Safety and Efficacy of SP-103 in Subjects With Moderate to Severe Acute Lower Back Pain

Inclusion Criteria: * Able and willing to read, write, and understand the informed consent prior to beginning any study procedures. * Male or female, age 18 to 75 years (inclusive). * Based on medical history, current episode of lower back pain (LBP) must have been present for not more than 3 months. * Currently experiencing localized area of muscular tenderness in lower back area between the lowest rib and the gluteal fold in moderate-to-severe intensity as evaluated by the investigator. * If deemed necessary by the Investigator, has a willing partner (facilitator) that can apply study drug to the designated anatomical area. * Intact skin at the site of pain with no skin breakdown or inflammation. * Negative urine drug screen. * Average LBP numeric pain rating scale (NPRS) score of sufficient severity over the last 24 hours. * Sufficiently compliant with electronic Diary entries. * If a woman of childbearing potential (WOCBP) agrees to use an effective method of birth control during the study. * If a WOCBP (i.e., not surgically sterile or at least 2 years postmenopausal), must have negative pregnancy tests. * Have the means and willing to conduct a video-based televisits. * Reviewed all study specific educational materials and has, in the opinion of the Investigator, the cognitive abilities to understand and appropriately complete all study mandated procedures. Exclusion Criteria: * A body mass index (BMI) ≥40 kg/m2 * Significant pain unrelated to LBP which, in the Invest…