STP PHARMA SCIENCES, vol.9, no.3, pp.249-252, 1999 (SCI-Expanded)
The effect of two types of absorption enhancers, i.e, dimethyl-beta-cyclodextrin and sodium taurocholate, on nasal absorption of salmon calcitonin was studied in rabbits. The gel formulations were prepared using polyacrylic acid (Carbopol941). Dimethyl-beta-cyclodextrin (5%) and sodium taurocholate (1%) were incorporated into a gel formulation containing salmon calcitonin (400 IU/ml). We compared the nasal absorption of salmon calcitonin gel formulations, which included absorption enhancers, with a formulations without enhancer and with a commercial intravenous product and a commercial nasal spray. The plasma calcitonin levels were measured by radioimmunoassay. To evaluate nasal absorption of salmon calcitonin, we estimated t(max), Delta C-max, AUC and absolute bioavailability (F%). The highest calcitonin level was obtained with the commercial intravenous product. The results showed that dimethyl-beta-cyclodextrin and sodium taurocholate had markedly increased the nasal absorption of salmon calcitonin. The absolute bioavailability of salmon calcitonin was found to be 12.9 and 11.2% for the salmon calcitonin formulation without absorption enhancer and the commercial nasal spray, respectively. On the other hand the bioavailabilities of salmon calcitonin were calculated as 33.9 and 42.4% for the salmon calcitonin/dimethyl-beta-cyclodextrin and salmon calcitonin/sodium taurocholate formulations, respectively.