An alternative to oral administration for the delivery of therapeutic substances is the topical route, which frequently has comparable efficacy but may have a better tolerability profile. Gamma scintigraphy is a noninvasive technique that involves the application of radioactive substances to conduct biodistribution studies of therapeutic substances delivered through various routes. Nimesulide (NSD) was radiolabeled with technetium pertechnetate (Technetium99m [99mTc]) and this radiolabeled drug complex (99mTc-NSD) was used to prepare a topical gel formulation. The permeation of the radiolabeled drug from the topical gel was determined by gamma scintigraphy on human volunteers. The region of interest was calculated for the quantification of permeated radiolabeled drugs. This was observed that the mean percentage permeation of 99mTc-NSD was found to be 0.32 ± 0.22 to 36.37 ± 2.86 at 5 and 240 min. It was demonstrated that gamma scintigraphy may be a noninvasive and reliable technique for the determination of drug permeation through topical routes.
* Title and MeSH Headings from MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.