PETER DYKES
Cutest Systems Ltd, Pendragon House, Caxton Place,
Cardiff CF23 8XE, United Kingdom

Abstract

At first sight cosmetics and clinical trials are worlds apart, like chalk and cheese. After all cosmetics are linked to the aesthetics of beauty; they are used to improve appearance and enhance attractiveness. Clinical trials are associated with the pharmaceutical world, the development of medicines and rules and regulations! However consumers expect to see benefits and demand evidence that the products actually work. There is also increased pressure from regulatory bodies and advertising watchdogs for data to support claims. So cosmetic clinical trials are becoming more common and a clear understanding of what is needed to conduct a successful study is now essential. The basic rules of clinical trials will be discussed and their importance emphasised by examples from studies. In particular the role of controls (placebos), bias and number of subjects needed for a study will be examined.
The aim of this article is not to provide an in depth review of the state of the art but rather to be an introduction to the topic for people approaching this interesting and complex topic for the first time.

INTRODUCTION

Cosmetics are linked to the aesthetics of beauty and have been used for centuries to improved the appearance and enhance attractiveness. They enhance self esteem and give a general sense of well being. Beauty has an important role in our society. It is well known that attractive males and females not only get more attention from the opposite sex but they also get more attention from their mothers, more money at work, more votes from the electorate and more leniency from judges (1). Clinical trials are as different a world as could be imagined. They relate to the pharmaceutical industry and drug development; they involve ground rules such as Good Clinical Practice and regulatory authorities such as the European Medicines Agency. Their history goes back more than 100 years; the first real clinical trial being a serum therapy trial for diphtheria conducted by Johannes Fibiger in 1898 (2).
So why have clinical trials for cosmetics? Consumer awareness is one driving force. Consumers are better educated, thanks partly to the internet, and demand evidence that the product works. They also expect to see visible benefits when used. Another fa ...