimental start date. Determination of the stability and solubility of the test, control, or reference substance in the mixture shall be done under the environmental conditions specified in the protocol and as required by the conditions of the experiment. Where periodic analysis of the mixture is required by the protocol, there shall be written standard operating procedures that shall be followed. 

Consider the statements that an experiment starts at "the date on which the first study specific data are collected. and is completed on the last date on which data are collected from the study. Could these dates not be defined in a more straightforward way Why, for instance, should the experimental starting date not be the date on which the test item is first applied to the test system, as it is stated in the GLP Regulations of the Environmental Protection Agency (40 CFR 160 and 792, resp., see Appendix II.III, page 329) And, conversely, why should the experimental completion date not be the date on which the test item is last applied to the test system The answer to these questions is, however, not as simple as it would seem at the first glimpse. It may be true that in the majority of cases, test item application can best define the experimental phase, i.e. its beginning and end. However, consider two situations, one of which has been already used to elucidate another point. 

Consider the two-year lysimeter study which has been described above, and in which there is just one application of the test item. Could this be the experimental starting as well as already the experimental completion date For the experimental starting date, this may well be correct but is it equally true for the completion date Certainly not, because the main experimental effort in such a study is the analytical determination of the test item concentration in the effluents and its distribution within the core of the lysimeter. Therefore, it is completely out of the question to set the experimental completion date as the date on which the test item has last been applied to the test system. 

This may certainly prove to be difficult at times, especially in the context of a study of relatively short duration. In such a case, one can imagine that the Study Director would possibly have had to decide on the spot about some necessary (but nevertheless planned) change. To dictate the amendment and to have it typed by the secretary, or to go back to the office and to type it himself, to date and sign it, and to distribute the necessary copies to all the persons concerned, including the Quality Assurance, would in such a case take too much time. Unless the change could be immediately implemented (and the amendment written later), the study would in all probability have to be aborted. Thus, a certain latitude in the interpretation of the resemblance of an amendment with the study plan can certainly be exercised. When, however, in longer term toxicity or field studies amendments are uncovered that are concerned with some start parameters of the study, but which are written (or at least dated and signed) well after the experimental start date, or maybe even after the experimental study completion date, then the correct term for such a document is certainly not Amendment anymore, because in this instance it has failed the intentions of the GLP Principles, namely that the amendment... 

Experimental starting date means the date on which the first study specific data are collected. 

When relevant to the conduct of the study (792 experiment), to determine the solubility of each test, control, or reference substance in the mixture by the testing facility or the sponsor before the experimental start date. 

Four time points have been defined in the OECD Principles for start and end of a study. The so-called study initiation and study completion dates do not contain any ambiguities that could give rise to interpretation difficulties. The dates when the Study Director signs study plan and final report are unambiguous calendar dates, and they clearly mark the two time points between which a study has been conducted. However, more difficulties are encountered with the experimental starting and completion dates for themselves and for their connection with initiation and termination dates. 

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