Safety of surfactant excipients in oral drug formulations

Gabapentin drug interactions in water and aqueous solutions of green betaine based compounds through volumetric, viscometric and interfacial properties

Betaine as a bio-based surfactant, has been found in a variety of natural sources. Betaine improves drug absorption, protect drugs from degradation, and enhance the performance of various therapeutic and hygiene products. To investigate the interactions between gabapentin (an antiepileptic drug) and betaine-based compounds, series of experiments were conducted at 298 K. These experiments involved volumetric, viscometric, and surface tension measurements of aqueous solutions containing gabapentin and various betaine-based compounds, including betaine, betaine octyl ester chloride ionic liquid and betaine-urea deep eutectic solvent (molar ratio of 1:2). Additionally, the Conductor like Screening Model (COSMO) method were employed to gain further insights into molecular interactions governing these systems. The volumetric studies revealed that the standard partial molar volumes V0φ of the betaine-based compounds increased with increasing gabapentin concentration, suggesting significant solute-solvent interactions. The apparent specific volume (ASV) and the hydration number (nH) for gabapentin in the examined systems were calculated. The analysis of the obtained ASV and nH values indicated that gabapentin exhibits a bitter taste in aqueous deep eutectic solvent (DES) solutions and in the presence of betaine it gets most dehydrated. The viscosity measurements, analyzed using the Jones-Dole equation, yielded negative viscosity B-coefficient values for the betaine octyl ester chloride ionic liquid, suggesting its potential to enhance the drug-related properties of gabapentin. Surface tension measurements were used to determine the critical micelle concentration (CMC) of the betaine-based compounds and their related surface properties such as interface surface pressure (Π), and Gibbs maximum excess surface concentration ([Formula: see text]). The CMC values decreased with increasing gabapentin concentration, indicating enhanced micellization. The betaine octyl ester chloride ionic liquid exhibited the lowest CMC, suggesting its superior ability to form micelles. The results of this study suggested that the betaine-based compounds improve drug absorption, protect drugs from degradation, and enhance the performance of various therapeutic and hygiene products underscores their importance in both the pharmaceutical and industrial sectorsunds, particularly the betaine octyl ester chloride, may have the potential to improve the drug-related properties of gabapentin.

An overview of oral bioavailability enhancement through self-emulsifying drug delivery systems

INTRODUCTION

The pharmaceutical technologists face a lot of challenges and limitations when designing novel drug delivery systems such as low oral bioavailability of many drugs, primarily due to poor solubility, slow dissolution rates, limited permeability through gastrointestinal mucosa, and rapid degradation within the body.

AREAS COVERED

The biopharmaceutical classification (BCS) classification represents a map in drug delivery research. Numerous active ingredients are characterized by low bioavailability due to poor water solubility, especially active ingredients of BCS class II and IV. Self-emulsifying drug delivery systems (SEDDS) could act as game changer in order to overcome the challenges and limitations of poor bioavailability. In this review, timelines representing the launch of self-emulsifying drug delivery systems, their introduction to the pharmaceutical platform and their benefits will be discussed in detail.

EXPERT OPINION

The development of multifunctional systems capable of combining controlled release, targeted delivery, and diagnostic capabilities is a promising avenue. As the technology matures, self-microemulsifying drug delivery systems and self-nanoemulsifying drug delivery systems are likely to become a standard approach for delivering BCS class II and IV drugs, transforming the pharmaceutical landscape.

Fabrication and characterization of algal oil-loaded Pickering emulsion gels stabilized by whey protein isolate/starch complex as an emergency food

Pickering emulsion gels (PEGs) as emergency food have garnered significant attention due to encapsulate and protect bioactive compounds, ensuring prolonged stability and controlled release under harsh conditions. In this study, whey protein isolate (WPI) and starch nanocomposites (SNPs) with different WPI/SNPs ratios were formulated to stabilize PEGs for the delivery of algal oil as an emergency food. The addition of gelatinized starch enhanced the wettability of the WPI/SNPs, reaching a peak three-phase contact angle of 81.9° at a WPI/SNPs 5:8. Analysis of appearance, micromorphology, droplet size distribution, and rheological behavior confirmed the formation of stable PEGs stabilized by WPI/SNPs. The PEGs demonstrated remarkable stability, maintaining integrity at room temperature for at least 12 weeks, which is attributed to their compact three-dimensional network structure. Additionally, in vitro digestion studies revealed that the starch-based PEGs retained their form during simulated oral and gastric digestion, successfully reaching the intestine. PEGs increased blood glucose by 24.25 % within 30 min and enhanced HepG2 cell migration by 10.47 %, aiding wound healing. Despite their potential, challenges include scalability, regulatory approval, and long-term safety validation. These findings highlight PEGs' promise as nutrient-rich emergency food carriers.

Optimized suction patch design for enhanced transbuccal macromolecular drug delivery

Peptides represent a rapidly expanding class of drugs with broad therapeutic potential. However, due to their large molecular weight and susceptibility to degradation in the gastrointestinal tract, most peptide drugs are administered via subcutaneous injections. Despite extensive research, a painless broad delivery platform for these drugs is still lacking. Recently, an octopus-inspired buccal patch has shown promise in addressing this challenge by leveraging a synergistic combination of mechanical stretching and permeation enhancers. In this study, the patch and the loaded formulation were optimized to improve ease of use, scalability, and efficacy. Through assessments of mechanical properties, finite element simulations, and ex vivo experiments, we evaluated the effects of patch design and material, as well as the drug matrix composition and the formulation preparation methods on the delivery performance. A patch with a > 9-fold larger effective surface area, produced via mold casting of medical-grade silicone (shore hardness 50) and loaded with a lyophilized drug matrix, emerged as the most promising system. In beagle dogs, 30-min application of this patch resulted in a 14.6 % bioavailability for teriparatide (4118 g mol-1), while bioavailability of semaglutide (4114 g mol-1) was 9.6 times higher than that of the commercial tablet. This work showcases how systematic optimization of this technology can improve and simplify the buccal administration of macromolecular drugs, facilitating the clinical translation of this non-invasive dosage form.

Topical Ocular Drug Delivery: The Impact of Permeation Enhancers

Topical ophthalmic drug delivery targeting the posterior segment of the eye has become a key area of interest due to its non-invasive nature, safety, ease of application, patient compliance, and cost-effectiveness. However, achievement of effective drug bioavailability in the posterior ocular segment is a significant challenge due to unique ocular barriers, including precorneal factors and anatomical barriers, like the cornea, the conjunctiva, and the sclera. Successful ocular drug delivery systems require increased precorneal residence time and improved corneal penetration to enhance intraocular bioavailability. A promising strategy to overcome these barriers is incorporating drug penetration enhancers (DPEs) into formulations. These compounds facilitate drug delivery by improving permeability across otherwise impermeable or poorly permeable membranes. At the ocular level, they act through three primary mechanisms: breaking tear film stability by interfering with the mucous layer; disrupting membrane components such as phospholipids and proteins; and loosening epithelial cellular junctions. DPEs offer significant potential to improve bioavailability and therapeutic outcomes, particularly for drugs targeting the posterior segment of the eye. This review is focused on analyzing the current literature regarding the use of penetration enhancers in topical ocular drug delivery, highlighting their mechanisms of action and potential to revolutionize ophthalmic treatments.

Deep eutectic solvents in analysis, delivery and chemistry of pharmaceuticals

Deep eutectic solvents (DES) have an emerging scientific role, assisting modern pharmaceutics. They are uniquely supporting the resolution of crucial issues, such as the effective extraction and isolation of bio-actives. They act as media and catalysts for pharmaceutical drug synthesis, and as green solvents and modifiers in pharmaceutical analysis. Their role in pharmaceutical formulation and drug delivery is also up-and-coming, for instance, as alternative drug-solubilizing agents, drug stabilizers and functional additives, as therapeutic deep eutectic solvents, deep eutectic API, and monomers and reaction media for the synthesis of biomaterials for advanced drug delivery. The DES also help transforming medicinal/pharmaceutical chemistry. Although DES were described in 1918, their first pharmaceutical use is only reported in 1960. In view of their broad applicability in pharmaceutics, it may be interesting to review their history, origin, evolution, potential advantages, limitations, and specific applications as green solvents. A chronological and comparative study of the literature showed the important role of DES in green approaches for modern pharmaceuticals. The concepts, applications, and outcomes of DES in pharmaceutical analysis, formulation/drug delivery, and pharmaceutical/medicinal chemistry are presented. A comprehensive outline of the atypical applications of DES as effective green solvents in pharmaceutical bioactive extraction was assessed. Efforts to present classifications of DES explored in pharmaceuticals were also made. The present manuscript also covers computational trend, adds on commercial aspects with potential future applications of DES in pharmaceutical sciences.

Advancements in Nanoemulsion-Based Drug Delivery Across Different Administration Routes

Nanoemulsions (NEs) have emerged as effective drug delivery systems over the past few decades due to their multifaceted nature, offering advantages such as enhanced bioavailability, protection of encapsulated compounds, and low toxicity. In the present review, we focus on advancements in drug delivery over the last five years across (trans)dermal, oral, ocular, nasal, and intra-articular administration routes using NEs. Rational selection of components, surface functionalization, incorporation of permeation enhancers, and functionalization with targeting moieties are explored for each route discussed. Additionally, apart from NEs, we explore NE-based drug delivery systems (e.g., NE-based gels) while highlighting emerging approaches such as vaccination and theranostic applications. The growing interest in NEs for drug delivery purposes is reflected in clinical trials, which are also discussed. By summarizing the latest advances, exploring new strategies, and identifying critical challenges, this review focuses on developments for efficient NE-based therapeutic approaches.

Exploration of solubilisation effects facilitated by the combination of Soluplus® with ionic surfactants

Preclinical testing of new drug candidates frequently necessitates high-dose solution formulations to support robust testing in rodent models. This study aimed to expand the range of high solubilisation capacity formulations by exploring the solubilisation effects of the polymeric surfactant Soluplus® in combination with ionic surfactants. The interactions between Soluplus® and three ionic surfactants, sodium dodecyl sulphate, dioctyl sodium succinate, and sodium oleate, with a primary focus on solubility enhancement were investigated over a range of ionic surfactant concentrations. The solubilisation profiles for seven model drugs were obtained, and the vehicles were characterised by their visual characteristics, dynamic light scattering, and viscosity measurements. The solubilisation profiles were non-linear, indicating the formation of different colloidal species with individual solubilisation strengths depending on surfactant type and concentration, demonstrating substantial solubility enhancement. For certain drugs more than additive solubilisation, facilitated by synergistic interactions between Soluplus® and the ionic surfactants, was obtained. Overall, the solubility increase provided by the excipient combinations resulted in non-linear and drug specific solubilisation profiles. The non-linearities observed were reflected in visual observations of the vehicles appearance, DLS and viscosity measurements, which collectively indicated a change in polymer aggregation with increasing concentration of anionic surfactant. This investigation highlights that already low quantities of ionic surfactants introduced to Soluplus® may substantially enhance solubility, which offers a promising approach for further exploration in preclinical drug development where more conventional solubilising formulation strategies may fall short.

Towards antimicrobial agents: Design and antibacterial activity of a hybrid fluorophore where porphyrin and Rose Bengal moieties are linked through the hydroxyl group of a xanthene dye

The axial complex of Sn(IV)-tetra(4-sulfophenyl)porphyrin (SnP) with Rose Bengal (RB) was obtained where RB axial binding is realized through the hydroxyl groups of the xanthene dye [SnP(RB)2]. The luminescent properties of the SnP(RB)2 (fluorescence and ability to generate singlet oxygen at room temperature) in aqueous media with additives of surfactant cetylpyridinium chloride (CPC) and ε-poly-l-lysine (EPL) were studied. It was found that nature of the medium (surfactant additives of different concentrations) determines the effectiveness of the photoinduced energy transfer from the RB fragment to the SnP fragment of the hybrid fluorophore (HF). It has been established that the ability of the HF to generate singlet oxygen in D2O and D2O-micellar media is higher than that of its constituent fragments. The dark and photodynamic antibacterial activity of the HF against two microorganisms [Pseudomonas aeruginosa (P. aeruginosa) and Staphylococcus aureus (S. aureus)] was determined and analyzed. It was shown how the antibacterial activity of the HF depends on the nature of the bacteria, the micellar environment and radiation dose.

Encapsulation of astaxanthin in OSA-starch based amorphous solid dispersions with HPMCAS-HF/Soluplus® as effective recrystallization inhibitor

In this study, the interaction among multifunctional excipients, including polysaccharides, cellulose derivatives, and surfactants, was particularly investigated, together with its impact on the physicochemical properties of astaxanthin amorphous solid dispersions (ASTX ASDs). It was indicated that Span 20 could rapidly form hemimicelles or aggregates in the presence of hypromellose acetate succinate HF (HPMCAS-HF, HF) or Soluplus®, while octenyl succinic anhydride modified starch (OSA-starch) efficiently assisted in the coalescence inhibition of drug-excipients aggregates, which was jointly beneficial to the recrystallization inhibition of amorphous ASTX. ASTX ASDs were further prepared with OSA-starch, HPMCAS-HF/Soluplus®, and Span 20 as the wall materials. DSC, SEM, and XRD confirmed that crystalline ASTX had transformed to amorphous state in the ASDs, while FT-IR spectra provided evidence suggesting the existence of hydrogen bonds and hydrophobic interaction between ASTX and the excipients. The dissolution of ASTX ASDs in different media revealed significant promotion, while the pharmacokinetic results further demonstrated the oral bioavailability of ASTX ASDs enhanced remarkably, exhibiting 2.75-fold (SD1) and 1.87-fold (SD2) increase, respectively, compared to ASTX bulk powder. In summary, the cellulose derivatives-surfactant interaction had great impact on the physicochemical properties of ASTX ASDs, and their combinations exhibited great potential for delivering the hydrophobic bioactive compounds efficiently.

LabrafacTM MC60 is an efficacious intestinal permeation enhancer for macromolecules: Comparisons with Labrasol® ALF in ex vivo and in vivo rat studies

Labrafac™ MC60 (glycerol monocaprylocaprate) is a lipid-based excipient used in oral formulations as a solubiliser. Due to the high proportions of established permeability enhancers, caprylate (C8) and caprate (C10), in Labrafac™ MC60, we hypothesised that it might behave as an intestinal permeation enhancer. We therefore evaluated this using two paracellular markers (ex vivo) and insulin (in vivo) as model molecules. Ex vivo studies were conducted in isolated muscle-stripped rat colonic mucosae mounted in Ussing chambers. Apical addition of Labrafac™ MC60 (8, 12, and 16 mg/ml) enhanced the apparent permeability coefficients (Papp) of [14C] mannitol and FITC-dextran 4 kDa (FD4) across colonic mucosae. Similar effects were observed in isolated jejunal mucosae, but at higher concentrations (40 mg/ml). The enhancing capacity of Labrafac™ MC60 was transient due to reversibility of reductions in transepithelial electrical resistance (TEER) upon wash-out and effects on fluxes were molecular weight-dependent (MW) as suggested by fluxes of a set of high MW FITC-dextrans. The permeability enhancing effects of Labrafac™ MC60 ex vivo were maintained in the presence of simulated intestinal fluids, FaSSIF and FaSSCoF, in both jejunal and colonic mucosae, respectively. Following intra-intestinal regional instillations to rats, the relative bioavailability of 50 IU/kg insulin ad-mixed with Labrafac™ MC60 was 5 % in jejunum (40 mg/ml) and 6 % in colon (8 mg/ml). When Labrafac™ MC60 was combined with PEG-60 hydrogenated castor oil (1 % v/v), this further increased the bioavailability of insulin to 8 % in jejunum. Absorption enhancement was also maintained in the presence of FaSSIF in jejunal instillations. Histology after 120 min exposure to Labrafac™ MC60 in vivo for both jejunum and colon was similar to untreated control. Labrafac™ MC60 therefore acts as a non-damaging intestinal permeation enhancer for macromolecules and can be considered as another excipient in screening programmes to develop orally administered macromolecules.

Effects of Commonly used Surfactants, Poloxamer 188 and Tween 80, on the Drug Transport Capacity of Intestinal Glucose Transporters

Some glycoside drugs can be transported through intestinal glucose transporters (IGTs). The surfactants used in oral drug preparations can affect the function of transporter proteins. This study aimed to investigate the effect of commonly used surfactants, Poloxamer 188 and Tween 80, on the drug transport capacity of IGTs. Previous studies have shown that gastrodin is the optimal drug substrate for IGTs. Gastrodin was used as a probe drug to evaluate the effect of these two surfactants on intestinal absorption in SD rats through pharmacokinetic and in situ single-pass intestinal perfusion. Then, the effects of the two surfactants on the expression of glucose transporters and tight-junction proteins were examined using RT-PCR and western blotting. Additionally, the effect of surfactants on intestinal permeability was evaluated through hematoxylin-eosin staining. The results found that all experimental for Poloxamer 188 (0.5%, 2.0% and 8.0%) and Tween 80 (0.1% and 2.0%) were not significantly different from those of the blank group. However, the AUC(0-∞) of gastrodin increased by approximately 32% when 0.5% Tween 80 was used. The changes in IGT expression correlated with the intestinal absorption of gastrodin. A significant increase in the expression of IGTs was observed at 0.5% Tween 80. In conclusion, Poloxamer 188 had minimal effect on the drug transport capacity of IGTs within the recommended limits of use. However, the expression of IGTs increased in response to 0.5% Tween 80, which significantly enhanced the drug transport capacity of IGTs. However, 0.1% and 2.0% Tween 80 had no significant effect.

Cannabidiol-Loaded Solid Lipid Nanoparticles Ameliorate the Inhibition of Proinflammatory Cytokines and Free Radicals in an In Vitro Inflammation-Induced Cell Model

Cannabidiol (CBD) is a non-psychoactive compound derived from Cannabis sativa. It has demonstrated promising effects in combating inflammation and holds potential as a treatment for the progression of chronic inflammation. However, the clinical application of CBD is limited due to its poor solubility and bioavailability. This study introduces an effective method for preparing CBD-loaded solid lipid nanoparticles (CBD-SLNs) using a combination of low-energy hot homogenization and ultrasonication. We enhanced this process by employing statistical optimization with response surface methodology (RSM). The optimized CBD-SLN formulation utilizes glyceryl monostearate as the primary lipid component of the nanocarrier. The CBD-SLN formulation is screened as a potential tool for managing chronic inflammation. Stable, uniformly dispersed spherical nanoparticles with a size of 123 nm, a surface charge of -32.1 mV, an encapsulation efficiency of 95.16%, and a drug loading of 2.36% were obtained. The CBD-SLNs exhibited sustained release properties, ensuring prolonged and controlled CBD delivery, which could potentially amplify its therapeutic effects. Additionally, we observed that CBD-SLNs significantly reduced both reactive oxygen and nitrogen species and proinflammatory cytokines in chondrocyte and macrophage cell lines, with these inhibitory effects being more pronounced than those of free CBD. In conclusion, CBD-SLNs demonstrated superiority over free CBD, highlighting its potential as an effective delivery system for CBD.

Interactions of oral permeation enhancers with lipid membranes in simulated intestinal environments

The oral bioavailability of therapeutic peptides is generally low. To increase peptide transport across the gastrointestinal barrier, permeation enhancers are often used. Despite their widespread use, mechanistic knowledge of permeation enhancers is limited. To address this, we here investigate the interactions of six commonly used permeation enhancers with lipid membranes in simulated intestinal environments. Specifically, we study the interactions of the permeation enhancers sodium caprate, dodecyl maltoside, sodium cholate, sodium dodecyl sulfate, melittin, and penetratin with epithelial cell-like model membranes. To mimic the molecular composition of the real intestinal environment, the experiments are performed with two peptide drugs, salmon calcitonin and desB30 insulin, in fasted-state simulated intestinal fluid. Besides providing a comparison of the membrane interactions of the studied permeation enhancers, our results demonstrate that peptide drugs as well as intestinal-fluid components may substantially change the membrane activity of permeation enhancers. This highlights the importance of testing permeation enhancement in realistic physiological environments and carefully choosing a permeation enhancer for each individual peptide drug.

Caffeic Acid Phosphanium Derivatives: Potential Selective Antitumor, Antimicrobial and Antiprotozoal Agents

Caffeic acid (CA) is one of the most abundant natural compounds present in plants and has a broad spectrum of beneficial pharmacological activities. However, in some cases, synthetic derivation of original molecules can expand their scope. This study focuses on the synthesis of caffeic acid phosphanium derivatives with the ambition of increasing their biological activities. Four caffeic acid phosphanium salts (CAPs) were synthesized and tested for their cytotoxic, antibacterial, antifungal, and amoebicidal activity in vitro, with the aim of identifying the best area for their medicinal use. CAPs exhibited significantly stronger cytotoxic activity against tested cell lines (HeLa, HCT116, MDA-MB-231 MCF-7, A2058, PANC-1, Jurkat) in comparison to caffeic acid. Focusing on Jurkat cells (human leukemic T cell lymphoma), the IC50 value of CAPs ranged from 0.9 to 8.5 μM while IC50 of CA was >300 μM. Antimicrobial testing also confirmed significantly higher activity of CAPs against selected microbes in comparison to CA, especially for Gram-positive bacteria (MIC 13-57 μM) and the yeast Candida albicans (MIC 13-57 μM). The anti-Acanthamoeba activity was studied against two pathogenic Acanthamoeba strains. In the case of A. lugdunensis, all CAPs revealed a stronger inhibitory effect (EC50 74-3125 μM) than CA (>105 µM), while in A. quina strain, the higher inhibition was observed for three derivatives (EC50 44-291 μM). The newly synthesized quaternary phosphanium salts of caffeic acid exhibited selective antitumor action and appeared to be promising antimicrobial agents for topical application, as well as potential molecules for further research.