1. Participant is < 21 years of age 2. Parent/ Legal Guardian/ Adult Participant can understand the consent process and is willing to provide informed consent/HIPAA: 3. (a) Participant is receiving one or more of the study drugs of interest at the time of enrollment or (b) Participant is NOT receiving one or more of the study drugs of interest but is SARS-COV-2 positive within 60 days prior to enrollment 1. Participant has a known pregnancy Below exclusion criteria apply only to: Participants receiving one or more of the study drugs of interest at the time of enrollment, DOI administration or PK sampling: (Refer to DOI specific appendices for details on enrollment cohort specifications and additional eligibility criteria) 2. Has had intermittent dialysis within previous 24 hours 3. Has had a kidney transplant within previous 30 days 4. Has had a liver transplant within previous 1 year 5. Has had a stem cell transplant within previous 1 year 6. Has had therapeutic hypothermia within previous 24 hours 7. Has had plasmapheresis within the previous 24 hours 8. Has a Ventricular Assist Device 9. Has any condition which would make the participant, in the opinion of the investigator, unsuitable for the study

1. Able to provide informed consent. Legally Authorized Representatives (LARs) will not be permitted. 2. 18 years of age and older 3. Diagnosis of diabetes mellitus 4. Meets the Toronto Criteria for probable clinical sensorimotor polyneuropathy, with PDPN symptoms present for at least six months. This is defined as a combination of symptoms and signs with any two or more of the following (must be present bilaterally in the distal lower extremities): neuropathic symptoms, decreased distal sensation, or unequivocally decreased (or absent) ankle reflexes. Specifically: a. The presence of any neuropathic symptoms on either the "Douleur Neuropathique en 4 Questions" (DN4) or the EPPIC-Net Neuropathy Exam will suffice to demonstrate "neuropathic symptoms." b. Decreased distal sensation is satisfied by any of the following: i. "Yes" is checked at least once under Question 3 of the DN4 which queries hypoesthesia to touch and pinprick. ii. At least one score of "reduced" or "absent" on the right AND at least one score of "reduced" or "absent" on the left in any of the following items from the EPPIC-Net Neuropathy Exam:
• Pin sensation in segments 1 or 2 (i.e. the toes and feet)
• Vibration at the great toe
• Joint position at the great toe
• Light touch/touch pressure at the great toe
• Temperature at the great toe
• Monofilament at the great toe c. Decreased or absent ankle reflexes is satisfied by a score of "reduced" or "absent" on the right AND left in the "Ankle reflex" item in the EPPIC-Net Neuropathy Exam. 5. A score of at least 4 on the "Douleur Neuropathique en 4 Questions" (DN4). 6. Pain reporting during a pre-defined 7-day screening period meets study criteria (to be established using a centrally-administered screening algorithm) which may account for mean pain intensity reported, variability in reported values, and adherence in reporting. 7. Patient reported daily 11-point NRS (for average and worst pain over the last 24 hours) is completed on at least 5 out of the 7 days in the baseline period. 8. Participants must be willing and able to comply with scheduled visits, the treatment schedule, laboratory testing, and other requirements of the study (e.g., completion of app-based daily reporting). 9. Females may be included if they meet at least one of the following criteria (note that individual ISAs may specify more stringent measures to prevent pregnancy): a. Are not of childbearing potential, defined as one or more of the following: i. Post-menopausal for at least 1 year ii. Surgically sterile (bilateral tubal ligation, bilateral oophorectomy, or hysterectomy) iii. XY genotype iv. Turner syndrome v. Uterine agenesis. b. Are completely abstinent from sexual activity capable of resulting in pregnancy (as part of their preferred and usual lifestyle). This will include females whose sole sexual partner is a male who has undergone surgical sterilization or vasectomy. c. Women of childbearing potential will agree to practice an effective form of two types of birth control, which are defined as those, alone or in combination, that result in a low failure rate (i.e., less than 1% per year) when used consistently and correctly. This must be done before, throughout, and for 30 days after the last dose of study drug. Acceptable methods are: i. Hormonal methods such as the vaginal ring, or oral, implantable, injectable, or transdermal contraceptives for a minimum of 1 full cycle (based on the participant's usual menstrual cycle period) before study drug administration. ii. Intrauterine device. iii. Barrier method of contraception: condoms with or without a spermicidal agent, diaphragm or cervical cap with spermicide 10. Specific requirements of male participants (regarding contraception) will be defined in the ISAs based on the potential toxicity profile of the asset. 3.1.1. Neuropathy Confound Exclusion Criteria 1. Peripheral neuropathy caused by a condition other than diabetes (e.g. HIV, cancer/chemotherapy-induced, other medication-induced, alcohol-induced, hereditary, autoimmune neuropathies, uncontrolled or untreated hypothyroidism). Note that participants will not be tested for HIV, this will be established by patient report or review of the medical record. 2. Other significant pain conditions involving the same area as the neuropathy (e.g. physical deformity of the feet, plantar fasciitis, lumbosacral radiculopathy with distal lower extremity pain, fibromyalgia involving the lower limbs, Morton's neuroma). 3. Other pain conditions not involving the same area as the neuropathy which (in the opinion of the investigator) interfere with the participant's ability to rate the neuropathy pain. 4. Any amputation of the lower limb which interferes with the participant's ability to rate the neuropathy pain. If there is any amputation please contact the MM. 5. The presence of any current foot ulcer. 6. Significant peripheral vascular disease defined as symptoms consistent with intermittent claudication. 3.1.2. Medication/Treatment Exclusion Criteria 7. Use of other investigational drugs within 3 months before screening and throughout the study. 8. Known or suspected hypersensitivity to all of the assets (active component and excipients) currently being tested in the Platform Protocol. 9. Undergone neurolytic or neurosurgical therapy or used an implanted neurostimulating device for neuropathic pain in the distal lower limbs within 3 months of screening. 10. Use of the high dose capsaicin patch (8%) in the 6 months before screening and throughout the study (for the treatment of PDPN). Use of the capsaicin patch in a manner that is not expected to interfere with the measurement of PDPN severity is allowed. 11. Participants who receive and are unwilling to discontinue episodic or periodic treatments for pain in the distal legs and/or feet (e.g., injections of local anesthetics) will be excluded. Non-pharmacological pain treatment (e.g. relaxation/hypnosis, physical or occupational therapy, any exercise-based therapy, any talk-based therapy, acupuncture, TENS) for the treatment of conditions other than PDPN is allowed. If the treatment is for PDPN it is allowed if it has been stable for at least 4 weeks prior to screening and is expected to remain stable throughout the study. 12. Active use of opioids or marijuana for any reason at screening and unwilling or unable to discontinue use. 3.1.3. Medical Exclusion Criteria 13. Clinically significant ECG or laboratory abnormalities at the Screening Visit that would put the participant at undue risk or affect the ability of the participant to participate in the trial (in the opinion of the investigator). Screening ECG and lab results may be repeated without requiring a rescreen, as long as the participant is still within the screening window. 14. Participants whose glycemic control has been unstable within 3 months before screening (e.g. ketoacidosis requiring hospitalization, any recent episode of hypoglycemia requiring assistance through medical intervention). 15. Proliferative retinopathy or maculopathy requiring acute treatment. 16. Requiring dialysis. 17. Myocardial infarction or stroke in the past 6 months. 18. Known diagnosis of moderate to severe hepatic impairment (equivalent to Child-Pugh class B or C) OR aspartate aminotransferase or alanine aminotransferase ≥ 3 times the upper limit of normal. 19. A clinically significant illness or operative procedure within 4 weeks of screening. 20. Clinically significant surgery planned during the study period. If a surgery is planned, please contact the MM. 21. History of or currently active malignancy or other medical condition that would put the participant at undue risk or affect the ability of the participant to participate in the trial (in the opinion of the investigator). 22. Pregnant or nursing (lactating) women. 3.1.4. Psychosocial and Substance Use Disorders Exclusion Criteria 23. A clinically significant psychiatric disease that would put the participant at undue risk or affect the ability of the participant to participate in the trial (in the opinion of the investigator). 24. Alcohol use disorder or other substance use disorders (other than nicotine or caffeine) in accordance with DSM-5 criteria within 12 months of screening. 25. Positive urine drug tests defined as follows: 1. Two positive urine drug tests for prescription opioids or marijuana, prior to the initiation of investigational product (IP); or 2. One positive urine drug test for any illegal drugs (other than marijuana) prior to the initiation of IP. 26. Vulnerable persons defined as either of the following: 1. Individuals whose willingness to volunteer in a clinical study may be unduly influenced by the expectation, whether justified or not, of benefits associated with participation or of a retaliatory response from senior members of a hierarchy in case of refusal to participate. 2. Individuals whose judgment has been impaired by their physical, mental, or socio-economical condition and those incapable of giving informed consent.

• Ability to understand and the willingness to sign a written informed consent document
• Patients undergoing exploratory laparotomy via midline vertical skin incision for gynecologic indications at UW Hospital and Clinics
• Patients must be >18 years old
• English speaking (able to provide consent and complete questionnaires)
• Patients must have the ability to understand visual and verbal pain scales
• Patients must be eligible for TAP block placement. This will be confirmed during preoperative visit with the primary surgeon. Patient's are not eligible if they have allergies to the anesthetic medications or have had prior abdominal reconstructive surgery that would alter their abdominal wall anatomy in a way where the block would not be expected to be effective.
• Known allergy to local anesthetics.
• Known history of chronic pain disorders and/or chronic opioid use defined as greater than 10mg of PO morphine or equivalent used daily for at least 30 days prior to enrollment.
• Patient has a history of opioid dependence requiring rehabilitation or the use of opioid antagonists.
• Patients with a planned exploration with biopsies (no organs removed) will be excluded from the study.
• Individuals who are pregnant, lactating or planning on becoming pregnant during the study.
• Significant liver disease that would inhibit prescription of opioids.
• Significant kidney disease that would inhibit administration of gabapentin.
• Not suitable for study participation due to other reasons at the discretion of the investigators.