Formulation, in vitro release and transdermal diffusion of vitamin B3 for treatment of acne

Abstract

Acne is an extremely common condition, affecting almost 80% of adolescents and young adults. It is an inflammatory disease, characterised by comedones, papules, pustules and sometimes cysts. Factors causing acne include enhanced sebum excretion, hypercornification of the sebaceous duct, ductal coloniazation with Propionibacterium acnes and production of inflammation (Gollnick & Cunliffe, 2003:1). Because of the widespread use of topically applied antimicrobial agents in the treatment of inflammatory acne, resistance of disease-related micro-organisms developed. Therefore new strategies for the treatment of moderate inflammatory acne are necessary. Nicotinamide is a new approach to topical treatment of moderate inflammatory acne without the development of resistant micro-organisms (Otte et al., 2005:257). Using the skin as an alternative route for the administration of nicotinamide for the treatment of acne, may be beneficial. When nicotinamide permeates through the skin, it is directly delivered to the dermis, the place where action is needed and better results can thus be expected after the treatment has started. Another benefit is that smaller amounts of the drug are absorbed systemically with decreased adverse reactions. Unfortunately, using the skin as an alternative route for administering drugs (transdermal drug delivery), has numerous limitations. One of these limitations is the barrier function of the skin (Naik et al., 2000:319). Because of the skin's outstanding ability to protect the body against unwanted substances from its surroundings, it is necessary to use methods to enhance drug penetration through the skin. A new technology, named Pheroid™ technology, was used in this study to enhance penetration through the skin. This technology is based on the use of vesicular structures with no phospholipids or cholesterol to enhance penetration (Grobler et al., 2008:283). The aim of this study was to formulate four different semi-solid formulations with nicotinamide as the active ingredient, and to determine which of the formulations deliver nicotinamide best to the target site. Stability tests over a six months period were also performed on the different formulations. A 3% nicotinamide cream, with and without Pheroid™ vesicles, and a 3% nicotinamide gel, with and without Pheroid™ vesicles, were formulated.