Preclinical safety evaluation using nonrodent species: an industry/welfare project to minimize dog use.

This review of the dog, the primary nonrodent species used in toxicology, and its use in the safety evaluation of pharmaceuticals, provides data on the number used in particular projects in an effort to establish a baseline from which some minimization can be measured. Opportunities for reduction and replacement, as identified by a European Industry/Welfare Steering Group, are discussed. The three distinct areas of potential approaches to minimize dog use are categorized as industrial cooperation/data sharing, achieving best practice in study design, and assessing the need for a particular study. The Steering Group prioritized the approaches based on the impact on the number of animals used, the impact on the welfare of the remaining animals, the potential for industry's acceptance of the scientific approach, the potential for regulators' acceptance of the validated approach, and the time/cost of evaluation or implementation. Examples of each category are presented, and the work needed to facilitate industry/regulatory change is discussed.

An approach to minimise dog use in regulatory toxicology: production of a best practice guide to study design.

The primary non-rodent species used in toxicology is the dog. It is generally agreed that, for ethical reasons, dog use should be reduced to the minimum consistent with maintaining the scientific quality of toxicology studies and ensuring human safety. Dog use in toxicology has been discussed widely, both from a scientific and ethical viewpoint, and there appears to be real potential for achieving significant reductions in the number of dogs used in pharmaceutical safety testing. An industry animal welfare initiative commenced in 2000, with the aim of evaluating and, where possible, putting into practice, scientifically valid approaches to minimise dog use in regulatory toxicology without increasing the use of other non-rodent species, such as non-human primates or minipigs. The study's Steering Group categorised potential reduction approaches into three distinct areas, one of which is the production of a best practice guide on aspects of study design, including: group sizes, use of control animals, single sex studies and design of maximum tolerated dose (MTD) studies. Information on current practice and experience within the pharmaceutical industry is now being analysed, and additional input is invited.

Type B Ventricular Preexcitation With Abnormal Contraction of the Ventricular Septum in a Dog.

A 14monthold female beagle had ventricular preexcitation (VP).The finding was characterized by a wide positive QRS complex with a tall notched R wave in leads I, II, III, and aVF, an inverted QRS complex in leads aVR and aVL, a Q wave in lead I, and a short PR interval. Compression of the carotid sinus caused an anticipated marked decrease in heart rate, but did not reveal latent electrocardiographic abnormalities. We did not detect evidence of ventricular hypertrophy during echocardiography. Examination of the M-mode image indicated abnormal movements of the septum. There were 2 sharp waves at each systole instead of a single wider wave that is seen for clinically normal dogs. To further characterize this ECG finding, the affected dog and 2 clinically normal female beagles (positive control dogs) were given atropine (0.025 mg/kg of body weight, i. v.) Increases in heart rate, relative to values obtained before atropine administration, were evident in all 3 dogs. Increase in heart rate in the dog with VP appeared sooner after injection than in the clinically normal dogs; it was evident at the conclusion of the atropine injection. When the increase in heart rate was maximal in the affected dog (3 min after atropine administration), notching of the R wave disappeared, and the QRS duration decreased to about 60 ms. Echocardiographically, atropine produced a decrease in end diastolic, end systolic and stroke volumes in all treated dogs, which was similar between clinically normal dogs and the dog with VP. Atropine administration also was associated with a decrease in the percentage of thickening of the septum in the dog with VP, but not in the clinically normal dogs. We did not detect histopathologic abnormalities in the heart of the dog with VP.

Evaluation of lung tolerance of ethanol, propylene glycol, and sorbitan monooleate as solvents in medical aerosols.

BACKGROUND: Aerosol therapy is an expanding technique allowing administration of drugs acting locally in the bronchial tree and lungs or acting systemically after absorption through the respiratory tract. However, the choice of solvents and adjuvants is a critical step in the formulation process of new drugs. Pulmonary tolerance of ethanol, propylene glycol and sorbitan ester was evaluated in a rat model of intratracheal administration using a Microsprayer in a 4-day toxicity study. METHODS: Four groups of Sprague-Dawley rats (11 rats per group, n = 44) have received, on 4 consecutive days 150 microL of solutions containing the solvents, by intratracheal route using a IA-1B-2 inches-Microsprayer (PennCentury, Philadelphia, PA). Once a day, the rats received deionized water (control) or ethanol 10% or propylene glycol 30% or sorbitan monooleate 10%. All rats were sacrificed 24 h after the fourth administration. Biochemical analysis on bronchoalveolar lavage (BAL) fluid was performed on seven rats per group. The respiratory tract of the remaining four rats/group was examined histologically. RESULTS: Biochemistry and histopathology findings demonstrated that under the conditions tested, deionized water, 10% ethanol, and 30% propylene glycol were tolerated in a qualitatively similar way presenting limited cellular reaction. In contrast, 10% sorbitan monooleate produced an accumulation of foamy macrophages in the lungs and a higher degree of inflammation. In addition, animals in this group showed higher polymorphonuclear neutrophil recruitment and total proteins levels in BAL fluid. CONCLUSION: The overall results recommended ranking the vehicles according to the degree of inflammation which was induced: deionized water <10% ethanol < or =30% propylene glycol <10% Tween 80.

Optimising the design of preliminary toxicity studies for pharmaceutical safety testing in the dog.

A working party, comprising two animal welfare organisations and some 12 pharmaceutical companies in Europe, was established to minimise the use of the dog in safety testing. As first step, the participants defined the major objectives of preliminary dose-range finding/MTD toxicity studies in non-rodents, defined the principles and requirements for this study type and agreed on a proposal for an optimised study design, based on collective experience of conducting such studies in industry, involving an evaluation of 100 individual study data sets. The suggested study design is explained and described, and reflects current best practice in the pharmaceutical industry in Europe. The implementation of such an optimised design is believed to result in a reduction in the overall numbers of animals used for this purpose, without jeopardising the scientific rationale and usefulness of the studies for informing the conduct of later regulatory studies.