Answer:
invest in a new production plant right now.
Explanation:
The best long term solution for these constraints would be to invest in a new production plant right now. This would set the pharmaceutical company back for some time as it would be a big cost which would take them a long time to recover through profits. Regardless, it would completely solve their scaling problem and allow them to drastically increase their profits the more they grow. Which would also decrease the amount of time before they recover the cost of the new plant.