there is provided a new thermo - gelling composition made with methylcellulose and citric acid . this composition may also have an effective amount of a treating agent , which may be a medicinal agent , cosmetic agent , moisturizer , adjuvant , nutritional agent , other ingredients and combinations thereof . the composition is useful in delivering moisturizers or pharmaceutically active agents to the user in a controlled release manner through the mucosal tissues in a body cavity , or on body surfaces , or as a subcutaneously injected medicament . the composition may also be used as a replacement for the soft tissues of the body as in , for example , the foot cushion and cartilage repair .