Dispenser for viscous medicant

A dispenser for a viscous pharmaceutical composition comprises a tray, a support layer, a viscous pharmaceutically acceptable carrier which optionally contains a medicament and a removable protector layer. The support layer covers the base and at least two opposed sides of the tray and is capable of extending over the top edges of the said sides of the tray so that stiffening means may be fitted to the extended portion. A viscous pharmaceutically acceptable carrier overlies the support layer and may be lifted from the tray on the support layer using the stiffening means as handles. A removable protector layer covers the exposed surface of the carrier on the tray. The carrier adheres more strongly to the support layer than to the protector layer so that the latter may be peeled from the carrier without disturbing it on the support layer. Preferably the carrier contains from 1 to 12.5% by weight of antibacterial agent.

The present invention relates to a dispenser for a medicament contained in 
a viscous pharmaceutically acceptable carrier and more particularly to a 
dispenser which comprises a tray containing a support layer upon which 
lies the pharmaceutically acceptable carrier. 
The treatment of skin lesions such as burns and wounds to prevent bacterial 
contamination commonly involves the topical application of an 
antimicrobial-containing cream or ointment. One such cream which has 
proved particularly effective is Flamazine (Trade Mark) available from 
Smith and Nephew Pharmaceuticals Ltd, and which contains silver 
sulphadiazine as the active antimicrobial agent. Creams are usually spread 
by hand over the affected area and then covered by strips of gauze. This 
procedure may be painful, time consuming and provides only a variable and 
indeterminate dose. Another method of applying such creams is to 
impregnate a gauze with the antimicrobial composition and apply that to 
the affected area, see for example U.S. Pat. No. 4,018,186. Such dressings 
can also be painful and time consuming to apply and also run the risk of 
being accidentally contaminated during preparation or just prior to use. 
It has also been noted that in water based systems, the material of the 
gauze may act as an absorbent for water thereby affecting the integrity of 
the cream and the release characteristics of any medicament contained in 
the cream. 
A further method of applying a viscous pharmaceutical composition such as a 
cream may be by means of a spray dispenser, see for example U.S. Pat. No. 
4,551,139. This method avoids the disadvantage of being time consuming to 
apply. An aerosol method of application may be painful because of the high 
pressure of delivery, the nature of the propellant and the occurrence of 
intermittent flow of cream due to the introduction of air into the pump 
flow course. There is also a risk of introducing contaminants into the 
flow system which may cause problems of wound sepsis. A spray system may 
also be wasteful in terms of not evacuating all the cream from the 
container. 
It would be an advantage therefore to provide a means of dispensing viscous 
compositions such as antimicrobial creams in a manner which was 
substantially painless, quick, simple and with reduced risk of 
contamination. Such a means of dispensing has now been achieved in which a 
viscous pharmaceutically acceptable carrier is present on a support layer 
both held in a tray The carrier prior use is covered by a removable 
protector layer. The support layer preferably extends over two opposed 
edges of the tray so that handles may be fitted to the support layer 
whereby after removal of the protector the support layer and the viscous 
composition may be lifted as one from the tray. This means that the 
viscous carrier may be applied to the patient with reduced risk of 
contamination and without applied pressure of any kind. It is also an 
advantage that a known weight of the medicament may be applied in this 
way, which is safer for the patient and more economical in the use of the 
composition. 
Accordingly the present invention provides a dispenser for a viscous 
pharmaceutical composition which dispenser comprises a tray, a support 
layer which covers the base and at least two opposed sides of the tray and 
is capable of extending over the top edges of said sides of the tray, a 
viscous pharmaceutically acceptable carrier which optionally contains a 
medicament and which overlies the support layer and a removable protector 
layer covering the exposed surface of the pharmaceutically acceptable 
carrier and in which the pharmaceutically acceptable carrier adheres more 
strongly to the support layer than the protector layer. 
Aptly the tray may be formed from a vacuum mouldable polymeric material 
including a high density polyethylene or a polypropylene-polyethylene 
copolymer. Suitably these polymers will not be wetted by the 
pharmaceutical carrier thereby enabling the pharmaceutical carrier to be 
lifted on its support layer from the tray without leaving unacceptably 
large amounts of the carrier adhering to the sides of the tray and so 
being wasted. 
The tray may be any shape but is preferably rectangular or square. The tray 
may be any convenient size but sizes of 18 cm.times.24 cm, 24 cm.times.36 
cm and 18 cm.times.18 cm and which have a depth of from 2.5 to 8 mm and 
preferably 3 to 6 mm, for example 4 mm, have been found to be suitable for 
containing a pharmaceutically acceptable carrier containing a 
therapeutically effective amount of medicament. 
Suitably the support layer may comprise any material which is capable of 
supporting the weight of the pharmaceutical carrier without tearing or 
undue distortion and which may be peeled from the carrier so that 
substantially none of the carrier remains adhered to the support layer. In 
use it is envisaged that the pharmaceutical carrier will be applied to a 
patient's skin or to a conventional surgical gauze dressing so it is 
important that the pharmaceutical carrier adheres to the skin or gauze 
more strongly that it adheres to the support layer so that the support 
layer may be peeled from the carrier without unduly disturbing the carrier 
on the skin or the dressing. Preferably the support layer should be able 
to peel back on itself so as to minimise loss of carrier. Therefore the 
support layer should be flexible and may be coated on one side with a 
release-coat layer such as a silicone layer, for example the support layer 
could be a siliconised release paper. However, it is preferred if the 
support layer is formedfrom a polymeric material and in particular it is 
preferred if the support layer is in the form of a woven, non woven, 
knitted or net-like fabric. In one preferred form the support layer is 
polyester non-woven fabric. In a second preferred form the support layer 
is a net-like material which has been formed by stretching of an embossed 
film to cause fibrillation as described in for example, U.K. Pat. Nos. 
914489, 1055963, 1075487, 1110051, 1495151, 1496786 and 1531715. 
Aptly the size of the support layer is such that it covers the bottom and 
two sides of the tray and is capable of extending over the edges of the 
tray on two opposed edges. The extended support layer is aptly provided 
with a stiffening means at each of the two edges whereby the stiffening 
means may be used as handles to lift the support layer and the 
pharmaceutical carrier from the tray. The support given by the handles 
also prevents wrinkling of support layer. It has been observed that if the 
support layer wrinkles and air is admitted between the carrier and the 
support layer, upon inversion the carrier tends to prematurely separate 
from the support layer. The handles may be held in place by folding the 
extra support layer around each handle and then sealing into place. 
Suitably the handles may be made from waterproof, stiff paper or from 
polymeric material. When packaged the extended support layer may be folded 
on top of the protector layer for neatness. 
The handles may be permanent, that is present as strips heat sealed into 
the support layer or they may be positioned just prior to lifting the 
support layer from the tray and be retrieved for further use. 
The pharmaceutical carrier will be sufficiently viscous to be 
self-supporting that is it will not flow when it is removed from the tray 
on its supporting layer. 
Suitable forms of the topical composition of this invention include 
ointments, gels, creams, viscous emulsions, pastes, and the like which are 
capable of being self supporting. 
Preferably the composition will be in the form of an ointment and most 
preferably as a hydrophilic ointment such as an oil-in-water emulsion. 
Suitable bases are described in Chapter 87 Ointments: Emulsion Bases in 
Remingtons Pharmaceutical Sciences, 15th Ed. 1975, pages 1532-34. Other 
suitable ointment bases include those described in British Pat. No. 
1240545. 
A particularly suitable ointment base is therefore an oil-in-water emulsion 
containing from 0 to 25% of petrolatum or liquid paraffin, 2 to 20% of a 
fatty alcohol, 0 to 12% of an emulsifying agent, up to 10% of non-ionic 
surfactant and 5 to 25% of a polyhydric alcohol and the balance at 100% 
being water, preferably deionised or distilled water. Aptly the fatty 
alcohols are those conventionally used in ointments and are water 
insoluble. Suitable alcohols include stearyl alcohol, cetyl alcohol, 
lauryl alcohol and myristyl alcohol. Suitably the emulsifying agent is a 
glyceryl fatty acid ester and is peferably glyceryl monostearate. Suitable 
non-ionic surfactants include the polyoxyethylated sorbitan fatty acid 
esters and sorbitan fatty acid esters. An emulsifying wax may be used in 
place of both or part of both of the fatty alcohol and non-ionic 
surfactant. The polyhydric alcohol acts as a humectant and suitable 
alcohols include propylene glycol, sorbitol or glycerin or mixtures 
thereof. 
An alternative ointment may contain one or a mixture of polyalkylene 
glycols for example polyethylene glycol. Suitably the ointment may contain 
a mixture of a high molecular weight polyethylene glycol and a low 
molecular weight polyethylene glycol. 
The compositions used in the present invention may be in the form of an 
aqueous gel. Suitable gelling agents include 
polyoxyethylene-polyoxypropylene diol block copolymers, polyacrylic acid 
lightly cross-linked with triallyl sucrose which has been neutralised 
using an alkali metal hydroxide, cellulosic derivatives such as 
carboxymethyl cellulose, hydroxymethyl cellulose, natural gums and the 
like. A preferred group of gelling agents are the 
polyoxyethylene-polyoxypropylene diol block copolymers which are 
commercially available as the Pluronics from BASF-Wyandotte. (Pluronic is 
a registered trade mark of BASF-Wyandotte). 
Suitable gel forming block copolymers of polyoxyethylene-polyoxypropylene 
will have a molecular weight from 4,600 to 13,500 (approximately) and will 
be present in the gel in an amount from 50% for the lower molecular weight 
copolymers to 20% for the higher molecular weight copolymers, so that the 
gel when applied topically is neither too stiff nor too fluid. Typically 
the gels are formed by mixing together the copolymer and water to form an 
aqueous solution at a temperature of 2.degree. C. and adding the 
medicament and then allowing the solution to gel as it warms to ambient 
temperature. Suitable Pluronics are those designated as F108, F127 and 
P105. 
Alternatively the gel may be formed from a natural gum as described in U.K. 
Pat. Nos. 1,341,999, 1,593,953 and 1,593,954 or a synthetic gel formed 
from cross-linked polyoxyalkylene polymers as described in U.S. Pat. No. 
3,419,006. 
The composition used in the present invention may also be in the form of a 
hydrophobic ointment. Suitable hydrophobic ointments are those which are 
formed from white or yellow soft paraffin or a mixture of such with liquid 
paraffin. A preferred ointment base comprises a mixture of white soft 
paraffin and liquid paraffin in a ratio of 5:1 to 1:1. However, in general 
terms aqueous based systems will be preferred. 
The hydrophobic ointment base may also contain non-ionic surfactants such 
as polyoxyethylated sorbitan fatty acid esters and sorbitan fatty acid 
esters. The presence of non-ionic surfactants increases the miscibility of 
the ointment with wound fluid and aids release of the medicament. Suitably 
the non-ionic surfactant will be present in an amount from 0.1 to 0.5%. 
Preferably the non-ionic surfactant is 0.1% of polyoxyethylene sorbitan 
triolate and 0.1% sorbitan monopalmitate. 
Normally the pharmaceutical carrier will contain medicament but it is 
envisaged that bland compositions such as emollient creams and barrier 
creams could be applied using the dispenser of the present invention. 
The medicament present in the pharmaceutically acceptable carrier may be 
any one of those which may be topically applied to the skin including, 
steroids, debriding agents, wound healing promoters, local anaesthetics, 
antibacterial agents, antibiotics and like. Preferably the medicament will 
comprise antibacterial agent. Suitable antibacterial agents include 
iodophors such as polyvinyl pyrrolidone-iodine, chlorhexidine and its 
salts such as the diacetate, digluconate and dihydrochloride, silver 
compounds such as silver sulphadiazine and compatible mixtures thereof 
such as mixtures of silver sulphadiazine and chlorhexidine diacetate. 
The carrier will contain a therapeutically effective amount of medicament. 
Thus for example in a preferred embodiment the carrier will comprise an 
ointment containing antibacterial agent at a concentration of, for 
example, 1 to 12.5% by weight based on the weight of the carrier. 
The dose of a medicament may be controlled by thickness of the 
pharmaceutical carrier layer and/or the concentration of the medicament in 
the carrier. 
The exposed surface of the pharmaceutical carrier when in position in the 
tray is aptly covered by a protector layer. Thus preferred protector 
layers are silicone-coated release paper or a net-like material. 
The pharmaceutically acceptable carrier will adhere more strongly to the 
support layer than to the protector layer when the latter is peeled or 
lifted from the surface of the carrier. This means that in use when the 
protector layer is peeled from the surface of the carrier the carrier 
remains relatively undisturbed and does not lift from the support layer. 
The dispensers of the present invention may be prepared by vacuum forming 
the tray in the appropriate size, placing the support layer in the tray 
and filling the pharmaceutically acceptable carrier onto the support 
layer. The protector layer is then placed on top of the pharmaceutical 
carrier. 
The dispenser of the present invention is preferably sterile and may be 
packaged in a bacteria-proof and water-proof package. The dispenser and 
contents may be sterilised by means of gamma-irradiation or alternatively 
the dispenser and contents may be assembled under aseptic conditions from 
presterilised components. 
In use this dispenser is removed from its package in sterile form. The 
protector layer is peeled from the pharmaceutical carrier and the 
pharmaceutical carrier is lifted from the tray on its support layer by 
means of the two handles at opposed edges of support layer. The 
pharmaceutical carrier is then applied to the patient or on to a dressing 
by carefully inverting the pharmaceutical carrier-support layer and 
placing the pharmaceutical carrier against the appropriate surface. The 
support layer may be peeled away from the pharmaceutical carrier (or less 
preferred left in place). The pharmaceutical carrier may then be covered 
with a conventional gauze bandage. 
In an alternative though less preferred manner of use the support layer 
could be used next to the wound where the support layer would serve as a 
non-adherent wound contact layer. In this instance the support layer is 
preferably formed from a polymeric material such as a net. 
In another aspect the present invention provides a method of treating an 
animal by applying to the skin of the animal a pharmaceutically acceptable 
carrier from a dispenser as hereinbefore defined.

The dispenser (1) for a topically applied pharmaceutical composition which 
is shown in FIG. 1 comprises a tray (2) which is suitably vacuum moulded 
from high densitypolyethylene or from a polypropylene-polyethylene 
copolymer. The tray (2) is lined with a support layer (3) which is in the 
form of a net-like material formed by stretching an embossed film and is 
available as for example Net 909 P520 from Smith and Nephew Plastics Ltd, 
Gilberdyke, Hull (Net 909 is a Trade mark). A medicated pharmaceutically 
acceptable oil-in-water emulsion ointment (4) is filled into the tray (2) 
to overlay the support layer (3) and to substantially fill the tray (2). 
The extra pieces of support layer (5,6) are fitted with stiffening means 
(7,8) in the form of narrow water-proof cardboard strips which are sealed 
into the extra pieces (5,6) of the support layer (3). These handles (7, 8) 
are used to lift the pharmaceutical carrier (4) on its support layer (3) 
free from the tray (2) and to prevent the support layer (3) from 
wrinkling. The exposed surface of the pharmaceutical carrier (4) is 
covered by a protector layer (9) which is also formed from a net-like 
material. 
The dispenser (11) for a topically applied pharmaceutical composition which 
is shown in cross-section in FIG. 2 comprises a tray (12) which may be 
vacuum-moulded from a polypropylene-polyethylene copolymer. The tray (12) 
is lined with a support layer (13) which is in the form of a net-like 
material. A viscous pharmaceutical composition (14) is filled into the 
tray (12) to overlay the support layer (13) and to substantially fill the 
tray (12). The extra pieces of support layer (15, 16) which are capable of 
extending over the tops of two opposed edges are filled with a stiffening 
means (17, 18) in the form of a corrugated polystyrene strip. The tray has 
been extended to include two smaller trays (20, 21) into which the 
stiffening means (17, 18) may rest prior to use. The exposed surface of 
the pharmaceutical carrier (14) is covered by a protector (19) which is 
folded back on itself and has two handling areas (22, 23) at its edge. The 
handling areas (22, 23) may be formed by adhering adhesive tape along the 
two edges of the protector (19). The presence of the handling areas (22, 
23) facilitates removal of the protector (19) and reduces the risk of 
accidental contamination of the carrier during removal of the protector 
(19). 
EXAMPLE 1 
A tray, 18 cm.times.24 cm and 5 mm deep, was vacuum formed from a film of 
polypropylene-polyethylene copolymer. A piece of net material 18 
cm.times.40 cm was placed in the bottom of the tray so that the net 
covered the base of the tray and the two sides and extended for 3 cm on 
two opposed edges. A piece of card 1 cm.times.18 cm was sealed into each 
of the extended areas to form stiff handles. The tray was then filled with 
an oil-in-water emulsion having the following formula, 
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White petrolatum 16.5% (w/w) 
Stearyl alcohol 15.3% 
Isopropyl myristate 6.6% 
Sorbitan monostearate 
1.0% 
Polyoxyl 40 stearate 9.0% 
Propylene glycol 8.0% 
Silver sulphadiazine 1.0% 
Deionised water 42.6% 
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and prepared by the method described in Example 1 of U.S. Pat. No. 
3,761,590. A protector layer of a net-like material 18 cm.times.24 cm was 
placed on top of the pharmaceutical carrier. 
The tray, support layer and protector were presterilised using 2.5 Mrad 
gamma-irradiation. The oil-in-water emulsion was formed in a sterile 
manner. The oil-in-water emulsion was filled into the tray under aseptic 
conditions and packaged in a bacteria-proof and water-proof pouch. 
In use the sterile tray and contents were removed from the pouch and the 
protector layer was peeled away from the pharmaceutical carrier. The 
support layer and the pharmaceutical carrier were lifted from the tray and 
the pharmaceutical carrier was carefully placed on the skin of a patient 
with a skin lesion. The support layer was carefully peeled away from the 
pharmaceutical carrier and the carrier covered by a gauze dressing in the 
normal way. 
EXAMPLE 2 
A cream was prepared in a similar manner to that described in Example 1 
except that the antibacterial agent present was 2% of chlorhexidine 
digluconate. The cream was packaged in a dispenser of the invention. 
EXAMPLE 3 
A cream was prepared from the following ingredients 
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Polyvinylpyrrolidone-iodine 
10% 
Polethylene glycol 70% 
(molecular weight 400) 
Polyethylene glycol 20% 
(molecular weight 4000) 
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The cream was placed on a net support layer in a vacuum formed tray in a 
similar manner to that described in Example 1. 
The tray, support layer, cream and protector were packaged in a 
bacteria-proof and water-proof pouch and sterilised by 2.5 Mrad gamma 
irradiation. 
EXAMPLES 4 AND 5 
Two non-medicated pharmaceutical carriers which are useful as emollient or 
moisturising creams were prepared from. 
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Example 4 Example 5 
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Liquid paraffin 
25.0 (% w/w) 35.0 (% w/w) 
Petroleum jelly 
10.0 -- 
Lanolin 10.0 10.0 
White Beeswax 12.0 17.0 
*Arlacel 60 -- 2.0 
*Tween 60 -- 3.0 
Borax 0.7 
Water 42.3 33.0 
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*Trade marks 
The oil phase and the aqueous phase were each heated seperately to 
75.degree. C. (approx). The water phase was added to the oil phase and the 
mixture stirred until it had cooled to 50.degree. C. and was then poured 
onto a net support layer in a vacuum formed tray. On cooling to ambient 
room temperature the creams could be lifted from the tray on the support 
layer. 
EXAMPLE 6 
A zinc oxide/castor oil cream was prepared from the following ingredients. 
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White Beeswax 10.0 (% w/w) 
Cetastearyl alcohol 2.0 
Castor oil 50.0 
Zinc oxide 7.5 
Arachis oil 30.5 
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All the components except zinc oxide are mixed together and the temperature 
raised to 75.degree. C. The mixture is allowed to cool to 50.degree. C. and 
the zinc oxide is added and stirring continued to form an homogenious 
ointment. The cream was then placed on a net support layer on a 
polyethylene tray. At ambient temperature the cream may be lifted from the 
tray on the support layer.