Summary of Significant Accounting Policies (Policies)	12 Months Ended
Dec. 31, 2024
Accounting Policies [Abstract]
Basis of Presentation	Basis of Presentation The accompanying consolidated financial statements have been prepared in accordance with accounting principles generally accepted in the United States of America (“U.S. GAAP”). The consolidated financial statements include the accounts of the Company and its wholly-owned subsidiaries, Rockwell Transportation, Inc. and Rockwell Medical India Private Limited. Rockwell Medical India Private Limited was formed in 2020 for the purpose of conducting certain commercial activities in India. All intercompany balances and transactions have been eliminated in consolidation.
Use of Estimates	Use of Estimates The preparation of the consolidated financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that may affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the consolidated financial statements and reported amounts of expenses during the reporting period. Actual results could differ from those estimates. The most significant accounting estimates inherent in the preparation of the financial statements include estimates associated with revenue recognition, impairments of long‑lived assets, and deferred consideration.
Revenue Recognition	Revenue Recognition The Company recognizes revenue under Accounting Standards Codification (“ASC”) 606, Revenue from Contracts with Customers, issued by the Financial Accounting Standards Board ("FASB"). The core principle of the revenue standard is that a company should recognize revenue to depict the transfer of promised goods or services to customers in an amount that reflects the consideration to which the company expects to be entitled in exchange for those goods or services. The following five steps are applied to achieve that core principle: •Step 1: Identify the contract with the customer •Step 2: Identify the performance obligations in the contract •Step 3: Determine the transaction price •Step 4: Allocate the transaction price to the performance obligations in the contract •Step 5: Recognize revenue when the company satisfies a performance obligation Taxes assessed by a governmental authority that are both imposed on and concurrent with a specific revenue-producing transaction, that are collected by Rockwell from a customer, are excluded from revenue. Shipping and handling costs associated with outbound freight related to contracts with customers are accounted for as a fulfillment cost and are included in cost of sales when control of the goods transfers to the customer. Nature of goods and services The following is a description of principal activities from which the Company generates its revenue. For a discussion of significant market segments and customers, see Note 6. Product Sales The Company accounts for individual products and services separately if they are distinct (i.e., if a product or service is separately identifiable from other items and if a customer can benefit from it on its own or with other resources that are readily available to the customer). The consideration, including any discounts, is allocated between separate products and services based on their stand-alone selling prices. The stand-alone selling prices are determined based on the cost plus margin approach. Drug and dialysis concentrate products are sold directly to dialysis clinics and to wholesale distributors in both domestic and international markets. Distribution and license agreements for which upfront fees are received are evaluated upon execution or modification of the agreement to determine if the agreement creates a separate performance obligation from the underlying product sales. For all existing distribution and license agreements, the distribution and license agreement is not a distinct performance obligation from the product sales. In instances where regulatory approval of the product has not been established and the Company does not have sufficient experience with the foreign regulatory body to conclude that regulatory approval is probable, the revenue for the performance obligation is recognized over the term of the license agreement (over time recognition). Conversely, when regulatory approval already exists or is probable, revenue is recognized at the point in time that control of the product transfers to the customer. For the majority of the Company’s international customers, the Company recognizes revenue when the customer takes control at the shipping point, which is generally the Company’s plant or warehouse. For other customers, the Company recognizes revenue based on when the customer takes control of the product upon delivery. The amount of revenue recognized is based on the purchase order less returns and adjusted for any rebates, discounts, chargebacks or other amounts paid to customers estimated at the time of sale. Customers typically pay for the product based on customary business practices with payment terms averaging 30 days, while a small subset of customers have payment terms averaging 60 days. Deferred License Revenue The Company received upfront fees under five distribution and license agreements that have been deferred as a contract liability and presented on the accompanying consolidated balance sheets as deferred license revenue. The amounts received from Wanbang Biopharmaceuticals Co., Ltd. (“Wanbang”), Sun Pharmaceutical Industries Ltd. ("Sun Pharma"), Jeil Pharmaceutical Co., Ltd. ("Jeil Pharma") and Drogsan Pharmaceuticals ("Drogsan Pharma") are recognized as revenue over the estimated term of the applicable distribution and license agreement as regulatory approval was not received and the Company did not have sufficient experience in China, India, South Korea and Turkey, respectively, to determine that regulatory approval was probable as of the execution of the agreement. The amounts received from Baxter Healthcare Corporation (“Baxter”) were deferred and recognized as revenue at the point in time the estimated product sales under the agreement occurred. During the year ended December 31, 2023, all remaining deferred revenue relating to the distribution and license agreements with Wanbang and Baxters was recognized as revenue. For additional information related to the Company's deferred license revenue, see Note 10. Product Purchase Agreement On September 18, 2023, Rockwell and DaVita entered into the Amended Agreement, which amends and restates the Product Purchase Agreement, dated July 1, 2019, as amended, under which the Company supplies DaVita with certain dialysis concentrates. Under the Amended Agreement, the Company and DaVita agreed to an increase in product pricing, effective September 1, 2023 and a one-time payment of $0.4 million to Rockwell on or after December 1, 2023. The term of the Amended Agreement expired on December 31, 2024. Prior to the expiration, the Company received written notice from DaVita, notifying the Company that DaVita intended to extend the term of the Amended Agreement through December 31, 2025 (the "Extension Term"). Product pricing was increased for the Extension Term. However, DaVita subsequently indicated that it will completely transition to another supplier by mid-2025, subject to further discussions between Rockwell and DaVita, which are ongoing and include a potential contract extension and/or future volume commitments by DaVita to Rockwell. There can be no assurances that these discussions will yield a successful outcome for Rockwell.
Cash and Cash Equivalents	Cash and Cash Equivalents The Company considers all highly liquid investments purchased with original maturities of 90 days or less at acquisition to be cash equivalents. Cash and cash equivalents include cash held in banks, money market mutual funds and unrestricted certificates of deposit. The Company’s cash and cash equivalents exceeds the Federal Deposit Insurance Corporation insured limits. The Company has not experienced any credit losses for amounts in excess of insured limits. Currently, the Company does not reasonably believe a significant risk of credit loss exists.
Fair Value Measurement	Fair Value Measurement The Company applies the guidance issued with ASC 820, Fair Value Measurements, which provides guidance on the development and disclosure of fair value measurements. Under this accounting guidance, fair value is defined as an exit price, representing the amount that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date. As such, fair value is a market-based measurement that should be determined based on assumptions that market participants would use in pricing an asset or a liability. The accounting guidance classifies fair value measurements in one of the following three categories for disclosure purposes: Level 1: Quoted prices in active markets for identical assets or liabilities. Level 2: Inputs other than Level 1 prices for similar assets or liabilities that are directly or indirectly observable in the marketplace. Level 3: Unobservable inputs which are supported by little or no market activity and values determined using pricing models, discounted cash flow methodologies, or similar techniques, as well as instruments for which the determination of fair value requires significant judgment or estimation.
Investments - Available for Sale	Investments – Available for Sale The Company determines the appropriate classification of its investments in equity and debt securities at the time of purchase and reevaluates such determination at each balance sheet date. Marketable equity securities that are bought principally for the purpose of selling them in the near term are reported at fair value, with unrealized gains and losses recognized in earnings. Marketable debt securities classified as available for sale securities are carried at fair market value, with the unrealized gains and losses, net of tax, included in the determination of comprehensive income (loss) and reported in stockholders’ equity. The Company may be exposed to credit losses through its available-for-sale debt securities. Unrealized losses or impairments resulting from the amortized cost basis of any available-for-sale debt security exceeding its fair value are evaluated for identification of credit and non-credit related factors. Any difference between the fair value of the debt security and the amortized cost basis not attributable to credit related factors are reported in other comprehensive income. A credit-related impairment is recognized as an allowance on the balance sheet with a corresponding adjustment to earnings. When evaluating the investments for impairment at each reporting period, the Company reviews factors such as the extent of the unrealized loss, current and future economic market conditions and the economic and financial condition of the issuer and any changes thereto. Realized gains or losses resulting from the sale of these securities are determined based on the specific identification of the securities sold.
Accounts Receivable	Accounts Receivable Accounts receivable are stated at invoice amounts. The carrying amount of trade accounts receivable is reduced by an allowance for credit losses that reflects our best estimate of accounts that may not be collected. The Company reviews outstanding trade accounts receivable balances and based on its assessment of expected collections, the Company estimates the portion, if any, of the balance that may not be collected based on future forecasts, historical loss information, and current economic conditions. All accounts or portions thereof deemed to be uncollectible are written off to the allowance for credit losses and credit loss expense.
Inventory	Inventory Inventory is stated at the lower of cost or net realizable value. Cost is determined on the first‑in first‑out (FIFO) method. Inventory that is not expected to be converted to cash over the next year is classified as non-current. The Company's policy is to reserve for its drug product inventory that it determines is unlikely to be sold to, or if sold, unlikely to be utilized by its customers on or before its expiration date.
Property and Equipment	Property and Equipment Property and equipment is recorded at cost and is depreciated using the straight‑line method over the useful lives of the assets, which range from three to ten years. Expenditures for routine maintenance and repairs are expensed as incurred. Leasehold improvements are amortized using the straight‑line method over the shorter of the useful lives or the related lease term.
Impairment of Long-lived Assets and Goodwill	Impairment of Long-lived Assets and Goodwill Long-lived assets, such as property and equipment and definite-lived intangible assets, are reviewed for impairment whenever events or changes in circumstances indicate that the carrying amounts may not be recoverable. Impairment losses on long-lived assets are recognized when events or changes in circumstances indicate that the undiscounted cash flows estimated to be generated by such assets are less than their carrying value and, accordingly, all or a portion of such carrying value may not be recoverable.Rockwell reviews goodwill and indefinite-lived intangible assets at least annually for possible impairment. Goodwill and indefinite-lived intangible assets are reviewed for possible impairment between annual tests if an event occurs or circumstances change that would more likely than not reduce the fair value of the reporting unit or the indefinite-lived intangible assets below their carrying values.
Goodwill and Intangible Assets	Goodwill and Intangible Assets Goodwill is the excess of purchase price over the fair value of identified net assets of businesses acquired. Intangible assets with indefinite useful lives are measured at their respective fair values as of the acquisition date. Goodwill was $0.9 million at both December 31, 2024 and 2023. Definite-lived intangible assets consist of our customer list associated with the Evoqua Asset Acquisition and license fees related to the technology, intellectual property and marketing rights for Triferic covered under certain issued patents. Definite-lived intangible assets have been capitalized and are being amortized over their useful life.
Income Taxes	Income Taxes Rockwell accounts for income taxes in accordance with the provisions of ASC 740‑10, Income Taxes. A current tax liability or asset is recognized for the estimated taxes payable or refundable on tax returns for the year. Deferred tax liabilities or assets are recognized for the estimated future tax effects of temporary differences between book and tax accounting and operating loss and tax credit carryforwards. A valuation allowance is established for deferred tax assets if the Company determine it to be more likely than not that the deferred tax asset will not be realized. The effects of tax positions are generally recognized in the financial statements consistent with amounts reflected in returns filed, or expected to be filed, with taxing authorities. For tax positions that the Company considers to be uncertain, current and deferred tax liabilities are recognized, or assets derecognized, when it is probable that an income tax liability has been incurred and the amount of the liability is reasonably estimable, or when it is probable that a tax benefit, such as a tax credit or loss carryforward, will be disallowed by a taxing authority. The amount of unrecognized tax benefits related to current tax positions is insignificant. The Company recognizes interest and penalties accrued related to unrecognized tax benefits as income tax expense.
Research and Product Development	Research and Product Development The Company recognizes research and product development expenses as incurred.
Stock-Based Compensation	Stock-Based Compensation Service-Based Stock Unit Awards The Company expenses stock-based compensation to employees and non-employees over the requisite service period based on the grant-date fair value of the awards. The Company estimates the fair value of stock option grants using the Black-Scholes option pricing model, and the assumptions used in calculating the fair value of stock-based awards represent management’s best estimates and involve inherent uncertainties and the application of management’s judgment. For the years ended December 31, 2024 and 2023, the Company recorded stock-based compensation expense on its options granted under the Company’s equity compensation plans to its directors and officers, and its employees (See Note 13). Market and Performance-Based Stock Unit Awards In addition to awards with service-based vesting conditions, the Company has granted performance share units with market and performance conditions, to certain of its executives. The fair value of awards with performance conditions are based on the fair value of the Company’s common stock on the date of grant. The fair value of awards with market conditions are based on a Monte Carlo simulation model. Assumptions and estimates utilized in the calculation of the fair value of the market awards include the risk-free interest rate, dividend yield, average closing price, expected volatility based on the historical volatility of the Company, and the remaining period of the award. The awards with performance conditions vest and result in issuance, at settlement, of common stock for each recipient based upon the recipient’s continued employment with the Company through the settlement date of the award and the Company’s achievement of specified milestones. The requisite service period of the awards with performance conditions is generally 1-2 years. In the case of awards with performance conditions, the Company recognizes stock-based compensation expense based on the grant date fair value of the award when achievement of the underlying performance-based targets become probable. The awards with market conditions vest and result in the issuance of common stock based upon the recipient’s continuing employment with the Company through the settlement date of the award related to the market capitalization criteria. The fair value related to the awards with market conditions is recorded as stock-based compensation expense over the period from date of grant to the settlement date regardless of whether the market capitalization is achieved.
Leases	Leases The Company accounts for its leases under ASC 842, Leases. Under this guidance, arrangements meeting the definition of a lease are classified as operating or finance leases and are recorded on the consolidated balance sheets as both a right-of-use asset and lease liability, calculated by discounting fixed lease payments over the lease term at the rate implicit in the lease or the Company's incremental borrowing rate. Lease liabilities are increased by interest and reduced by payments each period, and the right-of-use assets are amortized over the lease term. For operating leases, interest on the lease liability and the amortization of the right-of-use asset result in straight-line expense over the lease term. Variable lease expenses, if any, are recorded when incurred. In calculating the right-of-use assets and lease liabilities, the Company elected the practical expedient to combine lease and non-lease components. Additionally, the Company excludes short-term leases having initial terms of 12 months or less as an accounting policy election and recognizes rent expense on a straight-line basis over the lease term.
Commitments and Contingencies	Commitments and Contingencies In the normal course of business, the Company may become subject to loss contingencies, such as legal proceedings and claims arising out of its business, including government investigations. An accrual for a loss contingency is recognized when it is probable that an asset had been impaired or a liability had been incurred and the amount of loss can be reasonably estimated. The Company expenses legal costs associated with loss contingencies as they are incurred.
Loss Per Share	Loss Per Share ASC 260, Earnings Per Share, requires dual presentation of basic and diluted earnings per share (“EPS”), with a reconciliation of the numerator and denominator of the basic EPS computation to the numerator and denominator of the diluted EPS computation. Basic EPS excludes dilution. Diluted EPS reflects the potential dilution that could occur if securities or other contracts to issue common stock were exercised or converted into common stock or resulted in the issuance of common stock that are then shared in the earnings of the entity. Basic income (loss) per share (“EPS”) is computed by dividing net loss attributable to common stockholders by the weighted average number of shares of common stock outstanding during the period, excluding the effects of any potentially dilutive securities. Diluted EPS gives effect to the potential dilution that could occur if securities or other contracts to issue common stock were exercised or converted into common stock, using the more dilutive of the two-class method and the if-converted method in the period of earnings. The two-class method is an earnings allocation method that determines income (loss) per share (when there are earnings) for common stock and participating securities. The if-converted method assumes all convertible securities are converted into common stock. Diluted EPS excludes all dilutive potential shares of common stock if their effect is anti-dilutive. The Company’s potentially dilutive securities include stock options, restricted stock awards and units, convertible preferred stock and warrants.
Accumulated Other Comprehensive Income	Accumulated Other Comprehensive Income Accumulated other comprehensive income includes all changes in equity during a period except those that resulted from investments by or distributions to the Company’s stockholders. Accumulated other comprehensive income refers to revenues, expenses, gains and losses that are included in comprehensive income, but excluded from net income as these amounts are recorded directly as an adjustment to stockholders’ equity. Accumulated other comprehensive income consists of unrealized gains and losses on available‑for‑sale investment in debt securities and foreign currency translation adjustments.
Adoption of Recent Accounting Pronouncements and New Accounting Pronouncements	Adoption of Recent Accounting Pronouncements and New Accounting Pronouncements The Company continually assesses any new accounting pronouncements to determine their applicability. When it is determined that a new accounting pronouncement affects the Company’s financial reporting, the Company undertakes a study to determine the consequences of the change to its consolidated financial statements and assures that there are proper controls in place to ascertain that the Company’s consolidated financial statements properly reflect the change. In November 2023, the FASB issued ASU 2023-07, Segment Reporting - Improvements to Reportable Segment Disclosures, which updates reportable segment disclosure requirements, primarily through enhanced disclosures about significant segment expenses and information used to assess segment performance. The Company adopted ASU 2023-07 on January 1, 2024, and the information presented in Note 6 reflects the enhanced disclosures. In December 2023, the FASB issued ASU 2023-09, Improvements to Income Tax Disclosures, which updates income tax disclosures primarily related to the rate reconciliation and income taxes paid information. This ASU also includes certain other amendments to improve the effectiveness of income tax disclosures. The amendments in this ASU are effective for annual periods beginning after December 15, 2024. The Company is in the process of determining the effect this ASU will have on the consolidated financial statements. In November 2024, the FASB issued ASC 2024-03, Income Statement—Reporting Comprehensive Income—Expense Disaggregation Disclosures (Subtopic 220-40): Disaggregation of Income Statement Expenses, which is intended to provide more detailed information about specified categories of expenses (purchases of inventory, employee compensation, depreciation and amortization) included in certain expense captions presented on the consolidated statement of operations. This new standard is effective for fiscal years beginning after December 15, 2026, and interim periods within fiscal years beginning after December 15, 2027. Early adoption is permitted. The amendments may be applied either (1) prospectively to financial statements issued for periods after the effective date of this ASU or (2) retrospectively to all prior periods presented in the consolidated financial statements. The Company is currently assessing the impact this ASU will have on the consolidated financial statements and footnote disclosures.

Summary of Significant Accounting Policies (Policies)

12 Months Ended

Dec. 31, 2024

The accompanying consolidated financial statements have been prepared in accordance with accounting principles generally accepted in the United States of America (“U.S. GAAP”). The consolidated financial statements include the accounts of the Company and its wholly-owned subsidiaries, Rockwell Transportation, Inc. and Rockwell Medical India Private Limited. Rockwell Medical India Private Limited was formed in 2020 for the purpose of conducting certain commercial activities in India. All intercompany balances and transactions have been eliminated in consolidation.

Use of Estimates

The preparation of the consolidated financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that may affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the consolidated financial statements and reported amounts of expenses during the reporting period. Actual results could differ from those estimates. The most significant accounting estimates inherent in the preparation of the financial statements include estimates associated with revenue recognition, impairments of long‑lived assets, and deferred consideration.

Revenue Recognition

The Company recognizes revenue under Accounting Standards Codification (“ASC”) 606, Revenue from Contracts with Customers, issued by the Financial Accounting Standards Board ("FASB"). The core principle of the revenue standard is that a company should recognize revenue to depict the transfer of promised goods or services to customers in an amount that reflects the consideration to which the company expects to be entitled in exchange for those goods or services. The following five steps are applied to achieve that core principle:

•Step 1: Identify the contract with the customer

•Step 2: Identify the performance obligations in the contract

•Step 3: Determine the transaction price

•Step 4: Allocate the transaction price to the performance obligations in the contract

•Step 5: Recognize revenue when the company satisfies a performance obligation

Taxes assessed by a governmental authority that are both imposed on and concurrent with a specific revenue-producing transaction, that are collected by Rockwell from a customer, are excluded from revenue.

Shipping and handling costs associated with outbound freight related to contracts with customers are accounted for as a fulfillment cost and are included in cost of sales when control of the goods transfers to the customer.

Nature of goods and services

The following is a description of principal activities from which the Company generates its revenue. For a discussion of significant market segments and customers, see Note 6.

Product Sales

The Company accounts for individual products and services separately if they are distinct (i.e., if a product or service is separately identifiable from other items and if a customer can benefit from it on its own or with other resources that are readily available to the customer). The consideration, including any discounts, is allocated between separate products and services based on their stand-alone selling prices. The stand-alone selling prices are determined based on the cost plus margin approach.

Drug and dialysis concentrate products are sold directly to dialysis clinics and to wholesale distributors in both domestic and international markets. Distribution and license agreements for which upfront fees are received are evaluated upon execution or modification of the agreement to determine if the agreement creates a separate performance obligation from the underlying product sales. For all existing distribution and license agreements, the distribution and license agreement is not a distinct performance obligation from the product sales. In instances where regulatory approval of the product has not been established and the Company does not have sufficient experience with the foreign regulatory body to conclude that regulatory approval is probable, the revenue for the performance obligation is recognized over the term of the license agreement (over time recognition). Conversely, when regulatory approval already exists or is probable, revenue is recognized at the point in time that control of the product transfers to the customer.

For the majority of the Company’s international customers, the Company recognizes revenue when the customer takes control at the shipping point, which is generally the Company’s plant or warehouse. For other customers, the Company recognizes revenue based on when the customer takes control of the product upon delivery. The amount of revenue recognized is based on the purchase order less returns and adjusted for any rebates, discounts, chargebacks or other amounts paid to customers estimated at the time of sale. Customers typically pay for the product based on customary business practices with payment terms averaging 30 days, while a small subset of customers have payment terms averaging 60 days.

Deferred License Revenue

The Company received upfront fees under five distribution and license agreements that have been deferred as a contract liability and presented on the accompanying consolidated balance sheets as deferred license revenue. The amounts received from Wanbang Biopharmaceuticals Co., Ltd. (“Wanbang”), Sun Pharmaceutical Industries Ltd. ("Sun Pharma"), Jeil Pharmaceutical Co., Ltd. ("Jeil Pharma") and Drogsan Pharmaceuticals ("Drogsan Pharma") are recognized as revenue over the estimated term of the applicable distribution and license agreement as regulatory approval was not received and the Company did not have sufficient experience in China, India, South Korea and Turkey, respectively, to determine that regulatory approval was probable as of the execution of the agreement. The amounts received from Baxter Healthcare Corporation (“Baxter”) were deferred and recognized as revenue at the point in time the estimated product sales under the agreement occurred. During the year ended December 31, 2023, all remaining deferred revenue relating to the distribution and license agreements with Wanbang and Baxters was recognized as revenue. For additional information related to the Company's deferred license revenue, see Note 10.

Product Purchase Agreement

On September 18, 2023, Rockwell and DaVita entered into the Amended Agreement, which amends and restates the Product Purchase Agreement, dated July 1, 2019, as amended, under which the Company supplies DaVita with certain dialysis concentrates. Under the Amended Agreement, the Company and DaVita agreed to an increase in product pricing, effective September 1, 2023 and a one-time payment of $0.4 million to Rockwell on or after December 1, 2023. The term of the Amended Agreement expired on December 31, 2024. Prior to the expiration, the Company received written notice from DaVita, notifying the Company that DaVita intended to extend the term of the Amended Agreement through December 31, 2025 (the "Extension Term"). Product pricing was increased for the Extension Term. However, DaVita subsequently indicated that it will completely transition to another supplier by mid-2025, subject to further discussions between Rockwell and DaVita, which are ongoing and include a potential contract extension and/or future volume commitments by DaVita to Rockwell. There can be no assurances that these discussions will yield a successful outcome for Rockwell.

Cash and Cash Equivalents

The Company considers all highly liquid investments purchased with original maturities of 90 days or less at acquisition to be cash equivalents. Cash and cash equivalents include cash held in banks, money market mutual funds and unrestricted certificates of deposit. The Company’s cash and cash equivalents exceeds the Federal Deposit Insurance Corporation insured limits. The Company has not experienced any credit losses for amounts in excess of insured limits. Currently, the Company does not reasonably believe a significant risk of credit loss exists.

Fair Value Measurement

The Company applies the guidance issued with ASC 820, Fair Value Measurements, which provides guidance on the development and disclosure of fair value measurements. Under this accounting guidance, fair value is defined as an exit price, representing the amount that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date. As such, fair value is a market-based measurement that should be determined based on assumptions that market participants would use in pricing an asset or a liability.

The accounting guidance classifies fair value measurements in one of the following three categories for disclosure purposes:

Level 1: Quoted prices in active markets for identical assets or liabilities.

Level 2: Inputs other than Level 1 prices for similar assets or liabilities that are directly or indirectly observable in the marketplace.

Level 3: Unobservable inputs which are supported by little or no market activity and values determined using pricing models, discounted cash flow methodologies, or similar techniques, as well as instruments for which the determination of fair value requires significant judgment or estimation.

Investments - Available for Sale

Investments – Available for Sale

The Company determines the appropriate classification of its investments in equity and debt securities at the time of purchase and reevaluates such determination at each balance sheet date. Marketable equity securities that are bought principally for the purpose of selling them in the near term are reported at fair value, with unrealized gains and losses recognized in earnings. Marketable debt securities classified as available for sale securities are carried at fair market value, with the unrealized gains and losses, net of tax, included in the determination of comprehensive income (loss) and reported in stockholders’ equity.

The Company may be exposed to credit losses through its available-for-sale debt securities. Unrealized losses or impairments resulting from the amortized cost basis of any available-for-sale debt security exceeding its fair value are evaluated for identification of credit and non-credit related factors. Any difference between the fair value of the debt security and the amortized cost basis not attributable to credit related factors are reported in other comprehensive income. A credit-related impairment is recognized as an allowance on the balance sheet with a corresponding adjustment to earnings. When evaluating the investments for impairment at each reporting period, the Company reviews factors such as the extent of the unrealized loss, current and future economic market conditions and the economic and financial condition of the issuer and any changes thereto.

Realized gains or losses resulting from the sale of these securities are determined based on the specific identification of the securities sold.

Accounts Receivable

Accounts receivable are stated at invoice amounts. The carrying amount of trade accounts receivable is reduced by an allowance for credit losses that reflects our best estimate of accounts that may not be collected. The Company reviews outstanding trade accounts receivable balances and based on its assessment of expected collections, the Company estimates the portion, if any, of the balance that may not be collected based on future forecasts, historical loss information, and current economic conditions. All accounts or portions thereof deemed to be uncollectible are written off to the allowance for credit losses and credit loss expense.

Inventory

Inventory is stated at the lower of cost or net realizable value. Cost is determined on the first‑in first‑out (FIFO) method. Inventory that is not expected to be converted to cash over the next year is classified as non-current. The Company's policy is to reserve for its drug product inventory that it determines is unlikely to be sold to, or if sold, unlikely to be utilized by its customers on or before its expiration date.

Property and Equipment

Property and equipment is recorded at cost and is depreciated using the straight‑line method over the useful lives of the assets, which range from three to ten years. Expenditures for routine maintenance and repairs are expensed as incurred. Leasehold improvements are amortized using the straight‑line method over the shorter of the useful lives or the related lease term.

Impairment of Long-lived Assets and Goodwill

Long-lived assets, such as property and equipment and definite-lived intangible assets, are reviewed for impairment whenever events or changes in circumstances indicate that the carrying amounts may not be recoverable. Impairment losses on long-lived assets are recognized when events or changes in circumstances indicate that the undiscounted cash flows estimated to be generated by such assets are less than their carrying value and, accordingly, all or a portion of such carrying value may not be recoverable.Rockwell reviews goodwill and indefinite-lived intangible assets at least annually for possible impairment. Goodwill and indefinite-lived intangible assets are reviewed for possible impairment between annual tests if an event occurs or circumstances change that would more likely than not reduce the fair value of the reporting unit or the indefinite-lived intangible assets below their carrying values.

Goodwill and Intangible Assets

Goodwill is the excess of purchase price over the fair value of identified net assets of businesses acquired. Intangible assets with indefinite useful lives are measured at their respective fair values as of the acquisition date. Goodwill was $0.9 million at both December 31, 2024 and 2023.

Definite-lived intangible assets consist of our customer list associated with the Evoqua Asset Acquisition and license fees related to the technology, intellectual property and marketing rights for Triferic covered under certain issued patents. Definite-lived intangible assets have been capitalized and are being amortized over their useful life.

Income Taxes

Rockwell accounts for income taxes in accordance with the provisions of ASC 740‑10, Income Taxes. A current tax liability or asset is recognized for the estimated taxes payable or refundable on tax returns for the year. Deferred tax liabilities or assets are recognized for the estimated future tax effects of temporary differences between book and tax accounting and operating loss and tax credit carryforwards. A valuation allowance is established for deferred tax assets if the Company determine it to be more likely than not that the deferred tax asset will not be realized.

The effects of tax positions are generally recognized in the financial statements consistent with amounts reflected in returns filed, or expected to be filed, with taxing authorities. For tax positions that the Company considers to be uncertain, current and deferred tax liabilities are recognized, or assets derecognized, when it is probable that an income tax liability has been incurred and the amount of the liability is reasonably estimable, or when it is probable that a tax benefit, such as a tax credit or loss carryforward, will be disallowed by a taxing authority. The amount of unrecognized tax benefits related to current tax positions is insignificant. The Company recognizes interest and penalties accrued related to unrecognized tax benefits as income tax expense.

Research and Product Development

The Company recognizes research and product development expenses as incurred.

Stock-Based Compensation

Service-Based Stock Unit Awards

The Company expenses stock-based compensation to employees and non-employees over the requisite service period based on the grant-date fair value of the awards. The Company estimates the fair value of stock option grants using the Black-Scholes option pricing model, and the assumptions used in calculating the fair value of stock-based awards represent management’s best estimates and involve inherent uncertainties and the application of management’s judgment. For the years ended December 31, 2024 and 2023, the Company recorded stock-based compensation expense on its options granted under the Company’s equity compensation plans to its directors and officers, and its employees (See Note 13).

Market and Performance-Based Stock Unit Awards

In addition to awards with service-based vesting conditions, the Company has granted performance share units with market and performance conditions, to certain of its executives. The fair value of awards with performance conditions are based on the fair value of the Company’s common stock on the date of grant. The fair value of awards with market conditions are based on a Monte Carlo simulation model. Assumptions and estimates utilized in the calculation of the fair value of the market awards include the risk-free interest rate, dividend yield, average closing price, expected volatility based on the historical volatility of the Company, and the remaining period of the award.

The awards with performance conditions vest and result in issuance, at settlement, of common stock for each recipient based upon the recipient’s continued employment with the Company through the settlement date of the award and the Company’s achievement of specified milestones. The requisite service period of the awards with performance conditions is generally 1-2 years. In the case of awards with performance conditions, the Company recognizes stock-based compensation expense based on the grant date fair value of the award when achievement of the underlying performance-based targets become probable.

The awards with market conditions vest and result in the issuance of common stock based upon the recipient’s continuing employment with the Company through the settlement date of the award related to the market capitalization criteria. The fair value related to the awards with market conditions is recorded as stock-based compensation expense over the period from date of grant to the settlement date regardless of whether the market capitalization is achieved.

Leases

The Company accounts for its leases under ASC 842, Leases. Under this guidance, arrangements meeting the definition of a lease are classified as operating or finance leases and are recorded on the consolidated balance sheets as both a right-of-use asset and lease liability, calculated by discounting fixed lease payments over the lease term at the rate implicit in the lease or the Company's incremental borrowing rate. Lease liabilities are increased by interest and reduced by payments each period, and the right-of-use assets are amortized over the lease term. For operating leases, interest on the lease liability and the amortization of the right-of-use asset result in straight-line expense over the lease term. Variable lease expenses, if any, are recorded when incurred.

In calculating the right-of-use assets and lease liabilities, the Company elected the practical expedient to combine lease and non-lease components. Additionally, the Company excludes short-term leases having initial terms of 12 months or less as an accounting policy election and recognizes rent expense on a straight-line basis over the lease term.

Commitments and Contingencies

In the normal course of business, the Company may become subject to loss contingencies, such as legal proceedings and claims arising out of its business, including government investigations. An accrual for a loss contingency is recognized when it is probable that an asset had been impaired or a liability had been incurred and the amount of loss can be reasonably estimated. The Company expenses legal costs associated with loss contingencies as they are incurred.

Loss Per Share

ASC 260, Earnings Per Share, requires dual presentation of basic and diluted earnings per share (“EPS”), with a reconciliation of the numerator and denominator of the basic EPS computation to the numerator and denominator of the diluted EPS computation. Basic EPS excludes dilution. Diluted EPS reflects the potential dilution that could occur if securities or other contracts to issue common stock were exercised or converted into common stock or resulted in the issuance of common stock that are then shared in the earnings of the entity.

Basic income (loss) per share (“EPS”) is computed by dividing net loss attributable to common stockholders by the weighted average number of shares of common stock outstanding during the period, excluding the effects of any potentially dilutive securities. Diluted EPS gives effect to the potential dilution that could occur if securities or other contracts to issue common stock were exercised or converted into common stock, using the more dilutive of the two-class method and the if-converted method in the period of earnings. The two-class method is an earnings allocation method that determines income (loss) per share (when there are earnings) for common stock and participating securities. The if-converted method assumes all convertible securities are converted into common stock. Diluted EPS excludes all dilutive potential shares of common stock if their effect is anti-dilutive.

The Company’s potentially dilutive securities include stock options, restricted stock awards and units, convertible preferred stock and warrants.

Accumulated Other Comprehensive Income

Accumulated other comprehensive income includes all changes in equity during a period except those that resulted from investments by or distributions to the Company’s stockholders. Accumulated other comprehensive income refers to revenues, expenses, gains and losses that are included in comprehensive income, but excluded from net income as these amounts are recorded directly as an adjustment to stockholders’ equity. Accumulated other comprehensive income consists of unrealized gains and losses on available‑for‑sale investment in debt securities and foreign currency translation adjustments.

Adoption of Recent Accounting Pronouncements and New Accounting Pronouncements

The Company continually assesses any new accounting pronouncements to determine their applicability. When it is determined that a new accounting pronouncement affects the Company’s financial reporting, the Company undertakes a study

to determine the consequences of the change to its consolidated financial statements and assures that there are proper controls in place to ascertain that the Company’s consolidated financial statements properly reflect the change.

In November 2023, the FASB issued ASU 2023-07, Segment Reporting - Improvements to Reportable Segment Disclosures, which updates reportable segment disclosure requirements, primarily through enhanced disclosures about significant segment expenses and information used to assess segment performance. The Company adopted ASU 2023-07 on January 1, 2024, and the information presented in Note 6 reflects the enhanced disclosures.

In December 2023, the FASB issued ASU 2023-09, Improvements to Income Tax Disclosures, which updates income tax disclosures primarily related to the rate reconciliation and income taxes paid information. This ASU also includes certain other amendments to improve the effectiveness of income tax disclosures. The amendments in this ASU are effective for annual periods beginning after December 15, 2024. The Company is in the process of determining the effect this ASU will have on the consolidated financial statements.

In November 2024, the FASB issued ASC 2024-03, Income Statement—Reporting Comprehensive Income—Expense Disaggregation Disclosures (Subtopic 220-40): Disaggregation of Income Statement Expenses, which is intended to provide more detailed information about specified categories of expenses (purchases of inventory, employee compensation, depreciation and amortization) included in certain expense captions presented on the consolidated statement of operations. This new standard is effective for fiscal years beginning after December 15, 2026, and interim periods within fiscal years beginning after December 15, 2027. Early adoption is permitted. The amendments may be applied either (1) prospectively to financial statements issued for periods after the effective date of this ASU or (2) retrospectively to all prior periods presented in the consolidated financial statements. The Company is currently assessing the impact this ASU will have on the consolidated financial statements and footnote disclosures.