10. SEGMENT REPORTING (Details) (USD $)	3 Months Ended		6 Months Ended
	Oct. 31, 2013	Oct. 31, 2012	Oct. 31, 2013	Oct. 31, 2012
Segment Reporting [Abstract]
Contract manufacturing services revenue	$ 7,354,000	$ 6,061,000	$ 11,935,000	$ 10,196,000
Cost of contract manufacturing services	4,195,000	3,703,000	6,865,000	5,727,000
Gross profit	3,159,000	2,358,000	5,070,000	4,469,000
Revenue from products in research and development	0	78,000	107,000	194,000
Research and development expense	(6,957,000)	(6,053,000)	(12,261,000)	(13,034,000)
Selling, general and administrative expense	(4,016,000)	(3,440,000)	(8,350,000)	(6,357,000)
Other income (expense), net	24,000	0	44,000	7,000
Loss on early extinguishment of debt	0	(1,696,000)	0	(1,696,000)
Net loss	$ (7,790,000)	$ (8,753,000)	$ (15,390,000)	$ (16,417,000)