Microemulsion based nasal spray: A systemic approach for non-CNS drug, its optimization, characterization and statistical modelling using QbD principles

Enhancing Microemulsion-Based Therapeutic Drug Delivery: Exploring Surfactants, Co-Surfactants, and Quality-by-Design Strategies within Pseudoternary Phase Diagrams

Microemulsions (MEs) are homogeneous, isotropic, transparent, and thermodynamically stable mixtures of water, oil, and surfactants. Their unique properties have garnered increasing interest across various fields, including chemistry, pharmacology, biotechnology, and biology. This review aims to provide a comprehensive overview of ME compositions, their macroscopic appearances, and the roles of their essential components - oil, water, surfactant, and co-surfactant - in controlling the nature and stability of MEs. The review highlights the significance of MEs in drug delivery and other applications, highlighting their potential to enhance the solubility, stability, and bioavailability of active pharmaceutical ingredients (APIs). Key factors influencing ME formation, such as the types of surfactants, oils, water, temperature, and various additives, are thoroughly explored. The physicochemical properties of MEs, including small droplet size, large interfacial area, and solubilization capabilities for both hydrophilic and hydrophobic compounds, are discussed about their impact on biological behavior. The present work is an effort to discuss theories and phase diagrams crucial for ME formation, and the strategy of choosing appropriate surfactants and co-surfactants. and the advancements in the preparation and characterization techniques like the shift from visual inspection to advanced spectroscopic phase behavior studies. The work also describes the potential of MEs in drug delivery showcasing the most commonly used ME-based drug candidates as well as excipients highlighting how different excipients influence the release of active pharmaceutical ingredients and the way and quality-by-design approach has been utilized to optimize MEs, providing insights into the systematic design and development to achieve desired characteristics of ME formulations.

Quality by Design (QbD)-Driven Development and Optimization of Tacrolimus-Loaded Microemulsion for the Treatment of Skin Inflammation

Background: Skin inflammation represents a hallmark of many skin conditions, from psoriasis to eczema. Here, we present a novel microemulsion formulation for delivering a low dose of potent immunosuppressant, tacrolimus, to the skin for local inflammation control. The efficacy of topically delivered tacrolimus in controlling skin inflammation can be enhanced by packaging it into microemulsions. Microemulsions are small-size, thermodynamically stable, and surfactant-rich emulsions that can enhance tissue penetration and local tissue retention of poorly soluble drugs, which can reduce dosing frequency and potentially improve patient compliance. Methods: We present a novel approach for microemulsion manufacturing that uses a combination of both low and high-energy methods. The microemulsion composition and manufacturing parameters were optimized by adopting Quality by Design methodologies. The FMECA (Failure, Mode, Effects, Criticality Analysis)-based risk assessment, D-optimal Design of Experiment (DoE), and statistical analysis of parameters impacting responses through the multiple linear regression (MLR) was implemented for identifying critical formulation and process parameters. Results: Through QbD strategy, a stable microemulsion with optimized drug loading that met all critical quality attributes (CQAs) was identified. The optimal microemulsion candidate was successfully scaled up three-fold with retained CQAs. The presented microemulsion showed a slow and extended drug release profile in vitro. Conclusions: Presented findings suggest that microemulsions are a promising novel approach for tacrolimus delivery to the skin. Further, we also demonstrated that a combination of low-energy emulsification and microfluidization processes can produce stable and robust microemulsions with small droplet size that can be implemented in drug delivery of poorly soluble anti-inflammatory drugs. To the best of our knowledge, this is the first report of QbD-driven optimization of microemulsion manufacturing by microfluidization.

Question-based review for pharmaceutical development: An enhanced quality approach

Over the last years, the pharmaceutical industry has faced real challenges regarding quality assurance. In this context, the establishment of more holistic approaches to the pharmaceutical development has been encouraged. The emergence of the Quality by Design (QbD) paradigm as systematic, scientific and risk-based methodology introduced a new concept of pharmaceutical quality. In essence, QbD can be interpreted as a strategy to maximize time and cost savings. An in-depth understanding of the formulation and manufacturing process is demanded to optimize the safety, efficacy and quality of a drug product at all stages of development. This innovative approach streamlines the pharmaceutical Research and Development (R&D) process, provides greater manufacturing flexibility and reduces regulatory burden. To assist in QbD implementation, International Conference on Harmonisation (ICH), U.S. Food and Drug Administration (FDA) and European Medicines Agency (EMA) organized and launched QbD principles in their guidance for industry, identifying key concepts and tools to design and develop a high-quality drug product. Despite the undeniable advantages of the QbD approach, and the widespread information on QbD regulatory expectations, its full implementation in the pharmaceutical field is still limited. The present review aims to establish a crosswise overview on the current application status of QbD within the framework of the ICH guidelines (ICH Q8(R2) - Q14 and ICH Q2(R2)). Moreover, it outlines the way information gathered from the QbD methodology is being harmonized in Marketing Authorization Applications (MAAs) for European market approval. This work also highlights the challenges that hinder the deployment of the QbD strategy as a standard practice.

In Vivo Evaluation of Almotriptan malate Formulation through Intranasal Route for the Treatment of Migraine: Systematic Development and Pharmacokinetic Assessment

Migraine headaches are usually intolerable, and a quick-relief treatment remains an unmet medical need. Almotriptan malate is a serotonin (5-HT_1B/1D) receptor agonist approved for the treatment of acute migraine in adults. It is currently available in an oral tablet dosage form and has a T_max of 1-3 h, and therefore, there is a medical need to develop a non-invasive rapidly acting formulation. We have developed an intranasal formulation of almotriptan malate using the quality-by-design (QbD) approach. A 2-factor 3-level full factorial design was selected to build up the experimental setting. The developed formulation was characterized for pH, viscosity, in vitro permeation, ex vivo permeation, and histopathological tolerance. To assess the potential of the developed formulation to produce a rapid onset of action following intranasal delivery, a pharmacokinetic study was performed in the Sprague-Dawley rat model and compared to the currently available marketed oral tablet formulation. For this, the LC-MS/MS bioanalytical method was developed and used for the determination of plasma almotriptan malate concentrations. Results of a pharmacokinetic study revealed that intranasal administration of optimized almotriptan malate formulation enabled an almost five-fold reduction in T_max and about seven-fold increase in bioavailability in comparison to the currently available oral tablet formulation, suggesting the potential of developed almotriptan malate intranasal formulation in producing a rapid onset of action as well as enhanced bioavailability.

Applications and perspectives of polyphenol-loaded solid lipid nanoparticles and nanostructured lipid carriers for foods

Imbalanced nutrition in modern society is one of the reasons for disorders, such as cancer, cardiovascular disease, and diabetes, which have attracted the interest in bioactives (particularly polyphenols) to assist in the balanced diet of modern people. Although stability can be maintained during preparation and storage, the ingested polyphenols undergo harsh gastrointestinal digestion processes, resulting in limited bioaccessibility and low gut-epithelial permeation and bioavailability. Several lipid-based formulations have been proposed to overcome these issues. Solid lipid nanoparticles (SLNs) and nanostructured lipid carriers (NLCs) have also been highlighted as carrier systems for the oral delivery of lipophilic bioactives, including polyphenols. This paper summarizes the research on the ingredients, production methods, post-processing procedures, general characteristics, and advantages and disadvantages of SLNs and NLCs. Overall, this paper reviews the applications and perspectives of polyphenol-loaded SLNs and NLCs in foods, as well as their regulation, production, storage, and economic feasibility.