Acute rheumatoid arthritis (RAA) is an acute inflammatory disease caused by a pharyngeal-tonsillar infection induced by the group "A" hemolytic beta streptococcus that can affect: joints, heart, central nervous system, etc. The incidence of RAA is from 0.1 to 2% of the population, being higher in third world countries (3%) annually. RAA is a childhood disease, over 90% of cases occur between 5 and 15 years of age. In addition to antibiotics, the treatment includes the use of salicylates for a long period, up to 6 weeks. In order to avoid adverse effects on the stomach, the use of rectal suppositories with sodium salicylate represents an alternative. Suppositories were prepared by two methods: hand rolling with the use of cocoa butter and by casting method with semisynthetic glycerides. The dosing was performed photocolorimetrically based on the color reaction with iron chloride, at wave length 525 nm, with sodium salicylate calibration curve (R2=0.998, y+0,031/0,0015). All reagents were chemically pure. Sodium salicylate is a hydrophilic substance (log P -1.43), of acidic nature (pka 2.79), which meets Lipinski's “rule of 5”, therefore after rectal administration paracellular absorption of it shall occur. For the study of the availability of sodium salicylate from semisolid formulations, Erweka dissolution tester, paddle method, in medium of purified water, was used. Suppositories of 2,0 g were formulated on cocoa butter and semi-synthetic glycerides, with and without dispersion of sodium salicylate in 1% gel of sodium alginate. The results of sampling at 45 minutes, showed a good release and dissolution of the active pharmaceutical ingredient (API) from cocoa butter suppositories, followed by those with API dispersed in 1% polymer gel and cocoa butter. For the semisynthetic glycerides, the dispersion method did not statistically influence the dissolution % of the API. The benefits of taking substances rectal are high but must be well correlated with the physicochemical properties of the sodium salicylate, with qualities and quantities of excipients, addition of adjuvants (in our case sodium alginate has the role to improve the API transfer capacity through rectal membranes) and with preparation technology.