Patent Publication Number: US-2007098938-A1

Title: Container method for product integrity and identification

Description:
This application is a division of U.S. Ser. No. 10/143,076 filed May 7, 2002. 
    
    
      The present invention generally relates to containers for liquid products, and is more particularly directed to a container for providing protection for contained sterile liquid ophthalmic products from degradation by light, while also permitting the visual examination of the bottle contents.  
      Containers for ophthalmic solutions are typically sized and shaped for enabling drop wise dispensing of ophthalmic formulations. Often however, the ophthalmic formulations are light sensitive, as for example, those including Purite® (stabilized chlorine dioxide) peroxide compounds combined with a source of chlorine ions, hydrogen peroxide or perborate. While opaque containers may be utilized for the storage and dispensing such ophthalmic formulations, they do not enable, or provide to the user, the ability to examine the container contents for remaining volume, contamination or product degradation as may be evidenced by particulates. Further, it is important that product identification play an important function for ophthalmic formulations, which may be utilized by patients who otherwise have a diminished visual acuity.  
      Accordingly, in accordance with the present invention, a container system provides for a bottle which can provide product integrity, enable visual inspection of contents, while at the same time providing a distinctive color which can be recognized by the user in order to prevent miss-application of ophthalmic formulations.  
     SUMMARY OF THE INVENTION  
      A container in accordance with the present invention provides product protection/integrity and identification for an ophthalmic formulation including chlorine dioxide, or precursors to chlorine dioxide such as, for example, Purite® (stabilized chlorine dioxide) or hydrogen peroxide, perborate or other peroxide compounds with a source of chlorine ions, hereinafter generally referred to as chlorine dioxide.  
      The chlorine dioxide is not the active ingredient in the formulation. The container generally includes a bottle formed from resins comprising polyethylene terephthalate, with a first set of dyestuffs present in the bottle in an amount sufficient to absorb visual and ultraviolet wavelengths less than about 420 nm. The blockage, or absorption, of these wavelengths prevents degradation of the chlorine dioxide.  
      A second set of dyestuffs is present in the bottle in an amount sufficient to significantly absorb visual wavelengths greater than about 500 nm, with the first and second dyestuffs sets allowing transmission of visual blue wavelengths for enabling the visual inspection of the product contained in the bottle and providing a product identifying color to the bottle. This latter feature enables the user of limited, or diminished capacity, eyesight to readily identify the product contained within the bottle.  
      More particularly the resins include a first resin consisting of natural polyethylene terephthalate, (no dyestuffs), a second resin consisting of polyethylene terephthalate and the first dyestuffs and a third resin consisting of polyethylene terephthalate and the second dyestuffs  
      Polyethylene terephthalate (PET) is normally not utilized in small containers or bottles which are intended to be squeezed for dispensing, however, in the present instance, the bottle in accordance with the present invention, comprises relatively flat sidewalls for enabling dropwise squeeze dispensing of the product from the bottle.  
      A method, in accordance with the present invention, for storing a pharmaceutical formulation including chlorine dioxide, generally includes the step of forming a bottle from a resin comprising polyethylene terephthalate with a first set of dyestuffs present in the bottle in an amount sufficient to absorb visual and ultraviolet wavelengths less than about 420 nm and a second set of dyestuffs present in the bottle in an amount sufficient to significantly absorb visual wavelengths greater than about 500 nm. The first and second dyestuffs sets allow transmission of visual blue wavelengths for enabling visual inspection of the product contained in the bottle and providing a product identifying color to the bottle.  
      The method further includes the step of dispensing the pharmaceutical formulation in the bottle and sealing of the bottle. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
      The advantages and features of the present invention will be better understood by the following description when considered in conjunction with the accompanying drawing in which:  
       FIG. 1  is a perspective view of a container in accordance with the present invention generally including a bottle and also depicting visual observance of product disposed within the bottle;  
       FIG. 2  is a plot of light transmission as a function of wavelength for a 10 cc bottle having a wall thickness of about 1 mm and formed from a mixture of PET resin particles with a natural resin to yellow/green dye resin ratio of about 10 to 1;  
       FIG. 3  is a plot similar to  FIG. 2  with a natural resin to yellow/green dye resin ratio of about 30 to 1; and  
       FIG. 4  is a plot similar to  FIG. 2  with a three component PET resin particle mixture comprised of about 20 parts natural resin, 1 part yellow/green dye resin particles, and 2 parts of mixed resin particles incorporating blue and purple dyes in a ratio of about 1 part blue resin to 1 part purple resin.  
    
    
     DETAILED DESCRIPTION  
      With reference to  FIG. 1  there is generally shown a container  10  in accordance with the present invention for product integrity and identification. The container  10  includes a bottle  12  which is formed from a resin consisting of polyethylene terephthalate (PET). A cap  14  is provided to seal a product comprising an ophthalmic formulation including chlorine dioxide within the bottle  12 . Chlorine dioxide as used in the present application includes precursors to chlorine dioxide such as, for example, Purite®. Other compounds unstable to the same light wavelengths are also considered to be within the scope of the present invention.  
      A resin formulated with only a yellow dye which absorbs critical wavelengths below about 400 nm also absorbs visible wavelengths of light above 500 nm, the removal of which is desired for product identification. Yellow dyes also may pass wavelengths of light (visible or ultraviolet) which degrade Purite®. It has been found that a yellow/green combination of dyes, incorporated into the PET resin, provides for complete absorption of wavelengths below about 400 mm with no substantial absorption of blue wavelengths.  
       FIG. 2  shows the percent transmission of light as a function of wavelength for a 10 cc bottle wall section of PET with a ratio of natural PET resin pellets to yellow/green pellets to of about 10:1.  FIG. 3  shows the percent transmission of light as a function of wavelength for a 10 cc bottle wall section of PET with a ratio of natural PET resin pellets to yellow/green pellets of about 30:1. It can be seen that the use of an increased ratio of yellow/green pellets shifts the transmission curve, thus enabling more effective shielding from undesired wavelengths, while allowing transmission of desired blue wavelengths, see arrows marked “blue”.  
      The resin, formulated for the bottle  12 , is preferably formed from a blend of three polyethylene terephthalate resin pellets. A first of the resins consists of polyethylene terephthalate pellets including no dyestuffs, available form Shinko Corp., Japan, Shinko grade J125S.  
      The second resin consists of yellow/green polyethylene terephthalate pellets and a first set of dyestuffs present in the bottle in an amount sufficient to absorb all visual and ultraviolet wavelengths less than about 420 nm. The absorption of these wavelengths prevents degradation of the chlorine dioxide within the product. The yellow/green pellets are available from Shinko, Grade EPM4A1473 which include the following dyestuffs: A) Yellow: PL Number 2-31-(Yellow)- 177 , at 1.360% additive ratio; B) Blue: PL Number 2-31-(Blue)- 101 , at 0.013% additive ratio. This results in an overall yellow/green ratio of about 100:1.  
      Addition of the green dye gives the needed continuous light absorption across the ultraviolet/visible range between about 312 nm and up to about 420 nm. It should be noted that PET itself absorbs ultraviolet light at wavelengths below about 312 nm (unlike polyethylene and several other commonly used plastic materials). For that reason PET is a preferred base resin.  
      The third resin consists of polyethylene terephthalate pellets along with a second set of dyestuffs. These dyestuffs are present in order that the bottle significantly absorbs visual wavelengths greater than about 500 nm and include: A) Blue pellets: PL Number 2-31-(Blue)-101, at 0.015% additive ratio (the same dye used in 2A, but at a higher concentration) and B) Purple pellets: PL Number 2-32-(Blue)-6, at 0.135% additive ratio.  
      The first and second dyestuffs sets allow transmission of visual blue wavelength for enabling the visual inspection of the product contained in the bottle as indicated by the icon  16  in  FIG. 1 . In addition, this combination of dyestuffs provides a distinctive blue color to the bottle which identifies the product disposed therein.  
      As hereinabove noted, the distinctive color identification of the product is important for consumer identification both from a retail point of view and for product safety by enabling visually impaired users to readily identify the ophthalmic formulation within the bottle  12 .  
      The final resin pellet mixture from which the bottles are molded is prepared in two stages. First a “pre-mixture” of Natural (Type 1, above), Blue (Type 3A), and Purple (Type 3B) pellets in a ratio of about 10:1:1 made. This “pre-mixture” is then further blended with Yellow-Green pellets in the ratio of about 20 “pre-mixture” to 1 Yellow-Green. The mixed pellets are heated and formed into the bottle  12  in a conventional manner.  
      The bottle preferably may have a minimum wall thickness of between about 0.5 mm and about 2 mm and a volume of between about 5 cc and about 15 cc. As shown in  FIG. 1 , the bottle  12  preferably includes relatively flat sides  18  for enabling dropwise squeeze dispensing of the product from the bottle  12 . More specifically, the ophthalmic formulation may comprise an eye drop formulation along with the chlorine dioxide and the present invention further includes the combination of the pharmaceutical formulation and the container  10 .  
      A method in accordance with the present invention is provided for storing a pharmaceutical formulation including chlorine dioxide. As hereinabove noted the method generally includes forming the bottle  12  from natural polyethylene terephthalate resin pellets and including in the resin a first set of dyestuffs present in the bottle in an amount sufficient to absorb visual and ultraviolet wavelengths less than about 420 nm.  
      A second set of dyestuffs is also provided in the bottle in an amount sufficient to significantly absorb all visual wavelengths greater than about 500 nm. The first and second dyestuffs sets allow transmission of visual blue wavelengths for enabling visual inspection of the product contained in the bottle and providing a product identifying color to the bottle.  
      Thereafter the pharmaceutical formulation is disposed in the bottle and the bottle is sealed, by means, for example, but not limited to, the cap  14 .  
      Although there has been hereinabove above described a container for product protection/integrity and identification and a method in accordance with the present invention for the purpose of illustrating the manner in which the invention may be used to advantage, it will be appreciated that the invention is not limited thereto. Accordingly, any and all modifications, variations, or equivalent arrangements which may occur to those skilled in the art, should be considered to be within the scope of the claims as defined in the appended claims.