Detailed Analysis of the Scope and Claims of United States Patent 4,957,119
Introduction
United States Patent 4,957,119, titled "Contraceptive implant," is a significant innovation in the field of contraceptive devices. This patent, filed in 1988 and granted in 1990, pertains to a subcutaneously implantable device designed to release a contraceptive agent over an extended period. Here, we will delve into the scope, claims, and patent landscape surrounding this invention.
Background and History
The concept of subdermal contraceptive implants began to take shape in the 1960s, following the discovery of silicone's biocompatibility with the human body. Studies by Folkman and Long in 1964 and Dziuk and Cook in 1966 laid the groundwork for using such implants for drug delivery, including contraception[4].
Patent Overview
Publication and Priority Dates
The patent was filed on August 5, 1988, with a priority date of August 8, 1987. It was granted on September 18, 1990[1].
Inventors and Assignees
The patent was assigned to the inventors and their respective institutions, though specific details on the assignees are not provided in the patent document.
Scope of the Patent
Technical Description
The patent describes an implant made of polymeric material, specifically designed to release a contraceptive agent over a prolonged period when implanted subcutaneously. The implant is composed of a core containing the contraceptive agent, typically a steroid such as etonogestrel or levonorgestrel, encapsulated within a membrane made of a biocompatible polymer like ethylene vinyl acetate (EVA)[1][5].
Key Components
- Polymeric Material: The implant is made from a biocompatible polymer, ensuring minimal adverse reactions when implanted under the skin.
- Contraceptive Agent: The core of the implant contains a steroid that is slowly released over time to prevent pregnancy.
- Membrane: The EVA membrane controls the release rate of the contraceptive agent, ensuring a steady and effective dosage.
Claims of the Patent
Independent Claims
The patent includes several independent claims that define the scope of the invention. These claims cover:
- The composition of the implant, including the polymeric material and the contraceptive agent.
- The structure of the implant, such as the core and membrane.
- The method of implantation and the release mechanism of the contraceptive agent[1][5].
Dependent Claims
Dependent claims further specify the details of the independent claims, such as the types of polymeric materials and contraceptive agents that can be used, and the dimensions and shapes of the implant.
Patent Landscape
Related Patents and Applications
The patent is part of a larger family of applications and patents related to contraceptive implants. Other notable patents include:
- US5088505A: A divisional application of the original patent, also related to contraceptive implants[1].
- US5150718A: Another divisional application focusing on methods of contraception using similar implant technology[1].
International Patents
The invention has been protected in various countries, including Europe (EP0303306B1), Japan (JP2571831B2), and Australia (AU603475B2), among others[1].
Classification and Categories
The patent is classified under several categories, including:
- A61K: Preparations for medical, dental, or toilet purposes, specifically medicinal preparations containing organic active ingredients[1].
- A61K9/00: Medicinal preparations characterized by special physical form, such as galenical forms suited for specific sites of application[1].
Impact and Legacy
The invention described in US Patent 4,957,119 has significantly impacted the field of contraception. It led to the development of single-rod implants like Implanon and Nexplanon, which are less invasive and have fewer side effects compared to earlier multi-rod systems like Norplant[4].
Patent Scope Metrics
The scope of this patent can be analyzed using metrics such as independent claim length and independent claim count. Narrower claims, as seen in this patent, are often associated with a higher probability of grant and a shorter examination process[3].
Legal Status
The patent has expired, as indicated by its "Lifetime" status. This means that the technology described in the patent is now in the public domain and can be freely used and improved upon without infringing on the original patent rights[1].
Key Takeaways
- Innovative Design: The patent introduces a novel design for a subcutaneous contraceptive implant using polymeric materials.
- Extended Release: The implant is designed to release a contraceptive agent over several years, providing long-term birth control.
- Biocompatibility: The use of biocompatible polymers ensures minimal adverse reactions.
- Global Protection: The invention is protected by multiple international patents.
- Legacy: The patent has led to the development of more advanced and user-friendly contraceptive implants.
FAQs
What is the main innovation of US Patent 4,957,119?
The main innovation is a subcutaneously implantable device made of polymeric material that releases a contraceptive agent over an extended period.
What types of materials are used in the implant?
The implant is made from biocompatible polymers such as ethylene vinyl acetate (EVA) and contains a core with a steroid contraceptive agent like etonogestrel or levonorgestrel.
How long does the contraceptive effect of the implant last?
The implant is effective for at least three to four years, with some data indicating effectiveness for up to five years[4].
What are some of the related patents to US Patent 4,957,119?
Related patents include US5088505A and US5150718A, which are divisional applications focusing on similar contraceptive implant technology[1].
Why did the original Norplant system face issues?
The Norplant system, with its six-rod design, faced complications during removal, leading to the development of single-rod implants like Implanon and Nexplanon[4].
Sources
- US4957119A - Contraceptive implant - Google Patents
- US11090186B2 - Methods for using intrauterine systems and IUD insertion devices - Google Patents
- Patent Claims and Patent Scope - Hoover Institution
- Etonogestrel - Wikipedia
- US Patent for Contraceptive implant Patent (Patent # 4,957,119 ... - Justia
