Drug – bio-affecting and body treating compositions – Preparations characterized by special physical form – Biocides; animal or insect repellents or attractants
Reexamination Certificate
2001-10-22
2003-02-25
Jarvis, William R. A. (Department: 1614)
Drug, bio-affecting and body treating compositions
Preparations characterized by special physical form
Biocides; animal or insect repellents or attractants
C514S030000, C424S427000
Reexamination Certificate
active
06524602
ABSTRACT:
FIELD OF INVENTION
This invention relates to treatments for parasitic skin diseases such as infestations with lice or mites, and in particular to improved treatments for such diseases that contain a polymer delivery system.
BACKGROUND OF THE INVENTION
Parasitic skin diseases, such as infestations with lice or mites, cause much suffering in both humans and animals. For example, head lice is a persistent problem, especially among elementary school-aged children. It was reported that six million U.S. school children will become infested with head lice in one year, that is one out of every four students in elementary schools (
Consumer Reports
, February 1998). The total number of people in the U.S. infested with head lice in one year is about ten million when all ages are accounted for. The incidence of head lice is only slightly improved from the reported incidence in 1940, which was prior to the advent of insecticides and “superior” knowledge by the medical establishment.
Infestation with head lice typically causes itching of the scalp. In some cases, a person may develop lesions or papules on the scalp, swollen glands in the neck or under the arms, or other symptoms. A secondary problem is that many schools have enforced absenteeism if a child has any nits (lice eggs) in their hair. Such a “no-nit” policy has negative social implications for the child and parents. Head lice is becoming a sensitive social issue.
Although head lice are not generally considered to be vectors for systemic human infection, the evidence strongly supports the possibility that head lice could be vectors. For example, rickettsiae and spirochetes are known to be obtainable from the blood of the host (head lice are blood suckers like mosquitoes); these organisms multiply in the gut of the head lice, and are also found in high numbers in their feces. Viruses, like the AIDS virus, also can be found in the gut and feces of head lice, but these organisms do not multiply in the gut of the louse; thus, the number of viruses in the feces would not be high. However, any organism in the blood of the host would be found in the feces of the louse, and thereby, could be potentially transmitted when the louse finds a new host, i.e., a new human being to infest.
Various over-the-counter and prescription topical treatments for head lice are currently available. These treatments are no longer as effective as in previous years in killing adult head lice and nits. In fact, an article in the September, 1999 issue of Archives of Pediatrics and Adolescent Medicine reported that only 90% of adult head lice are killed by the two main products currently used in head lice therapy, Nix and Rid. It is clear that resistance or tolerance of head lice to insecticides has increased in recent years. The reduced effectiveness of current treatments raises the possibility that people may resort to the use of dangerous agents such as kerosene to treat head lice, or may resort to the use more toxic insecticides that could damage the scalp. Thus, it would be desirable to provide a more effective treatment for head lice and other parasitic skin diseases that avoids the need to use such drastic measures, particularly since the majority of head lice patients are children.
Various polymers are presently being used in medicine. TopiCare by Penederm and Berteck Laboratory is a polyolprepolymer included in “Avita”, a topical skin cream with vitamin A. Ortho Division of Johnson and Johnson produces “Retin A Micro”, a skin product containing vitamin A in a microsponge polymer made by Advanced Polymer Systems. Additionally, Chitogenics makes a polymer called N,O-carboxymethylchitosan (NOCC), a glycosaminoglycan synthesized from the natural polysaccharide, chitin. NOCC and other polymers have been proven to be of value in drug delivery, preventing post-surgical adhesions, wound management, and arthoscopic surgical aids. In Japan, polymers are used as flocculents in the clarification of waste water and beverages, in food processing, and in moisturizers that adhere well to skin and hair. In particular, chitosan polymers are used in many skin creams and hair care products in Japan. However, it has never been suggested to use a polymer delivery system in improved treatments for parasitic skin diseases.
SUMMARY OF THE INVENTION
This invention relates to a formulation for the treatment of a parasitic skin disease. In a preferred embodiment, the formulation is effective for the treatment of head lice. The formulation includes a parasiticide to kill the parasite. The formulation also includes a polymer effective to increase retention of the formulation on the skin, and to reduce absorption of the formulation into the skin. The formulation also includes a vehicle for the polymer and the parasiticide.
In another embodiment for the treatment of head lice, the formulation includes an insecticide and a polymer such as a beta-sheet breaker peptide which is effective to increase absorption of the insecticide into the head lice and/or the eggs of the head lice.
Various objects and advantages of this invention will become apparent to those skilled in the art from the following detailed description of the preferred embodiments.
DETAILED DESCRIPTION AND PREFERRED EMBODIMENTS OF THE INVENTION
The present invention relates to the use of a polymer delivery system in treatments for parasitic skin diseases, to provide improved therapeutics and to reduce potential hazards of the treatments. The parasitic skin diseases to be treated include any diseases in which parasites infest the surface of the skin, especially on those skin areas covered by hair, such as the scalp and pubic area. Such diseases include, for example, infestations with lice, especially head lice and pubic lice, and mites (e.g., scabies, chiggers, Demodex mites, and the like).
The polymer delivery system is effective to increase retention of the formulation on the outside surface of the skin, and to reduce absorption of the formulation into the skin. In a treatment for head lice, the polymer increases the retention of the treatment on the hair and the outside surface of the scalp, and reduces the absorption of the treatment into the skin. As a result, the polymer delivery system provides one or more of the following advantages. The polymer delivery system can allow the use of higher concentrations of parasiticide on the skin without risk of increased toxicity. The polymer delivery system can also allow parasiticides to stay on the skin for longer time periods without risk of increased toxicity. Additionally, the polymer delivery system can allow the use of parasiticides that are sometimes considered too toxic to be used, because the parasiticides are not significantly absorbed into the skin and are therefore measurably less toxic. There is a great demand for such a treatment in therapies for parasitic skin diseases.
Given the increasing resistance of head lice to various insecticides, the polymer delivery system will allow over-the-counter and prescription topical products to add efficacy by keeping the insecticide on the hair and skin surface for a longer period of time, while reducing absorption of the insecticide into the skin and thereby reducing the risk of toxicity. This is applicable because head lice normally shut down absorption by closing off their spiracles (respiratory channels). These channels are the method by which head lice obtain oxygen as they have no lungs. Head lice can shut down these spiracles for over an hour without ill effects, but by allowing insecticide products more time of exposure to the head lice, the formulations of the invention will allow more penetration when the head lice reopen their spiracles. More prolonged application by means of the polymer delivery system should also result in better penetration into the nit which is lipophilic with several membranes to penetrate before getting to the developing egg. Typically, the formulation is retained on the scalp for either about 10 minutes or overnight (e.g., about 7-9 hours), depending on the particular patient.
In the case of o
Burkhart Craig G.
Burkhart Craig N.
Jarvis William R. A.
Kim Vickie
MacMillan Sobanski & Todd LLC
LandOfFree
Polymer delivery system in treatments for parasitic skin... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Polymer delivery system in treatments for parasitic skin..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Polymer delivery system in treatments for parasitic skin... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3165398