Preparation of a Paeonol-Containing Temperature-Sensitive In Situ Gel and Its Preliminary Efficacy on Allergic Rhinitis

Abstract

In this paper, the optimal composition of a paeonol temperature-sensitive in situ gel composed of poloxamer 407 (P407) was determined, and a preliminary study of its effect on allergic rhinitis was performed. The optimal composition of the paeonol temperature-sensitive in situ gel included 2% paeonol inclusion, 22% P407, 2% poloxamer 188 (P188) and 2% PEG6000, as assessed by thermodynamic and rheological studies. The toad palate model was employed to study the toxicity of the paeonol temperature-sensitive in situ gel on the nasal mucosa. The result of this experiment showed low toxicity to cilia, which allows the gel to be used for nasal administration. The Franz diffusion cell method was used to study the in vitro release of paeonol and suggested that the in vitro release was in line with the Higuchi equation. This result suggests that the paeonol could be absorbed into the body through mucous membranes and had some characteristics of a sustained effect. Finally, the guinea pig model of ovalbumin sensitized allergic rhinitis was used to evaluate the preliminary efficacy of the gel, with the paeonol temperature-sensitive in situ gel showing a significant effect on the guinea pig model of sensitized allergic rhinitis (AR).

Research progress in the application of in situ hydrogel system in tumor treatment

“…Based on the problems mentioned above, the in situ hydrogel drug delivery system has attracted attention from more and more researchers in recent years. Being made of polymer materials with solution, suspension or semi-solid state, the in-situ hydrogel system can undergo phase change at the site of administration immediately after administration, making the solution or suspension transformed into a semisolid or solid state (Chu et al, 2013;Morsi et al, 2016). Due to its liquid nature, it is easy to apply to drug absorption sites and convenient to deliver drugs to wanted sites of patients after the formulation is formed (Paulsamy et al, 2018).…”

Cyclodextrin Derivative Enhances the Ophthalmic Delivery of Poorly Soluble Azithromycin

“…cellulose acetate hydrogen phthalate latex), ii) temperature dependent (e.g. pluronics and tetronics), and iii) ion activation (i.e., gelrite) [7] for gel formation. In fact, another group had prepared in situ gel for ophthalmic preparation containing ciprofloxacin hydrochloride that was successfully formulated as in situ gel-forming eye drops with the help of sodium alginate and hydroxypropyl methylcellulose (HPMC) [8].…”

Intranasal distribution and clearance of thermoreversible gel in an animal model

“…Nasal drug delivery systems have been researched for use in systemic and topical drug delivery because of the relatively high permeability of the nasal mucosa and the avoidance of first‐pass metabolism . Also, on a large surface area, the permeable and vascularized nasal mucosa facilitate drug absorption and rapid onset of therapeutic action .…”

“…However, most of the commercially available nasal formulations, such as aqueous pump sprays and nasal drops, are usually rapidly cleared from the nasal cavity by mucociliary action. The capacity of the nasal cavity is about 0.2 mL per nostril and the half‐life of clearance for both liquid and powder formulations is only about 15 to 30 minutes . Thus, conventional liquid nasal formulas have only a limited time for drug absorption, which results in poor nasal bioavailability …”

“…It can easily be instilled as liquid into the nasal cavity at room temperature, and it prolongs the drug contact time and releases the drug in a controlled manner as a gel state at above the phase inversion temperature. Besides, P407 has low toxicity, excellent water solubility, and compatibility with most of the proposed formulative excipients . A number of studies in the literature have examined the pharmacokinetic properties of P407 as an intranasal drug delivery system .…”