Package making – Methods – With contents treating
Reexamination Certificate
2001-03-20
2004-03-02
Yu, Mickey (Department: 3721)
Package making
Methods
With contents treating
C422S021000, C422S022000
Reexamination Certificate
active
06698162
ABSTRACT:
INTRODUCTION
1. Field of the Invention
The field of this invention is transdermal drug delivery, particularly, methods of producing topical patch preparations for transdermal drug delivery.
2. Background of the Invention
Transdermal delivery devices, e.g., topical patches, wound dressings, etc., are used to administer a variety of therapeutic agents, such as pharmaceutically active agents. The devices are generally applied to the surface of the skin and a therapeutically active agent contained therein is delivered to the systemic circulation via absorption through the skin. Advantages of transdermal delivery of a therapeutic agent over oral or parenteral administration include increased bioavailability (as first-pass liver metabolism is avoided), and more controlled (e.g., sustained, continuous) delivery. Topical preparations, e.g., topical patch preparations, for transdermal delivery typically contain an active agent dissolved or dispersed in an aqueous adhesive gel composition that is coated or spread onto a fibrous material.
Sterile topical patch preparations for transdermal delivery are currently commercially produced by clean room fabrication from sterilized components. The process requires specially designed facilities, special equipment, protective clothing for clean room personnel made of special materials (e.g., Tyvek®); and stringent environmental control and maintenance, e.g., of air quality, pressure, temperature and humidity. Accordingly, clean room fabrication is costly.
Accordingly, the development of methods of producing terminally sterilized topical patch preparations for transdermal delivery would be of great benefit in drug delivery.
3. Relevant Literature
Patents of interest include the following: 6,030,554; 6,028,242; 5,782,914; 5,730,933; 5,496,302; 5,011,660 and 4,652,763. See also U.S. Pat. Nos. 5,827,529; 5,480,649; 5,242,951; 5,116,621 and 5,082,663.
SUMMARY OF THE INVENTION
Methods of producing a terminally sterilized topical patch preparation are provided. In the subject methods, a topical patch preparation is exposed to electron beam radiation, preferably low level electron beam radiation, for a period of time sufficient to terminally sterilize the topical patch preparation. Also provided are the terminally sterilized topical patch preparations produced by the subject methods, as well as methods of using the same.
DESCRIPTION OF THE SPECIFIC EMBODIMENTS
Methods of producing a terminally sterilized topical patch preparation are provided. In the subject methods, a topical patch preparation is exposed to electron beam radiation, preferably low level electron beam radiation, for a period of time sufficient to terminally sterilize the topical patch preparation. Also provided are the terminally sterilized topical patch preparations produced by the subject methods, as well as methods of using the same. In further disclosing the subject invention, methods for producing the subject topical patches and the patches themselves will be described first in greater detail, followed by a review of representative methods of using the topical patches.
Before the subject invention is described further, it is to be understood that the invention is not limited to the particular embodiments of the invention described below, as variations of the particular embodiments may be made and still fall within the scope of the appended claims. It is also to be understood that the terminology employed is for the purpose of describing particular embodiments, and is not intended to be limiting. Instead, the scope of the present invention will be established by the appended claims.
In this specification and the appended claims, singular references include the plural, unless the context clearly dictates otherwise. Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood to one of ordinary skill in the art to which this invention belongs.
Method Of Producing A Terminally Sterilized Topical Patch Preparation
As summarized above, the subject invention provides methods for producing terminally sterilized topical patch preparations. The subject methods are suitable for use in terminally sterilizing a variety of different types of topical patch preparations. By topical patch preparation is meant a composition that includes an active ingredient in a topical delivery vehicle, i.e., a vehicle that is suitable for application to a skin surface (or epidermal surface) of an animal. A variety of different topical patch preparations are known to those of skill in the art. Representative topical patch preparations that may be terminally sterilizable according to the subject methods are provided infra. In many embodiments, the topical patch preparation is present in a sealed packaging means, i.e., it is sealed, as described in greater detail infra.
A feature of the subject methods is that the topical patch preparation, which in many embodiments is sealed in a packaging means, is exposed to electron beam irradiation for a period of time sufficient to terminally sterilize the composition while maintaining the activity of the active agent present therein. The topical patch preparation may be exposed to electron beam irradiation using any convenient protocol and device, where representative protocols and devices for exposing compositions of matter to electron beam irradiation are disclosed in U.S. Pat. Nos. 6,030,554; 6,028,242; 5,989,498 and 5,807,491; the disclosures of which are herein incorporated by reference. In many embodiments, the topical patch composition is exposed to low level electron beam irradiation. By low level electron beam irradiation is meant electron beam irradiation ranging in strength from about 5 to 19 kGy, and in many embodiments from about 8 to 15 kGy.
In practicing the subject methods, the topical patch preparation is exposed to electron beam irradiation for a period of time sufficient to terminally sterilize the topical patch preparation without adversely affecting the properties of the preparation to an unacceptable degree. Generally, the period of time during which the topical patch preparation is exposed to the electron beam irradiation is at least about 1 min., usually at least about 1-2 min. and more usually at least about 2 min., where the period of time may be as long as 3 min. or longer, but usually does not exceed about 5 min. and more usually does not exceed about 3 min. In many embodiments, the period of time ranges from about 1 to 3 and usually from about 1 to 2 min.
The above described process produces a terminally sterilized topical patch preparation. By “terminally sterilized” is meant that the topical patch preparation is substantially, if not completely, free of viable microorganisms, where by “substantially free” is meant that amount of viable microorganisms present in the patch preparation following the above described treatment does not exceed about 100, usually does not exceed about 10 and more usually does not exceed about 5 and by “completely free” is meant that no viable microorganisms are present in the topical patch preparation. As such, the subject patches are substantially, if not completely, free of microorganisms selected from the group consisting of:
Staphylococcus aureus; Psedlomonas aeruginosa; Escherichia coli; Candida albicans; Aspergillus niger
; and the like.
The subject methods are suitable for use in the sterilization of a wide variety of topical patch preparations. Examples of different types of topical patch preparations with which the subject sterilization methods may be employed include those described in U.S. Pat. Nos. 5,827,529; 5,480,646; 5,242,951; 5,116,621; and 5,082,663; the disclosures of which are herein incorporated by reference.
A representative topical patch preparation described in at least some of the above mentioned patents that may be terminally sterilized according to the subject methods is made up of active agent retaining layer present on a support, where the active agent retaining layer is made up of one or more active agents present in, e.g., dissolved
Caldwell Larry
Duong Tu Xuan
Shudo Jutaro
Bozicevic Field & Francis LLP
Field Bret E.
Tawfik Sameh
Teikoku Pharma USA Inc.
Yu Mickey
LandOfFree
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