Statements Of Income (USD $)	3 Months Ended
	Jun. 30, 2012	Jun. 30, 2011
Revenue
Product sales	$ 7,030,745	$ 7,023,274
Contract research and development	432,160	1,190,488
Total revenue	7,462,905	8,213,762
Cost of sales	1,802,353	2,595,592
Gross profit	5,660,552	5,618,170
Expenses
Selling, general , and administrative	536,110	615,830
Research and development	688,026	494,876
Total expenses	1,224,136	1,110,706
Income from operations	4,436,416	4,507,464
Interest income	562,618	565,529
Income before taxes	4,999,034	5,072,993
Provision for income taxes	1,621,376	1,633,765
Net income	$ 3,377,658	$ 3,439,228
Net income per share - basic	$ 0.70	$ 0.72
Net income per share - diluted	$ 0.69	$ 0.70
Weighted average shares outstanding
Basic	4,824,745	4,776,198
Diluted	4,886,873	4,893,915