Production & stability of stavudine solid lipid nanoparticles—From lab to industrial scale

Engineered urolithin A-laden functional polymer-lipid hybrid nanoparticles prevent cisplatin-induced proximal tubular injury in vitro

Functional polymer-lipid hybrid nanoparticles (H-NPs) are a promising class of nanocarriers that combine the benefits of polymer and lipid nanoparticles, offering biocompatibility, structural stability, high loading capacity, and, most importantly, superior surface functionalization. Here, we report the synthesis and design of highly functional H-NPs with specificity toward the transferrin receptor (TfR), using a small molecule ligand, gambogic acid (GA). A fluorescence study revealed the molecular orientation of H-NPs, where the lipid-dense core is surrounded by a polymer exterior, functionalized with GA. Urolithin A, an immunomodulator and anti-inflammatory agent, served as a model drug-like compound to prepare H-NPs via traditional emulsion-based techniques, where H-NPs led to smaller particles (132 nm) and superior entrapment efficiencies (70 % at 10 % drug loading) compared to GA-conjugated polymeric nanoparticles (P-NPs) (157 nm and 52 % entrapment efficiency) and solid lipid nanoparticles (L-NPs) (186 nm and 29 % entrapment efficiency). H-NPs showed superior intracellular accumulation compared to individual NPs using human small intestinal epithelial (FHs 74) cells. The in vitro efficacy was demonstrated by flow cytometry analysis, in which UA-laden H-NPs showed excellent anti-inflammatory properties in cisplatin-induced injury in healthy human proximal tubular cell (HK2) model by decreasing the TLR4, NF-κβ, and IL-β expression. This preliminary work highlights the potential of H-NPs as a novel functional polymer-lipid drug delivery system, establishing the foundation for future research on its therapeutic potential in addressing chemotherapy-induced acute kidney injury in cancer patients.

On the Structure, Stability, and Cell Uptake of Nanostructured Lipid Carriers for Drug Delivery

The efficacy of nanostructured lipid carriers (NLC) for drug delivery strongly depends on their stability and cell uptake. Both properties are governed by their compositions and internal structure. To test the effect of the lipid composition of NLC on cell uptake and stability, three kinds of liquid lipids with different degrees of unsaturation are employed. After ensuring homogeneous size distributions, the thermodynamic characteristics, stability, and mixing properties of NLC are characterized. Then the rates and predominant pathways of cell uptake are determined. Although the same surfactant is used in all cases, different uptake rates are observed. This finding contradicts the view that the surface properties of NLC are dominated by the surfactant. Instead, the uptake rates are explained by the structure of the nanocarrier. Depending on the mixing properties, some liquid lipids remain inside the nanocarrier, while other liquid lipids are present on the surface. Nanocarriers with liquid lipids on the surface are taken up more readily by the cells. This shows that the engineering of efficient lipid nanocarriers requires a delicate balance of interactions between all components of the nanocarrier on the molecular level.

Toward the scale-up production of polymeric nanotherapeutics for cancer clinical trials

Nanotherapeutics have gained significant attention for the treatment of numerous cancers, primarily because they can accumulate in and/or selectively target tumors leading to improved pharmacodynamics of encapsulated drugs. The flexibility to engineer the nanotherapeutic characteristics including size, morphology, drug release profiles, and surface properties make nanotherapeutics a unique platform for cancer drug formulation. Polymeric nanotherapeutics including micelles and dendrimers represent a large number of formulation strategies developed over the last decade. However, compared to liposomes and lipid-based nanotherapeutics, polymeric nanotherapeutics have had limited clinical translation from the laboratory. One of the key limitations of polymeric nanotherapeutics formulations for clinical translation has been the reproducibility in preparing consistent and homogeneous large-scale batches. In this review, we describe polymeric nanotherapeutics and discuss the most common laboratory and scale-up formulation methods, specifically those proposed for clinical cancer therapies. We also provide an overview of the major challenges and opportunities for scaling polymeric nanotherapeutics to clinical-grade formulations. Finally, we will review the regulatory requirements and challenges in advancing nanotherapeutics to the clinic.

Lipid-Based Nanoparticles as Oral Drug Delivery Systems: Overcoming Poor Gastrointestinal Absorption and Enhancing Bioavailability of Peptide and Protein Therapeutics

Delivery and formulation of oral peptide and protein therapeutics have always been a challenge for the pharmaceutical industry. The oral bioavailability of peptide and protein therapeutics mainly relies on their gastrointestinal solubility and permeability which are affected by their poor membrane penetration, high molecular weight and proteolytic (chemical and enzymatic) degradation resulting in limited delivery and therapeutic efficacy. The present review article highlights the challenges and limitations of oral delivery of peptide and protein therapeutics focusing on the application, potential and importance of solid lipid nanoparticles (SLNs) and nanostructured lipid carriers (NLCs) as lipid-based drug delivery systems (LBDDSs) and their advantages and drawbacks. LBDDSs, due to their lipid-based matrix can encapsulate both lipophilic and hydrophilic drugs, and by reducing the first-pass effect and avoiding proteolytic degradation offer improved drug stability, dissolution rate, absorption, bioavailability and controlled drug release. Furthermore, their small size, high surface area and surface modification increase their mucosal adhesion, tissue-targeted distribution, physiological function and half-life. Properties such as simple preparation, high-scale manufacturing, biodegradability, biocompatibility, prolonged half-life, lower toxicity, lower adverse effects, lipid-based structure, higher drug encapsulation rate and various drug release profile compared to other similar carrier systems makes LBDDSs a promising drug delivery system (DDS). Nevertheless, undesired physicochemical features of peptide and protein drug development and discovery such as plasma stability, membrane permeability and circulation half-life remain a serious challenge which should be addressed in future.

Rheumatoid Arthritis Treatment Potential of Stearic Acid Nanoparticles of Quercetin in Rats

This study aims to assess the anti-inflammatory potential of stearic acid nanoparticles of quercetin in an arthritic rat model. This article describes the fabrication of solid lipid nanoparticles (SLNs) using the hot melt encapsulation method, followed by the anti-inflammatory study of SLNs and other characterizations such as FTIR, XRD, and SEM. Thirty male healthy albino rats were taken and treated with FCA to induce rheumatoid arthritis. Quercetin loading of quercetin to stearic acid was confirmed by FTIR. The efficacy of quercetin-loaded SLNs to reduce inflammation was evaluated with the help of inflammatory biomarker levels. Quercetin-loaded stearic acid nanoparticles were successfully prepared by using a hot melt encapsulation method. Their average size and zeta potential were 100 nm and -25 mV, respectively. Rheumatoid arthritis was significantly (p < 0.001) reduced in the quercetin-loaded SLN group, as indicated by finding out the reduced levels of inflammatory mediators such as tumor necrosis factor (TNF-α) and rheumatoid factor. Quercetin-loaded stearic acid nanoparticles were found to be potentially effective in treating RA.

Chemistry and Art of Developing Lipid Nanoparticles for Biologics Delivery: Focus on Development and Scale-Up

Lipid nanoparticles (LNPs) have gained prominence as primary carriers for delivering a diverse array of therapeutic agents. Biological products have achieved a solid presence in clinical settings, and the anticipation of creating novel variants is increasing. These products predominantly encompass therapeutic proteins, nucleic acids and messenger RNA. The advancement of efficient LNP-based delivery systems for biologics that can overcome their limitations remains a highly favorable formulation strategy. Moreover, given their small size, biocompatibility, and biodegradation, LNPs can proficiently transport therapeutic moiety into the cells without significant toxicity and adverse reactions. This is especially crucial for the existing and upcoming biopharmaceuticals since large molecules as a group present several challenges that can be overcome by LNPs. This review describes the LNP technology for the delivery of biologics and summarizes the developments in the chemistry, manufacturing, and characterization of lipids used in the development of LNPs for biologics. Finally, we present a perspective on the potential opportunities and the current challenges pertaining to LNP technology.

Lipid-Based Nanoparticles for Drug/Gene Delivery: An Overview of the Production Techniques and Difficulties Encountered in Their Industrial Development

Over the past decade, the therapeutic potential of nanomaterials as novel drug delivery systems complementing conventional pharmacology has been widely acknowledged. Among these nanomaterials, lipid-based nanoparticles (LNPs) have shown remarkable pharmacological performance and promising therapeutic outcomes, thus gaining substantial interest in preclinical and clinical research. In this review, we introduce the main types of LNPs used in drug formulations such as liposomes, nanoemulsions, solid lipid nanoparticles, nanostructured lipid carriers, and lipid polymer hybrid nanoparticles, focusing on their main physicochemical properties and therapeutic potential. We discuss computational studies and modeling techniques to enhance the understanding of how LNPs interact with therapeutic cargo and to predict the potential effectiveness of such interactions in therapeutic applications. We also analyze the benefits and drawbacks of various LNP production techniques such as nanoprecipitation, emulsification, evaporation, thin film hydration, microfluidic-based methods, and an impingement jet mixer. Additionally, we discuss the major challenges associated with industrial development, including stability and sterilization, storage, regulatory compliance, reproducibility, and quality control. Overcoming these challenges and facilitating regulatory compliance represent the key steps toward LNP's successful commercialization and translation into clinical settings.

The role of silver nanoparticles effects in the homeostasis of metals in soybean cultivation through qualitative and quantitative laser ablation bioimaging

BACKGROUND

Nanoparticles (NPs) are currently found in the world in the form of natural colloids and volcanic ash, as well as in anthropogenic sources, such as nanofertilizers; however, in the literature, there is still a lack of toxicological evidence, risk assessment, and regulations about the use and environmental impact of NPs in the agroindustrial system. Therefore, the aim of this work was to evaluate alterations caused by the presence of AgNPs during the development of soybean plants.

METHODS

The BRS232 non-transgenic (NT) soybean plant and 8473RR (T_RR) and INTACTA RR2 PRO (T_Intacta) transgenic soybean plants were irrigated for 18 days under controlled conditions with deionized water (control), AgNPs, and AgNO₃. The isotopes ¹⁰⁷Ag⁺, ⁵⁵Mn⁺, ⁵⁷Fe⁺, ⁶³Cu⁺, and ⁶⁴Zn⁺ were mapped in leaves, using ¹³C⁺ as an internal standard (IS), and carried out using a laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) technique with a Nd:YAG (213 nm) laser source in the imagagin mode using the LA-iMageS software and also Mathlab.

RESULTS

Leaf images showed a low Ag translocation, indicated by the basal signal of this ion. Additionally, the presence of Ag in the ionic form and as NPs altered the homeostasis of ¹¹²Cd⁺, ⁶⁴Zn⁺, ⁵⁵Mn⁺, ⁶³Cu⁺, and ⁵⁷Fe⁺ in different ways. Quantitative image analysis was performed for Cu.

CONCLUSION

The behavior of T_RR and T_Intacta plants was different in the presence of ionic silver or AgNPs, confirming that the metabolism of these two plants, despite both being transgenic, are different. Through the images, it was observed that the response of plants was different in the face of the same stress conditions during their development.

Novel triphenylphosphonium amphiphilic conjugates of glycerolipid type: synthesis, cytotoxic and antibacterial activity, and targeted cancer cell delivery

This work deals with the creation of new cationic triphenylphosphonium amphiphilic conjugates of glycerolipid type (TPP-conjugates), bearing a pharmacophore terpenoid fragment (abietic acid and betulin) and a fatty acid residue in one hybrid molecule as a new generation of antitumor agents with high activity and selectivity. The TPP-conjugates showed high mitochondriotropy leading to the development of mitochondriotropic delivery systems such as TPP-pharmacosomes and TPP-solid lipid particles. Introducing the betulin fragment into the structure of a TPP-conjugate (compound 10) increases the cytotoxicity 3 times towards tumor cells of prostate adenocarcinoma DU-145 and 4 times towards breast carcinoma MCF-7 compared to TPP-conjugate 4a in the absence of betulin. TPP-hybrid conjugate 10 with two pharmacophore fragments, betulin and oleic acid, has significant cytotoxicity toward a wide range of tumor cells. The lowest IC50 of 10 is 0.3 μM toward HuTu-80. This is at the level of the reference drug doxorubicin. TPP-pharmacosomes (10/PC) increased the cytotoxic effect approximately 3 times toward HuTu-80 cells, providing high selectivity (SI = 480) compared to the normal liver cell line Chang liver.

One-Step Pharmaceutical Preparation of PEG-Modified Exosomes Encapsulating Anti-Cancer Drugs by a High-Pressure Homogenization Technique

The use of exosomes encapsulating therapeutic agents for the treatment of diseases is of increasing interest. However, some concerns such as limited efficiency and scalability of conventional drug encapsulation methods to exosomes have still remained; thus, a new approach that enables encapsulation of therapeutic agents with superior efficiency and scalability is required. Herein, we used RAW264 macrophage cell-derived exosomes (RAW-Exos) and demonstrated that high-pressure homogenization (HPH) using a microfluidizer decreased their particle size without changing their morphology, the amount of exosomal marker proteins, and cellular uptake efficiency into RAW264 and colon-26 cancer cells. Moreover, HPH allowed for modification of polyethylene glycol (PEG)-conjugated lipids onto RAW-Exos, as well as encapsulation of the anti-cancer agent doxorubicin. Importantly, the doxorubicin encapsulation efficiency became higher upon increasing the process pressure and simultaneous HPH with PEG-lipids. Moreover, treatment with PEG-modified RAW-Exos encapsulating doxorubicin significantly suppressed tumor growth in colon-26-bearing mice. Taken together, these results suggest that HPH using a microfluidizer could be useful to prepare PEG-modified Exos encapsulating anti-cancer drugs via a one-step pharmaceutical process, and that the prepared functional Exos could be applied for the treatment of cancer in vivo.

Colloidal delivery of vitamin E into solid lipid nanoparticles as a potential complement for the adverse effects of anemia treatment

Vitamin E (VitE) is one of the most important antioxidants and plays a key role in decreasing the inflammatory effects of oxidative stress caused by recurrent doses of iron administration in anemia treatment. However, VitE is poorly soluble in aqueous environments. Here, VitE encapsulation into solid lipid nanoparticles (SLN) composed of myristil myristate to improve its bioavailability was proposed. A 99.9 ± 0.1% encapsulation efficiency with a drug/lipid ratio of 500 µg/mg and 478 higher VitE solubility was obtained. The antioxidant properties of VitE after encapsulation were maintained. SLN-VitE showed a 228.2 nm mean diameter with low polidispersitivity (0.335), and negative Z potential (ζ ≈ -9.0 mV). The SLN were well-dispersed, displayed spherical and homogeneous morphology by TEM. A controlled release of VitE from SLN was found. The XRD and FTIR analyses revealed the presence of a nanostructured architecture of SLN after VitE incorporation. We probed the safety of SLN-VitE after contact with three in vitro cell models: erythrocytes, lymphocytes and HepG2 cells. The cell viability in presence of SLN, SLN-VitE, and their combinations with iron was not affected. The comet assay demonstrated that the DNA damage caused by iron administration was decrease in presence of SLN-VitE.

Review on the Scale-Up Methods for the Preparation of Solid Lipid Nanoparticles

Solid lipid nanoparticles (SLNs) are an alternate carrier system to liposomes, polymeric nanoparticles, and inorganic carriers. SLNs have attracted increasing attention in recent years for delivering drugs, nucleic acids, proteins, peptides, nutraceuticals, and cosmetics. These nanocarriers have attracted industrial attention due to their ease of preparation, physicochemical stability, and scalability. These characteristics make SLNs attractive for manufacture on a large scale. Currently, several products with SLNs are in clinical trials, and there is a high possibility that SLN carriers will quickly increase their presence in the market. A large-scale manufacturing unit is required for commercial applications to prepare enough formulations for clinical studies. Furthermore, continuous processing is becoming more popular in the pharmaceutical sector to reduce product batch-to-batch differences. This review paper discusses some conventional methods and the rationale for large-scale production. It further covers recent progress in scale-up methods for the synthesis of SLNs, including high-pressure homogenization (HPH), hot melt extrusion coupled with HPH, microchannels, nanoprecipitation using static mixers, and microemulsion-based methods. These scale-up technologies enable the possibility of commercialization of SLNs. Furthermore, ongoing studies indicate that these technologies will eventually reach the pharmaceutical market.

Poly(N-vinylcaprolactam) containing solid lipid polymer hybrid nanoparticles for controlled delivery of a hydrophilic drug gemcitabine hydrochloride

Folic acid tagged and hydrophilic polymer containing solid lipid nanoparticles (SLNs) were formulated for the controlled and targeted delivery of gemcitabine, a hydrophilic drug. Drug loaded SLNs were prepared by double emulsion method and optimized by 32 level factorial design. Then, a hydrophilic polymer, namely, poly(N-vinylcaprolactam) (PVCL) was incorporated in the optimized SLN batch in the first aqueous phase (W1) to obtain solid lipid polymer hybrid nanoparticles (SLPHNs) that were further decorated with folic acid (F-SLPHNs). TEM analysis of SLNs and SLPHNs revealed the spherical shape with no aggregation while SLPHNs showed higher % EE. SLPHNs exhibited limited burst release of gemcitabine compared to SLNs as well as lower overall % release. All the formulations showed good cytocompatibility against MDA-MB-231 cell lines and folic acid-tagged hybrid particles (F-SLPHNs) showed remarkably higher cellular uptake.

Lipid-Based Nanocarrier Systems for Drug Delivery: Advances and Applications

Lipid-based nanocarriers have been extensively investigated for drug delivery due to their advantages including biodegradability, biocompatibility, nontoxicity, and nonimmunogenicity. However, the shortcomings of traditional lipid-based nanocarriers such as insufficient targeting, capture by the reticuloendothelial system, and fast elimination limit the efficiency of drug delivery and therapeutic efficacy. Therefore, a series of multifunctional lipid-based nanocarriers have been developed to enhance the accumulation of drugs in the lesion site, aiming for improved diagnosis and treatment of various diseases. In this review, we summarized the advances and applications of lipid-based nanocarriers from traditional to novel functional lipid preparations, including liposomes, stimuli-responsive lipid-based nanocarriers, ionizable lipid nanoparticles, lipid hybrid nanocarriers, as well as biomembrane-camouflaged nanoparticles, and further discussed the challenges and prospects of this system. This exploration may give a complete idea viewing the lipid-based nanocarriers as a promising choice for drug delivery system, and fuel the advancement of pharmaceutical products by materials innovation and nanotechnology.

Magnetic Solid Nanoparticles and Their Counterparts: Recent Advances towards Cancer Theranostics

Cancer is currently a leading cause of death worldwide. The World Health Organization estimates an increase of 60% in the global cancer incidence in the next two decades. The inefficiency of the currently available therapies has prompted an urgent effort to develop new strategies that enable early diagnosis and improve response to treatment. Nanomedicine formulations can improve the pharmacokinetics and pharmacodynamics of conventional therapies and result in optimized cancer treatments. In particular, theranostic formulations aim at addressing the high heterogeneity of tumors and metastases by integrating imaging properties that enable a non-invasive and quantitative assessment of tumor targeting efficiency, drug delivery, and eventually the monitoring of the response to treatment. However, in order to exploit their full potential, the promising results observed in preclinical stages need to achieve clinical translation. Despite the significant number of available functionalization strategies, targeting efficiency is currently one of the major limitations of advanced nanomedicines in the oncology area, highlighting the need for more efficient nanoformulation designs that provide them with selectivity for precise cancer types and tumoral tissue. Under this current need, this review provides an overview of the strategies currently applied in the cancer theranostics field using magnetic nanoparticles (MNPs) and solid lipid nanoparticles (SLNs), where both nanocarriers have recently entered the clinical trials stage. The integration of these formulations into magnetic solid lipid nanoparticles—with different composition and phenotypic activity—constitutes a new generation of theranostic nanomedicines with great potential for the selective, controlled, and safe delivery of chemotherapy.

Efficacy assessments of tretinoin-loaded nano lipid carriers in acne vulgaris: a double blind, split-face randomized clinical study

Here, we assessed the efficacy and safety of Nano lipid carrier (NLC) drug delivery system containing tretinoin (NLC-TRE) in comparison with the conventional 0.05% tretinoin cream (TRE cream) in mild to moderate acne vulgaris. A stable and appropriate NLC-TRE formulation was prepared using a high-pressure homogenizer and particle characterization and physicochemical properties were evaluated under accelerated conditions. Efficacy assessment was performed via a split-face clinical study, by comparing the number of acne lesions, porphyrin production and skin biophysical parameters in both sides of the face randomly treated with NLC-TRE and TRE cream. Plasma concentration of tretinoin after topical application of NLC-TRE was measured for primary safety evaluation. We acquired a stable, spherical nanoparticles with particle size of 118.5 nm, PI equal to 0.485 and ZP of - 44.7 mV. The rate of decrease of acne lesions was significantly higher in NLC- TRE side (p value < 0.001). The size and intensity of porphyrin production in pilosebaceous follicles were significantly reduced only on NLC-TRE side (p value < 0.01). The plasma concentration of the tretinoin, after 8 weeks' application remained lower than the toxic levels. The NLC-TRE formula provides better efficiency and good loading capacity of TRE in the drug delivery system.

Quality by design (QbD)-based fabrication of atazanavir-loaded nanostructured lipid carriers for lymph targeting: bioavailability enhancement using chylomicron flow block model and toxicity studies

Atazanavir (ATV) is widely used as anti-HIV agent having poor aqueous solubility needs to modulate novel drug delivery system to enhance therapeutic efficiency and safety. The main objective of the present work was to fabricate ATV-loaded nanostructured lipid carriers (NLCs) employing quality by design (QbD) approach to address the challenges of bioavailability and their safety after oral administration. Herein, the main objective was to identify the influencing variables for the production of quality products. Considering this objective, quality target product profile (QTPP) was assigned and a systematic risk assessment study was performed to identify the critical material attributes (CMAs) and critical process parameter (CPP) having an influence on critical quality attributes (CQAs). Lipid concentrations, surfactant concentrations, and pressure of high-pressure homogenizer were identified as CMAs and CPP. ATV-NLCs were prepared by emulsification-high pressure homogenization method and further lyophilized to obtain solid-state NLCs. The effect of formulation variables (CMAs and CPP) on responses like particle size (Y₁), polydispersity index (Y₂), and zeta potential (Y₃) was observed by central composite rotatable design (CCRD). The data were statistically evaluated by ANOVA for confirmation of a significant level (p < 0.05). The optimal conditions of NLCs were obtained by generating design space and desirability value. The lyophilized ATV-NLCs were characterized by DSC, powder X-ray diffraction, and FT-IR analysis. The morphology of NLCs was revealed by TEM and FESEM. In vitro study suggested a sustained release pattern of drug (92.37 ± 1.03%) with a mechanism of Korsmeyer-Peppas model (r² = 0.925, and n = 0.63). In vivo evaluation in Wistar rats showed significantly higher (p < 0.001) plasma drug concentration of ATV-NLCs as compared to ATV-suspension using chylomicron flow block model. The relative bioavailability of ATV-NLCs was obtained to be 2.54 folds. Thus, a safe and promising drug targeting system was successfully developed to improve bioavailability and avoiding first-pass effect ensures to circumvent the acute-toxicity of liver.

Different Microfluidic Environments for In Vitro Testing of Lipid Nanoparticles against Osteosarcoma

The use of lipid nanoparticles as biodegradable shells for controlled drug delivery shows promise as a more effective and targeted tumor treatment than traditional treatment methods. Although the combination of target therapy with nanotechnology created new hope for cancer treatment, methodological issues during in vitro validation of nanovehicles slowed their application. In the current work, the effect of methotrexate (MTX) encapsulated in different matrices was evaluated in a dynamic microfluidic platform. Effects on the viability of osteosarcoma cells in the presence of recirculation of cell media, free MTX and two types of blank and drug-containing nanoparticles were successfully assessed in different tumor-mimicking microenvironments. Encapsulated MTX was more effective than the equal dose free drug treatment, as cell death significantly increased under the recirculation of both types of drug-loaded nanoparticles in all concentrations. In fact, MTX-nanoparticles reduced cell population 50 times more than the free drug when 150-µM drug dose was recirculated. Moreover, when compared to the equivalent free drug dose recirculation, cell number was reduced 60 and 100 points more under recirculation of each nanoparticle with a 15-µM drug concentration. Thus, the results obtained with the microfluidic model present MTX-lipid nanoparticles as a promising and more effective therapy for pediatric osteosarcoma treatment than current treatment options.

Formulation development of itraconazole PEGylated nano-lipid carriers for pulmonary aspergillosis using hot-melt extrusion technology

Pulmonary delivery is a promising alternative for the oral treatment of pulmonary aspergillosis. This study aimed to develop continuous and scalable itraconazole PEGylated nano-lipid carriers (ITZ-PEG-NLC) for inhalation delivery. The feasibility of preparing NLCs utilizing hot-melt extrusion (HME) coupled with probe sonication was investigated. The process parameters for HME and sonication were varied to optimize the formulation. ITZ-PEG-NLC (particle size, 101.20 ± 1.69 nm; polydispersity index, 0.26 ± 0.01) was successfully formulated. The drug entrapment efficiency of ITZ-PEG-NLC was 97.28 ± 0.50%. Transmission electron microscopy was used to characterize the shape of the particles. The developed formulations were evaluated for their aerodynamic properties for pulmonary delivery. The lung deposition of ITZ-PEG-NLC was determined using an Anderson Cascade Impactor and Philips Respironics Sami the Seal Nebulizer Compressor. In vitro cytotoxicity studies were performed using A549 cells. A burst-release pattern was observed in ITZ-PEG-NLC with a drug release of 41.74 ± 1.49% in 60 min. The in vitro aerosolization of the ITZ-PEG-NLC formulation showed a mass median aerodynamic diameter of 3.51 ± 0.28 μm and a geometric standard deviation of 2.44 ± 0.49. These findings indicate that HME technology could be used for the production of continuous scalable ITZ-PEG-NLC.

An Update on Self-Amplifying mRNA Vaccine Development

This review will explore the four major pillars required for design and development of an saRNA vaccine: Antigen design, vector design, non-viral delivery systems, and manufacturing (both saRNA and lipid nanoparticles (LNP)). We report on the major innovations, preclinical and clinical data reported in the last five years and will discuss future prospects.

Streptomycin sulphate loaded solid lipid nanoparticles show enhanced uptake in macrophage, lower MIC in Mycobacterium and improved oral bioavailability

Present study addresses the challenge of incorporating hydrophilic streptomycin sulphate (STRS; log P -6.4) with high dose (1 g/day) into a lipid matrix of SLNs. Cold high-pressure homogenization technique used for SLN preparation achieved 30% drug loading and 51.17 ± 0.95% entrapment efficiency. Polyethylene glycol 600 as a supporting-surfactant assigned small size (218.1 ± 15.46 nm) and mucus-penetrating property. It was conceived to administer STRS-SLNs orally rather than intramuscularly. STRS-SLNs remained stable on incubation for varying times in SGF or SIF. STRS-SLNs were extensively characterised for microscopic (TEM and AFM), thermal (DSC), diffraction (XRD) and spectroscopic (NMR and FTIR) properties and showed zero-order controlled release. Enhanced (60 times) intracellular uptake was observed in THP-1 and Pgp expressing LoVo and DLD-1 cell lines, using fluorescein-SLNs. Presence of SLNs in LoVo cells was also revealed by TEM studies. STRS-SLNs showed 3 times reduction in MIC against Mycobacterium tuberculosis H37RV (256182) in comparison to free STRS. It also showed better activity against both M. bovis BCG and Mycobacterium tuberculosis H37RV (272994) in comparison to free STRS. Cytotoxicity and acute toxicity studies (OECD 425 guidelines) confirmed in vitro and in vivo safety of STRS-SLNs. Single-dose oral pharmacokinetic studies in rat plasma using validated LCMS/MS technique or the microbioassay showed significant oral absorption and bioavailability (160% - 710% increase than free drug).

Preparation of Solid Lipid Nanoparticles and Nanostructured Lipid Carriers for Drug Delivery and the Effects of Preparation Parameters of Solvent Injection Method

Solid lipid nanoparticles (SLNs) and nanostructured lipid carriers (NLCs) have emerged as potential drug delivery systems for various applications that are produced from physiological, biodegradable, and biocompatible lipids. The methods used to produce SLNs and NLCs have been well investigated and reviewed, but solvent injection method provides an alternative means of preparing these drug carriers. The advantages of solvent injection method include a fast production process, easiness of handling, and applicability in many laboratories without requirement of complicated instruments. The effects of formulations and process parameters of this method on the characteristics of the produced SLNs and NLCs have been investigated in several studies. This review describes the methods currently used to prepare SLNs and NLCs with focus on solvent injection method. We summarize recent development in SLNs and NLCs production using this technique. In addition, the effects of solvent injection process parameters on SLNs and NLCs characteristics are discussed.

Nanomaterials for cancer medication: from individual nanoparticles toward nanomachines and nanorobots

The nanomaterials for cancer medication are already reality providing a wide range of new tools and possibilities, from earlier diagnostics and improved imaging to better, more efficient, and more targeted anticancer therapies. The purpose of this critical review is to focus on the current use of clinically approved nanoparticles for cancer theranostic, nanovaccines and delivery platforms for gene therapy. These include inorganic, metal and polymer nanoparticles, nanocrystals and varieties of drug delivery nanosystems (micelles, liposomes, microcapsules and etc.). The recent progress in cancer nanomedicine enables to combine the benefits of individual nanoparticles with biomolecules into a multifunction nanomachines and even highly advanced nanorobots for targeted therapies. Nowadays clinical trials with advanced anticancer nanomachines provide potential for more accurately and effective identification and destruction of the cancer cells present in the human body.

Effects of the solid lipid nanoparticle of carvacrol on rodents with lung injury from smoke inhalation

The aim of this present study was to evaluate the effect of solid lipid nanoparticles (SLN) containing carvacrol over the lung damage of airway smoke inhalation. The study was conducted with 30 rats subjected to smoke inhalation and divided into 5 groups such as, normal control, negative control, oxygen group, SLN alone, and SLN+CARV group. The animals were sacrificed 24 h after the induction of inhalation injury further, the tissues of larynx, trachea, and lungs were collected for the histological, hematological, myeloperoxidase, and malondialdehyde analysis. The obtained results showed that treatment with CARV+SLN minimized the inhalation injury, since it reduced malondialdehyde significantly, when compared to the negative control group and minimized the histological changes which proves the absence of pulmonary emphysema and exudate in laryngeal and tracheal lumen in the CARV+SLN-treated group. Meanwhile, the presence of lesion with chronic characteristics was observed in the negative control and oxygen groups. It is suggested that the SLN containing carvacrol minimized oxidative stress and histological damages generated from smoke inhalation in rodents.

Reverse Transcriptase Inhibitors Nanosystems Designed for Drug Stability and Controlled Delivery

An in-depth analysis of nanotechnology applications for the improvement of solubility, distribution, bioavailability and stability of reverse transcriptase inhibitors is reported. Current clinically used nucleoside and non-nucleoside agents, included in combination therapies, were examined in the present survey, as drugs belonging to these classes are the major component of highly active antiretroviral treatments. The inclusion of such agents into supramolecular vesicular systems, such as liposomes, niosomes and lipid solid NPs, overcomes several drawbacks related to the action of these drugs, including drug instability and unfavorable pharmacokinetics. Overall results reported in the literature show that the performances of these drugs could be significantly improved by inclusion into nanosystems.

Exploring the Nano Spray-Drying Technology as an Innovative Manufacturing Method for Solid Lipid Nanoparticle Dry Powders

To take advantage of solid-state properties, the nano spray-drying (NSD) technique was investigated as an innovative one-step method to produce solid lipid nanoparticles (SLN) in the form of a dry powder starting from a lipid/leucine O/W emulsion. Compritol was chosen as wall-forming lipid. Rapamycin (Rp) was employed as a model drug to be loaded into SLN. Based on an initial screening, Lutrol F68 was chosen as surfactant and high-shear homogenization as an emulsification method. A two-level fractional factorial design and an extended factorial design were employed to determine critical factors and best preparation conditions. Compritol concentration, L-leucine/lipid ratio, and Lutrol F68 concentration resulted critical. Best conditions granted 51% yield, 3.2 μm L-leucine/SLN particle size, and a SLN population around 150 nm. All samples showed the presence of lipid aggregates. Material loss in the emulsification step was found responsible for SLN aggregation and low yield. The almost quantitative Rp loading increased SLN population span. Replacing compritol with cetyl palmitate produced aggregation of dry powders and SLN. Overall, NSD was found a fast method to produce SLN dry powders. More insightful assessment of the emulsification step and lipid property effects will be critical to the optimization of the NSD process. Hypotheses account for direct coupling of high-pressure homogenization with NSD for future successful development of this promising manufacturing method.

Polymer-Based Nanocarriers for Co-Delivery and Combination of Diverse Therapies against Cancers

Cancer gives rise to an enormous number of deaths worldwide nowadays. Therefore, it is in urgent need to develop new therapies, among which combined therapies including photothermal therapy (PTT) and chemotherapy (CHT) using polymer-based nanocarriers have attracted enormous interest due to the significantly enhanced efficacy and great progress has been made so far. The preparation of such nanocarriers is a comprehensive task involving the cooperation of nanomaterial science and biomedicine science. In this review, we try to introduce and analyze the structure, preparation and synergistic therapeutic effect of various polymer-based nanocarriers composed of anti-tumor drugs, nano-sized photothermal materials and other possible parts. Our effort may bring benefit to future exploration and potential applications of similar nanocarriers.

Rational design of polysorbate 80 stabilized human serum albumin nanoparticles tailored for high drug loading and entrapment of irinotecan

Human serum albumin (HSA) nanoparticles are considered to be versatile carrier of anticancer agents in efficiently delivering the drug to the tumor site without causing any toxicity. The aim of the study was to develop stable HSA nanoparticles (NPs) of drug irinotecan (Iro) having slightly water solubility and moderate HSA binding. A novel strategy of employing a hydrophilic non-ionic surfactant polysorbate 80 which forms protein-polysorbate 80 complex with increased affinity and improvement in Iro-HSA binding has been used to maximize the loading and entrapment efficiency of Iro in HSA-NPs. Bespoke nanoparticles with entrapment efficiency (79.09%) and drug loading of 9.62% could be achieved with spherical shape and particle size of 77.38 nm, 0.290 polydispersity index and -23.7 mv Zeta potential. The drug entrapment in nanoparticles was confirmed by Differential Scanning Calorimeter, Fourier Transformation Infrared Spectroscopy and Fluorescence Spectroscopy. In vitro release of Iro from NPs showed biphasic-release with initial burst followed by prolonged release upto 24 h. The short-term stability investigation of nanodispersion showed no significant changes in physicochemical properties of NPs. Long-term studies on freeze dried Iro-HSA-NPs indicated good stability of NPs up to 12 months. This is the first report for efficient fabrication of Iro delivery system based on HSA nanoparticles.

Nanoparticle-Delivered 2-PAM for Rat Brain Protection against Paraoxon Central Toxicity

Solid lipid nanoparticles (SLNs) are among the most promising nanocarriers to target the blood-brain barrier (BBB) for drug delivery to the central nervous system (CNS). Encapsulation of the acetylcholinesterase reactivator, pralidoxime chloride (2-PAM), in SLNs appears to be a suitable strategy for protection against poisoning by organophosphorus agents (OPs) and postexposure treatment. 2-PAM-loaded SLNs were developed for brain targeting and delivery via intravenous (iv) administration. 2-PAM-SLNs displayed a high 2-PAM encapsulation efficiency (∼90%) and loading capacity (maximum 30.8 ± 1%). Drug-loaded particles had a mean hydrodynamic diameter close to 100 nm and high negative zeta potential (-54 to -15 mV). These properties contribute to improve long-term stability of 2-PAM-SLNs when stored both at room temperature (22 °C) and at 4 °C, as well as to longer circulation time in the bloodstream compared to free 2-PAM. Paraoxon-poisoned rats (2 × LD₅₀) were treated with 2-PAM-loaded SLNs at a dose of 2-PAM of 5 mg/kg. 2-PAM-SLNs reactivated 15% of brain AChE activity. Our results confirm the potential use of SLNs loaded with positively charged oximes as a medical countermeasure both for protection against OPs poisoning and for postexposure treatment.

Systematic Approach for the Formulation and Optimization of Solid Lipid Nanoparticles of Efavirenz by High Pressure Homogenization Using Design of Experiments for Brain Targeting and Enhanced Bioavailability

The nonnucleoside reverse transcriptase inhibitors, used for the treatment of HIV infections, are reported to have low bioavailability pertaining to high first-pass metabolism, high protein binding, and enzymatic metabolism. They also show low permeability across blood brain barrier. The CNS is reported to be the most important HIV reservoir site. In the present study, solid lipid nanoparticles of efavirenz were prepared with the objective of providing increased permeability and protection of drug due to biocompatible lipidic content and nanoscale size and thus developing formulation having potential for enhanced bioavailability and brain targeting. Solid lipid nanoparticles were prepared by high pressure homogenization technique using a systematic approach of design of experiments (DoE) and evaluated for particle size, polydispersity index, zeta potential, and entrapment efficiency. Particles of average size 108.5 nm having PDI of 0.172 with 64.9% entrapment efficiency were produced. Zeta potential was found to be −21.2 mV and the formulation was found stable. The in-vivo pharmacokinetic studies revealed increased concentration of the drug in brain, as desired, when administered through intranasal route indicating its potential for an attempt towards complete eradication of HIV and cure of HIV-infected patients.

Losartan loaded liposomes improve the antitumor efficacy of liposomal paclitaxel modified with pH sensitive peptides by inhibition of collagen in breast cancer

The dense collagen network in tumors restricts the penetration of drugs into tumors. Free losartan could inhibit collagen, but it would cause hypotension at the dosage of 10 mg/kg/d. In this study, losartan was encapsulated in liposomes (LST-Lip) and the collagen inhibition ability of LST-Lip was investigated. Our results showed the blood pressure was not affected by LST-Lip at the dosage of 2.5 mg/kg every other day. The amount of Evans Blue in tumor in LST-Lip group was 1.98 times of that in control group. Confocal laser scanning microscopy images showed that prior injection of LST-Lip could inhibit collagen and further improve the tumorous accumulation of liposomes modified with TH peptides (AGYLLGHINLHHLAHL(Aib)HHIL-NH₂) (TH-Lip) in 4T1 tumors. Compared with control group, the tumor inhibition rate of combined strategy of LST-Lip and paclitaxel loaded TH-Lip (PTX-TH-Lip) was 41.73%, while that of group only treated with PTX-TH-Lip was 14.94%. Masson's trichrome staining confirmed that collagen was inhibited in LST-Lip group. Thus, the administration of LST-Lip in advance could inhibit the collagen in tumors effectively and did not affect the blood pressure, then PTX-TH-Lip injected subsequently could exert enhanced antitumor efficacy. In conclusion, this combined strategy might be promising for breast cancer therapy.

Industrialization of lipid nanoparticles: From laboratory-scale to large-scale production line

This work aimed at developing a large-scale modular production line, which referred to coenzyme Q₁₀ loaded-NLC as well as its continuous and scalable emulsification and homogenization process. The production line exhibited good control over the emulsification and homogenization process and enabled the particle size of NLC below 210nm at a throughput of 25kg/h (for lipid solution at a flow rate of 0.4kg/min). Among the several process parameters investigated, the size of the NLC was mainly influenced by the pre-emulsification temperature, homogenization pressure and homogenization. Suitable emulsification temperature (70°C), homogenization pressure (600, 800bar), and homogenization cycle (3, 4cycles) resulted in relatively smaller particles. These results proved that coenzyme Q₁₀, a model active, had been successfully loaded into the NLC. Meanwhile, the large-scale production line can be effectively applied for continuous and modular production of NLC. The line had modern networking features-essential in the Internet age-and a modular design that was easily modified and upgraded. In addition, the long-term stability over 6month was monitored at 30°C and at 40°C to assess a potential effect of the laboratory scale and large scale on stability. All batches at room temperature and below were stable, and only a negligible increase in size was observed.

Bio-inspired artemether-loaded human serum albumin nanoparticles for effective control of malaria-infected erythrocytes

AIM

The intra-erythrocytic development of the malarial parasite is dependent on active uptake of nutrients, including human serum albumin (HSA), into parasitized red blood cells (pRBCs). We have designed HSA-based nanoparticles as a potential drug-delivery option for antimalarials.

METHODS

Artemether-loaded nanoparticles (AANs) were designed and antimalarial activity evaluated in vitro/in vivo using Plasmodium falciparum/Plasmodium berghei species, respectively.

RESULTS

Selective internalization of AAN into Plasmodium-infected RBCs in preference to healthy erythrocytes was observed using confocal imaging. In vitro studies showed 50% dose reduction for AAN as compared with drug-only controls to achieve IC₅₀ levels of inhibition. The nanoparticles exhibited twofold higher peak drug concentrations in RBCs with antimalarial activity at 50% of therapeutic doses in P. bergei infected mice.

CONCLUSION

Novel HSA-based nanoparticles offer safe and effective approach for selective targeting of antimalarial drugs.

Transition from passive to active targeting of oral insulin nanomedicines: enhancement in bioavailability and glycemic control in diabetes

Oral insulin nanomedicines are effective tools for therapy and management of both Type I and Type II diabetes. This review summarizes the various nanocarriers developed so far in the literature for oral delivery of insulin. It includes lipid-based (i.e., solid lipid nanoparticles and liposomes) and polymeric-based insulin nanomedicines (i.e., chitosan nanoparticles, alginate nanoparticles, dextran nanoparticles and nanoparticles of synthetic polymers) for sustained, controlled and targeted oral delivery of insulin. Mainly, goblet cell-targeting, vitamin B12 receptor-targeting, folate receptor-targeting and transferrin receptor-targeting aspects were focused. Currently, passive and active targeting approaches of oral insulin nanomedicines have improved the oral absorption of insulin and its bioavailability (up to 14%) that produced effective glycaemic control in in vivo models. These results indicate a promising future of oral insulin nanomedicines for the treatment of diabetes.

Solid lipid nanoparticles as attractive drug vehicles: Composition, properties and therapeutic strategies

This work briefly reviews up-to-date developments in solid lipid nanoparticles (SLNs) as effective nanocolloidal system for drug delivery. It summarizes SLNs in terms of their preparation, surface modification and properties. The application of SLNs as a carrier system enables to improve the therapeutic efficacy of drugs from various therapeutic groups. Present uses of SLNs include cancer therapy, dermatology, bacterial infections, brain targeting and eye disorders among others. The usage of SLNs provides enhanced pharmacokinetic properties and modulated release of drugs. SLN ubiquitous application results from their specific features such as possibility of surface modification, increased permeation through biological barriers, resistance to chemical degradation, possibility of co-delivery of various therapeutic agents or stimuli-responsiveness. This paper will be useful to the scientists working in the domain of SLN-based drug delivery systems.

Folic acid functionalized long-circulating co-encapsulated docetaxel and curcumin solid lipid nanoparticles: In vitro evaluation, pharmacokinetic and biodistribution in rats

The purpose of this study was to develop folic acid functionalized long-circulating co-encapsulated docetaxel (DTX) and curcumin (CRM) solid lipid nanoparticles (F-DC-SLN) to improve the pharmacokinetic and efficacy of DTX therapy. F-DC-SLN was prepared by hot melt-emulsification method and optimized by face centered-central composite design (FC-CCD). The SLN was characterized in terms of size and size distribution, drug entrapment efficiency and release profile. The cytotoxicity and cell uptake of the SLN formulations were evaluated in MCF-7 and MDA-MB-231 cell lines. The in vivo pharmacokinetic and biodistribution were studied in Wistar rats. F-DC-SLN exhibited 247.5 ± 3.40 nm particle size with 73.88 ± 1.08% entrapment efficiency and zeta potential of 14.53 ± 3.6 mV. Transmission electron microscopy (TEM) revealed spherical morphology of the SLN. Fluorescence microscopy confirmed the targeting efficacy of F-DC-SLN in MCF-7 cells. F-DC-SLN exhibited a significant increase in area under the curve (594.21 ± 64.34 versus 39.05 ± 7.41 μg/mL h) and mean residence time (31.14 ± 19.94 versus 7.24 ± 4.51 h) in comparison to Taxotere®. In addition, decreased DTX accumulation from F-DC-SLN in the heart and kidney in comparison to Taxotere may avoid to toxicity these vital organs. In conclusion, the F-DC-SLN improved the efficacy and pharmacokinetic profile of DTX exhibiting enhanced potential in optimizing breast cancer therapy.

Development of a topical adapalene-solid lipid nanoparticle loaded gel with enhanced efficacy and improved skin tolerability

The present investigation substantiates the efficacy of adapalene loaded solid lipid nanoparticles (Ada-SLNs) in ameliorating the skin irritation potential of adapalene owing to its altered skin distribution.

Lipid polymer hybrid as emerging tool in nanocarriers for oral drug delivery

The oral route for drug delivery is a widely accepted route. For that reason, many researchers are currently working to develop efficient oral drug delivery systems. Use of polymeric nanoparticles (NPs) and lipid carrier systems, including liposomes, solid lipid nanoparticles (SLNs) and nanostructured lipid carriers (NLC), has limitations such as drug leakage and high water content of dispersions. Thus, lipid polymer hybrid nanoparticles (LPNs) have been explored by the researchers to provide a better effect using properties of both polymers and lipids. The present review is focused on the challenges, possibilities, and future perspectives of LPNs for oral delivery.

Issues and concerns in nanotech product development and its commercialization

The revolutionary and ubiquitous nature of nanotechnology has fetched it a considerable attention in the past few decades. Even though its enablement and application to various sectors including pharmaceutical drug development is increasing with the enormous government aided funding for nanotechnology-based products, however the parallel commercialization of these systems has not picked up a similar impetus. The technology however does address the unmet needs of pharmaceutical industry, including the reformulation of drugs to improve their solubility, bioavailability or toxicity profiles as observed from the wide array of high-quality research publications appearing in various scientific journals and magazines. Based on our decade-long experience in the field of nanotech-based drug delivery systems and extensive literature survey, we perceive that the major hiccups to the marketing of these nanotechnology products can be categorized as 1) inadequate regulatory framework; 2) lack of support and acceptance by the public, practicing physician, and industry; 3) developmental considerations like scalability, reproducibility, characterization, quality control, and suitable translation; 4) toxicological issues and safety profiles; 5) lack of available multidisciplinary platforms; and, 6) poor intellectual property protection. The present review dwells on these issues elaborating the trends followed by the industry, regulatory role of the USFDA and their implication, and the challenges set forth for a successful translation of these products from the lab and different clinical phases to the market.

Preparation and evaluation of tilmicosin-loaded hydrogenated castor oil nanoparticle suspensions of different particle sizes

Three tilmicosin-loaded hydrogenated castor oil nanoparticle (TMS-HCO-NP) suspensions of different particle sizes were prepared with different polyvinyl alcohol surfactant concentrations using a hot homogenization and ultrasonic technique. The in vitro release, in vitro antibacterial activity, mammalian cytotoxicity, acute toxicity in mice, and stability study were conducted to evaluate the characteristics of the suspensions. The in vitro tilmicosin release rate, antibacterial activity, mammalian cytotoxicity, acute toxicity in mice, and stability of the suspensions were evaluated. When prepared with polyvinyl alcohol concentrations of 0.2%, 1%, and 5%, the mean diameters of the nanoparticles in the three suspensions were 920±35 nm, 452±10 nm, and 151±4 nm, respectively. The three suspensions displayed biphasic release profiles similar to that of freeze-dried TMS-HCO-NP powders, with the exception of having a faster initial release. Moreover, suspensions of smaller-sized particles showed faster initial release, and lower minimum inhibitory concentrations and minimum bactericidal concentrations. Time-kill curves showed that within 12 hours, the suspension with the 151 nm particles had the most potent bactericidal activity, but later, the suspensions with larger-sized particles showed increased antibacterial activity. None of the three suspensions were cytotoxic at clinical dosage levels. At higher drug concentrations, all three suspensions showed similar concentration-dependent cytotoxicity. The suspension with the smallest-sized particle showed significantly more acute toxicity in mice, perhaps due to faster drug release. All three suspensions exhibited good stability at 4°C and at room temperature for at least 6 months. These results demonstrate that TMS-HCO-NP suspensions can be a promising formulation for tilmicosin, and that nanoparticle size can be an important consideration for formulation development.

Continuous manufacturing of solid lipid nanoparticles by hot melt extrusion

Solid lipid nanoparticles (SLN) can either be produced by hot homogenization of melted lipids at higher temperatures or by a cold homogenization process. This paper proposes and demonstrates the formulation of SLN for pharmaceutical applications by combining two processes: hot melt extrusion (HME) technology for melt-emulsification and high-pressure homogenization (HPH) for size reduction. This work aimed at developing continuous and scalable processes for SLN by mixing a lipid and aqueous phase containing an emulsifier in the extruder barrel at temperatures above the melting point of the lipid and further reducing the particle size of emulsion by HPH linked to HME in a sequence. The developed novel platform demonstrated better process control and size reduction compared to the conventional process of hot homogenization (batch process). Varying the process parameters enabled the production of SLN below 200 nm (for 60 mg/ml lipid solution at a flow rate of 100ml/min). Among the several process parameters investigated, the lipid concentration, residence time and screw design played major roles in influencing the size of the SLN. This new process demonstrates the potential use of hot melt extrusion technology for continuous and large-scale production of SLN.

Buparvaquone loaded solid lipid nanoparticles for targeted delivery in theleriosis

Background:

Buparvaquone (BPQ), a hydroxynaphthoquinone derivative, has been investigated for the treatment of many infections and is recommended as the gold standard for the treatment of theileriosis. Theileriosis, an intramacrophage infection is localized mainly in reticuloendotheileial system (RES) organs. The present study investigates development of solid lipid nanoparticles (SLN) of BPQ for targeted delivery to the RES.

Materials and Methods:

BPQ SLN was prepared using melt method by adding a molten mixture into aqueous Lutrol F68 solution (80°C). Larger batches were prepared up to 6 g of BPQ with GMS: BPQ, 2:1. SLN of designed size were obtained using ultraturrax and high pressure homogenizer. A freeze and thaw study was used to optimize type and concentration of cryoprotectant with Sf: Mean particle size, Si: Initial particle size <1.3. Differential scanning calorimetry (DSC), powder X-ray diffraction (XRD) and scanning electron microscope (SEM) study was performed on optimized formulation. Formulation was investigated for in vitro serum stability, hemolysis and cell uptake study. Pharmacokinetic and biodistribution study was performed in Holtzman rat.

Results:

Based on solubility in lipid; glyceryl monostearate (GMS) was selected for preparation of BPQ SLN. Batches of BPQ SLN were optimized for average particle size and entrapment efficiency at <100 mg solid content. A combination of Solutol HS-15 and Lutrol F68 at 2% w/v and greater enabled the desired Sf/Si < 1.3. Differential scanning calorimetry and powder X-ray diffraction revealed decrease in crystallinity of BPQ in BPQ SLN while, scanning electron microscope revealed spherical morphology. BPQ SLN revealed good stability at 4°C and 25°C. Low hemolytic potential (<8%) and in vitro serum stability up to 5 h was observed. Cytotoxicity of SLN to the U937 cell was low. The macrophage cell line revealed high (52%) uptake of BPQ SLN in 1 h suggesting the potential to RES uptake. SLN revealed longer circulation and biodistrbution study confirmed high RES uptake (75%) in RES organs like liver lung spleen etc.

Conclusion:

The high RES uptake suggests BPQ SLN as a promising approach for targeted and improved delivery in theileriosis.