Optimization of the Micellar-Based In Situ Gelling Systems Posaconazole with Quality by Design (QbD) Approach and Characterization by In Vitro Studies

Development of lacosamide-loaded in-situ gels through experimental design for evaluation of ocular irritation in vitro and in vivo

Lacosamide (LCM) selectively increases the slow inactivation of voltage-gated sodium channels (VGSCs) and is a N-methyl d-aspartate acid (NMDA) receptor glycine site antagonist. Therefore, it can be used in dryness-related hyperexcitability of corneal cold receptor nerve terminals. Ocular in-situ gels remain in liquid form until they reach the target site, where they undergo a sol-gel transformation in response to specific stimuli. They can show mucoadhesive properties related to the polymer used and increase the residence time of the drug in the mucosa. In the presented study, ocular in-situ gel formulation of LCM, which has potential for use in ocular diseases and consists of hyaluronic acid and poloxamer 407 as polymers, was developed using cold method. The effect of formulation components on target product properties (pH, gelation temperature and viscosity) was evaluated by design of experiments (DoE) design. The optimized LCM-loaded in-situ gel had a pH value of 6.90 ± 0.01, showed pseudo-plastic flow with a viscosity of 562 ± 58 cP at 25 °C, gelled at 33 ± 0.47 °C, and released drugs via the Peppas-Sahlin mechanism. Ocular safety was confirmed via in vitro tests using two different cell lines (L929 and Arpe-19), along with in vivo Draize tests, histological examinations, and Hen's Egg Chario-Allontioc-Membrane (HET-CAM) analysis. In vitro studies confirmed the optimized LCM-loaded in-situ gel's suitability for ocular use, demonstrating long-acting effects through controlled release. In addition, ocular irritation and histological studies have supported that it will not show any toxic effect on the eye tissue.

The effect of mucoadhesive polymers on ocular permeation of thermoresponsive in situ gel containing dexamethasone-cyclodextrin complex

Dexamethasone (DXM) is a commonly used corticosteroid in the treatment of ocular inflammatory conditions that affect more and more people. The aim of this study was to evaluate the effect of the combination of hydroxypropyl-β-cyclodextrin (HPBCD), in situ gelling formulations, and other mucoadhesive polymers, i.e., hydroxypropyl methylcellulose (HPMC) and zinc-hyaluronate (ZnHA), on permeation by applying in vitro and ex vivo ophthalmic permeation models. Additionally, gelling properties, in vitro drug release, and mucoadhesion were measured to determine the impact of these factors on permeation and ultimately on bioavailability. The results showed that GEL1 and GEL2 had an optimal gelling temperature, 36.3 ℃ and 34.6 ℃, respectively. Moreover, the combination of Poloxamer 407 (P407) with other polymers improved the mucoadhesion (GEL1: 1333.7 mN) compared with formulations containing only P407 (P12: 721.8 mN). Both HPBCD and the gel matrix had a considerable influence on the drug release and permeability of DXM, and the combination could facilitate the permeation into the aqueous humor. After 30 min of treatment, the DXM concentration in the aqueous humor was 1.16-1.37 µg∕mL in case of the gels, whereas DXM could not be detected when treated with the DXM suspension. The results of the experiments using an in vitro cell line indicated that the formulations could be considered safe for topical treatment of the eye. In conclusion, with application of a small amount of HPMC (0.2 % w∕w), the concentration of P407 could be reduced to 12 % w/w while maintaining the ideal gelling properties and gel structure without negatively affecting permeability compared with the formulation containing a higher amount of P407. Furthermore, the gel matrix may also provide programmed and elongated drug release.

Development of an Intranasal In Situ System for Ribavirin Delivery: In Vitro and In Vivo Evaluation

Recently, ribavirin has demonstrated effectiveness in treating glioblastoma through intranasal administration utilizing the nose-to-brain delivery route. Enhancing ribavirin's bioavailability can be achieved by utilizing intranasal stimuli-responsive systems that create a gel on the nasal mucosa. The research examined thermosensitive, pH-sensitive, and ion-selective polymers in various combinations and concentrations, chosen in line with the current Quality by Design (QbD) approach in pharmaceutical development. Following a thorough assessment of key parameters, the optimal composition of gellan gum at 0.5%, Poloxamer 124 at 2%, and purified water with ribavirin concentration at 100 mg/mL was formulated and subjected to in vivo testing. Through experiments on male rats, the nose-to-brain penetration mechanism of the active pharmaceutical ingredient (API) was elucidated, showcasing drug accumulation in the olfactory bulbs and brain.

Injectable hybrid hydrogels enable enhanced combination chemotherapy and roused anti-tumor immunity in the synergistic treatment of pancreatic ductal adenocarcinoma

Chemotherapy and immunotherapy have shown no significant outcome for unresectable pancreatic ductal adenocarcinoma (PDAC). Multi-drug combination therapy has become a consensus in clinical trials to explore how to arouse anti-tumor immunity and meanwhile overcome the poorly tumoricidal effect and the stroma barrier that greatly hinders drug penetration. To address this challenge, a comprehensive strategy is proposed to fully utilize both the ferroptotic vulnerability of PDAC to potently irritate anti-tumor immunity and the desmoplasia-associated focal adhesion kinase (FAK) to wholly improve the immunosuppressive microenvironment via sustained release of drugs in an injectable hydrogel for increasing drug penetration in tumor location and averting systematic toxicity. The injectable hydrogel ED-M@CS/MC is hybridized with micelles loaded with erastin that exclusively induces ferroptosis and a FAK inhibitor defactinib for inhibiting stroma formation, and achieves sustained release of the drugs for up to 12 days. With only a single intratumoral injection, the combination treatment with erastin and defactinib produces further anti-tumor performance both in xenograft and KrasG12D-engineered primary PDAC mice and synergistically promotes the infiltration of CD8+ cytotoxic T cells and the reduction of type II macrophages. The findings may provide a novel promising strategy for the clinical treatment of PDAC.

Application of the Quality by Design Concept (QbD) in the Development of Hydrogel-Based Drug Delivery Systems

Hydrogel-based drug delivery systems are of interest to researchers for many reasons, such as biocompatibility, high diversity, and the possibility of administration from different routes. Despite these advantages, there are challenges, such as controlling the drug release rate and their mechanical properties during the manufacturing of these systems. For this reason, there is a need for the production and development of such drug delivery systems with a scientific strategy. For this reason, the quality by design (QbD) approach is used for the development of drug delivery systems. This approach, by identifying the most effective factors in the manufacturing of pharmaceutical products and controlling them, results in a product with the desired quality with the least number of errors. In this review article, an attempt is made to discuss the application and method of applying this approach in the development of hydrogel-based drug delivery systems. So that for the development and production of these systems, according to the type of drug delivery system, what target characteristics should be considered (QTPP) and what factors, such as material properties (CMA) or process parameters (CPP), should be taken into account to reach the critical quality attributes of the product (CQA).

Curcumin Transferosome-Loaded Thermosensitive Intranasal in situ Gel as Prospective Antiviral Therapy for SARS-Cov-2

Purpose

Immunomodulatory and broad-spectrum antiviral activities have motivated the evaluation of curcumin for Coronavirus infection 2019 (COVID-19) management. Inadequate bioavailability is the main impediment to the therapeutic effects of oral Cur. This study aimed to develop an optimal curcumin transferosome-loaded thermosensitive in situ gel to improve its delivery to the lungs.

Methods

Transferosomes were developed by using 33 screening layouts. The phospholipid concentration as well as the concentration and type of surfactant were considered independent variables. The entrapment efficiency (EE%), size, surface charge, and polydispersity index (PDI) were regarded as dependent factors. A cold technique was employed to develop thermosensitive in-situ gels. Optimized transferosomes were loaded onto the selected gels. The produced gel was assessed based on shape attributes, ex vivo permeability enhancement, and the safety of the nasal mucosa. The in vitro cytotoxicity, antiviral cytopathic effect, and plaque assay (CV/CPE/Plaque activity), and in vivo performance were evaluated after intranasal administration in experimental rabbits.

Results

The optimized preparation displayed a particle size of 664.3 ± 69.3 nm, EE% of 82.8 ± 0.02%, ZP of -11.23 ± 2.5 mV, and PDI of 0.6 ± 0.03. The in vitro curcumin release from the optimized transferosomal gel was markedly improved compared with that of the free drug-loaded gel. An ex vivo permeation study revealed a significant improvement (2.58-fold) in drug permeability across nasal tissues of sheep. Histopathological screening confirmed the safety of these preparations. This formulation showed high antiviral activity against SARS-CoV-2 at reduced concentrations. High relative bioavailability (226.45%) was attained after the formula intranasally administered to rabbits compared to the free drug in-situ gel. The curcumin transferosome gel displayed a relatively high lung accumulation after intranasal administration.

Conclusion

This study provides a promising formulation for the antiviral treatment of COVID-19 patients, which can be evaluated further in preclinical and clinical studies.

Nanofibers in Ocular Drug Targeting and Tissue Engineering: Their Importance, Advantages, Advances, and Future Perspectives

Nanofibers are frequently encountered in daily life as a modern material with a wide range of applications. The important advantages of production techniques, such as being easy, cost effective, and industrially applicable are important factors in the preference for nanofibers. Nanofibers, which have a broad scope of use in the field of health, are preferred both in drug delivery systems and tissue engineering. Due to the biocompatible materials used in their construction, they are also frequently preferred in ocular applications. The fact that they have a long drug release time as a drug delivery system and have been used in corneal tissue studies, which have been successfully developed in tissue engineering, stand out as important advantages of nanofibers. This review examines nanofibers, their production techniques and general information, nanofiber-based ocular drug delivery systems, and tissue engineering concepts in detail.

Biocompatible phospholipid-based mixed micelles for posaconazole ocular delivery: Development, characterization, and in - vitro antifungal activity

Current study intended to prepare and evaluate phospholipid-based, mixed micelles (MMs) to improve the ocular delivery of posaconazole (POS), a broad-spectrum antifungal drug. For this, MMs based on egg phosphatidylcholine (EPC), as the main component, in combination with various bile salts (sodium cholate (NaC), sodium deoxycholate (NaDC), sodium taurocholate (NaTC)) or non-ionic surfactants (Pluronic® F-127, Pluronic® F-68, Tween 80, Labrasol® ALF, and d-a-tocopheryl polyethylene glycol 1000 succinate (TPGS)) were prepared. Particle size, polydispersity index, zeta potential and entrapment efficiency were evaluated to optimize the composition and preparation method of the MMs. Finally, morphology, stability, in vitro release pattern, and in vitro antifungal activity of the optimized formulation were investigated. Among the prepared MMs, vesicles composed of EPC: TPGS with a molar ratio of 70:30, prepared by the thin-film hydration method, showed more appropriate features. Among the prepared MMs, vesicles composed of EPC: TPGS with a molar ratio of 70:30 showed more appropriate features, including an entrapment efficiency (EE) greater than 80%, spherical shape morphology, an average particle size of about 58 nm, desirable stability over a month, slow-release without a noticeable initial burst, and a significantly higher in vitro antifungal activity in comparison with the drug suspension. Therefore, this formulation was selected as the optimal MMs and could be considered as a promising carrier for topical ocular delivery of POS.

Design and Optimization of In Situ Gelling Mucoadhesive Eye Drops Containing Dexamethasone

Poor bioavailability of eye drops is a well-known issue, which can be improved by increasing the residence time on the eye surface and the penetration of the active pharmaceutical ingredient (API). This study aims to formulate in situ gelling mucoadhesive ophthalmic preparations. To increase the residence time, the formulations were based on a thermosensitive polymer (Poloxamer 407 (P407)) and were combined with two types of mucoadhesive polymers. Dexamethasone (DXM) was solubilized by complexation with cyclodextrins (CD). The effect of the composition on the gel structure, mucoadhesion, dissolution, and permeability was investigated with 3³ full factorial design. These parameters of the gels were measured by rheological studies, tensile test, dialysis membrane diffusion, and in vitro permeability assay. The dissolution and permeability of the gels were also compared with DXM suspension and CD-DXM solution. The gelation is strongly determined by P407; however, the mucoadhesive polymers also influenced it. Mucoadhesion increased with the polymer concentration. The first phase of drug release was similar to that of the CD-DXM solution, then it became prolonged. The permeability of DXM was significantly improved. The factorial design helped to identify the most important factors, thereby facilitating the formulation of a suitable carrier for the CD-DXM complex.