A critical review of the novelties in the development of intravenous nanoemulsions

Harnessing algae oil as a sustainable DHA source for parenteral nutrition in vegan patients

Parenteral nutrition (PN) is a life-saving intervention for patients unable to meet their nutritional needs through oral or enteral routes. However, long-term PN therapy is often associated with complications, including intestinal failure-associated liver disease (IFALD), largely attributed, among other factors, to oxidative stress induced by pro-inflammatory unsaturated fatty acids. To mitigate the risk of developing IFALD, NEs have been optimized by increasing the content of Ω-3 fatty acids, particularly docosahexaenoic acid (DHA). This study aimed to develop a novel NE utilizing algae oil as a sustainable source of DHA, along with soybean lecithin as an emulsifier, to create a fully animal-free alternative to commercial intravenous NEs. The formulated algae oil-based NEs met pharmacopeial and physicochemical standards for intravenous administration, achieving a mean droplet diameter below 166.2 nm, a narrow polydispersity index, and a minimal percentage of fat globules larger than 5 μm, capped at a maximum of 0.01%. They demonstrated excellent compatibility with commercial PN admixtures, biocompatibility with red blood cells, and stability over six months of storage. Among the formulations, NE P100, prepared using non-GMO soybean-derived phospholipids containing over 90% phosphatidylcholine, exhibited the most favorable properties, indicating its potential for further development. These findings highlight algae oil as a sustainable and effective source of DHA, offering a viable option for PN-dependent patients, including those following vegan diets, while reducing the risk of IFALD. Further in vitro and in vivo research is warranted to expand applications and refine this vegan alternative in PN therapy.

Impact of sterilization method on the system performance of lipid-based novel drug delivery

Sterilization plays a crucial role in the safety and efficacy of lipid-based novel drug delivery systems (NDDS), particularly because of the high sensitivity of lipid components to various sterilization processes. This literature review investigates the impact of different sterilization methods, such as heat sterilization, filtration, radiation, as well as chemical and gas methods, on the physicochemical properties, stability, and therapeutic performance of lipid-based NDDS (LB-NDDS), including liposomes, microemulsions, nanoemulsions, solid lipid nanoparticles (SLN), and nanostructured lipid carriers (NLC). Special emphasis is placed on lipid degradation, drug content, and particle size alterations, that may occur during sterilization. Overall, understanding the suitable sterilization technique for LB-NDDS is critical for maintaining the integrity of drug delivery systems integrity and achieving optimal therapeutic outcomes. The findings provide a comprehensive analysis of the current challenges and recent advancement (supercritical CO2, electron beam, and ozone) of sterilization techniques that align with the sensitive nature of LB-NDDS.

Development and Validation of In Vitro Assessment Protocol of Novel Intravenous Nanoemulsions for Parenteral Nutrition

Background: Parenteral nutrition (PN) is a lifesaving therapeutic approach for patients unable to meet nutritional needs through oral or enteral routes. Lipid nanoemulsions (NEs), a critical component of PN, provide essential fatty acids and influence the formulation's physicochemical properties. Advances in drug delivery systems have led to novel intravenous NEs with improved stability, purity, or ability for nutrient/active substance delivery. Due to scattered information and the lack of a standardized protocol for testing intravenous lipid NEs, this study aimed to develop a robust assessment method. The protocol focuses on characterizing the physicochemical properties, stability, and biological efficacy of novel NEs while adhering to bioethical standards. Methods: Four NEs were formulated based on fatty acid profile analysis, and to demonstrate the applicability of our protocol, each NE utilized a distinct emulsifier system. A comprehensive in vitro assessment protocol integrating multiple analytical techniques was employed to evaluate their performance. Results: The mean droplet diameter (MDD) of developed NEs ranged from 180.7 to 185.9 nm, significantly smaller than commercial formulations (249.6-335.4 nm). PFAT5 remained below 0.02%, except for ILE-HS (0.12%), and the zeta potential (ZP) was below -29.8 mV. The freeze-thaw stability constant (KF) of developed NEs was in the range of commercial formulation, and the sterilization stability constant (KS) was below 10, except for ILE-HS (23.61 ± 1.65). Injectability tests confirmed that ILE-ELP and ILE-T could be infused at 50 mL/h using an intravenous access with a minimum diameter of 21 G. Hemolytic activity met the strictest criteria (<5%), and MTT assays showed higher cell viability at low concentrations for all NEs except ILE-ELP. Conclusions: The developed five-step protocol provides a unified framework for assessing intravenous lipid NEs, allowing for the selection of NEs with the highest potential for further in vivo assessment.

Parenteral Nanoemulsion for Optimized Delivery of GL-II-73 to the Brain-Comparative In Vitro Blood-Brain Barrier and In Vivo Neuropharmacokinetic Evaluation

Background/Objectives: GL-II-73 is a positive allosteric modulator that is selective for α5GABAA receptors and has physicochemical properties that favor nanocarrier formulations when parenteral delivery to the central nervous system is desired. Our aim was to develop an optimized nanoemulsion containing GL-II-73 and subsequently test whether this would improve permeation across the blood-brain barrier (BBB) and availability in the brain. Methods: The nanoemulsions were formulated and subjected to detailed physiochemical characterization. The optimized formulation was tested in comparison to a solution of GL-II-73 in the appropriate solvent in an in vitro model of the blood-brain barrier based on human induced pluripotent stem cell-derived microvascular endothelial cells, astrocytes, and pericytes. Plasma and brain exposure to GL-II-73 and its metabolite MP-III-022 was investigated in an in vivo neuropharmacokinetic study in rats exposed to the selected nanoemulsion and the conventional solution formulation. Results: The selected biocompatible nanoemulsion exhibited satisfactory physicochemical properties for parenteral administration, with a Z-ave of 122.0 ± 1.5, PDI of 0.123 ± 0.009 and zeta potential of -40.7 ± 1.5, pH of 5.16 ± 0.04, and adequate stability after one year of storage, and allowed the localization of GL-II-73 in the stabilization layer. The permeability of GL-II-73 through the BBB was twice as high with the selected nanoemulsion as with the solution. The availability of GL-II-73 and MP-III-022 (also a positive allosteric modulator selective for α5GABAA receptors) in the brain was 24% and 61% higher, respectively, after intraperitoneal administration of the nanoemulsion compared to the solution; the former increase was statistically significant. Conclusions: The increased permeability in vitro proved to be a good predictor for the improved availability of GL-II-73 in brain tissue in vivo from the formulation obtained by encapsulation in a nanoemulsion. The putative additive effect of the parent molecule and its metabolite MP-III-022 could lead to enhanced and/or prolonged modulation of α5GABAA receptors in the brain.

Novel Intravenous Nanoemulsions Based on Cannabidiol-Enriched Hemp Oil-Development and Validation of an HPLC-DAD Method for Cannabidiol Determination

BACKGROUND

Intravenous nanoemulsions (NEs) are gaining attention as potential delivery systems for poorly water-soluble substances like cannabidiol (CBD). This study aimed to develop novel NEs based on CBD-enriched hemp oils and evaluate their physiochemical properties.

METHODS

The stability of hemp oils enriched with various concentrations of CBD (0.5%, 1.0%, and 1.5%) with and without the addition of α-tocopherol was determined, and the most stable oils were subsequently incorporated into NEs. In order to determine the CBD content in the obtained CBD-enriched oils and NEs, as well as to conduct stability tests, a new HPLC method was developed and validated.

RESULTS

The HPLC method demonstrated very good linearity, precision, accuracy, specificity, and robustness, enabling reliable assessment of the quality of newly developed formulations. The formulated NEs were characterized by droplet size of below 200 nm and polydispersity index PDI ≤ 0.14 satisfactory for intravenous application.

CONCLUSION

This research presents a preliminary study on the development of CBD-enriched hemp oil-based NEs that showed promising potential for further investigation. A new HPLC-DAD method was appropriate to register changes in CBD concentration in various matrices, including CBD-hemp oil and intravenous NEs during their preparation and storage. Additionally, the effect of certain emulsifiers used in NE formulations on the course of the chromatographic analysis of CBD was examined, providing valuable insights concerning the application of the provided methodology in future formulation analysis.

Solubilization techniques used for poorly water-soluble drugs

About 40% of approved drugs and nearly 90% of drug candidates are poorly water-soluble drugs. Low solubility reduces the drugability. Effectively improving the solubility and bioavailability of poorly water-soluble drugs is a critical issue that needs to be urgently addressed in drug development and application. This review briefly introduces the conventional solubilization techniques such as solubilizers, hydrotropes, cosolvents, prodrugs, salt modification, micronization, cyclodextrin inclusion, solid dispersions, and details the crystallization strategies, ionic liquids, and polymer-based, lipid-based, and inorganic-based carriers in improving solubility and bioavailability. Some of the most commonly used approved carrier materials for solubilization techniques are presented. Several approved poorly water-soluble drugs using solubilization techniques are summarized. Furthermore, this review summarizes the solubilization mechanism of each solubilization technique, reviews the latest research advances and challenges, and evaluates the potential for clinical translation. This review could guide the selection of a solubilization approach, dosage form, and administration route for poorly water-soluble drugs. Moreover, we discuss several promising solubilization techniques attracting increasing attention worldwide.

The Development of Magnolol-Loaded Intravenous Emulsion with Low Hepatotoxic Potential

Intestinal failure-associated liver disease (IFALD) is a severe liver injury occurring due to factors related to intestinal failure and parenteral nutrition administration. Different approaches are studied to reduce the risk or ameliorate the course of IFALD, including providing omega-3 fatty acids instead of soybean oil-based lipid emulsion or administering active compounds that exert a hepatoprotective effect. This study aimed to develop, optimize, and characterize magnolol-loaded intravenous lipid emulsion for parenteral nutrition. The preformulation studies allowed for chosen oils mixture of the highest capacity of magnolol solubilization. Then, magnolol-loaded SMOFlipid was developed using the passive incorporation method. The Box-Behnken design and response surface methodology were used to optimize the entrapment efficiency. The optimal formulation was subjected to short-term stress tests, and its effect on normal human liver cells and erythrocytes was determined using the MTT and hemolysis tests, respectively. The optimized magnolol-loaded SMOFlipid was characterized by the mean droplet diameter of 327.6 ± 2.9 nm with a polydispersity index of 0.12 ± 0.02 and zeta potential of -32.8 ± 1.2 mV. The entrapment efficiency of magnolol was above 98%, and pH and osmolality were sufficient for intravenous administration. The magnolol-loaded SMOFlipid samples showed a significantly lower toxic effect than bare SMOFlipid in the same concentration on THLE-2 cells, and revealed an acceptable hemolytic effect of 8.3%. The developed formulation was characterized by satisfactory stability. The in vitro studies showed the reduced cytotoxic effect of MAG-SMOF applied in high concentrations compared to bare SMOFlipid and the non-hemolytic effect on human blood cells. The magnolol-loaded SMOFlipid is promising for further development of hepatoprotective lipid emulsion for parenteral nutrition.