11. SEGMENT REPORTING (Details) (USD $)	3 Months Ended								12 Months Ended
	Apr. 30, 2013	Jan. 31, 2013	Oct. 31, 2012	Jul. 31, 2012	Apr. 30, 2012	Jan. 31, 2012	Oct. 31, 2011	Jul. 31, 2011	Apr. 30, 2013	Apr. 30, 2012	Apr. 30, 2011
Segment Reporting Details
Contract manufacturing services revenue									$ 21,333,000	$ 14,783,000	$ 8,502,000
Cost of contract manufacturing services									12,595,000	10,153,000	7,296,000
Gross profit	959,000	3,310,000	2,358,000	2,111,000	1,053,000	719,000	436,000	2,422,000	8,738,000	4,630,000	1,206,000
Revenue from products in research and development									350,000	450,000	4,990,000
Research and development expense									(24,306,000)	(35,688,000)	(29,462,000)
Selling, general and administrative expense									(13,134,000)	(11,462,000)	(11,421,000)
Other income (expense), net									268,000	(49,000)	536,000
Loss on early extinguishment of debt									(1,696,000)	0	0
Net (loss)	$ (8,449,000)	$ (4,914,000)	$ (8,753,000)	$ (7,664,000)	$ (10,882,000)	$ (11,090,000)	$ (12,055,000)	$ (8,092,000)	$ (29,780,000)	$ (42,119,000)	$ (34,151,000)