Detailed Analysis of the Scope and Claims of United States Patent 5,456,851
Introduction
United States Patent 5,456,851, titled "Ketoconazole shampoo containing butylated hydroxytoluene or butylated hydroxyanisole," is a significant patent in the field of cosmetic and pharmaceutical formulations. This patent, filed on April 7, 1994, and granted on October 10, 1995, addresses the stabilization of ketoconazole in shampoo formulations.
Background
Ketoconazole is an antifungal agent commonly used in the treatment of dandruff, seborrheic dermatitis, and other scalp conditions. However, its stability in shampoo formulations has been a challenge due to degradation over time.
Invention Overview
The patent describes a formulation for a ketoconazole-containing shampoo that incorporates antioxidants to enhance the stability of ketoconazole. The key innovation is the use of butylated hydroxytoluene (BHT) or butylated hydroxyanisole (BHA) as stabilizers.
Claims
The patent includes 14 claims that define the scope of the invention. Here are the key aspects:
Main Claims
- The patent claims a shampoo formulation containing ketoconazole and an antioxidant selected from BHT or BHA[4].
- The effective range of BHT or BHA is specified as 0.01 to 1 weight percent, with a preferred range of 0.1 to 0.025 weight percent based on the total weight of the shampoo formulation[4].
Formulation Components
- The shampoo formulation includes ketoconazole as the active antifungal ingredient.
- Antioxidants such as BHT or BHA are added to stabilize ketoconazole against degradation.
- Other components include surfactants (e.g., sodium lauryl sulfate, cocamidopropyl betaine), conditioners (e.g., polyquaternium-7), preservatives (e.g., quaternium-15, tetrasodium EDTA), and pH adjusters (e.g., sodium hydroxide)[4].
Preparation Method
- The method involves dissolving BHT in a mixture, followed by the addition of ketoconazole while maintaining a slightly acidic pH to facilitate dissolution.
- The mixture is then cooled, and additional components such as conditioners, preservatives, colorants, and fragrances are added. The pH is adjusted to a range of 6.9-7.4[4].
Scope of the Patent
The scope of the patent is defined by the specific formulation and the method of preparation.
Stability
- The patent emphasizes the stability of ketoconazole in the shampoo formulation, ensuring that the active ingredient does not degrade by more than 10% during storage at ambient temperatures for two years[4].
Cosmetic Attributes
- The formulation is designed to exhibit excellent cosmetic attributes, such as good lather, conditioning properties, and a pleasant texture[4].
Patent Landscape
The patent landscape surrounding US 5,456,851 involves several key aspects:
Prior Art
- The patent builds upon prior art related to the use of ketoconazole in topical treatments, particularly for psoriasis and seborrheic dermatitis[1].
Related Patents
- There are several related patents and applications filed around the same time, including international filings in Japan, Europe, and other regions, which indicate a global interest in stabilizing ketoconazole formulations[1].
Litigation and Reviews
- While this specific patent does not appear to be involved in significant litigation, the broader context of patent quality and scope, as discussed in other studies, highlights the importance of clear and narrow claims to avoid legal disputes[3].
Impact on Industry
The invention described in US 5,456,851 has had a significant impact on the cosmetic and pharmaceutical industries.
Commercial Use
- The stabilized ketoconazole shampoo formulation has been widely used in commercial products, enhancing the efficacy and shelf life of these products.
Innovation
- The use of BHT or BHA as stabilizers has set a precedent for similar formulations in other cosmetic and pharmaceutical products, promoting innovation in the field.
Key Takeaways
- Stabilization of Ketoconazole: The patent introduces a method to stabilize ketoconazole in shampoo formulations using BHT or BHA.
- Formulation Components: The formulation includes a specific range of antioxidants, surfactants, conditioners, and preservatives.
- Preparation Method: The method involves careful control of pH and temperature to ensure stability and cosmetic attributes.
- Patent Scope: The patent is narrowly defined to cover the specific formulation and preparation method.
- Industry Impact: The invention has enhanced the efficacy and shelf life of ketoconazole shampoos, influencing the broader cosmetic and pharmaceutical industries.
FAQs
What is the main innovation of US 5,456,851?
The main innovation is the use of butylated hydroxytoluene (BHT) or butylated hydroxyanisole (BHA) to stabilize ketoconazole in shampoo formulations.
What is the effective range of BHT or BHA in the formulation?
The effective range is from about 0.01 to 1 weight percent, with a preferred range of 0.1 to 0.025 weight percent based on the total weight of the shampoo formulation.
How is the pH adjusted in the formulation?
The pH is adjusted to a range of 6.9-7.4 using a 25% aqueous solution of sodium hydroxide.
What are the cosmetic attributes of the formulation?
The formulation is designed to exhibit excellent cosmetic attributes such as good lather, conditioning properties, and a pleasant texture.
Is this patent still in force?
No, the patent has expired, as indicated by its legal status.
Cited Sources
- US5456851A - Ketoconazole shampoo containing butylated hydroxytoluene or butylated hydroxyanisole - Google Patents
- Trials@uspto.gov Paper 17 - Banner Witcoff
- Patent Claims and Patent Scope - Hoover Institution
- US5456851A - Ketoconazole shampoo containing butylated hydroxytoluene or butylated hydroxyanisole - Google Patents
