Annual report pursuant to Section 13 and 15(d)

Summary of Significant Accounting Policies - Additional Information (Detail)

v3.2.0.727
Summary of Significant Accounting Policies - Additional Information (Detail) - USD ($)
 12 Months Ended
May. 31, 2015
May. 31, 2014
Summary Of Significant Accounting Policies [Line Items]    
Net loss $ (25,088,070) $ (12,431,413)
Working capital deficit 8,687,443  
Balance in excess of federally insured limits 1,164,000 4,589,000
Impairment charges 0 0
Pre-launch inventory qualified for capitalization $ 0 0
Estimated future unvested option forfeitures 0.00%  
Deferred offering costs $ 0 68,292
Direct costs associated with the convertible notes 708,000 120,000
Amortization of debt issuance costs $ 103,598 $ 120,000
Common stock options and warrants to purchase 31,008,915 30,806,361
Additional common shares if convertible debt is converted to common stock 10,559,919  
Unrecognized benefits $ 0  
Convertible Debt    
Summary Of Significant Accounting Policies [Line Items]    
Face amount of notes $ 7,531,050  
Debt and Equity Securities    
Summary Of Significant Accounting Policies [Line Items]    
Deferred offering costs   $ 2,084,000
Series B Convertible Preferred Stock    
Summary Of Significant Accounting Policies [Line Items]    
Preferred Stock Shares authorized to be issued 400,000 400,000
Common stock options and warrants to purchase 95,100 95,100
Common shares issued upon conversion of preferred stock 951,000  
Maximum    
Summary Of Significant Accounting Policies [Line Items]    
Preferred Stock Shares authorized to be issued 5,000,000  
Minimum    
Summary Of Significant Accounting Policies [Line Items]    
Income tax examination, year under examination 2012