I can't speak for the particular pharmaceutical company you're asking about (especially so since you didn't name it), but having been a part of (read that as a member of the management team of) a company that experienced phenomenal growth in the chemical industry, and having hired dozens of scientists just like you, and having heard all the horror stories, and having worked with recruiters who dropped off literally 100 resumes of pre-screened candidates per open position, I'll give you my 2 cents.
First, recruiters work on commission. Sometimes they earn about 30% of the starting salary, other times less but it's still substantial per person placed. What they do to earn that $ is this. Recruiters meet with companies, identify their people needs, help them define and write job descriptions for their open positions, run the finished job descriptions past the decision makers and IF their clients agree to fill those positions, the recruiters post those job descriptions on the internet and start pre-screening candidates. Then they present the candidates to their clients and hope the company bites. Sometimes they do all that prematurely. Sometimes, they try to identify strong candidates and present those people to their clients hoping to get them to move on filling the (or any other) position. That is, sometimes recruiters might stretch the truth a bit. Remember, they don't get paid until a candidate gets "on board".
Second, companies do change their minds. They might reorganize and move different managers into the "decision maker" role. That hiring manager may have a different skill set or job description in mind. They might even reorganize their team with completely different goals. They might find a different candidate they like better. Or they might freeze hiring during financial problems. Usually, good managers will inform the recruiters of changes, others may not worry about keeping a lowly recruiter just trying to make a buck peddling people up to date. Sometimes those recruiters still pursue candidates hoping that the position will open up again. Or at least they hope to get a list of candidates to present at a later date there or elsewhere. Sometimes, the recruiter might not even know what's happening with the position. Sometimes the recruiter might not inform the candidate because he's still hoping to make a sale. Big bucks right?
Third, a lot can happen between now and your first paycheck. I always say "you're not on board until you show up on your start date and are greeted by your hiring manager". Until then, anything can go wrong. Meetings can be moved around, offers can be rescinded, start dates can be changed, positions can be canceled, even contracts that you and the company sign can be broken (read the escape clauses). The company may burn up or fold up... force majeure... who knows... anything can go wrong. And your recruiter might not be telling you everything that's happening.
Get my point(s)?
As to the particular pharma company you've applied to? Sorry to say, if they wanted you, it would have happened by now. At our company, we made decisions about moving forward with candidates just like you the day of their interviews. We made offers that same day if we were "wowed", within a week if we weren't exactly wowed but needed to move forward with filling the job. In most cases, we had candidates on board within 2 weeks of the offer.
Given your situation, I highly recommend you keep looking for employment. Take a part time job at Starbucks or Home Depot while you're looking. Even if you accept a job offer, don't stop interviewing. Keep interviewing until you are on board! And from this point forward, don't rely exclusively on the recruiters to get you hired. Get contact information for the hiring manager and the company HR folks during your interviews. Contact them if you have questions or need more information.