Fungal infections are common to a large number of animal species. Common agents of fungal infections include various species of the genii Candida and Aspergillus, and types thereof, as well as others. While external fungus infections can be relatively minor, systemic fungal infections can give rise to serious medical consequences. The incidence of fungal infections has undergone a significant increase, particularly in humans. This increase is, at least in part, attributable to an ever increasing number of patients having impaired immune systems, both as a result of medical therapy for other conditions, and as a result of diseases such as AIDS which compromise the immune system. Fungal disease, particularly when systemic, can be life threatening to patients having an impaired immune system.
A number of prior art pharmaceutical agents have been developed for the treatment of fungal diseases. These materials include compounds such as amphotericin B (AMB), triazoles and flucytosin. AMB is the drug of choice for many systemic fungal infections due to its broad range of activity; however, it is harmful to the kidneys and must be administered intravenously. Many of the triazoles exhibit broad ranging activity and can be administered orally; however, many strains of fungi have become resistant to these materials. Consequently, there is a need for a new group of agents which are effective in eliminating fungus disease, but are of low toxicity to patients. Ideally, these materials should be simple to prepare, stable, and easy to administer.
As will be described in further detail hereinbelow, the present invention is directed to a highly effective agent for controlling fungus disease. The material of the present invention is derived from natural carbohydrate materials and is inherently low in toxicity. The material is specifically prepared from complex carbohydrates such as chitin or chitosan. These materials are widely distributed in nature, and are found, for example, in the shells of arthropods, and in the cell walls of fungi. These and other advantages of the present invention will be readily apparent from the discussion, description and examples which follow.