In vivo testing methods

In all antiseptic testing, it is recognized that skin and mucous membranes to which products ate appHed cannot be disinfected or sterilized but it is possible to significantly reduce the population of transient and resident pathogenic bacterial flora. AH in vivo test methods requite a deterrnination of the bacteria on the skin before and after treatment. Because of the normal variation in bacterial population of the skin of different people, a number of people must be tested in order to make a statistical analysis of the results. Different parts of the body are used for different tests. In aH of the tests the details of the protocol ate extremely important and must be strictly adhered to in order to obtain reproducible results. 

Keller, J. C., Hammond, B. D., Kowlay, K. K. Brauer, G. M. (1988). Biological evaluation of zinc hexyl vanillate cement using two in vivo test methods. Dental Materials, 4, 341-50. 

Some modifications to current in vivo testing methods both can and should be adopted. A current example of this would be in medical devices where a substantial portion of the requirements under the governing regulatory (ISO 10993) can be met with in vitro alternatives (cytogenicity, muscle cell implantation, the limulus test for pyrogens, and in vitro mutagenicity assays). 

The in vitro and in vivo test methods available to study combined actions and toxicological and biochemical interactions of chemicals in mixtures are essentially the same as those used for the study of single chemicals in order to examine their potential general toxicity and special effects such as mutagenicity, carcinogenicity, and reproductive toxicity. 

Olivarius PDF, Hansen AB, Karlsmark T, Wulf HC (1996) Water protective effect of barrier creams and moisturizing creams a new in vivo test method. Contact Dermatitis 35 219-225... 

In vitro methods Tissue binding assays. If no in vivo models are available, in vitro methods combined with in vivo testing in a pharmacologically nonreactive may suffice. 

Several in vitro methods, including the hen s egg chorioallantoic membrane test (HET-CAM) the bovine cornea opacity and permeability assay (BCOP) and the isolated rabbit eye (IRE) test, have gained regulatory acceptance in Europe for the classification of severe eye irritants. Many companies are using such techniques successfully to reduce in vivo testing during development. ... 

The potential reproductive toxicity of chemicals has been studied in both in vitro and in vivo test systems (5). However, in many of these tests a variety of methods were used to assess reproductive toxicity which makes it hard to compare the effects of chemicals from laboratory to laboratory. 

Sample Volume <100 L, High Concentration Factors. Lyophiliza-tion is a feasible process for concentrating limited numbers of 50-100-L samples to relatively high degrees of concentration (e.g., 3000-fold to dryness). Thus, it is one method of choice for the preparation of samples for in vivo tests (including teratology tests). 

The fact that thromboresistance of HCP is dependent on the method of immobilization of heparin, together with a rather low activity of covalently immobilized heparin, makes the idea of long-term enhancement of thromboresistance of polymers on their heparinization doubtful 54,70,71J. Naturally, the answer can be given only after a detailed analysis of the interaction of HCP with blood and its components and clarification of the mechanism of the effect of the immobilized heparin on the blood clotting system and relying on the results of in vivo tests of these materials are necessary. 

The protein digestibility values for pH-shift methods generally correlate well with in vivo digestibility methods in the sense that both tests yield the same relative ranking for test proteins (Pedersen and Eggum, 1983). The difficulty with an in vitro method is that it does not accurately estimate qualitative differences between samples with low and high protein digestibilities. 

---