Alternatives to animal experimentation: developing in-vitro methods and changing legislation.

Despite recent changes in legislation in several countries and general reduction in the use of animals in biomedical research, the impatience of antivivisectionists to see reductions in animal experimentation shows no signs of abating. Gerhard Zbinden analyses the reasons for this continuing dissatisfaction, arguing that real progress has been made in biomedical research, but that the complexities of developing internationally recognized regulations constitute a barrier to rapid change in product safety testing methods.