RESUMO
Ondansetron HCl is a (5-HT3) serotonin receptor antagonist, used as anti-emetic drug in combination with anticancer agents. Conventional dosage forms have poor bioavailability and patient compliance. These problems can be reduced by the use of nasal niosomal thermo-reversible in situ gelling system. Niosomes were formulated using various surfactants (Span 60, Span 80, Tween 20, and Tween 80) in different ratios using the thin-film hydration technique. Niosomes were evaluated for particle size, zeta potential, transmission electron microscopy (TEM) imaging, drug entrapment efficiency, and in vitro drug release. Niosomes prepared using Span 60 and cholesterol in the ratio 1:1 (F5) showed higher entrapment efficiency (76.13 ± 1.2%) and in vitro drug release (91.76%) after 12 h was optimized. The optimized niosomes were developed into thermo-reversible in situ gel, composed of Poloxamer 407 and sodium carboxymethyl cellulose, prepared by cold method technique. Compatibility study (FTIR, DSC) was made for drugs and excipients that showed no significant interaction. The gel formulation G5 showed the most suitable gelation temperature (31 °C), viscosity (1250 mpoise), bioadhesion force (5860 ± 28 dyne/cm2), and in vitro drug release (70.6%) after 12 h. Comparative in vivo pharmacokinetic study on rabbits showed a sustained release and higher relative bioavailability of the prepared nasal in situ gel compared to similar dose of oral tablets (202.4%) which make ondansetron HCl niosomal nasal thermo-sensitive in situ gel a more convenient dosage form for the administration of ondansetron HCl than oral tablets.
