Most intravenous infusions come as ready-to-administer liquids, but some medications are unstable in liquid form and must be diluted immediately before use. The medication comes as a powder and is prepared for use by injecting the diluent into the vial through the rubber stopper, mixing the solution, and then withdrawing the medication into a syringe for injection. If the syringe is removed after injecting the diluent and then reinserted (either the same syringe or a different one), it is not going to be inserted through the same hole as the first syringe. The holes created are so tiny, that if the syringe was inserted into the same hole twice it would be completely by chance.
How should this be performed on Shabbos? R’ Mordechai Orlansky, a member of our Beis Medrash, reviewed this topic and we will present his conclusions below.
Does inserting the needle through the stopper constitute the Melacha of Makeh b’Patish? Since making the hole allows the insertion or extraction of the diluent, one has prepared a Kli and this would appear to be an act of Makeh b’Patish.
However, one may distinguish between the act of making a hole in the Kli itself and in its cover. The Mishna in Shabbos states (146a):
“A person may break a barrel in order to eat a dried fig from it as long as he does not intend to fashion a Kli. One may not pierce the seal of a barrel, these are the words of Rabbi Yehuda. But the Chachamim permit it.”
We see that the Chachamim permit piercing a barrel seal even though making a Pesach (an opening) in a Kli is forbidden. However, the Gemara qualifies the view of the Chachamim:
“Rav Huna said. The Machlokes [between Rabbi Yehuda and the Chachamim is when the hole] is on the top [of the barrel], but when it is on the side [of the barrel] everybody agrees that it is forbidden.”
This qualification is codified by the Shulchan Aruch (O.C. 314:6):
“It is permissible to cut off the top of a barrel with a sword… but to make a hole in its side – whether in the barrel itself or whether in the seal – is forbidden, as since it is on its side he must be intending to make a Pesach. However, it is permissible to make a hole in the top since he does not intend to make a Pesach since it is not the practice to make a Pesach at the top – instead one would remove the entire seal.”
Returning to the vial, may one pierce the rubber stopper on Shabbos and insert a syringe?
At first glance, this seems to resemble the case of the barrel, which may be pierced at the top. However, the comparison is flawed. As explained above, the reason it is permissible to make a hole at the top of a barrel is because one’s intention is not to make a Pesach. In this case, the intention is certainly to form a Pesach; the vial is designed such that the diluent is injected and the medication is then withdrawn via the stopper on the top of the vial.
Moreover, the reason that one’s intention is never to make a Pesach in the top of a barrel is because of the concern that dirt will fall into it. This does not apply in this case; the rubber stopper hermetically seals the vial, and even after a (tiny) hole is made there is no chance that dirt could enter.
In light of this, a hole in the rubber stopper should be akin to a hole in the side of a barrel, which is forbidden. (R’ Avraham Eisenthal Shlit”a in his Sefer, Megilas Sefer Shabbos 14:3, makes a similar argument regarding making a hole in the cover on top of a yogurt container. Since the optimal manner of usage is to make a hole at the top, it is similar to a hole in the side of a barrel which is forbidden.)
Nevertheless, there seem to be two reasons to permit piercing the vial:
The Gemara rules (Shabbos 48b) that one who makes the head-opening in a garment is liable to bring a Korban Chatas. It then asks why this act is different than removing a barrel seal. It answers: “This is a Chibur and this is not a Chibur.” In other words, the barrel seal is not part of the barrel itself and one may therefore remove it (or pierce it). On the other hand, a hole in a garment for a person’s head is a de novo opening in the garment itself.
The Chazon Ish (O.C. 51:10) observes that the Gemara clearly states that a barrel seal is not considered to have a Chibur to the barrel, and it is therefore permissible to remove it or pierce it on Shabbos. If so, the Issur to pierce the seal when it is located on the side of the barrel is only a Gezera d’Rabbanan, since in some cases the seal on the side of a barrel looks like the barrel itself. The Shulchan Aruch’s ruling that one may pierce the seal on the top of a barrel because an opening is not usually made there (due to the possibility that dirt will enter) is according to Rashi’s interpretation of the Gemara. However, according to Tosfos, the reason for this ruling is that the seal is not considered to have a Chibur to the barrel, and the Issur when the seal is on the side of the barrel is only a Gezera, as we have stated.
In short, according to the Chazon Ish (who appears to rule like Tosfos, rather than Rashi), the reason one may pierce a seal on the top of a barrel is because it does not have a Chibur to the barrel. Moreover, it does not even appear to have a Chibur thus there is no reason to forbid it due to a Gezera. If so, the reasoning that “it is not customary to make a Pesach on the top of a barrel due to the concern of dirt” is not relevant; the Shulchan Aruch only invoked it because he understands the Gemara as Rashi does. According to Tosfos, however, the Gemara’s essential distinction is simply between piercing the top of the barrel (which is permissible) and the side of the barrel (which is Asur mi’d’Rabbanan). If so, piercing the top of a vial should be permissible.
Since the Shulchan Aruch and Mishna Berura follow Rashi’s interpretation of the Sugya, piercing the stopper should be forbidden because it is akin to piercing the side of a barrel, as explained above.
Another reason to rule leniently is based on the discussion by contemporary Poskim about piercing the top of a yogurt container to insert a straw. Rav Yitzchak Mordechai Rubin Shlit”a (Orchos Shabbos 1:12:13, and footnote 23) permits it based on the view of Rav Shlomo Zalman Auerbach zt”l (Minchas Shlomo 2:12 – he also relates that this appears to have been the view of Rav Elyashiv zt”l,) that there is no Issur of making a hole in a Kli that is designed to be used only once (as evident in the ruling of “Chosalos Shel Temarim” – Shulchan Aruch 314:8 and “Or sheAl Pi haChavis” – Tosefta cited by the Mishna Berura ibid. 25.) This is why opening a beverage can is permissible. (He also does not consider this a violation of the Melacha of Mechatech.) Since it is designed to be used just once, the opening only serves to remove the contents.
The Megilas Sefer ibid. makes a similar point (though he does not rule on this conclusively). The Sefer Shalmei Yehonasan (Shabbos 314:6) also writes similarly. Their basic contention is that whenever the Kli is not intended to be used after the creation of the hole and the opening only serves to enable the removal of the contents, it does not constitute Makeh b’Patish. This is also stated by the Minchas Ish (Shabbos 1:17:16 & 13, and footnote 23 ibid.), though his main reason for leniency is the position of the Chazon Ish, delineated above.
The same may be applied to a medication vial. The hole is only made to facilitate the addition of the diluent and the immediate removal of the medication. This may be considered a “one-off” usage and not the creation of a Kli for ongoing use. Though its usage takes place in two stages – first the addition of the diluent and second the removal of the solution, this does not render it a “Kli of ongoing usage”. The reason for Rav Shlomo Zalman’s Heter is that the Kli is Batel to its contents; as soon as it is opened it has no importance. This is equally true in this case.[See the Minchas Shlomo ibid. who makes a similar point about opening metal sardine cans:
“It appears to me that the barrel of “Mustaki” is a Kli, but it is not significant, therefore its breakage does not constitute Stira. Likewise regarding a sardine can – though it is very strong, nevertheless the Kli is only to be used one time – to be opened and then discarded. Therefore, though the fish in it are protected for a long time by the Kli and are moved from place to place, nevertheless, the Kli itself is only meant to be thrown in the garbage.”]
Thus, piercing the stopper of the vial would be permissible because the Kli will be discarded as soon as the contents are removed.
 Since dirt may fall into the barrel (Rashi ibid. s.v. “Aval miTzida”, and Mishna Berura ibid. 27).
 This is Rashi’s interpretation. Tosfos hold that the question is from the case of making a hole in a barrel seal which is permissible.
 See the Megilas Sefer ibid.