https://www.dlsite.com/books/work/=/product_id/BJ045600.html
https://book.dmm.co.jp/detail/b073bktcm00447/

translation info:
raw: https://e-hentai.org/s/a1a405b785/798430-71
group: desudesu https://desudesu.mangadex.com
commissioner: espeon https://gender.tf

read early and support more gb at https://gender.tf !

Either the pages are out of order or there's another different chapter of manga mixed in.

Base +6

Idk if it was re-edited at some point but from what I've seen just is weird writing, the 'lab' seems to be in a different location reachable by train, odd transition but looks to be correct

Base +6, Penumbral +6, DesRed +6

looks like the drug completely failed to control his sexual urges.

Base +5, h4g4ne +6, m42a +16, BonoBono08 +6, Lesamuen +8, RuRo-dono +6, Penumbral +6, DesRed +6, Kues +6, BooPooDoop +5

A pity that the process of him turning into a girl isn't shown...

Base +6, Luke2009 -6, SplitSkull +3, kirakabuki +6

Wonderful ethics there "Oh . . . . this drug has had a weird effect on the first human tested lets give you another shot just in case the effects wear off it can't possibly have more odd effects."

Base +6, m42a +16, reroda +14, DesRed +6, BooPooDoop +5

About the suddenly subway thing:
They injected him with the drug in the lab, then they went home, because nothing unusual happened, over night he suddenly turned into a girl. so they started examining him, but then they needed to go to the lab for more examinations because that's where their stuff is, and for that they used the train.

Base +18, firesage2000 +6, RuRo-dono +6, Penumbral +6, DesRed +6