This invention relates to a device for once-only use, preferably for application to hygiene.
In the field of the aforementioned devices and in particular those used for administering vaginal washes or enemas, devices for once-only use are known comprising a deformable container, to the mouth of which a cannula can be sealedly fixed for insertion into the patient's body.
Known devices for once-only use are sold with the container already filled with the solution ready for use and with their mouth sealed by a stopper which is removable, preferably manually. For hygienic reasons the cannula is packaged separately in a sealed packet, but sold together with the container.
The user (after necessarily shaking the container to revive the solution) removes the stopper from the mouth, withdraws the cannula from its package and fits it to the container mouth to obtain a device ready for use.
The container of such devices is made of plastics material, as it has necessarily to be impermeable, soft and flexible.
Experience has, however, shown that plastics material is not the best material for preserving certain substances which, being ready for use, are particularly active and hence aggressive and/or instable, and consequently of limited life.
To overcome this drawback, devices have been considered comprising two containers of different capacity, plus the already known cannula. One container is filled with some of the components of the solution and the other is filled with the remaining components. The division is obviously made so as to reduce the chemical activity of the components to a minimum, so achieving low aggressivity, substantial chemical stability and a long life. Such devices can therefore be constructed of plastics material at low cost.
Forming the device as two containers can also be dictated by other requirements known to the expert but not mentioned herein for brevity.
To form the solution ready for use the user has to pour the contents of the smaller container into the larger container in addition to carrying out all the operations already mentioned in relation to the preceding case, i.e., removing the stopper from two containers and fitting the cannula. There is also an obvious danger in pouring substances which usually have a high capacity for impregnation and hence a high staining power.
In addition, this type of device does not allow optimum mixing of the contents of the two containers if the contents are poorly miscible with each other. In such a case, the solution ready for use can only be achieved in an open container closable by the user's fingers during shaking, with the possibility both of contaminating the product and producing accidental splashing.
Hence, in the current state of the art, the devices in use may comprise one or two containers. The choice is obviously dictated by the type of solution to be sold.