Through the third quarter of fiscal 2013, we generated product revenue from the sale of Dermacyte® through on-line retailers, physicians and medical spa facilities, and through distribution agreements with unrelated companies. Net product revenue for the years ended April 30, 2013 and 2012 was $49,572 and $49,266, respectively. The decrease in product revenue was primarily due to the elimination of our internal sales force and the suspension of our direct marketing and advertising programs. Gross profit as a percentage of revenue was 53% and 49% for the years ended April 30, 2013 and 2012, respectively. In the fourth quarter of fiscal 2013 we out-licensed the Dermacyte® product line to the cosmetics division of Valor SA of Switzerland.
We also earn revenues through a cost-reimbursement grant sponsored by the United States Army (Grant Revenue). Grant Revenue is recognized as milestones under the grant program are achieved. Grant Revenue is earned through reimbursements for the direct costs of labor, travel, and supplies, as well as the pass-through costs of subcontracts with third-party contract research organizations. For the year ended April 30, 2013, we recorded approximately $1,141,356, a 263% increase over $314,515 in revenue under the grant program for the year ended April 30, 2012.
Total operating expenses for the year ended April 30, 2013 were $6,379,955 compared to $8,583,978 for the same period in 2012. The 26% decrease in total operating expenses was the result of reductions in selling, general and administrative costs, partially offset by an increase in restructuring expense.Marketing and sales expenses for the year ended April 30, 2013 decreased 73% to $108,165 compared to $393,922 in the prior year. The decrease in marketing and sales expenses for the year was driven primarily by reductions in costs incurred for direct marketing and compensation. General and administrative (G&A) expenses for the year ended April 30, 2013 decreased 37% to $3,567,980 compared with $5,697,884 in the prior year. The decrease in G&A expenses was driven primarily by reductions in costs incurred for legal and professional fees, compensation, facilities, travel and depreciation and amortization.