If you are charged with trafficking, due to the large number of tablets you had, it is very serious with a penalty of:
First Offense: Not more that 20 yrs. If death or serious injury, not less than 20 yrs, or more than Life. Fine $1 million if an individual, $5 million if not an individual.
This is considered a Schedule II drug and there is no limit to the amount.
For the H Felony charge of larceny you could get up to 4 years and face civil action by your employer. For the possession with intent to sell (a Class I Felony) you could get up to 6 years.
You can read more HERE on the drug charges and penalties for your state and HERE for the federal.
If you had a buyer for the medication, you may be able to plead to a lesser charge or have time taken off your sentence if you can offer up those names to law enforcement. Since this is your first offense like this, or for any matter, and it can be assumed you will never do this again as I am sure you will not be allowed to work in a pharmacy again, they may be more lenient with your sentencing. Also the fact that you have already admitted guilt in the matter may allow them to make a deal with you.The main thing you need to do right now is ask for an attorney immediately upon being arrested before you say anything else to anyone to protect yourself.
You may also want to go HERE.