Drug – bio-affecting and body treating compositions – Anti-perspirants or perspiration deodorants
Reexamination Certificate
2001-04-05
2004-03-09
Krass, Frederick (Department: 1619)
Drug, bio-affecting and body treating compositions
Anti-perspirants or perspiration deodorants
C424S065000, C424S066000, C424S401000, C424SDIG005, C514S944000, C514S951000, C264S102000, C264S211210, C264S212000, C264S211230, C141S082000, C222S251000
Reexamination Certificate
active
06703005
ABSTRACT:
TECHNICAL FIELD
The present invention relates to a process for the production of a deodorant or antiperspirant composition, and particularly to a soft solid composition. The invention further relates to the incorporation of such a composition in a dispensing container, and to a product produced thereby.
BACKGROUND AND PRIOR ART
Deodorant or antiperspirant compositions in soft solid form have achieved a significant market share in many countries in recent years. A soft solid product conventionally comprises the composition in a container, which is usually in the form of a canister or barrel provided at one end with a closure perforated by one or more apertures and at the opposite end with elevator or piston means for urging the canister contents through the aperture in the closure. Such compositions flow readily when subjected to pressure, but when the pressure is released stiffen and cease to flow or flow only very slowly. Accordingly, they remain as on the top surface of the closure and are distributed topically by rubbing the closure across the chosen area of body skin, and particularly in the axilla or other sweaty parts of the body.
Soft solid products are conventionally manufactured by casting premixed compositions into the canister or barrel, those two terms being used interchangeably herein. In conventional hot casting processes, the constituents of a deodorant or antiperspirant soft solid composition are mixed in a large vessel, and heated to form a mobile composition. Whilst the composition is in a mobile and readily pourable state, it is poured into the barrel. The composition is thereafter cooled or permitted to cool until it is non-flowing. A top closure or base is fitted to the barrel, depending on whether bottom fill or the more normal top fill has been employed.
There are several disadvantages associated with preparing a large volume of molten deodorant or antiperspirant. First, in such batch processes, the composition usually remains in a molten state for a long period, not only whilst it is being prepared, but also whilst it is being cast into the barrels. During this period, heat is dissipated, thereby increasing the overall energy consumption for the process. Secondly, the maintenance of a relatively high temperature needed to keep the composition molten for an extended period can cause the degradation of some common constituents, such as the oxidation of waxes or fats, resulting potentially in rancid odours that need to be masked by additional perfume. Moreover, such temperatures also constrain the incorporation of heat sensitive constituents, such as the perfume or malodour masking fragrances, on account of the likelihood that the composition smell will be different for the last barrels filled compared with those filled at the beginning of the batch. It is important to maintain a fragrance which is reasonably constant within a batch.
Moreover, in addition to processing and filling times of individual batches, there is potentially a significant holding time for fractions of master batches which are prepared for example to produce variants.
In addition, the conventional batch process is poorly suited to switching between different formulations in view of the time taken to cleanse the apparatus between batch preparations to avoid cross contamination.
Various soft solid formulations can be obtained by subjecting firm structured formulations to an appropriate level of shear during the preparative and/or filling stages of the manufacture process, thereby rupturing a certain extent the structure. However, tight control of the shearing process is needed so as to avoid excessive shearing or shearing under inappropriate conditions which can result in an excessively runny material or undue separation of the composition constituents during storage, thereby retaining enough structure to inhibit the material from flowing easily under its own weight when present in its container or when deposited on the skin, but producing a product which is capable of flowing though dispensing apertures when subjected to mild pressure. An excessively runny material has the attributes of a lotion rather than a soft solid and would require a different type of dispenser, and undue constituent separation can manifest itself in syneresis problems, ie presence of a liquid phase which can readily leak from the barrel during storage or in use.
A further difficulty can arise because the composition must be kept mobile whilst it is being fed from its production/storage vessel to the filling station so as to avoid line blockage which would be extremely disruptive to production. In practice, this means that during the casting operation, the composition is usually introduced into the barrel at a temperature that is still significantly above its set temperature. As a consequence of a high fill temperature, the composition is likely to remain for a relatively long period of time within the barrel in a mobile state during which segregation can arise, particularly in respect of particulates, such as active antiperspirant materials, intended to be distributed reasonably evenly throughout the composition. Segregation is inherently undesirable for users of the product, because its performance can vary depending on how much of the product has been consumed.
In EP 135315 to the Mennen Company, there is described a process in which a batch of a soft solid antiperspirant composition is subject to shear mixing until the formulations has cooled below its normal setting temperature. Shear mixing in the vicinity of the normal setting temperature is designed to impair structure formation, in order to allow the composition to retain a lower viscosity and flow more freely. However, batches take a considerable period to be filled into the containers. This means that the composition cast into the last containers has been subjected to shear mixing for a much longer period of time than the material which was cast first. Accordingly the Theological properties of the product can alter between the first and last products cast.
For some soft solid products, there is a related manufacturing process, but one which is carried out at a temperature that is at or relatively close to ambient temperature, depending on local conditions and, often, in the region of about 25 to 35° C. This is sometimes called a cold fill process. In such a process, the formulation is subjected to shear mixing throughout and is cast with difficulty into containers, because its viscosity is relatively high and approaching that which it will eventually attain after storage in the container. Close control of the processing is required to minimise the risk of pipe blockage and incomplete filling of the containers.
Therefore, there is a need for a process that is capable of producing soft solid products containing deodorant or antiperspirant compositions which overcomes or ameliorates one or more of the problems identified hereinbefore or disadvantages associated with the existing casting process.
Apparatus and methods for injecting thermoplastics into moulds are known and used. For example, in U.S. Pat. No. 4,678,420 to Inoue, assigned to Inoue (Japax Research Inc), there is described apparatus in which a thermoplastic is fed through a hopper into a single screw mixer, plasticised and injected into a mould. Such apparatus and methods do not provide teaching that is directly applicable to producing products comprising soft solid deodorant or antiperspirant composition in a dispensing container, due to very different structuring mechanisms and the different constraints on processing thermoplastics into moulds compared with soft solid antiperspirant or deodorant formulations into dispensing containers.
In U.S. Pat. No. 4,688,609 (Diaz) assigned to Fluid Packaging Company, there is described a system for producing firm sticks of a deodorant composition in which a large vat of molten deodorant composition is produced, and progressively delivered into stick barrels through dispensing apparatus injected at an operating pressure of 10-15 psi and within which the c
Allan Peter Stewart
Browne Michael Andrew
Langeveld Elfriede Maria
Lloyd Paul
Manley Reginald
Krass Frederick
Ostrup Clinton
Stein Kevin J.
Unilever Home & Personal Care USA , division of Conopco, Inc.
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