chapter  22
32 Pages

Surfactant-Free Sun Care

Introduction 462

Background 462

Issues with the Current Sunscreen Products 462

Issues with Emulsions 465

Use of Surfactant-Free Dispersions in Sun Care 468

Properties of Lamellar Phase Dispersions 469

La Dispersions of Ultraviolet Absorbers 474

Dispersions of Organic UV Absorbers 474

Physical Sunscreen Suspensions 475

Formulating with Dispersions 475

Defining a Semiquantitiative Aesthetic Scale 475

Preparing the Final Formulation 479

The Advantages of Surfactant-Free Sunscreens 480

Beyond Conventional Sunscreens 485

Conclusion 488

References 488

Appendix 1 489

Sunscreen Formulations 489

INTRODUCTION

The sun may be considered one of life’s ultimate enigmas. On the one hand, it is

critical for the support of life on earth. From photosynthesis in plants to vitamin

D production in mammals, the sun plays an integral role in sustaining our existence.

On the other hand, studies during the past half-century have clearly demonstrated

that too much sun can give rise to physiological complications that can lead to the pre-

mature appearance of aging, the development of uneven pigmentation, the formation

of cancer, and even death in some cases. In fact, incidents of skin cancer are one of the

fastest growing problems in the field of dermatology. Why is this trend occurring

when the knowledge of the damage done by the sun is so well recognized?