For the six months ended June 30, 2020, cost of sales was $0.7 million and consisted of product costs, royalty expense and certain fixed costs associated with the manufacturing of ANJESO including supply chain and quality costs. Certain product costs of ANJESO units recognized as revenue during the six months ended June 30, 2020 were incurred prior to the FDA approval of ANJESO in February 2020, and therefore are not included in cost of sales during the period. We expect cost of sales to increase as we build new inventory not expensed during the pre-approval period, validate a larger manufacturing suite and deplete our initial inventory levels. No cost of sales were recorded for the six months ended June 30, 2019.
For the six months ended June 30, 2020, research and development expenses were $4.4 million, compared to $16.7 million for the six months ended June 30, 2019, a decrease of $12.3 million. Excluding $2.8 million of costs associated with the strategic restructuring initiative recorded in the six months ended June 30, 2019, our research and development expenses decreased $9.5 million primarily resulting from a decrease in pre-commercialization manufacturing and clinical costs for ANJESO of $6.2 million, a decrease in development costs for other pipeline products of $2.1 million and a decrease in personnel and overhead expenses of $1.2 million as we re-allocated costs related to supply chain, regulatory, quality and medical affairs associated with support of the commercial launch of ANJESO.
For the six months ended June 30, 2020, selling, general and administrative expenses were $19.3 million, compared to $17.3 million for the same prior year period, an increase of $2.0 million. Excluding $4.4 million of costs associated with the strategic restructuring initiative recorded in the six months ended June 30, 2019, our selling, general and administrative expenses increased $6.4 million primarily due to increased selling and marketing expenses in connection with the commercial launch of ANJESO. Selling and marketing expenses of $8.9 million for the six months ended June 30, 2020 increased $3.5 million primarily due to increased personnel costs of $1.9 million and increased commercial costs of $1.6 million. General and administrative expenses of $10.4 million for the six months ended June 30, 2020 increased $2.9 million primarily due to increased personnel costs of $2.4 million, including over half of which was attributed to medical affairs and regulatory support functions which had previously been recorded within research and development expense in the prior year period and increased public company costs of approximately $0.5 million as the prior year costs represent an allocated portion of the costs in the historical combined financial statements prior to our separation from Recro Pharma, Inc.
For the six months ended June 30, 2020, Baudax reported a net loss (including non-cash charges of $51.8 million) of $70.7 million, or $5.11 per share. The non-cash charges of $51.8 million were associated with stock-based compensation, non-cash interest expense, depreciation, amortization, changes in warrant valuations, and changes in fair value of contingent consideration. This compares to a net loss of $14.9 million, or $1.60 per share, for the comparable period in 2019.
About ANJESO®
ANJESO (meloxicam) injection is a proprietary, long-acting, preferential COX-2 inhibitor that possesses analgesic, anti-inflammatory and antipyretic activities, which are believed to be related to the inhibition of cyclooxygenase type 2 pathway (COX-2) and subsequent reduction in prostaglandin biosynthesis. ANJESO was approved by the U.S. Food and Drug Administration in February 2020 for the management of moderate to severe pain, alone or in combination with other non-NSAID analgesics. Because of the delayed onset of analgesia, ANJESO alone is not recommended for use when rapid onset of analgesia is required. The ANJESO product approval was supported by two pivotal Phase III clinical efficacy trials, a large double-blind, placebo-controlled Phase III safety trial and four Phase II clinical efficacy trials, as well as other safety studies. As a non-opioid, Baudax Bio believes ANJESO has the potential to overcome many of