First of all scriptures have not dealt with the issue directly.So,what we need to do is find verses that are closely related & adapt them to the situation.
What the scientists do is clearly unlawful(Adharma) IMO because they are killing/torturing innocent animals for their own good/benefit.Even if they say "we are doing it for the benefit of humanity" then humanity is not the whole set of living beings that are on earth.Animals,insects and the trees are also Almighty's children just like we are.Their pains and sufferings also count
In Hindu Scriptures,all throughout,its being said that the only lawful killing of animals(or even plants) is when they will be used in sacrifices for the Gods or for the Manes(Pitrus).I have not found any exception to this rule.
And any killing apart from that, for one's own need, is more or less bad karma.
The whole essence of what i am saying is summed up well in Lord Shiva's words given below :
Trinam VApyaVidhanena Chedyenna KadAchana| Vidhina GAm Dvijam VApi
HatyA PApairna Lipyate ||
If its not prescribed in Shastras don't even tear a grass,but there is no sin even if one kills a cow or a dvija as per Shastra
KulArnava Tantram, 2-137.
AvidhAnena Yo HanyAdAtmArtham PrAninah Priye| Nivasennarake Ghore
One who kills an animal for one's own good/benefit/enjoyement goes after his death to hell and lives there for as many days as there are
hairs on the animal's body.
KulArnava Tantram 2-131
Manu Smriti also says the same thing in a different way:
5.38. As many hairs as the slain beast has, so often indeed will he who killed it without a (lawful) reason suffer a violent death in
The only lawful killing of an animal , as said earlier,is when done for sacrifices to Gods/Manes.
Manu Smriti 5.39. Svayambhu (the Self-existent) himself created
animals for the sake of sacrifices; sacrifices (have been instituted)
for the good of this whole (world); hence the slaughtering (of beasts)
for sacrifices is not slaughtering (in the ordinary sense of the
Who suffers the consequences and how much? The scientist doing the
testing? The group of collaborators working on the project? People who
sell the drugs that were created using this process? People who take
Everyone involved in the process IMO,from the start till the end,will be equally guilty of the crime.Even the persons who are buying the medicines and consuming them included.Everyone who is benefiting from the process of torturing the animal will have to pay the price for it.
A relevant verse from Manu that can be adapted here is this:
5.51. He who permits (the slaughter of an animal), he who cuts it up, he who kills it, he who buys or sells (meat), he who cooks it, he who
serves it up, and he who eats it, (must all be considered as) the
slayers (of the animal).
The purport of this Manu verse is that everyone is equally guilty, from the one who kills the animal to the one who partakes it.Even one who is cooking is guilty (although he might not be eating it). Similarly here.From one who is getting monetary benefits out the research to one who is getting the health benefits all of them will have to pay the price for the animals' sufferings.
Also, i don't think that we really need scriptures to tell us that what we are doing is wrong because our conscience will also tell us the same unless its dead.
Adding a couple of more verses from Parashara Smriti which say that the animals that are working for us should be taken good care of.We should not burden them with over weight, over work.Because,if they get hurt or get killed in the process of working for us then we need to do penance to overcome that guilt.
3. An ox that is hungry, or thirsty, or fatigued, should not be harnessed (to a plough) . A bull wanting in a limb, or diseased, or
impotent, should not, by a Brahman, be made to work.
24. If a bull happens to be unduly burnt, on the occasion of cauterizing an injured part ; or if a bull is loaded beyond his
strength ; and if he be sent, so loaded, to cross a river, or travel
over hills, — the following penances are prescribed by law :
These verses clearly prove that the practice of killing/torturing animals for our own use is unethical/unlawful from the Hindu perspective.