ABSTRACT
The Procter & Gamble Company, Miami Valley Laboratories, Cincinnati, Ohio, USA
Introduction 422
Materials and Methods 422
Cell Culture Methods 422
Collagen Synthesis Assay 423
NADPH Level Assay 423
Involucrin Synthesis Assay 424
Filaggrin Synthesis Assay 424
Keratin Synthesis Assay 424
Lipogenesis in Skin Biopsy Samples 425
Clinical Testing 425
Facial Tolerance Testing 425
Facial Benefits Study 1 426
Facial Benefits Study 2 427
Sebum Excretion Measurement Study 427
Pore Size Measurement Study 428
Skin Barrier Evaluation 428
Results 429
NADPH Levels 429
Collagen Synthesis 430
Barrier Layer Components 431
Skin Barrier Function 432
Facial Skin Tolerance of Niacinamide 434
Facial Benefits Study 1 435
Facial Benefits Study 2 435
Reduction in Sebum Excretion and Pore Size 435
Discussion 438
Acknowledgments 439
References 439
INTRODUCTION
The nutritional value of niacinamide is well recognized. However, its use as a
topical agent to provide skin care benefits has been less well studied until
recently.
