Mixture experiment methods in the development and optimization of microemulsion formulations

Development, characterization, and evaluation of the antioxidant activity of nanocarriers based on surfactant swollen micelles that encapsulate essential oils

This work aimed to compare the performance of two relatively underexplored methods for the swollen micelles (SMs) production as nanocarriers for essential oils (EOs). Origanum vulgare and Thymus vulgaris EOs were examined. The first method (SMs-1), involved a self-assembly process, while the second one (SMs-2), employed titration operation of an emulsion into a surfactant solution for SMs formation. Tween 80 and ethanol were used as surfactant and co-surfactant, respectively. The solubilization kinetics and the saturation concentration of EOs were determined. Particle size (measured by DLS) and encapsulation efficiency (EE) were the control parameters assessed, along with the EOs-loaded SMs' stability during 30 days of storage. Additionally, the EOs-loaded SMs' morphology was analyzed using atomic force microscopy (AFM). Finally, the antioxidant activity through the ABTS+ radical scavenging and the reducing power of EOs encapsulated in SMs was determined. The results showed that the solubilization of EOs in SMs was a rapid process with high EE. EOs-loaded SMs-2 systems exhibited greater colloidal stability and higher EE compared to EOs-loaded SMs-1 systems, showing smaller and more homogeneous particle sizes. Moreover, EOs-loaded SMs-2 systems maintained constant EE throughout the storage period. AFM imaging confirmed the rounded and heterogeneous morphology of EOs-loaded SMs-1 and the smaller, more homogeneous, and spherical morphology of EOs-loaded SMs-2. EOs-loaded SMs-2 showed high ABTS+ radical scavenging and reducing power when encapsulated in SMs. In conclusion, the SMs-2 method emerged as an effective approach for producing efficient nanocarriers for EOs, signifying a promising path for future developments in antioxidant delivery systems.

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.

Recent advances in nanocarriers for nutrient delivery

For the past few years, there has been a surge in the use of nutraceuticals. The global nutraceuticals market in 2020 was USD 417.66 billion, and the market value is expected to increase by 8.9% compound annual growth rate from 2020 to 2028. This is because nutraceuticals are used to treat and prevent various diseases such as cancer, skin disorders, gastrointestinal, ophthalmic, diabetes, obesity, and central nervous system-related diseases. Nutritious food provides the required amount of nutrition to the human body through diet, whereas most of the bioactive agents present in the nutrients are highly lipophilic, with low aqueous solubility leading to poor dissolution and oral bioavailability. Also, the nutraceuticals like curcumin, carotenoids, anthocyanins, omega-3 fatty acids, vitamins C, vitamin B12, and quercetin have limitations such as poor solubility, chemical instability, bitter taste, and an unpleasant odor. Additionally, the presence of gastrointestinal (GIT) membrane barriers, varied pH, and reaction with GIT enzymes cause the degradation of some of the nutraceuticals. Nanotechnology-based nutrient delivery systems can be used to improve oral bioavailability by increasing nutraceutical stability in foods and GIT, increasing nutraceutical solubility in intestinal fluids, and decreasing first-pass metabolism in the gut and liver. This article has compiled the properties and applications of various nanocarriers such as polymeric nanoparticles, micelles, liposomes, niosomes, solid lipid nanocarriers, nanostructured lipid carrier, microemulsion, nanoemulsion, dendrimers in organic nanoparticles, and nanocomposites for effective delivery of bioactive molecules.

Surfactant-Free Glibenclamide Nanoparticles: Formulation, Characterization and Evaluation of Interactions with Biological Barriers

PURPOSE

The aim of this work was to formulate and characterize surfactant-free glibenclamide nanoparticles using Eudragit RLPO and polyethylene glycol as sole stabilizer.

METHODS

Glibenclamide nanoparticles were obtained by nanoprecipitation and evaluated in terms of drug content, encapsulation efficiency, apparent saturation solubility, drug release profile, solid state and storage stability. The influence of different stirring speed on the particle size, size distribution and zeta potential of the nanoparticles was investigated. The nanoparticle biocompatibility and permeability were analyzed in vitro on Caco-2 cell line (clone HTB-37) and its interaction with mucin was also investigated.

RESULTS

It was found that increasing the molecular weight of polyethylene glycol from 400 to 6000 decreased drug encapsulation, whereas the aqueous solubility and dissolution rate of the drug increased. Particle size of the nanoformulations, with and without polyethylene glycol, were between 140 and 460 nm. Stability studies confirmed that glibenclamide nanoparticles were stable, in terms of particle size, after 120 days at 4°C. In vitro studies indicated minimal interactions of glibenclamide nanoparticles and mucin glycoproteins suggesting favorable properties to address the intestinal mucus barrier. Cell viability studies confirmed the safety profile of these nanoparticles and showed an increased permeation through epithelial cells.

CONCLUSION

Taking into consideration these findings, polyethylene glycol is a useful polymer for stabilizing these surfactant-free glibenclamide nanoparticles and represent a promising alternative to improve the treatment of non-insulin dependent diabetes.

Using Differential Evolution to Design Optimal Experiments

Differential Evolution (DE) has become one of the leading metaheuristics in the class of Evolutionary Algorithms, which consists of methods that operate off of survival-of-the-fittest principles. This general purpose optimization algorithm is viewed as an improvement over Genetic Algorithms, which are widely used to find solutions to chemometric problems. Using straightforward vector operations and random draws, DE can provide fast, efficient optimization of any real, vector-valued function. This article reviews the basic algorithm and a few of its modifications with various enhancements. We provide guidance for practitioners, discuss implementation issues and give illustrative applications of DE with the corresponding R codes to find different types of optimal designs for various statistical models in chemometrics that involve the Arrhenius equation, reaction rates, concentration measures and chemical mixtures.

An In Situ Gelling System for the Local Treatment of Inflammatory Bowel Disease (IBD). The Loading of Maqui (Aristotelia Chilensis) Berry Extract as an Antioxidant and Anti-Inflammatory Agent

The aim of the present work was the development of an innovative in situ gelling system, to be applied on the mucosa of the distal colon via rectal route. The system consisted of three polymers having different functions: gellan (GG), able to jellify in presence of ions; methylcellulose (MC), a thermosensitive polymer with a gelation temperature close to 50 °C; and hydroxypropylcellulose (HPC), a mucoadhesive polymer. The three polymers were able to act synergistically, increasing the permanence of the vehicle on the mucosa and forming a protective gel layer. A DoE approach, "simplex centroid mixture design," was used to identify the optimal quantitative composition of the vehicle. The response variables considered were: vehicle viscosity at room temperature; increase in vehicle viscosity on increasing temperature (from room to physiological value) and upon dilution with simulated colonic fluid (SCF); and viscoelastic behavior, thixotropic area, and mucoadhesion properties of the gel formed at 37 °C upon dilution in SCF. The optimized vehicle was loaded with maqui berry extract (MBE), known for its antioxidant and anti-inflammatory properties. MBE loading (0.5% w/w) into the vehicle improved rheological and mucoadhesive properties of the formulation. Both MBE and the optimized vehicle were not cytotoxic towards human fibroblasts and Caco-2 cells. Moreover, the optimized vehicle did not affect MBE antioxidant properties.

Quality by Design Approach Using Multiple Linear and Logistic Regression Modeling Enables Microemulsion Scale Up

The development of pharmaceutical nanoformulations has accelerated over the past decade. However, the nano-sized drug carriers continue to meet substantial regulatory and clinical translation challenges. In order to address some of these key challenges in early development, we adopted a quality by design approach to develop robust predictive mathematical models for microemulsion formulation, manufacturing, and scale-up. The presented approach combined risk management, design of experiments, multiple linear regression (MLR), and logistic regression to identify a design space in which microemulsion colloidal properties were dependent solely upon microemulsion composition, thus facilitating scale-up operations. Developed MLR models predicted microemulsion diameter, polydispersity index (PDI), and diameter change over 30 days storage, while logistic regression models predicted the probability of a microemulsion passing quality control testing. A stable microemulsion formulation was identified and successfully scaled up tenfold to 1L without impacting droplet diameter, PDI, or stability.

Optimization of a Vaginal Suppository Formulation to Deliver SHetA2 as a Novel Treatment for Cervical Dysplasia

Cervical dysplasia induced by the human papilloma virus unpredictably progresses to cervical cancer. Therapeutic options are invasive and affect the patient's quality of life. SHetA2 has demonstrated therapeutic efficacy against human and murine human papilloma virus-induced tumors, but its oral bioavailability is <1%. An optimized vaginal suppository formulation can deliver SHetA2 in sufficient doses to prevent cervical dysplasia. The quality by design approach was employed to optimize the suppository formulation consisting of cocoa butter as base with 5% Kolliphor and 40% SHetA2. The suppository had a content uniformity of 105.44 ± 0.42%, melted in <8 min, and had a complete release of SHetA2 in water. Administration of the suppository to mice-achieved cervix concentrations that were significantly higher than the SHetA2 therapeutic concentration, with the maximum concentration (C_max-cervix = 336.78 μg/g) being more than 100-fold the therapeutic SHetA2 concentration. Furthermore, the levels of cyclin D1 protein decreased 9-fold indicating a correlation of drug concentrations with the pharmacodynamic endpoint. These proof-of-concept studies suggest that the SHetA2 optimized vaginal suppository formulation may have a potential use in the prevention of cervical dysplasia, but detailed efficacy studies are required to confirm this assumption.

PREPARATION AND PROPERTIES OF COMPOUND ARNEBIAE RADIX MICROEMULSION GEL

Background:

Compound Arnebiae radix oil has been clinically applied to treat burns and scalds for a long time. However, it is unstable and inconvenient to use. The aim of this study was to prepare a compound Arnebiae radix microemulsion gel for transdermal delivery system and evaluate its characteristics.

Materials and Methods:

Based on the solubility of Shikonin, the active component of Arnebiae radix and the results of phase studies, adequate ratio of each component in microemulsion was determined. The optimized microemulsion gel was prepared using Carbomer 940. The gels were characterized in terms of appearance, preliminary stability test and the content of Shikonin in the compound Arnebiae radix microemulsion gel with HPLC analysis.

Results:

The optimized conditions for preparing microemulsion were Tween-80, glycerin, isopropyl myristate (IPM) with the ratio of 6:3:2. The optimal microemulsion gel was obtained with Carbomer 940 (1.0%).

Conclusion:

The prepared compound Arnebiae radix microemulsion gel showed good stability over time. It is more convenience in application than the previous used formulations.

Surface-adsorbed reverse micelle-loaded solid self-nanoemulsifying drug delivery system of talinolol

The aim of present investigation was to develop surface-adsorbed reverse-micelle-loaded solid self-nanoemulsifying drug delivery system (SNEDDS) of talinolol in order to enhance its in vitro dissolution rate, which in turn enhance the bioavailability. SNEDDS were prepared using aqueous phase titration method. Thermodynamically stable formulations were characterized in terms of droplet size, viscosity, % transmittance, drug content and surface morphology. Low cost acid-treated coffee husk was used as an effective biosorbent for preparation of solid SNEDDS. Developed SNEDDS were subjected to in vitro drug release/dissolution studies. In vitro drug release studies showed 99.6% release of talinolol from optimized solid SNEDDS TS3 after 120 min of study. The results of solubility studies showed 4849.5-folds enhancement in solubility of talinolol from optimized SNEDDS as compared to its aqueous solubility.

Design and Formulation of Optimized Microemulsions for Dermal Delivery of Resveratrol

The objective of this study was to formulate optimal formulations of microemulsions (MEs) and evaluate their feasibility for delivery of resveratrol into human skin ex vivo. Oil-in-water MEs were formulated using surfactant (S) PEG-8 caprylic/capric glycerides and cosurfactant (CoS) polyglyceryl-6-isostearate. Ethyl oleate was used as an oily phase. MEs were formulated using 5 : 1, 6 : 1, and 7 : 1 surfactant and cosurfactant (S : CoS) weight ratios. Pseudoternary phase diagrams were constructed and optimal compositions of MEs were obtained using Design Expert software. Mean droplet size for optimized ME formulations was determined to be 68.54 ± 1.18 nm, 66.08 ± 0.16 nm, and 66.66 ± 0.56 nm for systems with S : CoS weight ratios 5 : 1, 6 : 1, and 7 : 1, respectively. Resveratrol loading resulted in mean droplet size increase. The distribution of droplet size between fractions changed during storage of formulated MEs. Results demonstrated the increase of number of droplets and relative surface area when S : CoS weight ratios were 6 : 1 and 7 : 1 and the decrease when S : CoS weight ratio was 5 : 1. The highest penetration of resveratrol into the skin ex vivo was determined from ME with S : CoS weight ratio 5 : 1. It was demonstrated that all MEs were similar in their ability to deliver resveratrol into the skin ex vivo.

A Modified Particle Swarm Optimization Technique for Finding Optimal Designs for Mixture Models

Particle Swarm Optimization (PSO) is a meta-heuristic algorithm that has been shown to be successful in solving a wide variety of real and complicated optimization problems in engineering and computer science. This paper introduces a projection based PSO technique, named ProjPSO, to efficiently find different types of optimal designs, or nearly optimal designs, for mixture models with and without constraints on the components, and also for related models, like the log contrast models. We also compare the modified PSO performance with Fedorov's algorithm, a popular algorithm used to generate optimal designs, Cocktail algorithm, and the recent algorithm proposed by [1].

Lipid-based formulations for oral administration of poorly water-soluble drugs

Lipid-based drug delivery systems have shown great potentials in oral delivery of poorly water-soluble drugs, primarily for lipophilic drugs, with several successfully marketed products. Pre-dissolving drugs in lipids, surfactants, or mixtures of lipids and surfactants omits the dissolving/dissolution step, which is a potential rate limiting factor for oral absorption of poorly water-soluble drugs. Lipids not only vary in structures and physiochemical properties, but also in their digestibility and absorption pathway; therefore selection of lipid excipients and dosage form has a pronounced effect on the biopharmaceutical aspects of drug absorption and distribution both in vitro and in vivo. The aim of this review is to provide an overview of the different lipid-based dosage forms from a biopharmaceutical point of view and to describe effects of lipid dosage forms and lipid excipients on drug solubility, absorption and distribution.

Mixture designs to assess composition–structure–property relationships in SiO2–CaO–ZnO–La2O3–TiO2–MgO–SrO–Na2O glasses: Potential materials for embolization

Embolization with micron-sized particulates is widely applied to treat uterine fibroids. The objective of this work was to develop mixture designs to predict materials composition–structure–property relationships for the SiO2–CaO–ZnO–La2O3–TiO2–MgO–SrO–Na2O glass system and compare its fundamental materials properties (density and cytocompatibility), against a state-of-the-art embolic agent (contour polyvinyl alcohol) to assess the potential of these materials for embolization therapies. The glass structures were evaluated using 29Si MAS NMR to identify chemical shift and line width; the particulate densities were determined using helium pycnometry and the cell viabilities were assessed via MTT assay. 29Si MAS NMR results indicated peak maxima for each glass in the range of −82.3 ppm to −89.9 ppm; associated with Q2 to Q3 units in silicate glasses. All experimental embolic compositions showed enhanced in vitro compatibility in comparison to Contour PVA with the exceptions of ORP9 and ORP11 (containing no TiO2). In this study, optimal compositions for cell viability were obtained for the following compositional ranges: 0.095–0.188 mole fraction ZnO; 0.068–0.159 mole fraction La2O3; 0.545–0.562 mole fraction SiO2 and 0.042–0.050 mole fraction TiO2. To ensure ease of producibility in obtaining good melts, a maximum loading of 0.068 mole fraction La2O3 is required. This is confirmed by the desirability approach, for which the only experimental composition (ORP5) of the materials evaluated was presented as an optimum composition; combining high cell viability with ease of production (0.188 mole fraction ZnO; 0.068 mole fraction La2O3; 0.562 mole fraction SiO2 and 0.042 mole fraction TiO2).