CHAPTER ONE
1.0INTRODUCTION
Cosmetics (cream) are those preparation which are applied to skin for the purpose of beautifying the skin. They are used in some other cases for treatment purposes. Their composition can range from simple ingredients to an array of complex substances.
Cosmetics (cream) can be said to be topical preparations intended to be applied to/on the human body for cleaning or improving the appearance of the skin with negatively affecting the dermatological properties or structure of the skin. The warm and rather humid climatic conditions that prevail in most tropical countries including Nigeria would tend to support the survival and growth of many micro-organisms. In a situation whereby a nutritionally rich pharmaceutical/cosmetic product is severely contaminated, rapid growth and multiplication of micro organisms would be expected. Contaminating micro-organisms in creams may cause spoilage of the produce and, when pathogenic, they represent a serious health risk for consumers worldwide (Becks and Lorenzoni 1995, Behravan et al. 2005).
Due to their complex composition of substances, preservation of these preparations against microbial spoilage involves protection of the large number of different constituents with variable physical and chemicals properties.
Products contamination may arise from raw materials or water used in the formulation process or accidentally during use.
1.1 CONTAMINATION OF CREAMS AND LOTIONS
The hazards of inadequately preserved cosmetics to human health have been demonstrated by reports of staphylococcal infections from use of contaminated hand creams (Campana et al; 2006). Regardless of whether a cosmetic becomes contaminated during manufacture or during consumer use, the hazard is usually two fold, namely:
(1) The Direct effect of micro-organism on human health e.g. allergic reactions, skin irritations and even neurotoxic manifestation;
(2)The Indirect effect also on human health due to production contamination and spoilage as well as formation of harmful/noxious microbial metabolic.
Microbial contamination of cosmetics during manufacture was a major problem in the 1960’s and 1970’s. Since then, microbial contamination is still one of the major causes of product recall on the world, particularly in developing tropical countries (Okeke and Lamikanra 2001). However, significant progress has been made by cosmetic industry towards implementation of sanitary manufacturing practices, more rigorous microbiological control and the development of better preserved cosmetic products. Therefore, it is important to improve the preservation system. (Farrington et al 1994; inter and Genet 1998) in order to inhabit the growth of contaminating micro-organisms during manufacturing, storage and use by consumers, also by using non-invasive package (Brannan and Dille 1990).
1.2 Microbial Spoilage of Topical Preparations
The formulation of an efficacious, elegant and safe product which will be both stable and acceptable to the consumer may require the use of a variety of ingredients in a complex physical state. This complexity in the composition or constitution of the product could create conditions conducive to the survival of micro-organisms that contaminate the product either during manufacture or consumer use. A topical preparation may be considered microbiologically spoilt if depending on it intended use it possess:
i.low levels of acutely pathogenic micro-organism or higher level of opportunistic pathogen are present
ii.Toxic microbial metabolic persist even after dealth of the original/primary contaminants or
iii.Microbiological growth has initiated significant physical or chemical deterioration of the product. Such spoilage might result in financial loses for the manufacturer, either in the immediate loss of products or in the increasingly expensive cost of litigation should spoilage cause harm to the end user.
1.3 Manifestation and Mechanisms of Microbial Spoilage
Before spoilage can occur, organisms which are capable of altering the components of a product in situ must first be introduced via raw materials, the processing plant, packaging materials, operatives or elsewhere in the environment. Although spoilage does not necessarily depend upon the growth of these contaminants it is generally facilitated if the formulation and the ambient conditions of temperature and humidity encourage their multiplication. When these criteria are satisfied changes in the product will occur and may ultimately manifest themselves to the user in one or more of the following ways:
TOXIC EFFECTS
Microbial toxins: