Atorvastatin-loaded nanostructured lipid carriers (NLCs): strategy to overcome oral delivery drawbacks

Optimization of Nanostructured Lipid Carriers of Fenofibrate Using a Box-Behnken Design for Oral Bioavailability Enhancement

BACKGROUND

Fenofibrate (FNB) is a commonly used hypolipidemic agent. However, the oral bioavailability of FNB is limited by slow dissolution due to its low solubility. Thus, investigations on novel FNB formulations are necessary for their use.

OBJECTIVE

To enhance the oral bioavailability of FNB using optimized Nanostructured Lipid Carrier (NLC) formulations.

METHODS

Hot homogenization followed by ultrasonication was used to prepare FNB-NLCs. These formulations were optimized using a Box-Behnken design, where the amount of FNB (X1), a ratio of solid lipid/liquid lipid (X2), and the percentage of emulsifier (X3), were set as independent variables, while the particle size (Y1), and Entrapment Efficiency (EE%) (Y2), were used as dependent factors. An in vitro dissolution test was then performed using a paddle method, while an in vivo pharmacokinetic study of FNB-NLC formulation was performed in rats.

RESULTS

FNB-NLCs were successfully prepared and optimized using a Box-Behnken design. The particle size and EE% of the FNB-NLC had less than 5% difference from predicted values. The in vitro dissolution and oral bioavailability of the FNB-NLC were both higher than those of raw FNB.

CONCLUSION

A Box-Behnken design was successfully applied to optimize FNB-NLC formulation for the enhancement of the dissolution and bioavailability of FNB, a poorly water-soluble drug.

Skin penetration/permeation success determinants of nanocarriers: Pursuit of a perfect formulation

The advent of nanocarriers in the field of pharmaceutical drug delivery, while exhibiting considerable advantages, has created challenges for researchers. Among the applications of nanocarriers, drug delivery to the skin has attracted increasing attention in recent decades due to its advantages over oral and parenteral administration. Accordingly, this work attempts to discuss the major obstacles surrounding topically applied formulations and different nanocarriers' potential to overcome these barriers to investigate whether their passive penetration through the skin is likely. Therefore, skin anatomical views and transcutaneous pathways are briefly reviewed. Factors commonly thought to influence skin penetration are discussed from the perspective of particularly penetrating nanocarriers. The formulation of these nanocarriers is outlined, and promising constituents are highlighted to help investigators optimize nanocarrier formulations.

The biomedical significance of multifunctional nanobiomaterials: The key components for site-specific delivery of therapeutics

The emergence of nanotechnology has provided the possibilities to overcome the potential problems associated with the development of pharmaceuticals including the low solubility, non-specific cellular uptake or action, and rapid clearance. Regarding the biomaterials (BMs), huge efforts have been made for improving their multi-functionalities via incorporation of various nanomaterials (NMs). Nanocomposite hydrogels with suitable properties could exhibit a variety of beneficial effects in biomedicine particularly in the delivery of therapeutics or tissue engineering. NMs including the silica- or carbon-based ones are capable of integration into various BMs that might be due to their special compositions or properties such as the hydrophilicity, hydrophobicity, magnetic or electrical characteristics, and responsiveness to various stimuli. This might provide multi-functional nanobiomaterials against a wide variety of disorders. Meanwhile, inappropriate distribution or penetration into the cells or tissues, bio-nano interface complexity, targeting ability loss, or any other unpredicted phenomena are the serious challenging issues. Computational simulations and models enable development of NMs with optimal characteristics and provide a deeper knowledge of NM interaction with biosystems. This review highlights the biomedical significance of the multifunctional NMs particularly those applied for the development of 2-D or 3-D BMs for a variety of applications including the site-specific delivery of therapeutics. The powerful impacts of the computational techniques on the design process of NMs, quantitation and prediction of protein corona formation, risk assessment, and individualized therapy for improved therapeutic outcomes have also been discussed.

Ezetimibe-Loaded Nanostructured Lipid Carrier Based Formulation Ameliorates Hyperlipidaemia in an Experimental Model of High Fat Diet

Ezetimibe (EZE) possesses low aqueous solubility and poor bioavailability and in addition, its extensive hepatic metabolism supports the notion of developing a novel carrier system for EZE. Ezetimibe was encapsulated into nanostructured lipid carriers (EZE-NLCs) via a high pressure homogenization technique (HPH). A three factor, two level (2³) full factorial design was employed to study the effect of amount of poloxamer 188 (X1), pressure of HPH (X2) and number of HPH cycle (X3) on dependent variables. Particle size, polydispersity index (PDI), % entrapment efficiency (%EE), zeta potential, drug content and in-vitro drug release were evaluated. The optimized formulation displays pragmatic inferences associated with particle size of 134.5 nm; polydispersity index (PDI) of 0.244 ± 0.03; zeta potential of −28.1 ± 0.3 mV; % EE of 91.32 ± 1.8% and % CDR at 24-h of 97.11%. No interaction was observed after X-ray diffraction (XRD) and differential scanning calorimetry (DSC) studies. EZE-NLCs (6 mg/kg/day p.o.) were evaluated in the high fat diet fed rats induced hyperlipidemia in comparison with EZE (10 mg/kg/day p.o.). Triglyceride, HDL-c, LDL-c and cholesterol were significantly normalized and histopathological evaluation showed normal structure and architecture of the hepatocytes. The results demonstrated the superiority of EZE-NLCs in regard to bioavailability enhancement, dose reduction and dose-dependent side effects.

Preparation, characterization, and in vivo evaluation of perphenazine-loaded nanostructured lipid carriers for oral bioavailability improvement

OBJECTIVE

The main scope of the present investigation was to improve the bioavailability of perphenazine (PPZ) by incorporating it into the nanostructured lipid carriers (NLCs).

SIGNIFICANCE

As a result of lipophilic nature and poor aqueous solubility, as well as extensive hepatic metabolism, PPZ has low systemic bioavailability via the oral route. NLCs have shown potentials to surmount the oral delivery drawbacks of poorly water-soluble drugs.

METHODS

The PPZ-NLCs were prepared by the emulsification-solvent evaporation method and subjected for particle size, zeta potential, and entrapment efficiency (EE) analysis. The optimized NLCs were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), and powder X-ray diffractometry (PXRD). Besides, in vitro release behavior, storage stability, and pharmacokinetic studies followed by a single-dose oral administration in rats were performed.

RESULTS

Optimized PPZ-NLCs showed a particle size of less than 180 nm with appropriate EE of more than 95%. Microscopic images captured with SEM and TEM exhibited that NLCs were approximately spherical in shape. DSC and PXRD analysis confirmed reduced crystallinity of PPZ after incorporation in NLCs. FTIR spectra demonstrated no chemical interactions between PPZ and NLC components. In vitro release studies confirmed the extended-release properties of NLC formulations. PPZ-NLCs exhibited good stability at 4 °C within three months. The oral bioavailability of NLC-6 and NLC-12 was enhanced about 3.12- and 2.49-fold, respectively, compared to the plain drug suspension.

CONCLUSION

NLC can be designated as an effective nanocarrier for oral delivery of PPZ.

Fabrication and Evaluation of Spironolactone-Loaded Nanostructured Lipid Carries for Cardiac Tissue Regeneration

Background:

Spironolactone (SP) is a lipophilic aldosterone receptor antagonist that few studies have reported its effect on cardiac remodeling. In addition, fewer researches have considered its influence on cardiomyocyte viability and potential benefits for myocardial tissue remodeling.

Method:

In this study, stearic acid (SA) (solid lipid) and oleic acid (OA) (liquid lipid) were utilized to produce nanostructured lipid carries (NLCs) (various ratios of SA to OA and water amount, F1: 80:20 [30 ml water], F2: 80:20 [60 ml water], F3: 70:30 [30 ml water], and F4: 70:30 [60 ml water]) containing SP and their particle size, polydispersity index, zeta potential, entrapment efficiency, and release profile were measured. The purpose of encapsulating SP in NLCs was to provide a sustain release system. Meanwhile, 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay with different concentrations of SP-loaded NLCs (SP-NLCs) was conducted to evaluate the cytotoxicity of the NLCs on rat myocardium cells (H9C2).

Results:

Increase of oil content to 10 wt% reduced the particle size from 486 nm (F1) to 205 nm (F2). Zeta potential of the samples at around −10 mV indicated their agglomeration tendency. After 48 h, SP-NLCs with the concentrations of 5 and 25 μM showed significant improvement in cell viability while the same amount of free SP-induced cytotoxic effect on the cells. SP-NLCs with higher concentration (50 μM) depicted cytotoxic effect on H9C2 cells.

Conclusion:

It can be concluded that 25 μM SP-NLCs with sustain release profile had a beneficial effect on cardiomyocytes and can be used as a mean to improve cardiac tissue regeneration.

Gefitinib loaded nanostructured lipid carriers: characterization, evaluation and anti-human colon cancer activity in vitro

NLC containing Gefitinib (NANOGEF) was prepared using stearic acid, sesame oil and surfactants (sodium lauryl sulfate and tween 80). NANOGEFs were evaluated for particle size, polydispersity index (PdI), zeta potential, entrapment efficiency (EE), stability, release studies and cytotoxicity studies (MTT assay). The optimized NANOGEF exhibited particle size of 74.06 ± 9.73 d.nm, PdI of 0.339 ± 0.029 and EE of 99.76 ± 0.015%. The TEM study revealed spherical shape of NANOGEF formulations. The slow and sustained release behavior was exhibited by all NANOGEFs. The effects of surfactants were observed not only on particle size but also on zeta potential, entrapment efficiency, stability and release studies. The MTT assay revealed 4.5 times increase in cytotoxicity for optimized NANOGEF (IC₅₀ = 4.642 µM) when compared with Gefitinib alone (IC₅₀ = 20.88 µM in HCT-116 cells). Thus NANOGEF may be considered as a potential drug delivery system for the cure of colon cancer.

Comprehensive Study of Atorvastatin Nanostructured Lipid Carriers through Multivariate Conceptualization and Optimization

The aim of the current study is to establish a comprehensive experimental design for the screening and optimization of Atorvastatin-loaded nanostructured lipid carriers (AT-NLCs). Initially, combined D-optimal screening design was applied to find the most significant factors affecting AT-NLCs properties. The studied variables included mixtures of solid and liquid lipids, the solid/liquid lipid ratio, surfactant type and concentration, homogenization speed as well as sonication time. Then, the variables homogenization speed (A), the ratio of solid lipid/liquid lipid (B), and concentration of the surfactant (C) were optimized using a central composite design. Particle size, polydispersity index, zeta potential, and entrapment efficiency were chosen as dependent responses. The optimized AT-NLCs demonstrated a nanometric size (83.80 ± 1.13 nm), Polydispersity Index (0.38 ± 0.02), surface charge (-29.65 ± 0.65 mV), and high drug incorporation (93.1 ± 0.04%). Fourier Transform Infrared Spectroscopy (FTIR) analysis showed no chemical interaction between Atorvastatin and the lipid mixture. Differential Scanning Calorimetry (DSC) analysis of the AT-NLCs suggested the transformation of Atorvastatin crystal into an amorphous state. Administration of the optimized AT-NLCs led to a significant reduction (p < 0.001) in serum levels of rats' total cholesterol, triglycerides, and low-density lipoproteins. This change was histologically validated by reducing the relevant steatosis of the liver.

Preparation, Pharmacokinetics, and Antitumor Potential of Miltefosine-Loaded Nanostructured Lipid Carriers

BACKGROUND

The purpose of this study was to investigate the suitability of nanostructured lipid carriers (NLCs) loaded with miltefosine (HePC) as an anticancer drug for the treatment of breast cancer.

METHODS

HePC-NLCs were prepared using a microemulsion technique and then evaluated for particle size, polydispersity index (PDI), incorporation efficiency, in vitro release of entrapped drug, and hemolytic potential. Furthermore, pharmacokinetic, biodistribution, and liver toxicity analyses were performed in Sprague-Dawley rats, and antitumor efficacy was evaluated in Michigan Cancer Foundation-7 (MCF-7) and squamous cell carcinoma-7 (SCC-7) cells in vitro and in tumour-bearing BALB/c mice in vivo. Advanced analyses including survival rate, immunohistopathology, and terminal deoxynucleotidyl transferase dUTP nick end labelling (TUNEL) assays were performed to evaluate apoptosis in vivo.

RESULTS

The average particle size of the HePC-NLCs was 143 ± 16 nm, with a narrow PDI (0.104 ± 0.002), and the incorporation efficiency was found to be 91 ± 7%. The NLCs released HePC in a sustained manner, and this release was significantly lower than that of free drug. The in vitro hemolytic assay demonstrated a significantly reduced hemolytic potential (~9%) of the NLCs compared to that of the test formulations. The HePC-NLCs demonstrated enhanced pharmacokinetic behaviour over free drug, including extended blood circulation and an abridged clearance rate in rats. Furthermore, the HePC-NLCs exhibited higher cytotoxicity than the free drug in MCF-7 and SCC-7 cells. Moreover, the HePC-NLCs showed significantly enhanced (P < 0.005) antitumor activity compared to that of the control and free drug-treated mouse groups. Tumour cell apoptosis was also confirmed, indicating the antitumor potential of the HePC-NLCs.

CONCLUSION

These findings demonstrate the ability of NLCs as a drug delivery system for enhanced pharmacokinetic, antitumor, and apoptotic effects, most importantly when loaded with HePC.

Development, in vitro and in vivo evaluation of miltefosine loaded nanostructured lipid carriers for the treatment of Cutaneous Leishmaniasis

The purpose of this study was to enhance the anti-leishmanial efficacy of miltefosine (MTF) and reduce its toxic effects by loading it into nanostructured lipid carriers (NLCs). Micro-emulsion technique was used to prepare MTF-loaded NLCs. The optimized NLCs were characterized in terms of various physicochemical parameters including particle size, poly dispersity index (PDI), zeta potential, transmission electron microscopy (TEM), X-ray diffraction (XRD) and Fourier transform infrared (FTIR) technique. In vitro and in vivo assays were performed to evaluate the potential of NLCs as an effective nanocarrier system for oral delivery of MTF in Cutaneous Leishmaniasis. The optimized MTF-loaded NLCs exhibited mean particle size of 160.8 ± 5.3 nm with narrow PDI and high incorporation efficiency (IE%) of 96.17 ± 1.3%. MTF-loaded NLCs demonstrated slow release of the incorporated drug as compared to the drug solution. The optimized formulation showed significant decrease in hemolytic potential, 2.5~folds increase in anti-leishmanial efficacy and 6~fold decrease in macrophage cytotoxicity as compared to MTF solution, in vitro. Macrophage uptake study confirmed passive targeting ability of MTF-loaded NLCs. In-vivo analysis demonstrated enhanced anti-leishmanial effect of the MTF-loaded NLCs and better pharmacokinetic profiles with no gastrointestinal (GI) toxicity. NLCs are potential nanocarriers for the oral delivery of MTF with enhanced anti-leishmanial activity, better safety profile and reduced hemolytic potential.

Quality by Design Approach for Preparation of Zolmitriptan/Chitosan Nanostructured Lipid Carrier Particles - Formulation and Pharmacodynamic Assessment

Purpose

Zolmitriptan (ZT) is a selective serotonin agonist that is used for the treatment of migraine. It belongs to BCS class III with high solubility and low permeability. Besides, the drug is subjected to pre-systemic metabolism. Accordingly, new Zolmitriptan/chitosan nanostructured lipid carriers (ZT/CT NLCs) coated with Tween 80 (stealthy layer) have been developed to overcome such demerits.

Methods

The NLCs were developed by combining ultrasonication and double emulsion (w/o/w) techniques. The lipids were Gelucire and Labrasol. Herein, the quality by design (2³ full factorial design) was scrupulously followed, where critical process parameters and critical quality attributes were predefined. The optimized formulation (F8) was fully characterized with respect to entrapment efficiency (%EE), percentage yield (% yield), particle size, size distribution (PDI), zeta potential (ZP), morphological appearance (TEM). In vitro release, stability study and pharmacodynamic evaluations were also assessed. The optimized freeze dried formula was dispensed in in situ gelling hard gelatin capsule encompassing pectin and guar gum for further in vitro and pharmacodynamic evaluations.

Results

The optimized spherical nanoparticles experienced high percentage EE and yield (78.14% and 60.19%, respectively), low particle size and PDI (343.87 nm and 0.209, respectively), as well as high negative ZP (−25.5 mV). It showed good physical stability at refrigerated conditions. The NLCs dispensed in in situ gelling hard gelatin capsule comprising pectin and guar gum experienced sustained release for 30 h and significantly maintained the pharmacological effect in mice up to 8 h (p < 0.001).

Conclusion

ZT, a BCS class III drug that suffers from poor permeability and pre-systemic metabolism, was successfully maneuvered as nanostructured lipid carrier particles (NLCs). The incorporation of the NLCs in in situ gelling hard gelatin capsules fulfilled a dual function in increasing permeability, as well as sustaining the pharmacodynamic effect. This result would open new vistas in improving the efficacy of other class III drugs.

Boosting the Brain Delivery of Atazanavir through Nanostructured Lipid Carrier-Based Approach for Mitigating NeuroAIDS

Atazanavir (ATZ) presents poor brain availability when administered orally, which poses a major hurdle in its use as an effective therapy for the management of NeuroAIDS. The utilization of nanostructured lipid carriers (NLCs) in conjunction with the premeditated use of excipients can be a potential approach for overcoming the limited ATZ brain delivery. Methods: ATZ-loaded NLC was formulated using the quality by design-enabled approach and further optimized by employing the Box–Behnken design. The optimized nanoformulation was then characterized for several in vitro and in vivo assessments. Results: The optimized NLC showed small particle size of 227.6 ± 5.4 nm, high entrapment efficiency (71.09% ± 5.84%) and high drug loading capacity (8.12% ± 2.7%). The release pattern was observed to be biphasic exhibiting fast release (60%) during the initial 2 h, then trailed by the sustained release. ATZ-NLC demonstrated a 2.36-fold increase in the cumulative drug permeated across the rat intestine as compared to suspension. Pharmacokinetic studies revealed 2.75-folds greater C_max in the brain and 4-fold improvement in brain bioavailability signifying the superiority of NLC formulation over drug suspension. Conclusion: Thus, NLC could be a promising avenue for encapsulating hydrophobic drugs and delivering it to their target site. The results suggested that increase in bioavailability and brain-targeted delivery by NLC, in all plausibility, help in improving the therapeutic prospects of atazanavir.

Atorvastatin Solid Lipid Nanoparticles as a Promising Approach for Dermal Delivery and an Anti-inflammatory Agent

In the current research, the main focus was to overcome dermal delivery problems of atorvastatin. To this end, atorvastatin solid lipid nanoparticles (ATR-SLNs) were prepared by ultra-sonication technique. The prepared SLNs had a PDI value of ≤ 0.5, and the particle size of nanoparticles was in the range 71.07 ± 1.72 to 202.07 ± 8.40 nm. It was noticed that, when the concentration of lipid in ATR-SLNs increased, the size of nanoparticles and drug entrapment efficiency were also increased. Results showed that a reduction in the HLB of surfactants used in the preparation of SLN caused an increase in the particle size, zeta potential (better stability), and drug entrapment efficiency. Despite Tween and Span are non-ionic surfactants, SLNs containing these surfactants showed a negative zeta potential, and the absolute zeta potential increased when the concentration of Span 80 was at maximum. DSC thermograms, FTIR spectra, and x-ray diffraction (PXRD) pattern showed good incorporation of ATR in the nanoparticles without any chemical interaction. In vitro skin permeation results showed that SLN containing atorvastatin was capable of enhancing the dermal delivery of atorvastatin where a higher concentration of atorvastatin can be detected in skin layers. This is a hopeful promise which could be developed for clinical studies of the dermal delivery of atorvastatin nanoparticles as an anti-inflammatory agent.

Recent Advances in the Structural Design of Photosensitive Agent Formulations Using "Soft" Colloidal Nanocarriers

The growing demand for effective delivery of photosensitive active compounds has resulted in the development of colloid chemistry and nanotechnology. Recently, many kinds of novel formulations with outstanding pharmaceutical potential have been investigated with an expansion in the design of a wide variety of "soft" nanostructures such as simple or multiple (double) nanoemulsions and lipid formulations. The latter can then be distinguished into vesicular, including liposomes and "smart" vesicles such as transferosomes, niosomes and ethosomes, and non-vesicular nanosystems with solid lipid nanoparticles and nanostructured lipid carriers. Encapsulation of photosensitive agents such as drugs, dyes, photosensitizers or antioxidants can be specifically formulated by the self-assembly of phospholipids or other amphiphilic compounds. They are intended to match unique pharmaceutic and cosmetic requirements and to improve their delivery to the target site via the most common, i.e., transdermal, intravenous or oral administration routes. Numerous surface modifications and functionalization of the nanostructures allow increasing their effectiveness and, consequently, may contribute to the treatment of many diseases, primarily cancer. An increasing article number is evidencing significant advances in applications of the different classes of the photosensitive agents incorporated in the "soft" colloidal nanocarriers that deserved to be highlighted in the present review.

Nose-to-brain delivery of sumatriptan-loaded nanostructured lipid carriers: preparation, optimization, characterization and pharmacokinetic evaluation

OBJECTIVES

Migraine is a neurological disorder with unilateral pulsatile headache which can affect the functions of sufferers. Migraineurs experience some undesirable symptoms such as pain, nausea, vomiting and in some cases auras which make the oral delivery non-selective. The lipid nanoparticles are considered as good carriers for nose-to-brain drug delivery. The present study aimed to formulate and evaluate a sumatriptan-loaded nanostructured lipid carrier (NLC).

METHODS

A drug-loaded NLC was optimized using D-optimal design of experiment and then the characterization of the formulated NLC including particle size, zeta potential, electron microscopy, thermal analysis, drug loading efficiency and release kinetics were carried out. Pharmacokinetic evaluations were also performed during an in-vivo study on Sprague-Dawley rats and neuropharmacokinetic parameters such as drug targeting efficiency (DTE) and direct transport percentage (DTP) were calculated.

KEY FINDINGS

The optimization of experiments led to nanoparticles with 101 nm mean diameter and polydispersity index (PDI) of 0.27. The drug entrapment efficiency (EE) for optimized nanoparticle was found to be 91.00%. DTE and DTP of intranasal-administered NLC were calculated 258.02% and 61.23%, respectively.

CONCLUSIONS

Neuropharmacokinetic evaluation of intranasal NLC dispersion represents a suitable brain delivery system. The DTP of NLC formulation suggests the desirable entrance of sumatriptan into the brain.

QbD aided development of ibrutinib-loaded nanostructured lipid carriers aimed for lymphatic targeting: evaluation using chylomicron flow blocking approach

Ibrutinib (IBR) is the choice of drug for the treatment of chronic lymphocytic leukaemia (CLL) and mantle cell lymphoma (MCL). IBR has low oral bioavailability of 2.9% owing to its high first pass metabolism. Present study was aimed to develop the nanostructured lipid carriers (NLC) using glyceryl monostearate (GMS) as solid lipid and Capryol™ PGMC as liquid lipid. Plackett-Burman design (PBD) was applied to screen the significant factors; furthermore, these significant factors were subjected to optimisation using Central Composite design (CCD). The size, poly dispersity index (PDI) and entrapment efficiency (E.E.) of the developed NLC were 106.4 ± 8.66 nm, 0.272 ± 0.005 and 70.54 ± 5.52% respectively. Morphological evaluation using transmission electron microscope (TEM) and field emission scanning electron microscope (FESEM) revealed spherical particles. Furthermore, differential scanning calorimetry (DSC) indicates the formation of molecular dispersion of drug in the melted lipid matrix while Powder X-Ray Diffraction (PXRD) studies reveal the absence of crystalline drug peaks in the formulation diffractogram. In-vivo pharmacokinetics of NLC displayed an increase in C_max (2.89-fold), AUC_0-t (5.32-fold) and mean residence time (MRT) (1.82-fold) compared with free drug. Furthermore, lymphatic uptake was evaluated by chylomicron flow blocking approach using cycloheximide (CXI). The pharmacokinetic parameters C_max, AUC_0-t and MRT of NLC without CXI were 2.75, 3.57 and 1.30 folds higher compared with NLC with CXI. The difference in PK parameters without CXI indicates significant lymphatic uptake of the formulation. Hence, NLC can be a promising approach to enhance the oral bioavailability of drugs with high first-pass metabolism. Graphical abstract.

β-Sitosterol Loaded Nanostructured Lipid Carrier: Physical and Oxidative Stability, In Vitro Simulated Digestion and Hypocholesterolemic Activity

The objective of the present study was to explore the potential of nanostructured lipid carriers (NLCs) for improving the oral delivery of β-sitosterol, a poorly water-soluble bioactive component with hypocholesterolemic activity. Two β-sitosterol formulations with different solid lipid compositions were prepared by melt emulsification, followed by the sonication technique, and the effect of storage conditions and simulated digestion on the physical, chemical and oxidative stability, bioaccessibility and release were extensively studied. Both NLC preparations remained relatively stable during the four weeks of storage at different conditions (4, 25 and 40 °C), with more superior stability at lower temperatures. The in vitro digestion experiment indicated a high physical stability after exposure to the simulated mouth and stomach stages and an improved overall β-sitosterol bioaccessibility at the end of the digestion. The NLCs presented an increased solubility and gradual release which could be justified by the remarkable affinity of β-sitosterol to the complex lipid mixture. An in vivo study demonstrated an improved reduction in the total cholesterol and low-density lipoprotein cholesterol plasma levels in mice compared with the drug suspension. These investigations evidenced the potential of the developed NLC formulations for the enhancement of solubility and in vivo performance of β-sitosterol.

Enhanced delivery of melatonin loaded nanostructured lipid carriers during in vitro fertilization: NLC formulation, optimization and IVF efficacy

In this study, the potential of melatonin hormone loaded in nanostructured lipid carriers (Mel-NLCs) in the in vitro fertilization (IVF) environment is investigated by measuring the appropriate IVF parameters on the oocytes of mice.

Colloidal nanostructured lipid carriers of pentoxifylline produced by microwave irradiation ameliorates imiquimod-induced psoriasis in mice

Psoriasis is a chronic inflammatory disease occurring due to a large cascade of molecular and biological processes. Pentoxifylline (PTX) has a profound anti-inflammatory activity and is clinically indicated in the management of psoriasis. PTX is highly hydrophilic and thus is permeation-limited to exert its action on the psoriatic lesions. Colloidal nanostructured lipid carriers (NLCs) is a boon for dermal drug delivery, but incorporation of hydrophilic medicaments is not only difficult to be achieved but is accompanied by suboptimal loading, erratic drug release and time-consuming. The present study was designed to develop NLCs incorporating PTX using the recently explored thin lipid film based microwave assisted rapid technique. Prior to the formulation, the crystal structure of PTX was analyzed by molecular modeling. NLCs formed within 4 min having a size of <200 nm, PDI of <0.250 and a surface charge <-28 mV. PTX was loaded and encapsulated to an extent of 10% and 90% in the NLCs. The drug flux was 4.848 μg/cm²/h at the end of 24 h with a detection of 14% in the receptor fluid indicating a higher retention of PTX within the skin (>84%). In addition, the PTX loaded NLCs were tested against imiquimod-induced psoriasis in mouse model. Histological examinations clearly showed a higher levels of remodeling of the skin layers compared to disease control. These results justify NLCs to be a promising topical delivery system for PTX during psoriasis and can be rapidly produced without the requirement of complex equipment and conditions.

Enhanced Oral Absorption of Amisulpride Via a Nanostructured Lipid Carrier-Based Capsules: Development, Optimization Applying the Desirability Function Approach and In Vivo Pharmacokinetic Study

Amisulpride (AMS), a second generation antipsychotic, suffers from low oral bioavailability (48%). This might be due to its pH-dependent solubility or being a substrate of P-glycoprotein efflux pump. Nanostructured lipid carriers (NLCs) were proposed in this study to enhance the oral absorption of AMS. AMS-NLCs were prepared by solvent evaporation technique according to (2¹.4¹.3¹) factorial design, whereas the type of solid lipid (tripalmitin or Gelucire® 43/1), lipid to drug ratio (7:1, 10:1, or 13:1) and type of external suspending medium (double distilled water, 0.5% TSP pH 12, 1% HPMC or 2.5% glycerin) were the independent variables. The average entrapment efficiency, particle size, polydispersity index, and zeta potential of the prepared formulations ranged from 29.01 to 69.06%, 184.9 to 708.75 nm, 0.21 to 0.59, and - 21 to - 33.55 mV, respectively. AMS-NLCs were optimized according to the desirability function to maximize the entrapment efficiency and minimize the particle size. Formulae G12, G10, and G7 with the highest desirability values of 0.915, 0.84, and 0.768, respectively, were chosen for further investigations. Novel AMS-NLCs capsules were prepared from the lyophilized formulations (TG7 and MG10) to enhance stability and increase patient compliance. The capsules were evaluated in terms of weight variation, content uniformity, and in vitro release pattern. The pharmacokinetics of AMS-NLCs capsules (formula TG7) were tested in rabbits compared to the commercial Amipride® tablets. The relative bioavailability of AMS-NLCs capsules was found to be 252.78%. In conclusion, the NLC-based capsules show potential to improve the oral bioavailability of AMS.

Intranasal Surface-Modified Mosapride Citrate-Loaded Nanostructured Lipid Carriers (MOS-SMNLCs) for Treatment of Reflux Diseases: In vitro Optimization, Pharmacodynamics, and Pharmacokinetic Studies

Gastroesophageal reflux disease (GERD) is an esophageal injury occurred when the stomach contents reflux abnormally into the esophagus. GERD complications include esophageal adenocarcinoma. Mosapride (MOS) is a safe prokinetic agent potentially used to treat GERD. Yet, its low solubility and bioavailability due to extensive first-pass metabolism limits its applications. This study aimed to formulate MOS nanostructured lipid carriers (MOS-NLCs) via the intranasal route to improve its bioavailability. Melt-emulsification low temperature-solidification technique using 2³ full factorial design was adopted to formulate MOS-NLCs. Eight formulae were prepared and assessed in terms of entrapment efficiency (%EE), particle size, and in vitro release. Glycerol addition significantly reduced the particle sizes and improved %EE and %drug released. Surface modification using chitosan was applied. The optimized MOS surface-modified nanostructured lipid carriers (MOS-SMNLCs-F7)(stearic acid, 4% glycerol, 0.5% LuterolF127, 0.5% chitosan) showed low particle size 413.8 nm ± 11.46 nm and high %EE 90.19% ± 0.06% and a threefold increase in permeation of MOS with respect to the drug suspension. MOS-SMNLCs (F7) was also evaluated for its bioavailability compared with drug suspension and commercial product. Statistical analysis revealed a significant increase in gastric emptying rate to be 21.54 ± 1.88 contractions/min compared with10.02 ± 0.62 contractions/min and 8.9 ± 0.72 contractions/min for drug suspension and oral marketed product respectively. Pharmacokinetic studies showed 2.44-fold rise in bioavailability as compared to MOS suspension and 4.54-fold as compared to the oral marketed product. In vitro/in vivo studies proven to level A correlation between in vitro permeation through sheep nasal mucosa and in vivo absorption. Therefore, MOS-SMNLCs could be considered a step forward towards enhancing the clinical efficacy of Mosapride.

Development of novel rosuvastatin nanostructured lipid carriers for oral delivery in an animal model

Objective

The aim of this study was to prepare rosuvastatin nanostructured lipid carriers (RST-NLCs) in order to increase the bioavailability of RST.

Materials and methods

RST-NLCs were prepared by hot melt high-pressure homogenization method. The physicochemical parameters of RST-NLCs were characterized in terms of particle size, zeta potential, morphology, entrapment efficiency, and in vitro release behavior.

Results

The mean particle size was found to be 98.4±0.3 nm. The entrapment efficiency was 84.3%±1.3%. The RST was slowly released from NLCs over a period of 48 h in the PBS. A similar phenomenon was also observed in a pharmacokinetic study in rats, in which the area under the curve of NLCs was 1.65-fold higher than that of tablet powder.

Conclusion

The results of pharmacodynamics showed that the effective lipid-lowering activity of NLCs could be explained by the fact that NLCs resulted in sustained release of RST, which could have increased absorption and provided a higher bioavailability.

Pharmaceutical Dispersion Techniques for Dissolution and Bioavailability Enhancement of Poorly Water-Soluble Drugs

Over the past decades, a large number of drugs as well as drug candidates with poor dissolution characteristics have been witnessed, which invokes great interest in enabling formulation of these active ingredients. Poorly water-soluble drugs, especially biopharmaceutical classification system (BCS) II ones, are preferably designed as oral dosage forms if the dissolution limit can be broken through. Minimizing a drug’s size is an effective means to increase its dissolution and hence the bioavailability, which can be achieved by specialized dispersion techniques. This article reviews the most commonly used dispersion techniques for pharmaceutical processing that can practically enhance the dissolution and bioavailability of poorly water-soluble drugs. Major interests focus on solid dispersion, lipid-based dispersion (nanoencapsulation), and liquisolid dispersion (drug solubilized in a non-volatile solvent and dispersed in suitable solid excipients for tableting or capsulizing), covering the formulation development, preparative technique and potential applications for oral drug delivery. Otherwise, some other techniques that can increase the dispersibility of a drug such as co-precipitation, concomitant crystallization and inclusion complexation are also discussed. Various dispersion techniques provide a productive platform for addressing the formulation challenge of poorly water-soluble drugs. Solid dispersion and liquisolid dispersion are most likely to be successful in developing oral dosage forms. Lipid-based dispersion represents a promising approach to surmounting the bioavailability of low-permeable drugs, though the technique needs to traverse the obstacle from liquid to solid transformation. Novel dispersion techniques are highly encouraged to develop for formulation of poorly water-soluble drugs.