Exposure of patients with myofascial pain syndrome (SDM) to capsaicin: development of topical dosage form with possible analgesic action

• Grant number: 12/16610-0
• Support Opportunities: Regular Research Grants
• Start date: May 01, 2013
• End date: July 31, 2015
• Field of knowledge: Health Sciences - Pharmacy
• Principal Investigator: Guilherme Antonio Moreira de Barros
• Grantee: Guilherme Antonio Moreira de Barros
• Host Institution: Faculdade de Medicina (FMB). Universidade Estadual Paulista (UNESP). Campus de Botucatu. Botucatu , SP, Brazil

Abstract

The myofascial pain syndrome (SDM) is one of the most common causes of musculoskeletal pain. This pain may originate in a single muscle or several muscles may involve generating complex and variable patterns of pain. In this project, as an alternative for the treatment of SDM will use capsaicin. Capsaicin is a natural product obtained from red pepper, and has been used for the relief of pain. The objective of this project will evaluate the potential analgesic action of an analgesic dosage form semi-solid (cream) high concentration of capsaicin in patients with myofascial pain syndrome, in this population and to investigate the possible analgesic and adverse effects related to topic administration of capsaicin applied in patients with SDM, is also measured concentration of capsaicin in the blood plasma of patients undergoing treatment with SDM. In the initial stage of the project will be developed Fc1 formulations (cream base formula) and FC2 (formula + capsaicin cream). The products will be packaged in suitable containers dosage forms for topical or local, will be tested for microbiological and physical-chemical properties for evaluating the quality of the product as recommended by ANVISA, and after will be encoded to obtain better organization in the tests. The study will be developed in the Department of Pain Therapy and Palliative Care Program (TACP), located in the Hospital of the FMB-UNESP, reference to the treatment of pain syndromes. Always in the hospital, patients will be divided into two groups, a total of 40 patients, 20 patients identified by Group PLC will receive the cream base, and another 20 patients identified by CPS Group receive the built capsaicin cream 8%. Will be chosen by the patient PG you most causes discomfort and pain on palpation to be held the topical product. Topicals (cream base cream and incorporated to 8% capsaicin) are applied in amount of 10g per 30 minutes. The administration of creams will be held on topical or local, with complete spreadability in the defined area. Located immediately above the skin surface, corresponding to PG greater pain (diameter of approximately 2 cm), using trained and skilled professional. All personal protective equipment (PPE) will be offered for the security professional. After application, the product will be immediately removed, as well as parameters will be evaluated for toxicity and tolerability of the skin. Prior to application of the creams of the study, patients receive a topical anesthetic (EMLA â) for a period of 50 minutes in the area corresponding to PGs. A pain is measured immediately before and during application of the product, and, after their removed. This will be used as a tool for assessing the verbal numeric scale (0-10) where 0 means no pain and 10 the worst pain imaginable. After removal of the product, the application area is cleaned by a cleaning solution itself, non-ionic and at physiological pH. At the end of the cleaning will be collected from the patients blood samples for measurement of plasma concentration of capsaicin in HPLC and forwarded to the Center for Toxicological Analysis (CEATOX - UNESP). As capsaicin is present in many foods routinely eaten in the form of spice (pepper), will be investigated in clinical protocol the diet of the last 6h of all patients, even those of the PLC group - which will serve as a reference for the group analysis CPS. After a period of two months, patients will return to the TACP and will again be asked about their painful condition. The patient will not be notified of the assigned treatment until the study is completed. It is not envisaged the provision of the drug after completion of the project, for pain related to SDM would not return after complete remission with treatment. If no return of pain, a new clinical assessment and diagnosis should be performed. (AU)

Scientific publications

(References retrieved automatically from Web of Science and SciELO through information on FAPESP grants and their corresponding numbers as mentioned in the publications by the authors)

VALÉRIA ROMERO; JULIANA RODRIGUES LARA; FRANCISCO OTERO-ESPINAR; MANOEL HENRIQUE SALGADO; NORMA SUELI PINHEIRO MODOLO; GUILHERME ANTONIO MOREIRA DE BARROS. Creme tópico de capsaicina (8%) para o tratamento da síndrome da dor miofascial. Revista Brasileira de Anestesiologia, v. 69, n. 5, p. 432-438, 2019-12-20. (12/22294-3, 12/16610-0)