Evaluation of analgesic effect of Meloxicam liquisolid system in rat and it's comparison with conventional formulation

Abstract

Introduction: Meloxicam is a weakly water-soluble analgesic and anti-inflammatory drug. There are several methods that increase solubility of weakly soluble substances. Among them, the method of liquisolid compacts is a promising method that increases dissolution rate of weakly water-soluble drugs. The purpose of this study was the use of liquisolid method in increasing dissolution rate of Meloxicam for improvement of analgesic effects. Materials and Methods: This study was performed on seven groups of six male rats. Physical mixture powder and prepared liquisolid formulation from the drug in doses of 1, 2 and 4 mg/kg of rat weight were given to the animal orally. One hour later, pain was induced by subcutaneous injection of 75 μl of 2.5% (v/v) formalin solution into the hind paw of the rats. The licking time of the injected foot was measured and recorded between 0 to 5 minutes (acute phase) and 15 to 30 minutes (chronic phase) after injection. Results: In acute and chronic phase, more analgesic effect of liquisolid formulation of Meloxicam was observed than the physical mixture powder. The liquisolid formulation of Meloxicam induced greater analgesic effect during acute and chronic phases of formalin test when compared with physical mixture powder (P <0.005). In the dissolution test, by comparing the dissolution of Meloxicam between liquisolid formulation and physical mixture, a statistically significant difference was observed between the two formulations (P <0.001). So the dissolution rate of liquisolid formulation was higher than the powder of physical mixture. Therefore, the liquisolid formulation of Meloxicam has better analgesic effects than the physical mixture due to its higher dissolution, which indicates the high bioavailability of the drug from this formulation. Conclusion: It can be concluded that liquisolid method could be used for increasing analgesic effect of Meloxicam as a weakly water-soluble drug.