For example, our recent Mycophenolate approval was achieved in just under 10 months, the third such product we developed to achieve so called first cycle approval in the past few years.
We also formed a new strategic alliance partnership to launch Sevoflurane, a product with relatively few competitors and a market size of about $190 million based on IQVIA data.
We implemented and completed the cost reduction plan that included consolidating our R&D functions to a single location and lowered operating costs by approximately $15 million annually.
First, we extended the maturity of our debt to 2026 from 2022, which is now after several of our larger and more meaningful pipeline assets are expected to launch and contributed to a reduction in our debt.
We continue to launch products [Indecipherable] approximately 13 ANDAs pending at the FDA including partner products, plus four additional products that are approved and pending launch.
We also have more than 20 products in development and expect to add more from both external and internal efforts.
The development arc for this product should be approximately 12 months to 18 months behind the generic Flovent Diskus product.
Regarding biosimilar Insulin Aspart, the development of the product continues and we currently anticipate a potential launch of the product about 15 months following Insulin Glargine.
We also see opportunities to leverage our USA clinical data, 10 development and related IP, along with the manufacturing capacity at HEC to form a strategic alliance with third parties looking to accelerate their access to insulin products in international markets such as Europe.
We continue to believe that the exciting products in our advancing and expanding pipeline still have the potential to transform our firm into $1 billion company by 2025.
For the 2021 fourth quarter, net sales were $106.0 million, compared with $137.9 million for the fourth quarter of last year.
Gross profit was $26.4 million or 25% of net sales, compared with $48.9 million or 35% of net sales for the prior year fourth quarter.
R&D expenses declined to $6.0 million from $6.6 million.
SG&A expenses declined to $15.5 million from $15.6 million.
Operating income was $4.9 million, compared with $26.7 million.
Interest expense increased to $12.1 million from $11.3 million in last year's fourth quarter.
Net loss was $7.4 million or $0.19 per share versus net income of $13.4 million or $0.31 per diluted share.
Adjusted EBITDA was $12.1 million.
At June 30, 2021, cash and cash equivalents totaled approximately $93 million, up from $81 million at March 31.
Accordingly, we expect to maintain a healthy cash position throughout the year and end fiscal 2022 with approximately $80 plus million.
As for our liquidity, we also have access to our $45 million credit facility, which today we have not drawn upon.
For fiscal 2022, we expect net sales in the range of $400 million to $440 million, adjusted gross margin as a percentage of net sales of approximately 23% to 25%, adjusted R&D expense in the range of $26 million to $29 million, adjusted SG&A expense ranging from $58 million to $61 million, adjusted interest expense of approximately $52 million, the full year adjusted effective tax rate in the range of 21% to 22%, adjusted EBITDA in the range of $40 million to $55 million, and lastly, capital expenditures to be approximately $12 million to $18 million.

Summary:
First, we extended the maturity of our debt to 2026 from 2022, which is now after several of our larger and more meaningful pipeline assets are expected to launch and contributed to a reduction in our debt.
Net loss was $7.4 million or $0.19 per share versus net income of $13.4 million or $0.31 per diluted share.
For fiscal 2022, we expect net sales in the range of $400 million to $440 million, adjusted gross margin as a percentage of net sales of approximately 23% to 25%, adjusted R&D expense in the range of $26 million to $29 million, adjusted SG&A expense ranging from $58 million to $61 million, adjusted interest expense of approximately $52 million, the full year adjusted effective tax rate in the range of 21% to 22%, adjusted EBITDA in the range of $40 million to $55 million, and lastly, capital expenditures to be approximately $12 million to $18 million.