JPS6099143A - Natural rubber for medical container - Google Patents

Abstract

PURPOSE:To provide a natural rubber free from the tendency to cause the crystal precipitation on the rubber surface, by suppressing the content of zinc below a specific level. CONSTITUTION:A zinc-containing natural rubber is washed with an acid to decrease the zinc content to <=1.6%, preferably <=0.9%. The acid may be an inorganic acid or organic acid. When the rubber is spongy, it is immersed sufficiently in the acid at normal temperature, and washed with water.

Description

【発明の詳細な説明】 本発明は医療容器用天然ゴムに関するものである。[Detailed description of the invention] The present invention relates to natural rubber for medical containers.

天然ゴムはその耐酸、耐アルカリの優秀さから、広く医
薬品容器の一部に用いられている。Natural rubber is widely used in some pharmaceutical containers because of its excellent acid and alkali resistance.

具体的には注射用ゴム栓、外用容器の一部としてスポン
ジゴムなどの形で用いられている。Specifically, it is used in the form of rubber stoppers for injections and sponge rubber as part of external containers.

こｎら天然ゴムを製造するには各拙の添加剤が必須であ
り、中でも酸化曲鉛専の亜鉛化合物は加硫促進剤等添加
物として最も広く用いられている。従って通常の天然ゴ
ムは亜鉛を金属亜鉛に換算して数％以上を含有している
。しかしながら、亜鉛がゴム中残留することは、単にゴ
ムの劣化の問題にとどまらず、時として医薬品の品質に
も悪影響を及ぼすこともある。すなわちインドメタシン
等、酸性薬物等を含有する液状医薬品の容器に、この様
な亜鉛含有ゴム栓等が用いられろと、ゴム表面に結晶析
出が生ずる等の不都合がある。Various additives are indispensable for producing these natural rubbers, and among them, zinc compounds exclusively used for curved lead oxide are most widely used as additives such as vulcanization accelerators. Therefore, ordinary natural rubber contains zinc in an amount of several percent or more in terms of metallic zinc. However, residual zinc in rubber is not only a problem of rubber deterioration, but also sometimes has an adverse effect on the quality of pharmaceutical products. That is, if such zinc-containing rubber stoppers are used in containers for liquid pharmaceuticals containing acidic drugs such as indomethacin, there are disadvantages such as crystal precipitation on the rubber surface.

極端な場合には、医薬品と接触して、実験例１の如く２
４時間以内に析出することがある。In extreme cases, contact with pharmaceuticals may result in
Precipitation may occur within 4 hours.

本発明者らは、本発明者らが新たに見出した上記問題を
解決すべく検討し、亜鉛含量１．６％以下の天然ゴムを
用いれば２４時間以上結晶析出がなく、更には、０．９
％以下にすれば、数日経ても結晶析出が認められないこ
とを見出し、本発明を完成した。The present inventors have studied to solve the above-mentioned problem newly discovered by the present inventors, and found that if natural rubber with a zinc content of 1.6% or less is used, there will be no crystal precipitation for more than 24 hours, and furthermore, 0.6% or less zinc content will not occur for more than 24 hours. 9
% or less, crystal precipitation is not observed even after several days, and the present invention has been completed.

本発明は亜鉛含量１．６％以下であることを特徴とする
医療容器用天然ゴムである。The present invention is a natural rubber for medical containers characterized by a zinc content of 1.6% or less.

ここで、亜鉛含量１．６％以下とは酸化亜鉛等の亜鉛化
合物がゴムに添加されている場合には金属亜鉛に換算し
た値である。Here, the zinc content of 1.6% or less is a value converted to metallic zinc when a zinc compound such as zinc oxide is added to the rubber.

亜鉛含量は１．６％以−ドであるが、結晶析出をさらに
長期に抑制するｔこめに０．９％以−ドが好ましい。The zinc content is 1.6% or more, but is preferably 0.9% or more in order to suppress crystal precipitation for a longer period of time.

亜鉛含量１．６％以下の天然ゴムを得るには、当初より
酸化亜鉛等亜鉛添加量を抑制し、天然ゴムを製造する方
法も考えられるが、実際上、亜鉛添加量を抑制して良質
の天然ゴムを製造することは極めて困難である。従って
本発明の天然ゴムを得るには一般に、通常の方仏で製造
した天然ゴムを酸洗浄することにより、容易に亜鉛を除
去できる。かかる知見も本発明者らが新たに見出したも
のである。使用する酸としては、塩酸、硫酸、硝酸など
の無機酸だけでなく、酢酸等の有機酸も含めた、あらゆ
る酸があげられる。酸処理方法はゴムの形態にもよるが
、例えばスポンジゴムなどの場合には常温で充分浸漬す
るだけで、亜鉛を水浴性塩に変え、水洗により容易に除
去し得る。本発明の実用価値については、実験例１．２
からも明らかである。In order to obtain natural rubber with a zinc content of 1.6% or less, it is possible to produce natural rubber by suppressing the amount of zinc added, such as zinc oxide, from the beginning. It is extremely difficult to produce natural rubber. Therefore, in order to obtain the natural rubber of the present invention, zinc can generally be easily removed by acid washing natural rubber produced by a conventional method. This finding was also newly discovered by the present inventors. The acids used include all acids, including not only inorganic acids such as hydrochloric acid, sulfuric acid, and nitric acid, but also organic acids such as acetic acid. The acid treatment method depends on the form of the rubber, but in the case of sponge rubber, for example, by sufficiently soaking it at room temperature, the zinc is converted into a water-bathable salt, which can be easily removed by washing with water. Regarding the practical value of the present invention, Experimental Example 1.2
It is clear from this.

実験例１ 天然ゴムスポンジ１ｇを各種濃度の塩酸水溶液１００ｍ
Ａに１時間常温で浸漬し、水洗後、亜鉛含量を測定する
とともに、１％インドメタシンアルコール７８液中での
結晶析出の有無を調べｔこ。Experimental example 1 1g of natural rubber sponge was added to 100ml of hydrochloric acid aqueous solution of various concentrations.
After soaking in A for 1 hour at room temperature and washing with water, the zinc content was measured and the presence or absence of crystal precipitation in 1% indomethacin alcohol 78 solution was examined.

実験例２ 天然ゴムスポンジ１ｆを１％塩酸水溶液１００−に１時
間常温で浸漬し、水３Ｉ１８後破断荷重を測定し１こ。Experimental Example 2 A natural rubber sponge 1f was immersed in a 1% aqueous solution of hydrochloric acid at room temperature for 1 hour, and the breaking load was measured after 3I18 water.

Claims (1)

【特許請求の範囲】 １）亜鉛含量１．６％以下であることを特徴とする医療
容器用天然ゴム ２）亜鉛含有天然ゴムを酸洗沖することを特徴とする亜
鉛含斌１．６％以丁の医療８器用天然ゴムの製造法[Claims] 1) Natural rubber for medical containers characterized by having a zinc content of 1.6% or less 2) Zinc-containing 1.6% natural rubber characterized by pickling zinc-containing natural rubber Itcho's manufacturing method of natural rubber for medical use