While Sato was interested in saving the young lady's life, he didn't plan on endangering his own by roaming outside for too long. Luckily for him, Sato didn't take long to find the necessary herbs to complete the drug. The missing herbs were extremely low-level and not so special so it wouldn't be an issue finding them. There was also the fact that the ecosystem here was quite impressive, giving birth to such herbs as if they were weeds. Hence, it didn't take long after Sato had left the cave before he found them.
"I hope this works.'