Preclinical studies animals

Studies on tissues and whole animal (preclinical studies)... 

Toxicology studies must be performed in at least two animal species. If the toxicity profile of the compound is acceptable, then it joins the hit or lead list of compounds to proceed. The metabolism of the compound must be understood and pharmacokinetic studies must be performed in small and large animals. Efficacy studies must be performed in relevant animal models, especially in chimpanzees when more than one candidate is identified and a choice has to be made before proceeding to studies in humans. The ultimate preclinical steps include various studies testing drug combinations in vitro and in vivo, selection of resistant viruses, viral fitness, pyrophosphorolysis, and others. 

To determine whether human testing for a new drug or new drug product is reasonable, it is first necessary to conduct preclinical studies and to submit the IND. The necessary information needed to prepare the IND is outlined in Table 1. The IND is to contain information on appropriate prior animal studies for safety evaluation, any available clinical data, adequate drug identification and manufacturing instructions, and a detailed outline of the proposed clinical study, routs of administration, approximate number of patients to be used, and an estimate of the length of treatment and an environmental impact statement. 

The last step of the drug discovery process involves the testing of lead compounds to address issues such as efficacy, bioavailability, and safety. Testing may include in vitro assays but ultimately would require a suitable disease model and studies in animals. Many compounds may need to be designed and synthesized to identify the one compound with all the desired properties. Such a compound can be advanced to preclinical studies and eventually to the clinic. 

Preclinical studies should address the potential toxicity due to inappropriate release of the conjugated toxin. Preclinical toxicology of monoclonal antibodies may not require extensive animal studies but should be examined for cross-reactivity with antigenic epitopes present on normal cells in vitro and for the presence of human or rodent vimses. Early clinical trial should involve biodistribution studies with radiolabelled material. 

Preclinical studies Animal studies that support Phase I safety and tolerance studies and must comply with Good Laboratory Practice (GLP). Other preclinical studies are done in discovery research laboratories to support drug efficiency claims. 

One major purpose of preclinical (animal) toxicity studies of a potential new drug is to identify the toxic effects which most commonly occur at doses nearest to those to be used in humans. These observations serve to help ensure that care is taken to detect any such effects in humans. Additionally, a broad range of other indicators of adverse drug action may be identified to ensure that their occurrence is looked for. These are also commonly called safety parameters. 

Liquid instillation and nebulised aerosols are the most common methods for pulmonary administration to experimental animals [22, 54, 109, 134], The use of pressurised metered dose inhaler (pMDIs) and dry powder inhaler (DPIs) in preclinical studies is limited by the need for formulation development, which often cannot be performed in early drug discovery due to short supply of test materials. A number of alternative techniques for intra-tracheal administration of coarse sprays and powder formulations have been described [9, 15, 21, 36, 71, 80, 99, 138],... 

Undertake preclinical studies (Preclinical Development) this involves many different important steps, of which the most critical is safety evaluation of the efficacious drug candidate in animal models. Before introduction of any new drug in humans it must be shown to be safe in animals. 

Antithrombotic prophylactic in Europe, for interstitial cystitis in the United States Animal models to treat osteoarthritis, preclinical studies as anticancer agent, inhibits metastasis and angiogenesis 1, 32-37... 

Oligomers of perfluorohexyl-ethene fulfilled these expectations in all preclinical studies, in vitro tests as well in animal tests. A radical polymerisation, followed by ultra-purification steps, created a crystal clear gel-like substance. The behaviours of the mixture of dimeric, trimeric and tetrameric star-shaped species with an inner core of hydrocarbon bonds and an outer layer of perfluoro-alkyl chains could be adjusted by the ratio of the dimeric, trimeric and tetrameric species, using a thin layer distillation. In dependence on this ratio, the viscosity could be adjusted in the range between 90 mPas and 1700 mPas, the specific density between 1.60 g/ml and 1.66 g/ml and the interfacial tension against water between... 

As mentioned above, most of the preclinical studies on the effects of early stress have examined the impact of these experiences on adult animals. The preliminary work discussed in this section highlights the need for more developmentally focused preclinical studies of the effects of early stress. In addition, there is a need for more research on the development of the CC, and circadian control of cortisol secretion. 

Preclinical studies have shown that fetal tetrahydro-cannabinoid levels remain lower than maternal plasma levels, indicating that the placenta may act as a partial barrier to this class of compounds. Decreased birth weight and postnatal growth have been observed in rats prenatally exposed to cannabis. Some studies have observed learning deficits in prenatally exposed animals, while others have not (Lee, 1998). 

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