Note 6 - Debt

9 Months Ended

Sep. 30, 2025

Notes to Financial Statements

Debt Disclosure [Text Block]

(6)        Debt

In December 2013, the Company entered into a promissory note agreement with the chairman of our board of directors at the time and one of our major shareholders, pursuant to which we borrowed $500,000 (the “2013 Promissory Note”). The 2013 Promissory Note is secured and bears interest at 6% per annum and was originally due June 30, 2014. According to the terms of the 2013 Promissory Note, at any time, the lenders may settle any or all of the principal and accrued interest with shares of our common stock. Pursuant to four modifications in the time period between June 2014 and January 2022, the 2013 Promissory Note was modified to extend the maturity date to December 31, 2023, with all remaining terms unchanged. In February 2024, the 2013 Promissory Note was modified again to (i) extend the maturity date to March 31, 2026, (ii) remove the security provision to allow for the sale of all our assets related to the Fluorine Products segment and the Planned Uranium De-Conversion Facility to American Fuel Resources, LLC (the “DUF6 Asset Sale”), (iii) if reasonably possible, to reinstate a security provision against our Sodium iodide abbreviated new drug application (“ANDA”) and Iodine-131 Processing Hot Cell, and (iv) to reinstate all security interests if the DUF6 Asset Sale does not close by March 31, 2026, with all remaining terms unchanged. To date, the Company has not yet removed the security interests against any of our assets related to this note. In August 2025, the 2013 Promissory Note was modified again to extend the maturity date to March 31, 2028, with all remaining terms unchanged. At September 30, 2025, accrued interest payable on the 2013 Promissory Note was $354,234.

In April 2018, the Company borrowed $120,000 from our chief executive officer and the current chairman of our board of directors (“Chairman”) through an affiliated entity pursuant to a promissory note (the “2018 Promissory Note”). The 2018 Promissory Note is secured and accrues interest at 6% per annum, which is payable upon maturity of the 2018 Promissory Note. At any time, the holders of the 2018 Promissory Note may elect to have any or all of the principal and accrued interest settled with shares of our common stock based on the average price of the shares over the previous 20 trading days. The 2018 Promissory Note was originally due August 1, 2018. Pursuit to six modifications within the period of June 2018 and December 2023, the 2018 Promissory Note was modified to extend the maturity date to January 31, 2025, with all remaining terms unchanged. In February 2024, the 2018 Promissory Note was modified to (i) extend the maturity date to March 31, 2026, (ii) remove the security provision to allow for the DUF6 Asset Sale, (iii) if reasonably possible, to reinstate a security provision against our sodium iodide ANDA and iodine-131 Processing Hot Cell, and (iv) to reinstate all security interests if the DUF6 Asset Sale does not close by March 31, 2026, with all remaining terms unchanged. To date, the Company has not yet removed the security interests against any of our assets related to this note. In August 2025, the 2018 Promissory Note was modified again to extend the maturity date to March 31, 2028, with all remaining terms unchanged. At September 30, 2025, accrued interest on the 2018 Promissory Note totaled $53,570.

In December 2019 and February 2020, the Company borrowed an aggregate of $1,000,000 from our chief executive officer, Chairman, former Chairman, and one of our major shareholders pursuant to a promissory note (the “2019 Promissory Note”). The 2019 Promissory Note bears an interest rate of 4% annually and was originally due December 31, 2022. According to the terms of the 2019 Promissory Note, at any time, the lenders may settle any or all of the principal and accrued interest with shares of the Company’s common stock based on the average closing price of the Company’s common stock for the 20 days preceding the payment. In December 2022, the 2019 Promissory Note was modified to extend the maturity date to December 31, 2024, with all remaining terms unchanged. In February 2024, the 2019 Promissory Note was modified to (i) extend the maturity date to March 31, 2026, (ii) remove the security provision to allow for the DUF6 Asset Sale, (iii) if reasonably possible, to reinstate a security provision against our sodium iodide ANDA and Iodine-131 Processing Hot Cell, and (iv) to reinstate all security interests if the DUF6 Asset Sale does not close by March 31, 2026, with all remaining terms unchanged. To date, the Company has not yet removed the security interests against any of our assets related to this note. In August 2025, the 2019 Promissory Note was modified again to extend the maturity date to March 31, 2028, with all remaining terms unchanged. At September 30, 2025, the accrued interest on the 2019 Promissory Note totaled $229,131.

In June 2023, the Company executed an asset purchase agreement with AMICI, Inc. for the purchase of medical devices and related assets and intellectual property rights. In connection with the asset purchase agreement, the Company entered a promissory note to AMICI, Inc. with a principal amount of $558,593. According to the terms of the note, the Company made an initial cash payment of $100,000 into escrow, issued the seller $25,000 in shares of the Company’s common stock, and paid the seller $6,493 in a closing cash reimbursement payment. For the remaining principal balance of the promissory note of $427,100, the Company is required to pay the seller a minimum of $10,000 per month for a period of 45 months. The amount due was not subject to interest until the 25th month after the anniversary of the closing of the transaction. At September 30, 2025, the balance of this promissory note was $157,100.