Statements Of Income (USD $)	3 Months Ended		6 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Revenue
Product sales	$ 7,231,149	$ 5,231,332	$ 13,205,755	$ 12,262,077
Contract research and development	70,031	591,464	272,358	1,023,624
Total revenue	7,301,180	5,822,796	13,478,113	13,285,701
Cost of sales	1,503,546	1,606,913	2,881,901	3,409,266
Gross profit	5,797,634	4,215,883	10,596,212	9,876,435
Expenses
Selling, general , and administrative	660,076	607,694	1,212,880	1,143,804
Research and development	876,463	612,258	1,839,374	1,300,284
Total expenses	1,536,539	1,219,952	3,052,254	2,444,088
Income from operations	4,261,095	2,995,931	7,543,958	7,432,347
Interest income	520,802	621,950	1,047,141	1,184,568
Income before taxes	4,781,897	3,617,881	8,591,099	8,616,915
Provision for income taxes	1,552,246	1,174,998	2,794,623	2,796,374
Net income	$ 3,229,651	$ 2,442,883	$ 5,796,476	$ 5,820,541
Net income per share - basic	$ 0.67	$ 0.51	$ 1.19	$ 1.21
Net income per share - diluted	$ 0.66	$ 0.50	$ 1.19	$ 1.19
Weighted average shares outstanding
Basic	4,852,178	4,825,441	4,857,279	4,825,095
Diluted	4,873,106	4,884,656	4,878,599	4,882,524