JPH0456626B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a method for preventing an increase in container internal pressure. Sodium bicarbonate is often blended into medicinal aqueous solutions such as nasal washes, vaginal washes, and oral inhalants, or animal medicinal aqueous solutions such as dairy disinfectants. In particular, in an aqueous solution containing a cationic surfactant, that is, an inverse soap, for the purpose of sterilization, sodium hydrogen carbonate is mainly used.
Sodium bicarbonate is particularly useful in buffering the pH of aqueous solutions to physiological pH. Buffers include phosphate compounds such as sodium polyphosphate and sodium tripolyphosphate, silicates, sodium citrate, and sodium glyconate, but phosphate compounds tend to cause water pollution, and silicates are Sodium gluconate and sodium citrate have low solubility, change color over time, and have poor buffering capacity when diluted, so they are not used or are not practical even if they are used. Sodium bicarbonate does not have these drawbacks, and is therefore practically and conveniently used in the above-mentioned aqueous solutions for pharmaceuticals or veterinary medicines. However, it is well known that an aqueous sodium carbonate solution generates carbon dioxide gas when heated. Therefore, when a container is filled with an aqueous solution containing sodium bicarbonate and sealed, the container is not heated from the outside. When this occurs, there is a risk that the internal pressure of the container will increase due to the generated carbon dioxide gas. For example, plastic containers that are easily deformed by pressure are at risk of expansion, deformation, and breakage due to increased internal pressure, while glass and tin containers are at risk of being splashed by the liquid content when opened due to increased internal pressure. In order to eliminate this danger, the present inventor conducted a study with the aim of preventing an increase in the internal pressure of a container filled with an aqueous solution containing sodium bicarbonate, and as a result, a part of the container space was filled with carbon dioxide. The present invention was completed based on the knowledge that the objective can be achieved by replacing the gas with a gas. The present invention will be explained. Commercially available sodium bicarbonate and carbon dioxide gas may be used. The larger the replacement rate at which carbon dioxide gas occupies the container space, the more effective it is, and although it is not particularly limited, as shown in the experimental example below, when it reaches 40%, the internal pressure becomes negligible, and it is 40% or more. There will be no need. The concentration of sodium hydrogen carbonate can be freely determined as appropriate depending on the use of the aqueous solution and the required buffering capacity, and does not limit the present invention. The aqueous solution according to the present invention is used for medicine and veterinary medicine, and is particularly effective when a cationic surfactant is added for the purpose of sterilization, but the solution is not limited thereto. Further, the container according to the present invention is a general container filled with an aqueous solution for medicine or veterinary medicine, and is particularly effective in the case of a plastic container, but is not limited thereto. First, a predetermined container is filled with the aqueous solution according to the present invention,
Next, carbon dioxide gas may be injected into the space and immediately sealed. Next, the effects of the present invention will be explained using experimental examples. Experimental example 1 400ml of 3% sodium bicarbonate aqueous solution
Fill a 700ml vial and fill the space with carbon dioxide concentration of 5%, 10%, 15%, 20%, 25%, 30%, 35
After replacing the carbon dioxide gas to a concentration of 40%, the bottle was sealed with a rubber stopper and rolled up with an aluminum cap. After storing this in a constant temperature room at 45°C for 10 days, the pressure in the vial space was measured using a pressure gauge, and the results are shown in Table 1.

【table】

[Table] Experimental Example 2 The sodium bicarbonate-containing aqueous solution of Experimental Example 1 was placed in a high-density polyethylene container with a total capacity of 23 mm (minimum wall thickness).
(1.5mm or more, weight 1.5Kg or more) was filled with 18 carbon dioxide gases, and the space was replaced with carbon dioxide gas concentration of 15%, 20%, 25%, and 30%. After storing this in a constant temperature room at 45℃ for 10 days, the vertical and horizontal lengths of the container, that is, the lengths of A and B shown in Figure 1, were measured using passes, and the increased length due to expansion was determined. It is shown in Table 2.

[Table] The present invention will be explained in more detail with reference to the following examples. Example 1 Mixture of methyldodecylbentyltrimethylammonium chloride and methyldodecylxylylene bistrimethylammonium chloride 20 parts polyoxyethylene octyl phenyl ether
Dissolve 10 parts and 25 parts of sodium bicarbonate in purified water, fill 18 polyethylene containers with a total volume of 23, and replace 30% of the space with carbon dioxide gas. Example 2 Dimethylbenzylalkylammonium chloride (alkyl has 8 to 18 carbon atoms) 10 parts Sodium hydrogen carbonate 30 parts Dissolve in purified water, fill 18 polyethylene containers with a total volume of 23, and replace 20% of the space with carbon dioxide gas .

[Brief explanation of the drawing]

FIG. 1 corresponds to FIG. 1 described in Experimental Example 2 and is a drawing showing a top view of a high-density polyethylene container.

Claims (1)

[Claims] 1. When filling a container with a pharmaceutical or veterinary aqueous solution containing sodium bicarbonate,
A method for preventing an increase in internal pressure of a container, characterized by replacing a part of the space in the container with carbon dioxide. 2. The method for preventing an increase in internal pressure of a container according to claim 1, wherein the container is a plastic container. 3. The method for preventing an increase in internal pressure of a container according to claim 1 or 2, wherein a portion of the space is 5 to 40%.