In vitro release testing methods for vitamin E nanoemulsions

Nanocarrier Drug Delivery Systems: Characterization, Limitations, Future Perspectives and Implementation of Artificial Intelligence

There has been an increasing demand for the development of nanocarriers targeting multiple diseases with a broad range of properties. Due to their tiny size, giant surface area and feasible targetability, nanocarriers have optimized efficacy, decreased side effects and improved stability over conventional drug dosage forms. There are diverse types of nanocarriers that have been synthesized for drug delivery, including dendrimers, liposomes, solid lipid nanoparticles, polymersomes, polymer-drug conjugates, polymeric nanoparticles, peptide nanoparticles, micelles, nanoemulsions, nanospheres, nanocapsules, nanoshells, carbon nanotubes and gold nanoparticles, etc. Several characterization techniques have been proposed and used over the past few decades to control and predict the behavior of nanocarriers both in vitro and in vivo. In this review, we describe some fundamental in vitro, ex vivo, in situ and in vivo characterization methods for most nanocarriers, emphasizing their advantages and limitations, as well as the safety, regulatory and manufacturing aspects that hinder the transfer of nanocarriers from the laboratory to the clinic. Moreover, integration of artificial intelligence with nanotechnology, as well as the advantages and problems of artificial intelligence in the development and optimization of nanocarriers, are also discussed, along with future perspectives.

Chrysin-Loaded Microemulsion: Formulation Design, Evaluation and Antihyperalgesic Activity in Mice

Chrysin is a bioactive flavonoid found in pollens, passion flowers, honey, royal jelly, and propolis, which is commonly used as an ingredient in natural food supplements and is primarily responsible for their pharmacological properties. A transparent chrysin-loaded microemulsion (CS-ME) prepared through a ternary phase diagram was evaluated for use as an antihyperalgesic formulation. It was formulated with 40% Labrasol® (surfactant), 5% isopropyl myristate (oil phase) and 55% water (aqueous phase) and classified as an oil-in-water (O/W) microsized system (74.4 ± 15.8 nm). Its negative Zeta potential (−16.1 ± 1.9 mV) was confirmed by polarized light microscopy and dynamic light scattering analysis. In vitro studies in Franz-type static diffusion cells showed that chrysin release from CS-ME followed zero-order kinetics. Oral administration of CS-ME in mice resulted in a statistically significantly reduction (p < 0.05) in carrageenan-induced mechanical hyperalgesia compared to the control group. Treatment with CS-ME also showed anti-inflammatory activity by significantly decreasing the TNF-α level (p < 0.01) and increasing that of IL-10 (p < 0.05) compared to the control group. These results suggest that the proposed microsystem is a promising vector for the release of chrysin, being able to improve its capacity to modulate inflammatory and nociceptive responses.

In vitro dissolution considerations associated with nano drug delivery systems

Nano drug delivery systems (NDDS) offer promising solution for the translation of future nanomedicines. As bioavailability and therapeutic outcomes can be improved by altering the drug release from these NDDS, it becomes essential to thoroughly understand their drug release kinetics. Moreover, U.S. Food and Drug Administration requires critical evaluation of potential safety, efficacy, and public health impacts of nanomaterials. Spiraling up market share of NDDS has also stimulated the pharmaceutical industry to develop their cost-effective generic versions after the expiry of patent and associated exclusivity. However, unlike the conventional dosage forms, the in vivo disposition of NDDS is highly intricate and different from their in vitro behavior. Significant challenges exist in the establishment of in vitro-in vivo correlation (IVIVC) due to incomplete understanding of nanoparticles' in vivo biofate and its impact on in vitro experimental protocols. A rational design of dissolution may serve as quality and quantity control tool and help develop a meaningful IVIVC for favorable economic implications. Clinically relevant drug product specifications (critical quality attributes) can be identified by establishing a link between in vitro performance and in vivo exposure. In vitro dissolution may also play a pivotal role to understand the dissolution-mediated clearance and safety of NDDS. Prevalent in vitro dissolution methods for NDDS and their limitations are discussed in this review, among which USP 4 is gaining more interest recently. Researchers are working diligently to develop biorelevant in vitro release assays to ensure optimal therapeutic performance of generic versions of these NDDS. This article focuses on these studies and presents important considerations for the future development of clinically relevant in vitro release methods. This article is categorized under: Toxicology and Regulatory Issues in Nanomedicine > Regulatory and Policy Issues in Nanomedicine.

Fortification of Plant-Based Milk with Calcium May Reduce Vitamin D Bioaccessibility: An In Vitro Digestion Study

Many plant-based milks lack key micronutrients found in bovine milk, such as calcium and vitamin D. In this study, we fortified almond milk with these two micronutrients and used a standardized gastrointestinal model to examine the impact of product formulation on their bioaccessibility. The impact of different forms (CaCl₂ versus CaCO₃) and concentrations (0, 1, or 2 g per 240 mL) of calcium on the physicochemical properties, lipid digestibility, and vitamin D bioaccessibility was examined. Soluble calcium (CaCl₂) promoted particle aggregation by reducing the electrostatic repulsion, while colloidal calcium (CaCO₃) did not because there were fewer free calcium ions. High levels of calcium (soluble or insoluble) reduced vitamin D bioaccessibility, which was attributed to insoluble calcium soap formation in the small intestine. Calcium bioaccessibility was higher for CaCO₃ than CaCl₂. These findings are useful for the development of nutritionally fortified plant-based milks with improved physicochemical and nutritional properties.

Dermal Delivery Enhancement of Natural Anti-Ageing Compounds from Ocimum sanctum Linn. Extract by Nanostructured Lipid Carriers

This study aimed to develop nanodelivery systems for enhancing the Ocimum sanctum Linn. extract delivery into the skin. Rosmarinic acid (RA) was used as a marker for the quantitative determination of the extract by high-performance liquid chromatography. Nanostructured lipid carriers (NLC), nanoemulsion, liposome, and niosome, were developed and characterized for internal droplet size, polydispersity index (PDI), and zeta potential using photon correlation spectroscopy. Irritation properties of each formulations were investigated by hen's egg test on the chorioallantoic membrane. In vitro release, skin permeation, and skin retention are determined. NLC was suggested as the most suitable system since it enhances the dermal delivery of RA with the significant skin retention amount of 27.1 ± 1.8% (p < 0.05). Its internal droplet size, PDI, and zeta potential were 261.0 ± 5.3 nm, 0.216 ± 0.042, and -45.4 ± 2.4 mV, respectively. RA released from NLC with a sustained release pattern with the release amount of 1.29 ± 0.15% after 24 h. NLC induced no irritation and did not permeate through the skin. Therefore, NLC containing O. sanctum extract was an attractive dermal delivery system that was safe and enhanced dermal delivery of RA. It was suggested for further used as topical anti-ageing products.

A dialysis-based in vitro drug release assay to study dynamics of the drug-protein transfer of temoporfin liposomes

Today, a growing number of nanotherapeutics is utilized to deliver poorly soluble compounds using the intravenous route of administration. The drug release and the direct transfer of the active pharmaceutical ingredient to serum proteins plays an important role in bioavailability and accumulation of the drug at the target site. It is closely related to the formation of a protein corona as well as the plasma protein binding of the compound. In the present study, two in vitro drug release methods, the flow-through cell and the dispersion releaser technology, were evaluated with regards to their capability to measure a time-resolved profile of the serum protein binding. In this context, the photosensitizer temoporfin and temoporfin-loaded liposomes were tested. While in the fine capillaries of the flow-through cell a rapid agglomeration of proteins occurred, the dispersion releaser technology in combination with the four-step model enabled the measurement of the transfer of drugs from liposomes to proteins. In presence of 10% of fetal calf serum approximately 20% of the model compound temoporfin were bound to serum proteins within the first 3 h. At higher serum concentration this binding remained stable for approximately 10 h.

In Vitro Release Test of Nano-drug Delivery Systems Based on Analytical and Technological Perspectives

Background:

Nanotech products are gaining more attention depending on their advantages for improving drug solubility, maintenance of drug targeting, and attenuation of drug toxicity. In vitro release test is the critical physical parameter to determine the pharmaceutical quality of the product, to monitor formulation design and batch-to-batch variation.

Methods:

Spectrophotometric and chromatographic methods are mostly used in quantification studies from in vitro release test of nano-drug delivery systems. These techniques have advantages and disadvantages with respect to each other considering dynamic range, selectivity, automation, compatibility with in vitro release media and cost per sample.

Results:

It is very important to determine the correct kinetic profile of active pharmaceutical substances. At this point, the analytical method used for in vitro release tests has become a very critical parameter to correctly assess the profiles. In this review, we provided an overview of analytical methods applied to the in vitro release assay of various nanopharmaceuticals.

Conclusion:

This review presents practical direction on analytical method selection for in vitro release test on nanopharmaceuticals. Moreover, precautions on analytical method selection, optimization and validation were discussed.

A systematic review on nanoencapsulation of food bioactive ingredients and nutraceuticals by various nanocarriers

Today, there is an ever-growing interest on natural food ingredients both by consumers and producers in the food industry. In fact, people are looking for those products in the market which are free from artificial and synthetic additives and can promote their health. These food bioactive ingredients should be formulated in such a way that protects them against harsh process and environmental conditions and safely could be delivered to the target organs and cells. Nanoencapsulation is a perfect strategy for this situation and there have been many studies in recent years for nanoencapsulation of food components and nutraceuticals by different technologies. In this review paper, our main goal is firstly to have an overview of nanoencapsulation techniques applicable to food ingredients in a systematic classification, i.e., lipid-based nanocarriers, nature-inspired nanocarriers, special-equipment-based nanocarriers, biopolymer nanocarriers, and other miscellaneous nanocarriers. Then, application of these cutting-edge nanocarriers for different nutraceuticals including phenolic compounds and antioxidants, natural food colorants, antimicrobial agents and essential oils, vitamins, minerals, flavors, fish oils and essential fatty acids will be discussed along with presenting some examples in each field.

The dispersion releaser technology is an effective method for testing drug release from nanosized drug carriers

The dispersion releaser (DR) is a dialysis-based setup for the analysis of the drug release from nanosized drug carriers. It is mounted into dissolution apparatus2 of the United States Pharmacopoeia. The present study evaluated the DR technique investigating the drug release of the model compound flurbiprofen from drug solution and from nanoformulations composed of the drug and the polymer materials poly (lactic acid), poly (lactic-co-glycolic acid) or Eudragit®RSPO. The drug loaded nanocarriers ranged in size between 185.9 and 273.6nm and were characterized by a monomodal size distribution (PDI<0.1). The membrane permeability constants of flurbiprofen were calculated and mathematical modeling was applied to obtain the normalized drug release profiles. For comparing the sensitivities of the DR and the dialysis bag technique, the differences in the membrane permeation rates were calculated. Finally, different formulation designs of flurbiprofen were sensitively discriminated using the DR technology. The mechanism of drug release from the nanosized carriers was analyzed by applying two mathematical models described previously, the reciprocal powered time model and the three parameter model.

The effect of anionic dicephalic surfactants on fabrication of varied-core nanocarriers for sustained release of porphyrin photosensitizers

Double-headed anionic surfactants could provide a profound group of efficient stabilizers of new template-mediated nanocarriers for effective encapsulation and sustained release of highly hydrophobic photosensitizers, and therefore their improved therapeutic activity in photodynamic therapy (PDT) protocols. We have thus encapsulated porphyrin-origin dyes, i.e., verteporfin (VP) and meso-tetraphenylporphyrin (TPP) in different types of sodium alkyliminobisacetates, C_n(COONa)₂-stabilized nanosystems including biocompatible poly(l-glutamic acid)/poly(l-lysine) - PGA/PLL, multilayer nanocapsules (NCs). The latter were prepared via a layer-by-layer (LbL) approach with either solid (nanoprecipitated), or liquid (nanoemulsion-templated) oil core while zeta potential measurements enabled to evaluate progress of the polyelectrolytes LbL deposition on both cores and the NCs' stability. Backscattering profiles (BS) confirmed the long-lasting stability of the optimized nanosystems, which size (<200nm), polidyspersity and morphology were examined by dynamic light scattering (DLS) and atomic force microscopy (AFM) techniques. Our studies indicated that the encapsulation of VP and TPP in the both type of multilayer NCs increases their solubility in aqueous solution and protects them from the surrounding medium. Mainly, it reduces the photobleaching rate of these porphyrin-type photosensitizers and improves their photochemical properties during irradiation in regards to the free (non-encapsulated) molecules. As far as the core-type is considered, both nanoemulsion-loaded porphyrins, photobleached ca. 15-20% faster than the solid nanoparticle analogs. By using 9,10-anthracenediyl-bis(methylene)dimalonic acid (ABMDMA) as a singlet oxygen (¹O₂) scavenger molecule, the enhanced generation of reactive species was evaluated for the both encapsulated photosensitizers in comparison to their native form. In vitro sustained release under physiological conditions or in the presence of human serum albumin (HSA) was achieved in favor of the solid core NCs for VP and TPP. The designed NCs - offering better chemical and physical stability, high loading capacity for the cargo and ability to release it in a controlled and continuous manner - can be considered as efficacious nanocarriers for PDT.

Design and optimization of self-nanoemulsifying drug delivery systems for improved bioavailability of cyclovirobuxine D

Background

The main purpose of this research was to design a self-nanoemulsifying drug delivery system (SNEDDS) for improving the bioavailability of cyclovirobuxine D as a poorly water-soluble drug.

Materials and methods

Solubility trials, emulsifying studies, and pseudo-ternary phase diagrams were used to screen the SNEDDS formulations. The optimized drug-loaded SNEDDS was prepared at a mass ratio of 3:24:38:38 for cyclovirobuxine D, oleic acid, Solutol SH15, and propylene glycol, respectively. The optimized formulation was characterized in terms of physicochemical and pharmacokinetic parameters compared with marketed cyclovirobuxine D tablets.

Results

The optimized cyclovirobuxine-D-loaded SNEDDS was spontaneously dispersed to form a nanoemulsion with a globule size of 64.80±3.58 nm, which exhibited significant improvement of drug solubility, rapid absorption rate, and enhanced area under the curve, together with increased permeation and decreased efflux. Fortunately, there was a nonsignificant cytotoxic effect toward Caco-2 cells. The relative bioavailability of SNEDDS was 200.22% in comparison with market tablets, in rabbits.

Conclusion

SNEDDS could be a potential candidate for an oral dosage form of cyclovirobuxine D with improved bioavailability.

Denatured globular protein and bile salt-coated nanoparticles for poorly water-soluble drugs: Penetration across the intestinal epithelial barrier into the circulation system and enhanced oral bioavailability

Oral drug delivery is the most preferred route for patients; however, the low solubility of drugs and the resultant poor absorption compromise the benefits of oral administration. On the other hand, for years, the overwhelmingly accepted mechanism for enhanced oral absorption using lipid nanocarriers was based on the process of lipid digestion and drug solubilization in the small intestine. Few reports indicated that other bypass pathways are involved in drug absorption in the gastrointestinal tract (GIT) for oral delivery of nanocarriers. Herein, we report a new nanoemulsion system with a denatured globular protein with a diameter of 30 nm, soybean protein isolates (SPI), and bile salt as emulsifiers, aiming to enhance the absorption of insoluble drugs and explore other pathways for absorption. A BCS class II drug, fenofibrate (FB), was used as the model drug. The SPI and bile salt-coated Ns with a diameter of approximately 150 nm were prepared via a high-pressure homogenizing procedure. Interestingly, the present Ns could be converted to solid dosage form using fluid-bed coating technology, maintaining a nanoscale size. Most importantly, in a model of in situ rat intestinal perfusion, Ns could penetrate across the intestinal epithelial barrier into the systemic circulation and then obtain biodistribution into other tissues. In addition, Ns significantly improved FB oral absorption, exhibited as a greater than 2- and 2.5-fold increase in Cmax and AUC0-t, respectively, compared to the suspension formulation. Overall, the present Ns are promising nanocarriers for the oral delivery of insoluble drugs, and the penetration of intact Ns across the GIT barrier into systemic circulation may be a new strategy for improved drug absorption with the use of nanocarriers.

A miniaturized in vitro release method for investigating drug-release mechanisms

We have evaluated a miniaturized in vitro method, based on the μDISS Profiler™ technique that enables on-line monitoring of drug release from a 21 μl sample with 10 ml of release medium. Four model drugs in eight clinically used formulations, including both solid and non-solid drug delivery systems, were investigated. The acquired data were compared with historical in vitro release data from the same formulations. Use of the Weibull function to describe the in vitro drug-release profiles allowed discrimination between the selected formulations with respect to the drug-release mechanisms. Comparison of the release data from the same formulation in different in vitro set-ups showed that the methodology used can affect the mechanism of in vitro release. We also evaluated the ability of the in vitro methods to predict in vivo activity by comparing simulated plasma concentration-time profiles acquired from the application of the biopharmaceutical software GI-Sim to the in vitro observations. In summary, the simulations based on the miniaturized-method release data predicted the plasma profiles as well as or more accurately than simulations based on the historical release data in 71% of the cases and this miniaturized in vitro method appears to be applicable for both solid and non-solid formulations.