Statements Of Income (USD $)	3 Months Ended		6 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Revenue
Product sales	$ 8,113,806	$ 7,231,149	$ 16,461,887	$ 13,205,755
Contract research and development	153,567	70,031	258,521	272,358
Total revenue	8,267,373	7,301,180	16,720,408	13,478,113
Cost of sales	1,609,632	1,503,546	3,167,978	2,881,901
Gross profit	6,657,741	5,797,634	13,552,430	10,596,212
Expenses
Selling, general , and administrative	625,599	660,076	1,255,249	1,212,880
Research and development	787,279	876,463	1,590,707	1,839,374
Total expenses	1,412,878	1,536,539	2,845,956	3,052,254
Income from operations	5,244,863	4,261,095	10,706,474	7,543,958
Interest income	562,923	520,802	1,111,477	1,047,141
Income before taxes	5,807,786	4,781,897	11,817,951	8,591,099
Provision for income taxes	1,932,164	1,552,246	3,905,219	2,794,623
Net income	$ 3,875,622	$ 3,229,651	$ 7,912,732	$ 5,796,476
Net income per share - basic	$ 0.80	$ 0.67	$ 1.63	$ 1.19
Net income per share - diluted	$ 0.80	$ 0.66	$ 1.63	$ 1.19
Weighted average shares outstanding
Basic	4,855,071	4,852,178	4,853,068	4,857,279
Diluted	4,872,029	4,873,106	4,868,769	4,878,599