The R&D of cosmeceuticals has been booming in recent years. Many substances, either from botanical, animal, human or chemically synthesized sources, are tested or investigated as the active ingredients in cosmeceuticals. The interactions between cosmeceuticals and human skin are complex, depending on the specific composites in cosmeceutical products, condition of the skin, general health status of a subject and the environment where the action occurs. Therefore, careful preclinical evaluation of efficacy and safety is a prerequisite for the development of a specific cosmeceutical product.

Recent advances in testing of cosmeceuticals
The methods for engineering tissue samples are among the most complex of an expanding portfolio of technologies intended to eliminate or reduce animal testing. Developing the alternative methods has turned out to be daunting partly because it takes years of testing to satisfy users and regulators that the results are as-accurate-as or better than animal trials. Many researchers believe caution is justified. However, in vitro tests using human cells have been making headway. Analysts estimate that $716 million was spent last year for contract research at labs that specialize in such alternative techniques.

The field is crowded with companies like MatTek, Admet and Xceleron. MatTek, a company in Ashland, US, grows human tissues for testing from donor cells. Charles River Laboratories, the world's largest supplier of genetically engineered rodents for labs, has a subsidiary called Endosafe, which provides an alternative to the testing of solutions in rabbits' eyes for contamination with fever-producing bacteria. In many ways, the alternatives are driven by a few giants who are eager to move from animal testing for scientific, business and for reasons of self-image. Procter & Gamble has spent millions developing and deploying alternative testing methods for a wide range of personal-care products. And L'Oréal, the French cosmetics giant, has bought Episkin and SkinEthic, two companies that develop alternative tests.

DRF develops animal free models
Dabur Research Foundation (DRF) has taken the lead in developing alternative methods to animal testing in India. These methods accelerate the screening process by decreasing time taken for screening and hence are more economical than animal testing. We use laboratory-grown human skin cells to simulate the body's response to foreign chemicals. In the last few years we have developed in vitro models which can substitute animals in various preclinical studies.

The model uses submerged cultures of keratinocytes and/or fibroblasts permitting the production of a large number of cells, and large scale toxicity screening tests with many substances, that can be applied in a broad concentration range. Since the stratum corneum is absent in conventional (submerged) keratinocyte culture systems, this model is mainly suited for testing of water soluble compounds.

For the evaluation of safety and efficacy a number of tests have already been developed, including assessment of cell viability, changes in cell morphology, modulation of cell proliferation and differentiation, monitoring of membrane damage, the measurement of uptake, establishment of the modulation of cell metabolism, and determination of the release of inflammatory mediators among others. Preliminary experiments have shown promise and rigorous tests are under way to determine the accuracy of these models. We are also investigating the complex effect of cosmeceuticals on the cell signaling and its effect on key cytokines and chemokines when they directly come in contact with human cells. The challenge is to validate these models with best in class products and correlate with what happens in real life.