Abstract:
An iontophoretic apparatus for ocular iontophoresis comprising a housing element formed to cooperate with the eye. In cooperation with the housing element is a flexible current distribution element that is capable of transmitting electrical current. Coupled to the current distribution element is a conformable medicament containment element that is filled with a medicament which is released under the influence of an electrical current, while a barrier element is provided that is configured to reduce current flow outside of the barrier and aid in the preferential delivery of medicament.

Description:
BACKGROUND OF THE INVENTION  
         [0001]    1. The Field of the Invention  
           [0002]    The present invention relates to methods and apparatus for administering substances to the eye. More particularly, the present invention discloses methods and apparatus for administering medicaments to the eye by iontophoresis.  
           [0003]    2. The Relevant Technology  
           [0004]    During ophthalmic medical procedures it is necessary to deliver a medicament to the eyeball, although the requirements for delivering medication to the eyeball vary depending on the particular medicinal purpose. For example, concentration levels of a medicament may be needed in the vitreous fluid of the interior of the eyeball to treat a particular affliction. However, for other pathological conditions, it may be efficacious to deliver and distribute medication over the entire surface of a sclera or to intra-sclera tissues. Yet another procedure may require an anesthetic compound to be carried or transmitted into the corneal tissue prior to a surgical procedure, such as keratotomy. Therefore, a given medical condition may require the delivery of a medicament over a widespread area, or conversely may need to be concentrated onto a smaller area.  
           [0005]    One traditional method of delivering a medicament to the surface of the eye, either for treating a disorder or to aid in diagnosis, is through the use of eye drops. Generally, the lower eyelid is held away from the sclera and a drop of the medication is introduced into the gap formed between the eyelid and the sclera. During this procedure one must take care to avoid touching the eye with the dropper or one&#39;s fingers to reduce the risk of contamination. Through this procedure, numerous types of drug may be delivered to the eye, such as, antibiotics, corticosteroid, antihistamines. Additionally, eye drops may be used to administer drugs which control glaucoma and which either dilate or constrict the pupil. For example an ophthalmologist during an eye examination may drop tropicamide or phenylephrine onto the eye in order to dilate the pupil. By doing this the ophthalmologist will be able to fully view the crystalline lens and check for any defects. Furthermore, in cataract surgery, a physician may place a number of similar drops onto the surface of the eye in order to dilate the pupil so that most of the front surface of the lens is exposed. Additionally, a surgeon may use drops to introduce a local anesthetic instead of performing a local or general anesthetic with a needle.  
           [0006]    Unfortunately, with the administration of medication through the use of an eyedropper there is the possibility of contamination, especially when multiple individuals use the same dropper. Furthermore, one may inadvertently contact the dropper with one&#39;s finger and thereby transmit any bacteria located on one&#39;s finger to the dropper. Additionally, medication may be required within the vitreous body of the eye, but the eyedropper only delivers medication to the surface of the eye and allows the medication to pass through the layers of the eye. The passage of medicament into the vitreous body may take a long period of time and hence reduce the effectiveness of eyedropper medicament delivery.  
           [0007]    When a drug needs to be delivered below the surface of the eye, it is typical to utilize an injection. This is usually performed by inserting a needle into the tissue surrounding the eye or into the sclera of the eye. As a drug is injected into either region, it may be directed into the vitreous body or other surrounding tissue or other portions of the eye.  
           [0008]    The use of a hypodermic needle, however, also has its disadvantages. Injection of a medicament is invasive, inconvenient and sometimes risky, due to the sharpness of the needle. As the physician inserts the needle into the surrounding tissues, a minor increase in the force applied may result in a perforated eyeball or a detached retina with the numerous associated problems. Additionally, many individuals are uneasy about the use of needles for any type of injection and more so when it involves inserting a needle close to or into the eye.  
           [0009]    Another less common method used to administer a drug to an eye is known as iontophoresis. At the most basic level, iontophoresis involves the application of an electromotive force to drive ionic chemicals through a tissue so that they can be absorbed by adjacent tissues and blood vessels. In general terms, this is performed by placing a first bio-electrode containing an ionic medication solution in contact with a portion of the tissue which is to be phoresed. A second bio-electrode is placed on a part of the body near to the first bio-electrode, and a voltage is applied sufficient to cause current to pass through the tissue thereby completing the electrical circuit between the electrodes. As current flows, the ionized medication molecules migrate through the tissue under the influence of the second bio-electrode.  
           [0010]    A similar approach is taken with respect to ocular iontophoresis. Traditionally, ocular iontophoretic apparatus comes in one of two types, either an eyecup device or an applicator probe. The traditional eyecup device is formed from a half-spherical element. Normally the interior of the element is hollow and an electrode extends from the top of the half-spherical element. During iontophoresis, the eyecup is filled with a medicament solution and placed on the eye. As the voltage from a power source is applied, current passes from the electrode within the half-spherical element and flows into the surface of the eye. Simultaneously, the medicament ions are forced either from the cathodic bio-electrode within the half-spherical element towards the anodic bio-electrode, or vice versa, thereby forcing the medicament into the eye of the patient.  
           [0011]    In an alternative ocular iontophoretic device, an applicator probe may be used. An applicator probe has an electrode which extends into a probe end that is filled with a medicament. The probe end is placed on the patient&#39;s afflicted area and medicament migrates from the probe end into the patient&#39;s tissue as current is applied.  
           [0012]    Conventional ocular iontophoretic apparatus have a number of problems. For example, an applicator probe device requires one to precisely and continuously hold the probe against the patient&#39;s eyeball. Unfortunately, if the entire eyeball has to be phoresed this procedure can take a long period of time. Additionally, if one applies too great a force, too high a current, or maintains contact for too long a period of time, the patient&#39;s eyeball can be burned leaving lesions on the eye surface. Furthermore, with the eyecup-type apparatus, there is a possibility that one may scratch the eyeball of the patient if the probe is too long or if placement is not accurate. Also, medication which is placed within the eyecup may escape from beneath the edges of the eyecup due to conformability limitations of the eyecup and variations in the size and curvature of the eyeball. Additionally, contaminants, such as tears, saline, or other impurities may infiltrate the medicament thereby reducing the potency or pharmacological effectiveness of the medicament. The eyecup may be forced against the surface of the eye to reduce the effects of leaking and containment infiltration, however, the required force may damage the eye.  
           [0013]    Perhaps the most significant problem with prior ocular iontophoretic devices is the unintentional delivery of medicament to the surrounding soft tissues, including the eyelid, socket, etc, instead of to the eyeball or sclera. This inadvertent drug delivery to the surrounding tissues is due to the sclera and other eyeball tissues being wetted with conductive saline or tears. The saline or tears has considerably lower electrical resistance than alternative transscleral pathways, resulting in the electrical current preferentially following a pathway to the surrounding soft tissues.  
           [0014]    It would be an advantage, therefore, to provide an apparatus which may be used to administer medicaments to any region of an eyeball, while preventing inaccurate distribution of medicament to surrounding tissues and damage to the eye.  
         SUMMARY AND OBJECTS OF THE INVENTION  
         [0015]    It is, therefore, an object of the present invention to provide an apparatus for delivering a quantity of medicament to the eye.  
           [0016]    It is another object of the present invention to prevent loss of medicament potency by more preferentially directing the delivery of a quantity of medicament to a specific region or regions requiring treatment.  
           [0017]    It is yet another object of the present invention to provide an apparatus that reduces the effects of electrical shunting of the medicament over the surface of the eye and into the surrounding soft tissues.  
           [0018]    Yet another object of the present invention is to provide an apparatus that prevents inflow of saline or tears into the medicament and drug matrix thereby preventing contamination of the medicament and drug matrix.  
           [0019]    Still yet another object of the present invention is to provide an apparatus which prevents medicant delivery to tissues surrounding the eyeball.  
           [0020]    It is another object of the present invention to provide an apparatus which may be hand-held by a user or fixably connected to a patient.  
           [0021]    It is still yet another object of the present invention to provide an apparatus which prevents the possibility of damage to the eyeball during medicament delivery.  
           [0022]    Yet another object of the present invention is to provide an apparatus which minimizes the time and discomfort necessary for iontophoresis by increasing the effectiveness of medicament delivery.  
           [0023]    Yet another object of the present invention is to provide an apparatus which is flexible and capable of conforming to the surface upon which it is placed.  
           [0024]    Yet another object of the present invention is to provide an apparatus which may be disposable or reusable.  
           [0025]    To achieve the foregoing objects, and in accordance with the invention as embodied and broadly described herein, the present invention is an iontophoretic apparatus for ocular iontophoresis. The iontophoretic apparatus comprises a housing element formed to cooperate with the eye. Coupled to the housing element is a flexible current distribution element that is capable of transmitting an electrical current from a power source. In cooperation with the current distribution element is a conformable medicament containment element that is filled with a medicament. The medicament is released under the influence of an electrical current, while a barrier element is provided that is configured to reduce current flow outside of the barrier and hence prevent unwanted migration of the medicament.  
           [0026]    These and other objects and features of the present invention will become more fully apparent from the following description and appended claims, or may be learned by the practice of the invention as set forth hereinafter.  
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0027]    In order that the manner in which the above-recited and other advantages and objects of the invention are obtained, a more particular description of the invention briefly described above will be rendered by reference to a specific embodiment thereof which is illustrated in the appended drawings. Understanding that these drawings depict only a typical embodiment of the invention and are not therefore to be considered to be limiting of its scope, the invention will be described and explained with additional specificity and detail through the use of the accompanying drawings in which:  
         [0028]    [0028]FIG. 1 is a schematic depiction of an iontophoretic system.  
         [0029]    [0029]FIG. 2 is a side view of one embodiment of an iontophoretic apparatus of the iontophoretic system.  
         [0030]    [0030]FIG. 3 is an exploded cross-sectional view of the iontophoretic apparatus in FIG. 2 taken along the line  3 - 3 .  
         [0031]    [0031]FIG. 4 is a cross-sectional view of the iontophoretic apparatus in FIG. 3 taken along the line  4 - 4 .  
         [0032]    [0032]FIG. 5 is a perspective view of the iontophoretic apparatus in FIG. 2 in use.  
         [0033]    [0033]FIG. 6 is a perspective view of another embodiment of the iontophoretic apparatus of the present invention.  
         [0034]    [0034]FIG. 7 is a side view of the embodiment of FIG. 6.  
         [0035]    [0035]FIG. 8 is a perspective view of the embodiment of FIG. 6 shown in use.  
         [0036]    [0036]FIG. 9 is an exploded perspective view of another alternate embodiment of the iontophoretic apparatus of the present invention.  
         [0037]    [0037]FIG. 10 is a side view of the embodiment of FIG. 9.  
         [0038]    [0038]FIG. 11 is an exploded perspective view of another alternate embodiment of the invention.  
         [0039]    [0039]FIG. 12 is an exploded perspective view of yet another embodiment of the iontophoretic apparatus of the present invention.  
         [0040]    [0040]FIG. 13 is a plan view of the embodiment of FIG. 12.  
         [0041]    [0041]FIG. 14 is a side view of yet another embodiment of the iontophoretic apparatus of the present invention.  
         [0042]    [0042]FIG. 15 is a plan view of the embodiment of FIG. 14.  
         [0043]    [0043]FIG. 16 is a plan view of the embodiment of FIG. 14 in use.  
         [0044]    [0044]FIG. 17 is a plan view of the embodiment of FIG. 14 in use.  
         [0045]    [0045]FIG. 18 is a plan view of an alternate configuration of the embodiment of FIG. 14.  
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0046]    The present invention relates to an iontophoretic system which is used to administer medicament to an eye. The iontophoretic system includes an iontophoretic apparatus which may be used to administer a medicament to an eye. The iontophoretic apparatus is configured such that medicaments are preferentially delivered only to those areas which require the medicament. The iontophoretic apparatus allows a bio-electrode with a larger diameter than previously capable of being used in the delivery of a medicament. The increased diameter bio-electrode may be used without a loss in the penetration of a medicament into the eyeball. Furthermore, the iontophoretic apparatus is configured to be easily used by an operator and/or fixably positioned in communication with the eye.  
         [0047]    In general terms, as shown in FIG. 1, an iontophoretic systems  10  includes an electrical current source or a power supply  12  that is electrically connected to a dose controller  14  by way of a cable  16 . Dose controller  14  is in turn electrically connected to an iontophoretic apparatus  20  by way of cable  18 . The power supply  12  and dose controller  14  are well known in the art and perform the functions of providing and controlling various iontophoretic system properties such as, by way of example and not limitation, flow of electrical current, time of treatment, power cycling of treatment, strength of treatment, starting and/or pausing of treatment, and ramping of treatment current from an initial current to a steady state medicament delivery current. Power supply  12  and dose controller  16  may be formed from separate units which are coupled together by various electrical techniques, such as cable  16 , or may be integrally formed in a single unit as represented by dotted line  19 . As such, one skilled in the art can, in view of the teaching contained herein, identify various other embodiments and configurations of power supply  12 , dose controller  16  and methods of coupling thereof, such that they may cooperate with iontophoretic apparatus  20 . The subsequent discussion contained herein will be directed to the various configurations and embodiments of iontophoretic apparatus  20  which may be used in cooperation with various power supplies and/or dose controllers.  
         [0048]    FIGS.  2 - 5  depict an iontophoretic apparatus  20  that may be used to perform localized iontophoresis to particular areas of the body and cooperate with the iontophoretic system. As shown generally in FIG. 5, iontophoretic apparatus  20 , such as an application probe, is used to perform iontophoresis of the eye. It can be appreciated that iontophoretic apparatus  20  cooperates with the known elements of an iontophoretic system, such as a power supply and a dose controller (not shown) Generally speaking, iontophoretic apparatus  20  includes a housing element  22 , a current distribution element  24 , a medicament containment element  26 , and a barrier element  28 . It can be appreciated that many other variations of iontophoretic apparatus  20  may also effectively carry out the intended function thereof.  
         [0049]    According to one aspect of the present invention, housing element  22  comprises a first end  32 , a second end  34 , and a connector recess  36 . Preferably, housing element  22  has a generally tubular form, where first end  32  has a greater cross-section than second end  34 . First end  32  has a flange  38  located around the peripheral edge of first end  32 . Flange  38  has a plurality of apertures  40  therethrough which allow current distribution element  24  and medicament containment element  26  to be coupled thereto. Connector recess  36  is formed substantially through the center of housing element  22  from first end  32  to second end  34 . Additionally, connector recess  36  extends outwardly from the center of housing element  22  thereby bisecting second end  34  of housing element  22  into two portion. It will be appreciated, in view teachings contained herein, that one skilled in the art can identify various other configurations of housing element  22  and its associated features.  
         [0050]    For example, first end  32  may have the same cross-section as second end  34 , or first end  32  may have a smaller cross-section than second end  34 . Connector recess  36  may have different configurations dependent on the type of connection required between housing element  22  and a user handling device  30 . For example, connector recess  36  may have an internal thread which interconnects with an associated thread on user handling device  30 . In another alternative configuration, connector recess  36  may be tapered such that it may slip-fit with an associated tapered user handling device  30 . Also, connector recess  36  may divide second end  34  into numerous sections dependent on the connector used to attach housing element  22  to user handling device  30 . Various other means of connecting housing element  22  to the user handling device  30  are known to one skilled in the art. Additionally, in view of the teaching contained herein, one skilled in the art can identify numerous alternative configurations of housing element  22  which will perform the intended function thereof.  
         [0051]    In general, housing element  22  is configured to securely hold current distribution element  24 , medicament containment element  26 , and barrier element  28  if needed, while being able to connect with user handling device  30 . Housing element  22  is further  11  configured to withstand forces applied by the user during iontophoresis.  
         [0052]    Housing element  22  is preferably composed of materials which will be easily manufactured while giving sufficient strength, rigidity, and connecting possibilities for housing element  22 . The types of material may range from plastics, metals, composites, Teflon, nylon, polyester, polyethylene, and polycarbonates and the like. It is preferred that housing element  22  be substantially composed of a polycarbonate plastic.  
         [0053]    Coupled to housing element  22  is current distribution element  24 . In one preferred embodiment, current distribution element  24  has a generally circular portion  46 , have a disk shape similar to that of a washer. A plurality of holes  48  are located near the peripheral edge thereof, to allow current distribution element  24  to be coupled to first end  32  of housing element  22 . Additionally, a center orifice  50  passes through the center of circular portion  46 . It can be appreciated, in view of the information contained herein, that one skilled in the art can identify various other configurations of current distribution element  24 .  
         [0054]    For example, current distribution element  24  may have various shapes, such as, oval, rectangular, octagonal, trapezoidal or the like. Current distribution element  24  may be interconnected with housing element  22  while being fixably attached to user handling device  30 . In such a case, current distribution  24  may be a protruding wire that extends from proximal end  31  of user handling device  30  and is configured to couple with medicament containment element  26 . Current distribution element  24  is further formed to allow the external power source to electrically connect with the current distribution element  24 . As such, current distribution element  24  may have any form known by one skilled in the art which allows an electrical connection between housing element  22 , power source and medicament containment element  26 . Current distribution element  24 , therefore, requires sufficient strength, rigidity, temperature resistance, and electrical conductivity properties to resist damage when current is applied thereto. Various other configurations of current distribution element  24  are also effective in carrying out the intended function thereof.  
         [0055]    Current distribution element  24  is preferably composed of materials which will be flexible while still being able to conduct electrical current. These may comprise, for example, aluminum, copper, thin films of metallic substances, carbon conductive films, carbon conductive printable films, other printed films, or the like. It is preferred that current distribution element  24  be formed of a thin metallic film printed on a plastic sheet or polyester film. The thickness of the plastic sheets or films ranges from about 2 mils to about 5 mils. It is preferred that the thickness be from about 3 mils to about 4 mils. It is more preferred that the thickness be approximately 3 mils.  
         [0056]    In addition to the dimensions of current distribution element  24  alternate embodiments may be disposable or reusable. Therefore, different chemical compounds or metallic alloys may be used to provide cost effective means of delivering electrical current. If pH control is desired, then either silver (“Ag”) or silver chloride (“Ag/AgCl”) compounds can be used. For a reusable device, a cathodic current distribution element  24  could be made of a sintered version of Ag/AgCl, for example, to provide adequate Cl for several treatment applications. An anodic current distribution element  24  could be made from solid Ag metals or sintered Ag particles or inks, etc. If Ag or Ag/AgCl is desired for single-use disposable iontophoretic apparatus, then small amounts of Ag or Ag/AgCl could be employed in the form of pleated or printed ink-type films or the like. In other configurations of the present invention carbon conductors may be used as either anodic or cathodic current distribution element  24 .  
         [0057]    Coupled to current distribution element  24  is medicant containment element  26 . In the embodiment of FIGS.  2 - 5 , medicament containment element  26  has a generally cylindrical portion  52  having a first containment end  54  and a second containment end  56 . First containment end  54  is connected to both current distribution element  24  and housing element  22 . First containment end  54  has the same cross-section as that of first end  32  of housing element  22 . Additionally, first containment end  54  has a plurality of protruding portions  58  near the peripheral edge thereof, which extend from first containment end  54  parallel to the longitudinal axis of medicament containment element  26 . The plurality of protruding portions  58  pass through the plurality of holes  48  and lock within a corresponding plurality of apertures  40 . The plurality of protruding portions  58  are configured to more efficiently transfer electrical current from current distribution element  24  to medicament containment element  26 . It will be appreciated that medicament containment element  26  may have various other configurations that are also effective in carrying out the intended function thereof.  
         [0058]    In general, medicament containment element  26  is configured to hold a supply of medicament during the iontophoresis procedure. Furthermore, medicament containment element  26  provides for the transfer of electrical current from current distribution element  24  to the surface in which it is in contact. Medicament containment element  26  retains the requisite strength and rigidity to elastically deform during iontophoresis while being pliable to thereby not damage the eye during contact therewith.  
         [0059]    Various other configurations of medicament containment element  26  can be identified by one skilled in the art in view of the teachings herein. For example, the cross-section of medicament containment element  26  may vary depending on the manner by which medicament containment element  26  is coupled to either both current distribution element  24  and housing element  22  or to each one individually. Medicament containment element  26  may have the same cross-sectional profile as that of housing element  22  or current distribution element  24 . In another alternate configuration, medicament containment element  26  may be cone-shaped with a conic aperture partially through the center thereof. The conic&#39;s aperture is configured to cooperate with current distribution element  24  when it is fixably attached to user handling device  30  and has the form of a protruding wire that extends from proximal end  31  of user handling device  30 . Medicament containment element  26  may also have any cross-section or dimensions necessary to perform a specific type of iontophoresis, such as, rounded, angled, pointed, and the like. Furthermore, medicament containment element  26  may have a cross section of only a few millimeters or a few centimeters depending on the particular use. The dimensions may range from 1 mm to 20 mm. It is preferred that medicament containment element  26  be approximately between about 5 mm and 6 mm.  
         [0060]    One example of material structure capable of performing the function of medicament containment element  26  is a gel sponge composite containment matrix as defined in U.S. Pat. No. 5,558,632 issued to Lloyd et al., which is incorporated herein by reference. Various other materials used to form medicament containment element  26  are also effective in carrying out the intended function thereof. For example, a variety of reusable or single use disposable porous wicking materials, hydrogels, or composite materials may be used.  
         [0061]    For ocular iontophoresis, it is preferable that a cross-linked hydrogel be used since the cohesive nature of the cross-linked hydrogel prevents fibrous material, gels or residues being left on the eye after iontophoresis. The use of a cross-linked hydrogel also is beneficial during iontophoresis since no fibrous materials may abrade or irritate the eye. For alternative uses of iontophoresis apertures such as for treating skin or hair follicles, a gel which would wick and wet effectively would be preferable. Examples of such materials for alternative uses includes a hydrogel impregnated dry sponge matrix, and a multi-laminate cross-linked polyethylene oxide dried matrix.  
         [0062]    Various types of medicament may also be used in medicament containment element  26  dependant on the type of medical procedure which is to be performed. For example, anesthetics such as lidocaine may be contained within medicament containment element  26 . Another example is oligonucleutides, such as Vascular Endothelial Growth Factors or VEGF inhibitors. Other illustrative examples of drugs which may be used include antibiotics, corticosteroids, antihistamines, tropicamide, or phenylephrine. Various other medicaments may also be transmitted through the use of iontophoretic apparatus  20 .  
         [0063]    As shown in FIGS.  2 - 5 , barrier element  28  is coupled to medicament containment element  26 . Barrier element  28  has a toroidal form or doughnut shape having a barrier body  64  configured with a first recess  66  having an axis coinciding with the axis of barrier body  64 . A portion of first recess  64  connects with medicament containment element  26 , while another portion cooperates with a portion of the eyeball. Various other configurations of barrier element  28  are also effective in carrying out the intended function thereof.  
         [0064]    In general, barrier element  28  is formed to connect with medicament containment element  26  and aid in the preferential delivery of medicament. It is a feature of the present invention to provide preferential delivery during ocular iontophoresis to avoid the problems of electrical pathway shunting described previously.  
         [0065]    It is believed that electrical pathway shunting occurs when an electrical current is applied to the eyeball, resulting in the electrical current radiating in many directions at the same time. Under traditional electrical theory, current or flow of charge will follow the path of least resistance. With ocular iontophoresis, since the surface of the eyeball is continuously bathed in an electrically conductive ionic saline, tears and natural occurring saline will distribute the current throughout the surface of the eyeball and into surrounding tissues. This effect is believed to occur regardless of the exact location on the eyeball surface where the electrical current is introduced. Therefore, current may flow into the sclera, into the vitreous body of the eyeball, or even into the surrounding facial tissues, such as the inner eyelid and socket tissues. Recent studies support this proposition. In an attempt to deliver a drug compound via transscleral iontophoresis, substantially no levels of drug compound were detected in the vitreous of the eye, while considerable blood systemic levels of the compound were detected. This suggests that the drug compound and electrical driving current are being diverted or “shunted” from transscleral flow to travelling along the surface of the eyeball into nearby soft tissue. Barrier element  28  of the present invention is formed to aid in preventing medicament from following the electrical pathways on the surface of the eyeball, thereby assisting with preferential distribution of the medicament for specific medical procedures.  
         [0066]    Barrier element  28  may have various configurations dependent on the size and dimensions of medicament containment element  26 , current distribution element  24 , housing element  22  and the particular medical procedure involved. For example, iontophoretic apparatus  20  may not require barrier element  28  since a medical procedure may use electrical pathway shunting to aid in the distribution of medicament. Iontophoretic apparatus  20  may have more than one barrier element  28 , thereby creating a sealed area between the first and second barrier elements which more effectively and preferentially delivers medicament. Barrier element  28  may have triangular-shape, circular, oval-shaped, or the like. It will be appreciated that various other configurations may be used and are known by one skilled in the art, in view of the teachings contained herein.  
         [0067]    Barrier element  28  is preferably composed of materials which will provide sufficient resilience to flexing while being flexible to conform to the surface upon which it makes contact with to thereby form a fluid-tight seal. The types of material which may be used for barrier element  28  include soft silicone gels or other types of silicon compounds which generally conform to the surface upon which they are placed. For example, Dow Q7-2218 two-part soft silicone gel, silicone and elastomer equivalents from Nusil, low durometer urethanes, and similar materials are useful in the construction of barrier element  28 . It is preferred that barrier element  28  be composed of low-durometer silicone elastomeric gels.  
         [0068]    In forming iontophoretic apparatus  20  it is necessary to connect the above described elements together. There are a variety of methods to accomplish the bonding or joining of the individual elements. For example, housing element  22  may be sonically bonded, glued, screwed or bolted to medicament containment element  26  and current distribution element  24 . Barrier element  28  may be attached to medicament containment element  26  through the use of adhesives or the like. Various methods of bonding the elements of iontophoretic apparatus  20  together, in view of the teaching contained herein, can be identified by one skilled in the art. It is preferred that the elements be sonically bonded together. Referring now to FIG. 5, iontophoretic apparatus  20  may be used to phorese the eyeball. In operation, an electrical current is applied through connector recess  36 , to current distribution element  24 . The current then travels through medicament containment element  26  into the eyeball. The current is drawn through the eyeball as it travels to a second bio-electrode which is located near the eye. Barrier element  28  comes into contact with the eyeball as iontophoretic apparatus  20  is placed against the eye. Barrier element  28  reduces the electrical current which passes along the surface of the sclera or conjunctiva and hence directs the delivery of medicament to the area within the confines of barrier element  28 . As shown in FIG. 4 iontophoretic apparatus  20  may have a similar dimension to that of the visible iris, although various other dimensions and sizes are also effective in carrying out the intended function described herein.  
         [0069]    FIGS.  6 - 8  illustrate another embodiment of an ocular iontophoretic apparatus  120 . The majority of the features previously discussed with respect to iontophoretic apparatus  20  also apply to the iontophoretic apparatus  120 . Iontophoretic apparatus  120  has a housing element  122 , a current distribution element  124 , a medicament containment element  126 , and a barrier element  128 . Housing element  122  has a generally cup-shaped form, with a cup-shaped first portion  132 , second end  134  and a middle portion  138 . Cup-shaped first portion  132  is configured to comfortably be positioned about the eyeball, as shown in FIG. 8. Furthermore, the axis of cup-shaped first portion  132  is offset from the axis of second end  134 , such that middle portion  138  extends from a peripheral edge of cup-shaped first portion  132 . Cup-shaped first portion  132  has a hole  140  through the center thereof to allow access to the eyeball. In view of the teachings a contained herein, one skilled in the art can identify various other configurations capable of performing the intended function thereof.  
         [0070]    For example, cup-shaped first portion  132  may be enclosed and completely covers the eyeball as seen in FIG. 7. In yet another configuration, middle portion  138  extends along the longitudinal axis of cup-shaped first portion  132 . In other configurations, middle portion  138  may extend angularly from cup-shaped first portion  132 . Other configurations of housing element  122  are equally effective in carrying out the intended function thereof.  
         [0071]    Housing element  122  is preferably formed from materials which will be easily manufactured while giving sufficient strength, rigidity, and connection flexibility for housing element  122 . The types of material may range from plastics, composites, Teflon, nylon, polyester, polyethylene, and polycarbonates and the like. It is preferred that housing element  122  be composed of polycarbonates.  
         [0072]    Current distribution element  124 , as shown in FIG. 6, has a form similar to that of inner surface  143  of cup-shaped first portion  132 . Current distribution element  124  has a segmented formed with a plurality of conductive extensions  148  that extend from a conductive ring (no shown). Current distribution element  124  therefore has a similar form to inner cavity  142  of cup-shaped first portion  132 .  
         [0073]    In general, the segmented form of current distribution element  124  provides spherical conformability benefits to ocular iontophoretic apparatus  120 . The plurality of conductive extension  148  are capable of flexing in relation to the conductive ring and therefore conform to the surface of the eyeball while applying a pressure to the medicament containment element  126  to force the medicament containment element  126  against the surface of the eye. Various other configurations of current distribution element  124  are also effective in carrying out the intended function thereof.  
         [0074]    For example, current distribution element  124  may be connected to a user handling device  130  (as shown in FIG. 5) such that one or more conductive extensions  148  pass through connector recess  136  and into inner cavity  142  of cup-shaped first portion  132 . In another configuration, current distribution element  124  is positioned within connector recess  136  such that it comes into contact with medicament containment element  126 . Current distribution element  124  may be positioned at any longitudinal position within connector recess  136 , so long as it is configured to come into contact with medicament containment element  126 . Various other configurations of current distribution element  124  are also capable of carrying out the intended function thereof. It will be appreciated by one skilled in the art that any type of current distribution element  124  may be used with appropriate modifications to housing element  122 .  
         [0075]    According to another aspect of an alternate embodiment of the present invention, medicament containment element  126  has a cup-shaped member  152  which is formed to coincide with inner cavity  142  of cup-shaped first portion  132  while being provided with an interior curved portion that cooperates with the surface of the eye. Medicament containment element  126  has a double concaved shape with interior and exterior concaved curved profiles. The exterior concaved portion being shaped to cooperate with housing element  122 , while the interior concaved portion cooperates with the surface of the eye. Medicament containment element  126  is coupled to current distribution element  124  and housing element  122 , while being capable of conforming to the surface of the eye with which it is in contact. Various other configurations of medicament containment element are also effective in carrying out the intended function thereof.  
         [0076]    For example, medicament containment element  126  may be formed with at least one aperture which is configured to cooperate with at least one conductive extension  148 . In another configuration, medicament containment element  126  comprises a gel which is inserted within inner cavity  142  of cup-shaped first portion  132 . In another configurations, medicament containment element  126  has a toroidal form such that hole  140  allows for continual refilling of medicament containment element  126 . As such, medicant containment element  126  conforms to the surface upon which it is to contact. In view of the teachings contained herein, one skilled in the art can identify various other configurations of medicament containment element  126  which are capable of carrying out the intended function thereof.  
         [0077]    According to another aspect of an alternate embodiment of the present invention, barrier element  128  comprises a cup-barrier portion  164 . Cup-barrier portion  164  has a generally circular cross-section. Cup-barrier portion  164  is coupled to a lower external edge of cup-shaped first portion  132  such that it forms a seal with the eyeball when placed against the eyeball. Various other configurations of barrier element  128  are also effective in carrying out the intended function thereof.  
         [0078]    For example, as shown in FIG. 6, in one alternate configuration, barrier element  128  comprises cup-barrier portion  164  and an upper cup-barrier portion  166 . Upper cup-barrier portion  166  is coupled to the peripheral edge of hole  140  of cup-shaped first portion  132 , while cup-barrier portion  164  is coupled to the lower peripheral edge of cup shaped first end  132 . In combination, upper cup-barrier portion  166  and cup-barrier portion  164  create an inner recess which restricts medicament flow and thereby prevents medicament from passing into the inner portion of cup-shaped first portion  132  during certain medical procedures. Upper cup-barrier portions  166  and cup-barrier portion  164  may have the same cross-section or different cross-sections dependent on the medical procedure and needs of the apparatus. In view of the teaching contained herein, one skilled in the art can identify various other configurations of barrier element  128 .  
         [0079]    FIGS.  9 - 11  illustrate another embodiment of an ocular iontophoretic apparatus  220 . The majority of the features previously discussed with respect to iontophoretic apparatus  120  also apply to iontophoretic apparatus  220 . Iontophoretic apparatus  220  has a housing element  222 , a current distribution element  224 , a medicament containment element  226 , a barrier element  228 , and a securing element  270 . Each element has the same intended function as previously described.  
         [0080]    Housing element  222  is formed from two separate pieces, a lower rim  232  and an upper rim  234 . Lower rim  232  has a generally lower circular portion  236  with an arm  238  extending from the peripheral edge of lower circular portion  236 . Lower rim  232  has an internal. taper such that first lower end  240  has a smaller diameter than second lower end  242 . Upper rim  234  has a generally circular upper portion  235  having a similar form to that of a washer. Upper rim  234  is used to securely hold medicament containment element  226  and current distribution element  224  to lower rim  232 . It will be appreciated in view of the teachings contained herein, that one skilled in the art can identify various other configurations of housing element  222  which will perform the intended function thereof.  
         [0081]    For example, lower rim  232  can have a flange  244  which extends from the peripheral edge of lower rim  232  parallel to the longitudinal axis thereof. Flange  244  may then couple directly to upper rim  234  or a flange formed thereon to thereby securely hold current distribution element  224 , medicament containment element  226 , barrier element  228 , and in an alternate configuration, securing element  270 . Coupling may be performed through the use of sonic bonding, adhesives or other bonding techniques known to one skilled in the art. Various other configurations of upper rim  234  and lower rim  232  are also capable of carrying out the intended function thereof.  
         [0082]    Upper rim  234  and lower rim  232  are preferably composed of materials which will be easily manufactured while giving sufficient strength and rigidity for housing element  222 . The types of material may range from plastics, composites, Teflon, nylon, polyester, polyethylene, and polycarbonates and the like. It is preferred that upper rim  234  and lower rim  232  be substantially composed of polycarbonate.  
         [0083]    Coupled with housing element  222  is current distribution element  224 . Current distribution element  224  has a conductive ring portion  246  with a plurality of conductive extensions  248  extending from an inner peripheral edge thereof. The plurality of conductive extensions  248  extend toward the center of conductive ring portion  246  and are configured to flex when a force is applied thereto. Thus, current distribution element  224  is capable of conforming to the surface of a patient&#39;s eye during iontophoresis. Current distribution element  224 , furthermore, has an insulated portion  238  extending from the peripheral edge of ring portion  246 . In one configuration, current distribution element  224  is formed from a printed film provide with metallic portions printed thereon. Various other configurations of current distribution element  224  are also capable of carrying out the intended function thereof.  
         [0084]    For example, current distribution element  224  may include a single conductive extension  248 . Current distribution element  224  may have other dimensions and shapes based on housing element  222 , medicament containment element  226  and barrier element  228 . If housing element  222  is rectangular, then current distribution element  224  may also be rectangular. Other configurations are also effective in carrying out the intended function thereof.  
         [0085]    Current distribution element  224  is preferably manufactured from a thin metallic film, an acetate film with a metallic substance printed thereon. Other materials such as metals, conductive materials, printed plastics or films or the like are also effective in carrying out the intended function thereof. It is preferred that current distribution element  224  be composed of a polyester film. The thickness of the plastic sheets or films ranges from about 2 mils to about 4 mils. It is preferred that the thickness be from about 3 mils to about 4 mils. More preferably the thickness is approximately 3 mils.  
         [0086]    In cooperation with current distribution element  224  is medicament containment element  226 . Medicament containment element  226  has a body  252  having generally cylindrical form with a center hole  254  passing therethrough. The axis of center hole  254  coincides with longitudinal axis of body  254 . A flange  256  extends from the lower peripheral edge of body  252  perpendicular to the longitudinal axis of body  252 . Therefore, medicament containment element  226  has a generally L-shaped cross-section. Various other configurations of medicament containment element  226  are also effective in carrying out the intended function thereof.  
         [0087]    In general, medicament containment element  226  is configured such that it may connect with current distribution element  224  and lower rim  232 . Additionally, medicament containment element  226  allows upper rim  234  to securely fasten to lower rim  232  thereby sealing current distribution element  224  and medicament containment element  226  within housing element  222 . Center hole  254  is provided, such that a portion of an eye may extend thereon while contacting a top surface  258 .  
         [0088]    In view of the teachings herein, one skilled in the art can identify various other configurations of medicant containment element  226 . For example, in another configuration, medicament containment element  226  has no center hole  254 , but is formed from a solid piece of material. In yet another configuration, medicament containment element  226  is formed from a gel. Furthermore, medicament containment element  226  may have dimensions corresponding to those of housing element  222  and current distribution element  224 . For example, if housing element  222  has a curved form then medicament containment element  226  will either have a curved form or be formed from a material that allows conformability to a curved surface. Additionally, if current distribution element  224  has a single conductive extension  248 , then medicament containment element  226  may have a corresponding aperture which cooperates with the conductive extension  248 . It will be appreciated, in view of the teachings herein, that one skilled in the art can identify various other configurations of medicant containment element  226  that may perform the intended function thereof.  
         [0089]    Medicament containment element  226 , as previously discussed, may be manufactured from gel sponges, cross-linked hydrogels, gels or other similar materials. Other materials used to form medicament containment element  226  are known by one skilled in the art. It is preferred that medicament containment element  226  be composed of a compliant flexible gel or gel composite matrix which has a toroidal ring form or curved, spherical form as required for the particular treatment.  
         [0090]    Coupled to housing element  222  and medicament containment element  226  is barrier element  228 . Barrier element  228  has a generally circular body  264 , with a generally bell-shaped cross section. Barrier element  228  interlocks with upper rim  234  and/or medicament containment element  226  to thereby retain medicament containment element  226 . Barrier element  228 , in one configuration, extends beyond the horizontal plane of the top surface  258  of medicament containment element  226  by extending beyond the horizontal plane of top surface  258 . Barrier element  228  contacts the surface of the eye prior to medicament containment element  226  and provides the sealing function previously described. Various other configurations of barrier element  228  are known by one skilled in the art in view of the teaching contained herein.  
         [0091]    For example, barrier element  228  may be configured such that when lower rim  232  securely holds medicament containment element  226  and/or current distribution element  224 , barrier element  228  coincides with or is positioned below the horizontal plane of top surface  258  of medicament containment element  226 . In other configurations, barrier element  228  may have various cross-sections, known by one skilled in the art, to form a seal when barrier element  228  comes into contact with the eye. Additionally, the location of barrier element  228  is dependent on the particular use to which the iontophoretic apparatus  220  is to be used as has previously been discussed. Furthermore, iontophoretic apparatus  220  may be formed with a second barrier element that is coupled to the inner surface of center hole  254  to isolate an area of the eye such as, by way of example and not limitation, the cornea from the introduction of medicament. It can be appreciated that use of a second barrier may aid in the introduction of medicament to a specific location which is to be phoresed.  
         [0092]    According to another aspect of an alternate embodiment of the present invention, iontophoretic apparatus  220  comprises securing element  270 . Securing element  270 , in one illustrative configuration as shown in FIG. 11, has a securing arm  272  extending from the peripheral edge of lower rim  232  and an attachment portion  276  coupled to a distal end  274  of securing arm  272 . Attachment portion  276  has a bonding material coupled thereto to fixably attach to an individual&#39;s cheek, forehead or other part of a person&#39;s body. Various other configurations of securing element  270  are also effective in carrying out the intended function thereof.  
         [0093]    For example, securing element  270  may not be coupled to upper rim  234 . In an alternative configuration, securing element  270  has a generally circular body coupled to securing arm  272 . The body has a hole therethrough which may connect to the outer surface of lower rim  232  and surround lower rim  232 . In another configuration, securing body may be located between upper rim  234  and lower rim  232  and be fixably connected to housing element  222  when upper rim  234  is coupled to lower rim  232 . in yet another configuration, securing arm  272  may be formed from a harness which may be coupled to a patient&#39;s head, shoulders or other part of the patient&#39;s body to hold iontophoretic apparatus  220  during iontophoresis. Still yet another configuration, securing arm  272  is configured to allow a user to manually hold iontophoretic apparatus  20  in place. In yet another configuration attachment portion  276  may be affixed through the use of adhesives or other similar technique such that securing element  270  may be easily removed without causing damage to the patient&#39;s body. In view of the teachings contained herein, one skilled in the art can identify various other configurations of securing element  270 .  
         [0094]    Securing element  270  is preferably composed of materials which will be easily manufactured while giving sufficient strength and rigidity. The types of material may range from plastics, metals, composites, Teflon, nylon, polyester, polyethylene, and polycarbonates and the like. It is preferred that securing element  270  be substantially composed of polycarbonate.  
         [0095]    FIGS.  12 - 13  illustrate another embodiment of an ocular iontophoretic apparatus  320 . The majority of the features previously discussed with respect to iontophoretic apparatus  220  also apply to iontophoretic apparatus  320 . Iontophoretic apparatus  320  has a housing element  322 , a current distribution element  324 , a medicament containment element  326  and a barrier element  328 . Housing element  322  comprises a body portion  332  and an upper rim  334 . Body portion  332  is configured with at least one wing portion  333 . Body portion  332  and wing portions  333  are configured to be flexible to allow wing portions  333  to extend underneath the eyelids of the patient when in use as shown in FIG. 12. Body portion  332  is further configured with an orifice  337  which is formed to cooperate with medicant containment element  326  to allow the cornea of the eye to extend therethrough.  
         [0096]    Upper rim  334  has a generally circular form with a rim flange  336  extending from a rim body  335 . Flange  336  couples to the lower surface of body portion  332  and aids in the retention of medicament containment element  326  and current distribution element  324  again body portion  332 . Various alternative configurations of housing element  332  are also effective in carrying out the intended function thereof.  
         [0097]    Housing element  322  is preferably composed of materials which will be easily manufactured while giving sufficient strength and flexibility to be located beneath the eyelids of a patient. The types of material may range from plastics, metals, composites, Teflon, nylon, polyester, polyethylene, and polycarbonates and the like.  
         [0098]    Other elements of this embodiment are similar to those previously discussed while being coupled together in a similar manner. For example, current distribution element  324  is formed with a reduced insulated portion  338 . Reduced insulated portion  338  is much shorter than the insulated portion  238  of iontophoretic apparatus  220  to prevent injury to the eye because of penetration from the end thereof. Medicament containment element  326  has basically the same configuration as medicament containment element  326 ; however, in use, body  352  of medicament containment element  326  protrudes through orifice  337  and flange  356  rests upon a lower surface  338  of body portion  332 . Therefore, medicament containment element  326  has a generally inverted L-shaped cross-section. Flange  356  is further configured to cooperate with current distribution element  324  which is coupled thereto. Barrier element  328  couples to the portion of medicament containment element  326  which extends through orifice  337 . Various other configurations of medicament containment element  326  are known to one skilled in the art to carry out the intended function thereof.  
         [0099]    FIGS.  14 - 18  illustrate another embodiment of an ocular iontophoretic apparatus  420 . The majority of the features previously discussed with respect to other iontophoretic apparatus also apply to iontophoretic apparatus  420 . Iontophoretic apparatus  420  in general is formed to be easily located either at the temporal side of the eye socket, as shown in FIG. 16, or underneath the lower eyelid, as shown in FIG. 17, and be held in place by the frictional forces exerted by the surrounding tissues while providing the necessary iontophoretic delivery of a medicament. In the configuration depicted herein no adhesives are necessary to retain iontophoretic apparatus  420  in place because the eyelid or surrounding tissues maintain frictional contact with the iontophoretic apparatus  420 , thereby preventing movement of iontophoretic apparatus  420 .  
         [0100]    Referring now to FIGS. 14 and 15, a configuration of iontophoretic apparatus  420  which is to be used at the temporal side of the eye socket is depicted. Iontophoretic apparatus  420  includes a housing element  422  that is in cooperation with a current distribution element  424  that is linked via a wire  425  to a power supply (not shown). Coupled thereto is a medicament containment element  426  and a barrier element  428 . Housing element  422  comprises a generally triangular formed body portion  432  with a securing element  434  coupled at one side thereof. Body portion  432  is configured to retain current distribution element  424 , medicament containment element  426  and barrier element  428  for easily manipulation and insertion while being characterized as being impervious to the migration of medicament or electrical current. Therefore, body portion  432  prevents medicament from being passed therethrough to enter the surrounding tissues.  
         [0101]    In the configuration of FIG. 14, housing element  422  is provided with a securing element  434  to aid the frictional forces in releasably positioning iontophoretic apparatus  420 . Securing element  434  has a generally hooked form such that upon insertion of iontophoretic apparatus  420  at the temporal side of the eye socket securing element  434  cooperates with the corner or the eye as shown in FIG. 16. In other configurations of the present invention, the end of securing element  434  may be formed with an adhesive patch which may be used to releasably couple iontophoretic apparatus  420  in place. In still other configurations, housing element  422  is formed without securing element  434 , as shown in FIG. 18. In view of the teaching contained herein, one skilled in the art can identify various other configurations of housing element  422  which are also capable of performing the desire function thereof.  
         [0102]    For example, the size and dimensions of iontophoretic apparatus  420  may be varied as necessary to perform the necessary iontophoresis. As shown in FIGS. 17 and 18, housing element  422  can have an elongated form to cooperate and accommodate insertion under the lower eyelid. Housing element  422  and therefore iontophoretic apparatus  420  may have various cross-sectional forms such as, but not limited to, circular, ovular, rectangular, square, trapezoidal, or the like.  
         [0103]    In general, housing element  422  may be created from various types of material so long as they are flexible and prevent migration of electrical current and medicament therethrough during iontophoresis. The materials may include, but are not limited to, flexible plastics, films, composites, Teflon, nylon, polyester, polyethylene, polycarbonates, rubbers, elastomers, silicones, and the like. It is preferred that housing element  422  be substantially formed from a flexible silicone.  
         [0104]    Current distribution element  424 , in this embodiment is integrally formed with housing element  422 . As shown in FIGS. 14 and 15 by way of a dotted line, current distribution element  424  takes the form of an electrically conductive printed ink that is formed on the inner surface of housing element  422 . Through this configuration the flexibility of iontophoretic apparatus  420  is increased since the number of layers utilized to form the iontophoretic apparatus is decreased. Other configurations of current distribution element  424  are known by one skilled in the art, in view of the teaching contained herein.  
         [0105]    In use, as shown in FIG. 16, iontophoretic apparatus  420  is slipped between the orbit sides (not shown) and the eyeball. Housing element  422  contacts the surface of the orbit while medicament containment element  426  and barrier element  428  contacts the eyeball. During positioning of iontophoretic apparatus  420 , securing element  434  cooperates with the corner of the eye such that the end of securing element  434  attaches to the surrounding tissue of the eye. By so doing securing element  434  prevents movement of iontophoretic apparatus  420  during operation.  
         [0106]    As shown in FIGS. 17 and 18, another configuration of iontophoretic apparatus  420  is shown wherein securing element  434  is eliminated from housing element  422 . In this way iontophoretic apparatus  420  is retained in place by the frictional forces applied by the lower eyelid upon the surface of housing element  422 .  
         [0107]    In view of the teaching contained herein, one skilled in the art can identify various other configurations. For example, as shown in FIG. 18, iontophoretic apparatus  420  is formed with two barrier elements  428  to form a sealed interior space wherein medicament containment element  426  is located.  
         [0108]    The present invention may be embodied in other specific forms without departing from its spirit or essential characteristics. The described embodiments are to be considered in all respects only as illustrated and not restrictive. The scope of the invention is, therefore, indicated by the appended claims rather than by the foregoing description. All changes which come within the meaning and range of equivalency of the claims are to be embraced within their scope.