Experimentation on Hibiscus rosa Flower Mucilage as a Potential Nasal Mucoadhesive its Characterization as an In-situ Gel for some Anxiolytics

Abstract

Objective: The objective of the present study was to prepare mucoadhesive in situ nasal gels with mucilage isolated from hibiscus flower (Hibiscus rosa sinensis, family: malveceae) containing alprazolam. Methods-Nasal gels of alprazolam were prepared using three different concentration (0.5%, 1% and 1.5% w/v) of H Rosa mucilage (HRM) and synthetic polymers (Hydroxy propyl methyl cellulose and carbopol 934). In situ gels were prepared with mixture of pluronic F127 and mucoadhesive agent. Result: Evaluation of HRM showed that it was as safe as the synthetic polymer for nasal administration. Evaluation of the prepared gel was carried out, including determination of viscosity, texture profile analysis and mucoadhesive strength. In vitro drug permeation study was conducted with the gels prepared with and without permeation enhancer (0.5% w/v sodium taurocholate) using excised goat nasal mucosa. For the determination of any further histological changes, before and after in vitro permeation study of the gels, with and without the permeation enhancer was also conducted. In vivo experiment conducted in rabbits further confirms that in situ nasal gel prepared with HRM provided better bioavailability of alprazolam than the gels prepared from synthetic mucoadhesive polymer. Conclusion: It was observed that the nasal gel containing 0.5% HRM and 0.5% sodium taurocholate exhibited appropriate rheological, mechanical and mucoadhesive properties and showed better drug release profile. More over this formulation produced no damage to the nasal mucosa used for the permeation study, and absolute bioavailability was also higher compare to gels prepared from synthetic polymers.

Hibiscus Rosa-Sinensis Mucilage as a Functional Polymer in Pharmaceutical Applications: A Review

“…The pH of HRS mucilage is generally 6.2, which is nearly neutral [17,18,20] and therefore will not irritate the mucosal membranes of the body. Drug-excipient compatibility studies have shown no significant interactions [6,[21][22][23], indicating that HRS mucilage can be used for a wide range of drugs.…”

“…Roy et al [23] developed an in-situ nasal gel from HRS mucilage, using alprazolam as a model drug. In comparison to carbopol and hydroxypropyl methylcellulose (HPMC), HRS mucilage demonstrated superior bioadhesion to the nasal membrane due to its moderate swelling.…”

“…Tyagi et al [45] and Roy et al [23] demonstrated the feasibility of using HRS mucilage for nasal gel mucoadhesive drug delivery. HRS mucilage exhibited better mucoadhesive qualities than HPMC and carbopol 934, which are two synthetic polymers commonly used in the preparation of nasal gels (table 3) [23]. In addition, the rheological and mechanical properties of HRS mucilage were superior to those of synthetic polymers.…”

“…Moreover, as HRS mucilage is a natural polymer, it does not cause unfavourable reactions in the nasal mucosa. The bioavailability of the drug was also enhanced with HRS mucilage compared to HPMC and carbopol 934 gels [23]. The permeation of drugs into the systemic circulation is largely restricted by skin layers, namely the epidermis (non-viable and viable), dermis (viable), and subcutaneous fat tissues, with the stratum corneum located at the epidermis's outermost layer serving as a significant barrier.…”