Influence of the introduction of a solubility enhancer on the formulation of lipidic nanoparticles with improved drug loading rates

Characterization and bioavailability of a novel coenzyme Q10 nanoemulsion used as an infant formula supplement

Supplementation with Coenzyme Q₁₀ (CoQ₁₀), in patients with its deficiency, has greater odds of success if the treatment is carried out early with an appropriate formulation. For neonatal CoQ₁₀ deficiency, infant formula supplementation could be an attractive option. However, solid CoQ₁₀ cannot be solubilized or dispersed in milk matrix leading to an inefficient CoQ₁₀ dosage and poor intestinal absorption. We developed and characterized a high-dose CoQ₁₀ oil-in-water (O/W) nanoemulsion suitable to supplement infant formula without modifying its organoleptic characteristics. CoQ₁₀ powder and soy lecithin were solubilized in an oil phase consisted of Labrasol® and Labrafac^TM. The aqueous phase was Tween 80, TPGS, methylparaben and propylparaben. O/W nanoemulsion was prepared by adding dropwise the oil phase to the aqueous phase under stirring to a final concentration of CoQ₁₀ 9.5 % w/w followed by ultrasonic homogenization. Pharmacotechnical parameters were determined. This formulation resulted to be easily to be dispersed in milk matrix, stable for at least 90 days, with no cytotoxicity in in vitro assays, and higher bioavailability than CoQ₁₀ powder. CoQ₁₀ nanoemulsion supplementation in the infant formula facilitates the individualized administration for the child with accurate dosage, overcome swallowing difficulties and in turn could increase the treatment adherence and efficacy.

Formulation of Lipid-Based Nanoparticles for Simultaneous Delivery of Lapatinib and Anti-Survivin siRNA for HER2+ Breast Cancer Treatment

In this work, lipid-based nanoparticles (LBNP) were designed to combine tyrosine kinase inhibitor (TKI) Lapatinib (LAPA) with siRNA directed against apoptosis inhibitor protein Survivin (siSurvivin) in an injectable form. This nanosystem is based on lipid nanocapsules (LNCs) coated with a cationic polymeric shell composed of chitosan grafted through a transacylation reaction. The hydrophobic LAPA is solubilized in the inner oily core, while hydrophilic siRNA is associated electrostatically onto the nanocarrier’s surface. The co-loaded LBNP showed a narrow size distribution (polydispersity index (PDI) < 0.3), a size of 130 nm, and a slightly positive zeta potential (+21 mV). LAPA and siRNA were loaded in LBNP at a high rate of >90% (10.6 mM) and 100% (4.6 µM), respectively. The siRNA-LAPA_LBNP was readily uptaken by the human epidermal growth factor receptor 2 overexpressed (HER2+) breast cancer cell line SK-BR-3. Moreover, the cytotoxicity studies confirmed that the blank chitosan decorated LBNP is not toxic to the cells with the tested concentrations, which correspond to LAPA concentrations from 1 to 10 µM, at different incubation times up to 96 h. Furthermore, siCtrl.-LAPA_LBNP had a more cytotoxic effect than Lapatinib salt, while siSurvivin-LAPA_LBNP had a significant synergistic cytotoxic effect compared to siCtrl.-LAPA_LBNP. All these findings suggested that the developed modified LBNP could potentiate anti-Survivin siRNA and LAPA anti-cancer activity.

Design of Non-Haemolytic Nanoemulsions for Intravenous Administration of Hydrophobic APIs

Among advanced formulation strategies, nanoemulsions are considered useful drug-delivery systems allowing to improve the solubility and the bioavailability of lipophilic drugs. To select safe excipients for nanoemulsion formulation and to discard any haemolytic potential, an in vitro miniaturized test was performed on human whole blood. From haemolysis results obtained on eighteen of the most commonly used excipients, a medium chain triglyceride, a surfactant, and a solubilizer were selected for formulation assays. Based on a design of experiments and a ternary diagram, the feasibility of nanoemulsions was determined. The composition was defined to produce monodisperse nanodroplets with a diameter of either 50 or 120 nm, and their physicochemical properties were optimized to be suitable for intravenous administration. These nanoemulsions, stable over 21 days in storage conditions, were shown to be able to encapsulate with high encapsulation efficiency and high drug loading, up to 16% (w/w), two water practically insoluble drug models: ibuprofen and fenofibrate. Both drugs may be released according to a modulable profile in sink conditions. Such nanoemulsions appear as a very promising and attractive strategy for the efficient early preclinical development of hydrophobic drugs.

Long lasting in-situ forming implant loaded with raloxifene HCl: An injectable delivery system for treatment of bone injuries

Bone injury is very serious in elder people or osteoporotic patients. In-situ forming implants (IFI) for bone rebuilding are usually poly-lactic-co-glycolic acid (PLGA)-based, which have a burst release effect. This study aimed to prepare novel liquid lipid-based PLGA-IFI loaded with raloxifene hydrochloride for prolonged non-surgical treatment of bone injuries by applying solvent-induced phase inversion technique. Labrasol® and Maisine® were added to the selected IFI forming long lasting lipid-based IFI (LLL-IFI). The formulations were characterized by analysing their in-vitro drug release, solidification time, injectability, rheological properties, and DSC in addition to their morphological properties. Results revealed that the LLL-IFI composed of 10%w/v PLGA with a lactide to glycolide ratio of 75:25 with ester terminal and 10% Maisine® possessed the most sustained drug release and lowest burst effect, as well as delayed pore formation compared to its counterpart lacking Maisine®. The selected LLL-IFI and PLGA-IFI formulations were tested for their capability to enhance bone regeneration in bone injuries induced in rats. Both formulations succeeded in healing the bones completely with the superiority of LLL-IFI in the formation of well-organized bone structures lacking fibrous tissues. The results suggest that LLL-IFI and PLGA-IFI are innovative approaches for treating critical and non-critical sized bone injuries.

Comparison of 2 strategies to enhance pyridoclax solubility: Nanoemulsion delivery system versus salt synthesis

Pyridoclax is an original oligopyridine lead, very promising in treatment of chemoresistant cancers. However, from solubility measurement and permeability evaluation, it appeared that this compound can be considered as a BCS II drug, with a poor water solubility. To overcome this unfavorable property, two strategies were proposed and compared: pyridoclax di-hydrochloride salt synthesis and formulation of pyridoclax-loaded nanoemulsions (PNEs) efficiently performed by transposing the spontaneous emulsification process previously developed by our team. Whereas the salt improved the thermodynamic solubility of the drug by a factor 4, the apparent solubility of the encapsulated pyridoclax was 1000-fold higher. Their stability was assessed upon dilution in various complex biomimetic media relevant for oral administration (SGF, FaSSIF-V2, FeSSIF-V2) or for the intravenous route (PBS). The solubility of the salt was affected by the nature of the medium, indicating that it could precipitate after administration, negatively impacting its bioavailability and its efficiency in vivo. On the contrary, in all media, PNEs remained stable in terms of granulometric properties (determined by DLS), ζ-potential and encapsulation efficiency (measured by HPLC). Thus, such nanomedicines appear as a valuable option to perform preclinical studies on the promising pyridoclax.

Evaluation of the versatile character of a nanoemulsion formulation

The formulate-ability of six model active pharmaceutical ingredients (API), with different physico-chemical profiles, in a nanoemulsion designed to be intraveinously administrable was explored. Nanoemulsions were spontaneously generated at room temperature by pouring a phosphate buffer in an anhydrous mixture containing pharmaceutically acceptable triglycerides and non-ionic surfactants. After determination of the apparent solubility of each API in excipients and characterization of mixtures by DSC, API-loaded nanoemulsions were formulated and characterized in terms of granulometric properties, surface potential, drug recovery efficiency, pH, osmolarity, in vitro drug release, and stability. Except ciprofloxacin, a BCS class IV drug, all studied APIs were soluble in at least one excipient used, i.e. Labrasol. At 2 wt% API, all drug-loaded nanoemulsions present properties compatible with i.v. administration. The formulation should permit to increase apparent solubility of poorly water-soluble APIs, and also to prolong delivery of hydrophobic as well of more hydrophilic compounds. Herein, the relative affinity of the API for nanodroplets and the release medium would directly influence drug release profiles. Nanoemulsions were stable for 7 days. They could also been extemporaneously reconstituted before use. Such a versatile nanoemulsion would provide a valuable option as formulation strategy for improvement of drug properties.

Formulation and nebulization of fluticasone propionate-loaded lipid nanocarriers

Inhaled fluticasone propionate (FP) is often prescribed as a first-line therapy for the effective management of pulmonary diseases such as asthma. As nanocarriers offer many advantages over other drug delivery systems, this study investigated the suitability of lipid nanocapsules (LNCs) as a carrier for fluticasone propionate, examining the drug-related factors that should be considered in the formulation design and the behaviour of LNCs with different compositions and properties suspended within aerosol droplets under the relatively hostile conditions of nebulization. By adjusting the formulation conditions, particularly the nanocarrier composition, FP was efficiently encapsulated within the LNCs with a yield of up to 97%, and a concentration comparable to commercially available preparations was achieved. Moreover, testing the solubility of the drug in oil and water and determining the oil/water partition coefficient proved to be useful when assessing the encapsulation of the FP in the LNC formulation. Nebulization did not cause the FP to leak from the formulation, and no phase separation was observed after nebulization. LNCs with a diameter of 100 nm containing a smaller amount of surfactant and a larger amount of oil provided a better FP-loading capacity and better stability during nebulization than 30 or 60 nm LNCs.

Rapid and soft formulation of folate-functionalized nanoparticles for the targeted delivery of tripentone in ovarian carcinoma

We report the development of folate-functionalized nanoparticles able to target folate receptors, and to deliver a poorly water soluble cytotoxic agent, a tripentone, in ovarian carcinoma. The stability under incubation of lipid nanoparticles formulated by a low-energy phase inversion temperature method was investigated. Thanks to the presence of Labrasol(®), a macrogolglyceride into the composition of the nanocarriers, the conjugation of different quantities of a folate derivate (folic acid-polyethylene glycol2000-distearylphosphatidylethanolamine) to nanoparticles was possible by a rapid, soft, very simple post-insertion process. As determined by dynamic light scattering, nanoparticles present a monodisperse diameter of about 100 nm, a spherical shape as attested by transmission electron micrographs, a weakly negative surface zeta potential, and are able to encapsulate the tripentone MR22388. The presence of folate receptors on SKOV3 human ovarian cancer cells was identified by fluorescent immunocytochemistry. Cellular uptake studies assessed by flow cytometry indicated that these nanoparticles reached the SKOV3 cells rapidly, and were internalized by a folate-receptor mediated endocytosis pathway. Moreover, nanoparticles allowed the rapid delivery of the antitumor agent tripentone into cells as shown in vitro by real-time cellular activity assay. Such folate-lipid nanoparticles are a potential carrier for targeted delivery of poorly water soluble compounds into ovarian carcinoma.