Patents net

6 Months Ended

Dec. 31, 2021

Patents net

4. Patents, net

4. Patents, net

Patents, net consisted of the following (rounded to nearest thousand):

	Useful life (years)		December 31, 2021			June 30, 2021
Purchased Patent Rights- Brilacidin and related compounds		14	$	4,082,000		$	4,082,000
Purchased Patent Rights-Anti-microbial- surfactants and related compounds		12		144,000			144,000
Patents - Kevetrin and related compounds		17		1,324,000			1,280,000
				5,550,000			5,506,000
Less: Accumulated amortization for Brilacidin, Anti-microbial- surfactants and related compounds				(2,525,000	)		(2,373,000	)
Accumulated amortization for Patents-Kevetrin and related compounds				(418,000	)		(379,000	)
Total			$	2,607,000		$	2,754,000

The patents are amortized on a straight-line basis over the useful lives of the assets, determined to be 12-17 years from the date of acquisition.

Amortization expense for the three months ended December 31, 2021 and 2020 was approximately $96,000 and $94,000, respectively and was approximately $191,000, and $188,000 for the six months ended December 31, 2021 and 2020, respectively.

At December 31, 2021, the future amortization period for all patents was approximately 3.68 years to 16.75 years. Future estimated amortization expenses are approximately $191,000  for the year ending June 30, 2022, $381,000 for each year from 2023 to 2025, $372,000 for the year ending June 30, 2026 and a total of $901,000 for the year ending June 30, 2027 and thereafter.