Preparation of ion-activated in situ gel systems of scopolamine hydrobromide and evaluation of its antimotion sickness efficacy

Abstract

Aim: To develop a novel, in situ gel system for nasal delivery of scopolamine hydrobromide (SCOP) and study its efficacy on motion sickness. Methods: SCOP in situ gels at 0.2%, 0.5%, and 1.0% gellan gum concentration (w/v) were prepared, respectively, and characterized in terms of viscosity, in vitro release, and nasal ciliotoxicity. Single photon emission computing tomography technique was used to evaluate the nasal residence time of gel containing 99mTc tracer. The antimotion sickness efficacy produced by the in situ gel formulation was investigated in rats and compared with those achieved after subcutaneous and oral administration. Results: The viscosity of the gellan gum formulations either in solution or in gel increased with increasing concentrations of gellan gum. Its release in vitro was moderate in artificial nasal fluid. The micrographic results showed that in situ gels were safe, without nasal ciliotoxicity. In comparison with phosphate buffer saline, a prolonged radioactivity of 99mTc in the rabbit nasal cavity was observed after administration of the gellan gum formulation. Intranasal SCOP in situ gel at a dose of 100 μg/kg decreased symptoms of motion sickness significantly in comparison with subcutaneous and oral administration (P<0.01). Conclusion: SCOP nasal in situ gel is a safe and promising therapeutic alternative to existing medications for motion sickness.

Effect of Posture on Regional Deposition of Coarse Particles in the Healthy Human Lung

“…In animal models, scopolamine gel applied locally slows the nasal cilia beating rate. (31) If the observation were generalizable to humans, one could expect a slower clearance rate for the seated posture induced by scopolamine intake. However, scopolamine's pharmacokinetic half-life (reported values for oral administration vary between 3 h 10 min to 5 h) (32,33) results in no detectable drug level after 12 h in humans, (32) therefore leaving clearance rates at 22 h post exposure largely unaffected.…”

In situ gel of metoprolol tartrate: Physicochemical characterization, In vitro diffusion and histological studies

“…Jian et al . [6], studied the intranasal in situ gel system of scopolamine hydrobromide for antimotion sickness. The symptom of motion sickness was significantly decreased from intranasal in situ gel system in comparison with subcutaneous and oral administration of scopolamine hydrobromide ( P <0.01).…”

Introduction

“…In order to demonstrate that high molecular weight substances are capable of crossing the nasal mucosa, gellan gel formation upon contact with the nasal mucosa was investigated for an evaluation of the increased and prolonged uptake of 3000 Da fluorescein dextran in comparison with a mannitol solution [52]. Using different concentrations of gellan, Cao et al [12] prepared an ion-activated in situ gel system loaded with scopolamine HBr, and the antimotion sickness efficacy was investigated in rats and compared with subcutaneous and oral administrations of the same drug. The results obtained indicated that the new formulation was more effective than the references without nasal citotoxicity.…”