Note 7 - Notes Payable

During the year ended December 31, 2018, the Company entered into Note and Warrant Purchase Agreements (the "Purchase Agreements") with certain accredited investors (the "Investors") pursuant to which the Company issued to the Investors $3,902,500 aggregate principal amount of its 8% Unsecured Promissory Notes due in March 2021 (the "Notes"). The Notes were issued together with warrants to purchase up to an aggregate of 780,500 shares of the Company's common stock at an exercise price of $5.30 per share. Notes in the aggregate amount of $532,500 were purchased by officers and directors of the Company. The warrants are exercisable any time prior to March 29, 2021. The Company determined the fair value of the warrants issued using the Black-Scholes pricing model with the following assumptions:

The fair value of the warrants was $1,253,390 and was recorded as a debt discount. The Company also incurred offering costs of $57,923 to issue the debt. Both the debt discount and offering costs the Company incurred offset the carrying value of the Notes in the accompanying balance sheets. The Company amortized $439,851 and $325,150 during the twelve months ended December 31, 2019 and 2018, respectively, of the debt discount and issuance costs leaving a net Notes payable balance at December 31, 2019 and 2018 of $3,356,188 and $2,916,337, respectively. The Company uses the straight-line method which approximates the interest method for the amortization of the debt discount and issuance costs. As of December 31, 2019 and 2018, the Company recorded accumulated amortization of $765,001 and $325,150, respectively, for the debt discount and offering costs.