As a result, we are widening our guidance ranges. With those key updates, let’s now turn to the numbers. As indicated on slides 10 and 11, highlights in the third quarter include; total revenues of $271 million, primarily driven by NARCAN momentum from the U.S. public interest market, the retail market in Canada and the launch of NARCAN OTC and adjusted EBITDA of $20 million. Diving deeper into the quarterly revenues, important items include; Anthrax MCM sales of $33 million, including deliveries of BioThrax and CYFENDUS to the U.S. Government’s Strategic National Stockpile. NARCAN sales of $142 million, demonstrating the continued strength and durability of this product driven by consistent demand from the U.S. public interest channel and the growing market in Canada.
Revenue in the quarter also includes initial contributions from the launch of NARCAN OTC into retail channels. Smallpox MCM sales were $25 million, other product sales were $50 million, including solid BAT sales and combined CDMO service and lease revenues of $14 million reflects our continued transition to focus on existing customers. Turning to operating expenses. Cost of product sales in the quarter was $133 million, driven by sales of NARCAN, Anthrax and BAT. Cost of CDMO of $44 million reflects reduced production across the CDMO network and the actions taken on August 8th to reduce expenses, offset by investments in quality improvement initiatives at the Camden site. R&D expense was $15 million and SG&A expense was $86 million, including expenses supporting key NARCAN initiatives.
We also incurred a $218 million non-cash goodwill impairment charge in the quarter related to medical countermeasures. The impairment was primarily a result of higher interest rates and our lower market capitalization. Overall, we continue to see long-term value in this area of the business. With that, let’s move to slide 12 and review segment performance during the quarter. In the products segment, revenues were $250 million, driven by NARCAN, Anthrax and BAT and adjusted gross margin was $121 million or 49%. As for the services segment, revenues were $14 million and adjusted gross margin was negative $22 million. Moving on to slide 13, I will touch on select balance sheet and cash flow highlights. We ended the third quarter with $88 million in cash and $176 million of total liquidity, including availability under our revolving credit facility.
Total liquidity increased $40 million and cash was roughly flat versus the second quarter of 2023. This reflects the collection of accounts receivable, offset by debt repayments made in connection with the requirements of the May 2023 amendment to our senior secured credit facility. Operating cash flow was positive in the quarter and capital expenditures in the period were $13 million, and as of September 30, 2023, our net debt position was $779 million. I will now recap some of the progress we have made on our capital structure this year. Throughout 2023, we have taken significant steps to strengthen our financial position and derisk the business. We have executed the travel health divestiture, implemented actions to save over $160 million of annualized operating expense and announced a strategic shift to deemphasize our CDMO business as a source of growth.
We also amended and extended the maturity of our secured credit facility to May 2025. At the same time, we have achieved positive milestones in our core products business, including the receipt of about $250 million of U.S. Government orders for ACAM, VIG and BAT, the FDA approvals of CYFENDUS and NARCAN OTC, new long-term contracts for RSDL and Ebanga, and the ongoing growth of NARCAN. In short, our core business operations are fundamentally sound and healthy. Over the near- to medium-term, we will maintain our focus on optimizing our platform to further strengthen our business and credit profile and we are confident that our access to capital will improve as a result. We will keep you informed as we make progress on this journey. Turning to guidance, please see slide 14.
As announced in our press release this evening, we are updating our guidance for full year 2023 as follows; total revenues of $1 billion to $1.1 billion, consistent with prior guidance as the ongoing strength of NARCAN is offset by potential funding timing related to the remaining 2023 procurement of the FDA-approved CYFENDUS product. We are forecasting Anthrax MCM sales of $145 million to $250 million, a wider range than our prior guidance given the timing uncertainty we just discussed related to the remaining 2023 CYFENDUS procurement. While our conversations to-date are aligned to funding before the end of the quarter with deliveries by year-end, we are unable to have absolute confidence in this timing given the status of the U.S. Government’s continuing resolution.
