Abstrict This invention relates to a pharmaceutical composition for use
in treating an abnormal skin condition, such as a wound, a burn
or a blister, in an animal or human. The pharmaceutical composition
has an antiseptic or antimicrobial agent and a desiccant for adsorbing
moisture or liquid, in and around the area of the abnormal skin,
in a form such that the adsorbed moisture or liquid is not readily
available to the skin.
Claims I claim:
1. A dressing for use in treating an abnormal skin condition in
an animal or human, comprising a liquid permeable sachet containing
a dry topical pharmaceutical composition, the topical pharmaceutical
composition comprising:
(a) an antiseptic or antimicrobial agent; and
(b) a desiccant for adsorbing moisture or liquid in and around
the area of the abnormal skin condition through the liquid permeable
sachet so that the adsorbed moisture or liquid is not readily available
to the skin.
2. The dressing according to claim 1 wherein the desiccant is selected
from the group consisting of silica gel and anhydrous calcium chloride.
3. The dressing according to claim 1 wherein the desiccant is silica
gel.
4. The dressing according to claim 1 wherein the antiseptic or
antimicrobial agent is a hyperosmotic agent which operatively raises
the osmotic pressure in the environment around any bacteria arising
from the abnormal skin condition, thereby inhibiting or killing
the bacteria.
5. The dressing according to claim 1 wherein the antiseptic or
antimicrobial agent is a hyperosmotic agent which includes an inorganic
salt.
6. The dressing according to claim 1 wherein the antiseptic or
antimicrobial agent is selected from the group consisting of sodium
chloride, ammonium chloride and magnesium sulphate.
7. The dressing according to claim 1 wherein the antiseptic or
antimicrobial agent is sodium chloride.
8. The dressing according to claim 1 wherein the antiseptic or
antimicrobial agent is an antibacterial agent.
9. The dressing according to claim 1 wherein the antiseptic or
antimicrobial agent is silver oxide, iodine, a sulphonamide, penicillin
or a tetracycline.
10. The dressing according to claim 1 wherein the abnormal skin
condition is a skin lesion.
11. The dressing according to claim 1 wherein the abnormal skin
condition is a wound, a burn or a blister.
12. A method of treating an abnormal skin condition in an animal
or human including the step of applying to the abnormal skin condition
a dressing comprising a liquid permeable sachet containing a dry
topical pharmaceutical composition, the topical pharmaceutical composition
comprising:
(a) an antiseptic or antimicrobial agent; and
(b) a desiccant for adsorbing moisture or liquid, in and around
the area of the abnormal skin condition so that the adsorbed moisture
or liquid is not readily available to the skin.
13. The dressing of claim 1 wherein the contents of said sachet
consists essentially of a major portion of said desiccant and a
minor portion of said antiseptic or antimicrobial agent.
14. The dressing of claim 13 wherein the contents of said sachet
consists essentially of about 80% desiccant and about 20% antiseptic
or antimicrobial agent.
15. The dressing of claim 14 wherein the contents of said sachet
consists essentially of about 80% by weight silica gel and about
20% by weight sodium chloride.
Description BACKGROUND OF THE INVENTION
This invention relates to a pharmaceutical composition for treating
abnormal skin conditions in humans or animals.
Wounds, burns or blisters can cause great pain to patients. Further,
if such conditions are not treated properly, the skin may not heal
properly and the condition may turn septic causing further complications.
It is an object of this invention to suggest a pharmaceutical composition
which will assist the healing process and alleviate the aforesaid
problems.
SUMMARY OF THE INVENTION
According to the invention there is provided a pharmaceutical composition,
for use in treating an abnormal skin condition in an animal or human,
comprising:
(a) an antiseptic or antimicrobial agent; and
(b) a desiccant for adsorbing moisture or liquid, in and around
the area of the abnormal skin, in a form such that the adsorbed
moisture or liquid is not readily available to the skin.
Preferably, the desiccant is silica gel or anhydrous calcium chloride.
More preferably the desiccant is silica gel.
Preferably, the antiseptic agent is a hyperosmotic agent which
operatively raises the osmotic pressure in the environment around
any bacteria arising from the abnormal skin condition, thereby inhibiting
or killing the bacteria. Typically, the hyperosmotic agent is an
inorganic salt. Preferably, the inorganic salt is sodium chloride,
ammonium chloride or magnesium sulphate. More preferably the inorganic
salt is sodium chloride.
The antimicrobial agent may be an antibacterial agent such as silver
oxide, iodine, a sulphonamide, penicillin or a tetracycline.
Typically, the abnormal skin condition is a skin lesion, such as
a wound, a blister or a burn.
According to another aspect of the invention there is provided
a dressing, for use in treating an abnormal skin condition in an
animal or human, containing a pharmaceutical composition as summarised
above. Preferably, the dressing is a liquid or moisture permeable
sachet and the pharmaceutical composition is contained therein.
The sachet may include adhesive strips for adhering the sachet to
human or animal skin.
According to another aspect of the invention there is provided
a kit, for dressing an abnormal skin condition in an animal or human,
comprising a dressing as summarised above which, in use, is placed
over the abnormal skin, and a liquid or moisture impermeable sheet
which, in use, is wrapped over the sachet. The sheet may be formed
integral with, or separate from, the sachet.
According to another aspect of the invention there is provided
the use of a pharmaceutical composition as summarised above in the
manufacture of a medicament useful in treating an open or broken
skin condition in an animal or human.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will now be described in more detail, by way of example
only, with reference to the accompanying drawings in which:
FIG. 1 shows a sachet according to the invention, and part of a
human arm having a wound inflicted thereon; and
FIG. 2 shows the sachet of FIG. 1 applied to the human arm.
DESCRIPTION OF EMBODIMENTS
FIG. 1 shows a human arm 10 which has a wound 12 inflicted thereon.
There is also shown a sachet 14 according to the invention having
adhesive strips 16 attached thereto.
The sachet 14 is sealed along its edges and is made of a moisture
and liquid permeable material. A suitable material for the sachet
which is currently available is marketed under the trade name "Lutrisil".
The adhesive strips 16 are suitably manufactured to be removably
attachable to human skin.
The sachet 14 has a pharmaceutical composition according to the
invention located therein.
The following words have the definitions as set out hereunder for
the purposes of this specification. The definitions arise in part
from Churchill's Medical Dictionary, Second Edition, published by
Roshe Lexicon Medizine.
Antiseptic: Pertaining to, or capable of, effecting antisepsis.
A substance capable of inhibiting or killing infectious agents,
usually on a body surface.
Antimicrobial: Acting to kill or inhibit growth and multiplication
of microbes. An agent which kills or inhibits the growth and multiplication
of microbes. The term includes antibacterial and antifungal agents.
Abnormal skin condition: This term includes within its scope any
type of superficial wound or skin lesion such as a blister, a burn,
or a wound, open or closed, septic or aseptic. The term also includes
surgical wounds.
The pharmaceutical composition according to the invention includes
an antiseptic or antimicrobial agent and a desiccant. The desiccant
is specifically of the type which adsorbs moisture or liquid in
and around the area of an abnormal skin condition in an animal or
human, such as a wound, a blister or burn. The adsorbed moisture
of liquid is held by the desiccant in a form which is not readily
available to the wound.
Prior art pharmaceutical compositions contain antimicrobial agents
and water adsorbing agents such as ethyl cellulose, gelatine and
agar. The disadvantage of water adsorbing agents is that the water
which they adsorb is still available to the wound. An equilibrium
is typically reached where no more water can be adsorbed and the
remaining water merely remains in the wound creating an environment
which is ideal for bacterial growth. Even the adsorbent which holds
the adsorbed water is "wet" which again creates an environment
which is ideal for bacterial growth. However, in the pharmaceutical
composition of the present invention, a desiccant is used which
substantially removes moisture or liquid from the wound, and from
the atmosphere in and around the wound, by absorption, and which
subsequently holds the liquid in a form that is not readily available
to the wound again. Anhydrous calcium chloride can hold water in
the form of crystallization which is not available again to the
wound. A particularly suitable desiccant for use in the pharmaceutical
composition of the invention is silica gel. Silica gel is able to
hold water particularly effectively and in fact the only way to
remove adsorbed water from the silica gel is to heat it to 100.degree.
C. By using such a desiccant, liquid is actively removed from the
wound, and from the atmosphere around the wound, thereby keeping
the wound substantially dry at all times.
The antiseptic or antimicrobial agent may be inorganic or organic.
Although organic antimicrobials and antiseptics are included within
the scope of the pharmaceutical composition of the invention, it
has been found that such substances may cause allergies in patients
sensitive to these chemicals, and are also not relatively cost effective.
Preferably, the antimicrobial agent or antiseptic agent is an inorganic
salt. The antiseptic or antimicrobial agent may be of the type which
acts directly on the bacteria, such as an antibacterial or antifungal
agent, or they may be of the type which raise the osmotic pressure
around the bacteria so as to kill or inhibit the bacteria, commonly
known as hyperosmotic agents. Hyperosmotic agents are preferred
in the pharmaceutical composition of the invention. Sodium chloride,
ammonium chloride and magnesium sulphate have been found to be effective
hyperosmotic agents. Sodium chloride has proved to be particularly
effective in inhibiting bacterial growth and is also cost effective.
Iodine, silver oxide, a sulphonamide, penicillin and a tetracycline
are examples of antibacterial agents.
A typical example of a pharmaceutical composition according to
the invention comprises 20 grams of sodium chloride and 80 grams
of silica gel.
FIG. 2 illustrates how the sachet 14 of FIG. 1 is applied to the
wound 12. The sachet 14 is located over the wound 12 and the adhesive
strips 16 are applied to the skin of the arm 10. The liquid and
exudate, including any bacteria, of the wound pass through the permeable
walls of the sachet 14. The desiccant adsorbs the liquid such that
it cannot pass back through the walls of the sachet 14 onto the
wound. The antiseptic or antimicrobial agents kill or inhibit the
bacteria inside the sachet 14. The advantage of using a sachet is
that the desiccant and antiseptic/antimicrobial agents do not come
into physical contact with the skin. This obviates any possible
skin irritation problems which may occur with direct skin contact
with such chemicals. Further, the adsorbed liquid and inhibited/killed
bacteria are kept within the walls of the sachet 14 and do not come
into physical contact again with the skin. A sheet 18 is then wrapped
around the arm 10 and over the sachet 14. The sheet 10 is made of
a liquid and moisture impermeable material, such as polyethylene.
The sheet of polyethylene prevents atmospheric moisture from reaching
the sachet. The sheet 18 may be separate of the sachet 14 or may
be integrally formed with the sachet 14. Typically, the sachet is
replaced at regular intervals, for example every 4 to 6 hours, depending
on the state of the wound. The sachet 14 and sheet 18 are conveniently
provided in the form of a kit. The kit comprises the sheet 18 and
sachet 14 and both are typically placed in a moisture proof polymeric
plastic bag to maintain dryness and sterility. The entire product
may be sterilized by a suitable means, for example gramma irradiation. |