DEVELOPMENT AND EVALUATION OF BIGELS CONTAINING NAPROXEN SODIUM FOR TOPICAL ADMINISTRATION

The aim of this study was the development of three bigel formulations with naproxen sodium as a pharmaceutical ingredient (BG1N, BG2N, BG3N) and the evaluation of their pharmacotechnical properties compared to those of three blank bigels (BG1, BG2, BG3). The proposed bigels were evaluated in terms of appearance, pH, consistency, spreadability, rheology, bioadhesivity and stability while the samples were centrifugated. Two yellow bigels (BG1, BG1N) were obtained while the other four were coloured in white (BG2, BG3, BG2N and BG3N). The pH of the developed bigels ranged in the admitted values mentioned by the in-force Ph. Eur. 11 (ranged between 4.5 and 5.5) decreasing the irritation risk. In comparison with the blank samples, after 5 months from the preparation, in the case of BG2N, the sample consistency decreased significantly (p < 0.05). The evaluation of the spreadability after 5 months indicated that for BG1, the spreadability capacity decreased by 56%, whilst for the other bigels the changes were minor. All the bigels presented a plastic behaviour. In the case of blank bigels, the adhesivity decreased in the following order BG3 < BG2 < BG1, emphasizing that the Carbopol<(R)>940 bigels present a better adhesivity in comparison with sodium alginate bigels. The bigels BG1 and BG1N maintained a homogenous aspect after centrifugation, on the other hand, for BG2/BG2N and BG3/BG3N a visible separation of the two phases bigels was noticed. In conclusion, naproxen sodium bigels can represent an efficient alternative treatment for patients with inflammatory articular diseases. In addition, compared to the oral route, the cutaneous administration represents a route by which the side effects of the active substance can be avoided, so the developed formulations are proposed for future in vitro/in vivo release studies.