The Company’s goodwill results from the acquisition of Pacira Pharmaceuticals, Inc. (the Company’s California operating subsidiary) from SkyePharma Holding, Inc., or Skyepharma, (now a subsidiary of Vectura Group plc) in March 2007 (the “Skyepharma Acquisition”), MyoScience, Inc., or MyoScience, (the “MyoScience Acquisition”) in April 2019 and the Flexion Acquisition in November 2021. The balances at September 30, 2022 and December 31, 2021 were $157.4 million and $145.2 million, respectively. The increase was due to measurement period adjustments associated with the Flexion Acquisition. See Note 4, Flexion Acquisition, for more information.

The Skyepharma Acquisition occurred in March 2007, prior to the requirements to record contingent consideration at fair value under ASC 805-30. In connection with the Skyepharma Acquisition, the Company agreed to certain milestone payments for DepoBupivacaine products, including EXPAREL. The final Skyepharma milestone payment of $32.0 million when annual net sales collected reached $500.0 million was achieved in the fourth quarter of 2021 and paid during the first quarter of 2022.

Intangible assets, net, consist of the in-process research and development, or IPR&D, and developed technology from the Flexion Acquisition and developed technology and customer relationships from the MyoScience Acquisition and are summarized as follows (dollar amounts in thousands):


September 30, 2022	Gross Carrying Value		Accumulated Amortization		Intangible Assets, Net		Weighted-Average Useful Lives
Developed technologies	$	590,000	$	(70,057)	$	519,943	10 years, 5 months
Customer relationships	90		(31)		59		10 years
Total finite-lived intangible assets, net	590,090		(70,088)		520,002
Acquired IPR&D	61,000		—		61,000
Total intangible assets, net	$	651,090	$	(70,088)	$	581,002

December 31, 2021	Gross Carrying Value		Accumulated Amortization		Intangible Assets, Net		Weighted-Average Useful Lives
Developed technologies	$	590,000	$	(27,097)	$	562,903	10 years, 5 months
Customer relationships	90		(25)		65		10 years
Total finite-lived intangible assets, net	590,090		(27,122)		562,968
Acquired IPR&D	61,000		—		61,000
Total intangible assets, net	$	651,090	$	(27,122)	$	623,968

Amortization expense on intangible assets for the three and nine months ended September 30, 2022 was $14.3 million and $43.0 million, respectively. Amortization expense on intangible assets for the three and nine months ended September 30, 2021 was $2.0 million and $5.9 million, respectively. The increase in amortization expense in the current year is a result of the amortization of ZILRETTA for osteoarthritis knee pain acquired as part of the Flexion Acquisition in November 2021.

Assuming no changes in the gross carrying amount of these intangible assets, the future estimated amortization expense on the finite-lived intangible assets will be $14.3 million for the remaining three months of 2022, $57.3 million from 2023 to 2030, $37.4 million in 2031, $7.9 million in 2032 and $2.2 million in 2033.

The Company reviews its long-lived assets for impairment whenever an event or change in circumstances arise that indicate the carrying amount of an asset group is at risk of not being recoverable. During the three months ended June 30, 2022, a triggering event was identified for the ZILRETTA asset group due to a reduction in the near-term projected cash flows from the ZILRETTA product. The Company completed an impairment assessment through a recoverability test at June 30, 2022 by comparing the net carrying value of ZILRETTA asset group against the undiscounted net cash flows expected to be generated from ZILRETTA. It was determined that the ZILRETTA asset group was recoverable and not impaired.