220-Dictionary of Pharmaceutical Medicine, 2nd Edition-Gerhard Nahler Annette Mollet-3211898352-S

49defined daily dose (DDD) Assumed average dose per day for a drugused in its main indication in adults; basis for cost comparison ofmedicinal products for reimbursement; → see also acceptabledaily intake, overdose.delayed release modified release product in which the release ofthe active substance is delayed for a finite “lag time”, after whichrelease is unhindered (e.g., enteric coated or gastro-resistant oraltablets or capsules which remain intact in the stomach and onlydisintegrate in the higher pH of the small intestine); delayed releaseresults in a longer Tmax but with Tmax and elimination halflife unchanged (European Pharmacopoeia, EudraLex 3AQ19a:Quality of prolonged release oral solid dosage forms, Nov. 1992);→ see also controlled release, prolonged release.delta value syn. minimum relevant difference, smallest clinicallymeaningful difference; size of a clinically or therapeutically meaningfuldifference (e.g. improvement in outcome, tolerance, costs)that a trial is designed to detect; in experimental trials delta shouldbe set to define an improvement that is great enough that mostpeople would select the new treatment despite its potential unknownhazards; → see also alternative hypothesis, beta error,sample size estimation.demographic data Data describing basic characteristics of subjectsin a clinical trial, e.g. age, sex distribution, ethnic origin, length ofcurrent disease, number of subjects treated de novo a.s.o.descriptive statistics Presentation of results by their median, arithmetricmean, standard deviation, mode, distribution of data withmin. max. values a.s.o.; → see also inference statistics.design Cross-over d. (opp. parallel) = two period or multi-periodcomparison (within- or between-subject); each subject receivestwo treatments one after the other (or simultaneously e.g. left vsright for topical treatments), the order of treatment being decidedrandomly; this d. is appropriate when the disease process orsubject is relatively stable (e.g. bioequivalence studies in healthyvolunteers, M. Parkinson, myasthenia a.s.o.), when treatments arenot curative, when periods of treatment are short, when there is nointeraction or order effect and when the number of dropoutsand withdrawals can be kept low; within-subject studies allowin general a more precise comparison of treatments and require asmaller number of subjects than between-subject studies; a washoutperiod is usually essential between treatments to eliminatedrug or drug-effect carry-over; special types of cross-over d. arelatin square d., and graeco-latin square d.; a factorial d. canbe planned either as cross-over or as parallel d. and answers twoquestions at the “price” of one; parallel d. = simultaneous group-des