Full factorial design, physicochemical characterisation and biological assessment of cyclosporine A loaded cationic nanoparticles

Comparative study of cyclosporine A liposomes and emulsions for ophthalmic drug delivery: Process optimization through response surface methodology (RSM) and biocompatibility evaluation

Herein, cyclosporine A loaded liposomes (CsA-Lips) were fabricated aimed at improving the biocompatibility of the ophthalmic formulation and getting rid of the direct contact of ocular tissues with irritant excipients. Response surface methodology was exploited in order to investigate the influence of miscellaneous factors on the key characteristics of CsA-Lips. Ratio of EPC:CsA, ratio of EPC:Chol, and stirring speed were selected as the independent variables, while size, drug-loading content (DL), and drug-loading content (DL) loss rate were applied as the response variables. In case of the maximal lack-of-fit p-value and minimum sequential p-value, quadratic model was regarded as the fittest model to analyze the data. The correlation of independent variables with response variables was described by three-dimension surface figures. Optimized formulation for CsA-Lips was obtained with ratio of EPC:CsA set as 15, ratio of EPC:Chol set as 2, and stirring speed set as 800 rpm. The particle size of CsA-Lips was 129.2 nm after optimalization while their TEM images exhibited spherical unilamellar vesicles with clearly shell-core structure. CsA released more rapidly from CsA-Lips in comparison with self-made emulsion and Restasis®. Besides, minimum cytotoxicity of CsA-Lips was perceived via both MTT method and LDH method, indicating the excellent compatibility of the ophthalmic formulation. Simultaneously, CsA-Lips showed enhanced nonspecific internalization in the cytoplasm with a time-dose-dependent manner. In conclusion, CsA-Lips could be adhibited as the hopeful ophthalmic drug delivery system clinically for dry eye syndrome (DES).

'Transfersome-embedded-gel' for dual-mechanistic delivery of anti-psoriatic drugs to dermal lymphocytes

AIM

Develop a platform for co-delivering clobetasol propionate (CP) and cyclosporine (CyA) to the epidermis and dermis to treat psoriasis.

METHODS

The transfersomes were prepared by thin-film hydration method. Transfersomes were characterised by dynamic light scattering and transmission electron microscope (TEM). Then, the gel stability, viscosity, pH, and spreadability were measured. Cytotoxicity of the CyA-loaded transfersome embedded in CP-dispersed gel (TEG-CyA-CP) was assessed on both human keratinocyte cell line (HaCaT) and Jurkat cells. In vitro cellular uptake and ex vivo dermal distribution was measured. The expression of inflammatory markers was assessed by reverse-transcription PCR (RT-PCR).

RESULTS

Nanoscale (<150 nm) transferosomes with high CyA encapsulation efficiency (>86%) were made. TEG-CyA-CP demonstrated higher viscosity (4808.8 ± 12.01 mPas), which may help control dual drug release. Ex vivo results showed TEG-CyA-CP ability to deliver CyA in the dermis and CP in the epidermis. RT-PCR studies showed the optimised formulation helps reduce the tumour necrosis factor (TNF-α) and interleukin-1 (IL-1) levels to relieve psoriasis symptoms.

CONCLUSION

The developed TEG-CyA-CP represents a promising fit-to-purpose delivery platform for the dual-site co-delivery of CyA and CP in treating psoriasis.

A new nanosuspension prepared with wet milling method for oral delivery of highly variable drug Cyclosporine A: Development, optimization and in vivo evaluation

Cyclosporine A (CsA) is a cyclic polypeptide, that has been widely used for immunosuppression. This study aims to develop nanosuspension for oral administration of CsA using the wet milling (WM) method one of the top-down technologies. The WM method was optimized by studying the effects of critical process parameters for WM on the particle size (PS), particle size distribution (PDI), and zeta potential (ZP) of nanosuspensions using the Design of Experiment (DoE) approach. Nanosuspension was developed using hydroxypropyl methylcellulose (HPMC) and sodium dodecyl sulfate (SDS) and in vitro characterization studies were performed. In vitro dissolution and in vivo pharmacokinetic studies were conducted with biorelevant media (fasted and fed state simulated fluids) and fasted and fed states in rats, respectively. In vivo immunological studies were also performed. PS, PDI, and ZP values for nanosuspension were approximately 600 nm, 0.4, -25 mV, respectively. The solubility of CsA was increased by 4.5-folds by nanosuspensions. Dissolution studies showed that nanosuspension had higher dissolution than the commercial product in the FeSSIF medium. The pharmacokinetic study indicated that AUC_0-24 values of CsA nanosuspension were to be 2.09 and 5.51-fold higher than coarse powder in fasted and fed conditions, respectively. Immunological studies were carried out after oral administration of nanosuspension for 21 days, the ratio of CD4+/CD8+ was found to be more acceptable than the commercial product. These results demonstrated that nanosuspension is a promising approach for increasing the bioavailability and avoiding the food effect on absorption of CsA which one of the highly variable drugs.

Preparation and characterization of Eudragit L 100-55/chitosan enteric nanoparticles containing omeprazole using general factorial design: in vitro/in vivo study

Background and purpose:

Omeprazole (OMP) is broadly used for the treatment of gastroesophageal reflux and other acid-related diseases. The current study aimed to prepare enteric-coated nanoparticles containing OMP to achieve a stable powder formulation easily prescribed in children.

Experimental approach:

The nanoparticles were formed by complex coacervation method using chitosan (CTS) and Eudragit L100/55 (EU) and the impact of various formulation variables (the concentrations of EU solution and its volume ratio to CTS solution) were assessed using 3² fractional design. The mean particle size (PS), zeta potential (ZP), encapsulation efficiency (EE), and drug loading (DL) were determined. Finally, the pharmacological effects of the optimized OMP enteric nanoparticles were evaluated by an in vivo antiulcer study using Sprague-Dawley rats.

Findings/Results:

The highest desirability value was for formulation F5 (containing EU concentration 4 mg/mL and EU/CTS volume ratio 2:1). PS, ZP, EE, and DL of the optimized OMP-loaded nanoparticles were confirmed 810 ± 14 nm, -38.2 ± 1.8 mV, 83.1± 4.2%, and 13.1± 1.5%, respectively. in vitro release studies showed the pH sensitivity of nanoparticles and OMP release was pH-dependent. in vivo pharmacological assessment revealed that the optimized formulation was able to protect rat stomach against ulcer formation induced by indomethacin compared to the group that received normal saline which demonstrated severe peptic ulcer and hemorrhagic spots.

Conclusion and implication:

Our results indicated that the enteric EU/CTS nanoparticles were successfully prepared via a complex coacervation method and their efficacy could be comparable with commercial OMP pellets.

Drug-Integrating Amphiphilic Nanomaterial Assemblies: 1. Spatiotemporal control of cyclosporine delivery and activity using nanomicelles and nanofibrils

Immunomodulatory therapies are limited by unavoidable side effects as well as poor solubility, stability, and pharmacokinetic properties. Nanomaterial-based drug delivery may overcome these limitations by increasing drug solubility, site-targeting, and duration of action. Here, we prepared innovative drug-integrating amphiphilic nanomaterial assemblies (DIANA) with tunable hydrophobicity, size, and morphology, and we evaluated their ability to deliver cyclosporine A (CsA) for immunomodulatory applications. We synthesized amphiphilic block copolymers made of poly(ethylene glycol)-poly(propylene sulfide) (PEG-PPS) and poly(ethylene glycol)-oligo(ethylene sulfide) (PEG-OES) that can self-assemble into solid core nanomicelles (nMIC, with ≈20 nm diameter) and nanofibrils (nFIB, with ≈5 nm diameter and > 500 nm length), respectively. nMIC and nFIB displayed good CsA encapsulation efficiency (up to 4.5 and 2 mg/mL, respectively in aqueous solution), superior to many other solubilization methods, and provided sustained release (>14 and > 7 days for the nMIC and nFIB) without compromising CsA's pharmacological activity. Treatment of insulin-secreting cells with unloaded DIANAs did not impair cell viability and functionality. Both CsA-loaded DIANAs inhibited the proliferation and activation of insulin-reactive cytotoxic T cells in vitro. Subcutaneous injections of CsA-loaded DIANAs in mice provided CsA sustained release, decreasing alloantigen-induced immune responses in the draining lymph node at lower doses and reduced administration frequency than unformulated CsA. While nMIC solubilized higher amounts and provided more sustained release of CsA in vitro, nFIB enhanced cellular uptake and promoted local retention due to slower trafficking in vivo. DIANAs provide a versatile platform for a local immune suppression regimen that can be applied to allogeneic cell transplantation.

Improving cellular uptake and cytotoxicity of chitosan-coated poly(lactic-co-glycolic acid) nanoparticles in macrophages

Aim: This research aims to identify important formulation parameters for the enhancement of nanoparticle (NP) uptake and decreasing the cytotoxicity in macrophages. Materials & methods: Fluorescent poly(lactic-co-glycolic acid) (PLGA) nanocarriers were characterized for size distributions, zeta potential and encapsulation efficiency. Incubation time, size class, PLGA derivative and chitosan derivative were assessed for uptake kinetics and cell viability. Results: The major determining factor for enhancing cellular uptake were chitosan coatings, combined with acid-terminated PLGA and small NP size. Moreover, cytotoxicity was more favorable for small, chitosan glutamate-coated, acid-terminated PLGA NPs compared with its plain chitosan-coated counterparts. Conclusion: Chitosan glutamate has been shown to be a valuable alternative coating material for acid-terminated PLGA NPs to efficiently and safely target macrophages.

Cyclosporine CsA—The Physicochemical Characterization of Liposomal and Colloidal Systems

This paper presents an overview of the possibilities of testing various cyclosporine (CsA) formulations with an emphasis on parameters that may be key to improving the stability and biocompatibility. The feasibility of CsA colloidal systems for oral (injection) administration were investigated using different techniques and compared with similar investigations of other researchers. The chosen CsA systems were developed using dipalmitoylphosphocholine (DPPC) and/or cholesterol as a lipid matrix, stabilized with ethanol, with soybean oil or n-tetradecane as oil phase in emulsions, under natural pH, room and physiological temperature. Their integrity was found to be strictly dependent on the stabilizers. The highest CsA penetrability with the system containing phospholipid in the context of its interactions with lipid membranes was shown. Also, the bioavailability of CsA can be enhanced with the biopolymer antibacterial chitosan. This mini-review suggests the suitability of liposome/microemulsion as promising vehicles for CsA delivery. The most hopeful proved to be formulation with the smaller particle size facilitating absorption, but when safety is assessed, relying on just the particle size cannot be the only criteria. Reassumed, the CsA formulation stability known on the basis of the size and zeta potential measurements guarantees a decrease of the individual variations in the drug bioavailability, toxicity and minimizes rejection.

The Role of Nano-ophthalmology in Treating Dry Eye Disease

Dry eye disease (DED) is a common multifactorial disease linked to the tears/ocular surface leading to eye discomfort, ocular surface damage, and visual disturbance. Antiinflammatory agents (steroids and cyclosporine A), hormonal therapy, antibiotics, nerve growth factors, essential fatty acids are used as treatment options of DED. Current therapies attempt to reduce the ocular discomfort by producing lubrication and stimulating gland/nerve(s) associated with tear production, without providing a permanent cure for dry eye. Nanocarrier systems show a great promise to revolutionize drug delivery in DED, offering many advantages such as site specific and sustained delivery of therapeutic agents. This review presents an overview, pathophysiology, prevalence and etiology of DED, with an emphasis on preclinical and clinical studies involving the use of nanocarrier systems in treating DED. Lay Summary: Dry eye disease (DED) is a multifactorial disease associated with tear deficiency or excessive tear evaporation. There are several review articles that summarize DED, disease symptoms, causes and treatment approaches. Nanocarrier systems show a great promise to revolutionize drug delivery in DED, offering many advantages such as site specific and sustained delivery of therapeutic agents. Very few review articles summarize the findings on the use of nanotherapeutics in DED. In this review, we have exclusively discussed the preclinical and clinical studies of nanotherapeutics in DED therapy. This information will be attractive to both academic and pharmaceutical industry researchers working in DED therapeutics.

Biofabrication of Chitosan-Based Nanomedicines and Its Potential Use for Translational Ophthalmic Applications

Drug delivery to the anterior and posterior segment of eye remains a challenge. Nanoparticle-mediated drug delivery has indicated some promise. The presented review aims to summarize recent advancements in chitosan-based nanotherapies for ocular drug delivery and the challenges encountered during the process. Significant research using chitosan, a cationic linear polymer, is being conducted for ocular drug delivery. A vast number of publications exploit the mucoadhesive properties of the polymer, which arise due to interactions between the amino acids of chitosan and the sialic acid residues in mucous. The high degree of crosslinking in chitosan nanoparticles facilitates a dramatic increase in ocular drug retention of the desired drug, which subsequently helps in ocular penetration and improving the bioavailability of the drugs. A noted decrease in the initial burst of the drug is the basis for developing sustained drug release formulation using biodegradable and biocompatible chitosan polymer. In vitro as well as in vivo studies have indicated enhancement in the uptake, accumulation, and removal of chitosan nanoparticles from the site of delivery. In summary, chitosan- or modified-chitosan-based nanoparticles are being widely tested as drug carriers for treatment of bacterial and viral infections, glaucoma, age-related macular degeneration, and diabetic retinopathy.

Assembling Surfactants-Mucoadhesive Polymer Nanomicelles (ASMP-Nano) for Ocular Delivery of Cyclosporine-A

The physiological protective mechanisms of the eye reduce the bioavailability of topically administered drugs above all for those with high molecular weight and /or lipophilic characteristics, such as Cyclosporine A (CyA). The combined strategy based on the association of nanomicelles and mucoadhesive polymer seems promising since a limited number of commercial products containing CyA have been recently approved. The scope of this investigation was the design of Assembling Surfactants-Mucoadhesive Polymer Nanomicelles (ASMP-Nano), based on a binary system of two surfactants in combination with hyaluronic acid, and their biopharmaceutical evaluation. The optimisation of the ASMP-Nano in term of the amount of surfactants, CyA-loading and size determined the selection of the clear and stable Nano1HAB-CyA formulation containing 0.105% w/w CyA loaded-nanomicelles with a size of 14.41 nm. The nanostructured system had a protective effect towards epithelial corneal cells with a cell viability of more than 80%. It interacted with cellular barriers favouring the uptake and the accumulation of CyA into the cells as evidenced by fluorescent probe distribution, by hindering CyA permeation through reconstituted corneal epithelial tissue. In pharmacokinetics study on rabbits, the nanomicellar carrier prolonged the CyA retention time in the precorneal area mainly in presence of hyaluronic acid (HA), a mucoadhesive polymer.

Sorbitan ester nanoparticles (SENS) as a novel topical ocular drug delivery system: Design, optimization, and in vitro/ex vivo evaluation

We explored the potential of two types of sorbitan ester nanoparticles (SENS) as novel tools for topical ocular drug delivery. The optimized SENS formulation (SENS-OPT) consisted of nanoparticles (NPs) of 170.5 nm, zeta potential +33.9 mV, and cyclosporine loading of 19.66%. After hyaluronic acid (HA) coating, the resulting SENS-OPT-HA NPs had a particle size of 177.6 nm and zeta potential of -20.6 mV. The NPs were stable during 3 months of storage at different temperatures and did not aggregate in the presence of protein-enriched simulated lacrimal fluid. There was no toxicity to cultured human corneal epithelial (HCE) cells when exposed to NPs up to 0.4% (w/v). Both NPs were effectively internalized by HCE cells through active mechanisms. Endocytosis of SENS-OPT NPs was caveolin-dependent whereas SENS-OPT-HA NP endocytosis was mediated by HA receptors. HA-receptor-mediated endocytosis may be responsible for the higher cellular uptake of SENS-OPT-HA NPs. After cyclosporine incorporation into the NPs, corneal penetration of this immunosuppressive drug by loaded SENS-OPT NPs was 1.3-fold higher than the commercial reference formulation Sandimmun®. For cyclosporine-loaded SENS-OPT-HA NPs, the penetration was 2.1-fold higher than for Sandimmun®. In ex vivo stimulated lymphocytes, both formulations demonstrated the same reduction in IL-2 levels as Sandimmun®.

Co-nanoencapsulation of antimalarial drugs increases their in vitro efficacy against Plasmodium falciparum and decreases their toxicity to Caenorhabditis elegans

Drugs used for the treatment and prevention of malaria have resistance-related problems, making them ineffective for monotherapy. If properly associated, many of these antimalarial drugs may find their way back to the treatment regimen. Among the therapeutic arsenal, quinine (QN) is a second-line treatment for uncomplicated malaria but has side effects that limit its use. Curcumin (CR) is a natural compound with anti-plasmodial activities and low bioavailability. In this context, the aim of this work was to develop and characterize co-encapsulated QN + CR-loaded polysorbate-coated polymeric nanocapsules (NC-QC) to evaluate their activity on Plasmodium falciparum and the safety of the nanoformulations for Caenorhabditis elegans. NC-QC displayed a diameter of approximately 200 nm, a negative zeta potential and a slightly basic pH. The drugs are homogeneously distributed in the NCs in the amorphous form. Co-encapsulated NCs exhibited a significant reduction in P. falciparum parasitemia, better than QN/CR. The worms exposed to NC-QC showed higher survival and longevity and no decrease in their reproductive capacity compared to free and associated drugs. It was possible to prove that the NCs were absorbed orally by the worms using fluorescence microscopy. Co-encapsulation of QN and CR was effective against P. falciparum, minimizing the toxic effects caused by chronic exposure of the free drugs in C. elegans.

Preparation, optimization, and characterization of chitosan-coated solid lipid nanoparticles for ocular drug delivery

The present study aimed to develop and optimize chitosan coated solid lipid nanoparticles (chitosan-SLNs) encapsulated with methazolamide. Chitosan-SLNs were successfully prepared by a modified oil-in-water emulsification-solvent evaporation method with glyceryl monostearate as the solid lipid and phospholipid as the surfactant. Systematic screening of formulation factors was carried out. The optimized formula for preparation was screened by orthogonal design as well as Box-Behnken design with entrapment efficiency, particle size and zeta potential as the indexes. The entrapment efficiency of the optimized formulation (methazolamide-chitosan-SLNs) prepared was (58.5±4.5)%, particle size (247.7±17.3) nm and zeta potential (33.5±3.9) mV. Transmission electron microscopy showed homogeneous spherical particles in the nanometer range. A prolonged methazolamide in vitro release profile was obtained in the optimized chitosan-SLNs suspension compared with methazolamide solution. No ocular damages were observed in the susceptibility test on albino rabbits. The results suggest that the combination of orthogonal design and Box-Behnken design is efficient and reliable in the optimization of nanocarriers, and chitosan-SLNs is a potential carrier for ophthalmic administration.

Development of Timolol-Loaded Galactosylated Chitosan Nanoparticles and Evaluation of Their Potential for Ocular Drug Delivery

This study was conducted to develop timolol maleate (TM)-loaded galactosylated chitosan (GC) nanoparticles (NPs) (TM-GC-NPs) followed by optimization via a four-level and three-factor Box-Behnken statistical experimental design. The optimized nanoparticles showed a particle size of 213.3 ± 6.83 nm with entrapment efficiency of 38.58 ± 1.31% and drug loading of 17.72 ± 0.28%. The NPs were characterized with respect to zeta potential, pH, surface morphology, and differential scanning calorimetry (DSC). The determination of the oil-water partition coefficient demonstrated that the TM-GC-NPs had a high liposolubility at pH 6 as compared to timolol-loaded chitosan nanoparticles (TM-CS-NPs) and commercial TM eye drops. The in vitro release study indicated that TM-GC-NPs had a sustained release effect compared with the commercial TM eye drops. Ocular tolerance was studied by the hen's egg chorioallantoic membrane (HET-CAM) assay and the formulation was non-irritant and could be used for ophthalmic drug delivery. The in vitro transcorneal permeation study and confocal microscopy showed enhanced penetration, and retention in the cornea was achieved with TM-GC-NPs compared with the TM-CS-NPs and TM eye drops. Preocular retention study indicated that the retention of TM-GC-NPs was significantly longer than that of TM eye drops. The in vivo pharmacodynamic study suggested TM-GC-NPs had a better intraocular pressure (IOP) lowering efficacy and a prolonged working time compared to commercial TM eye drops (P ≤ 0.05). The optimized TM-GC-NPs could be prepared successfully promising their use as an ocular delivery system.

Cyclosporine A delivery to the eye: A comprehensive review of academic and industrial efforts

Local ocular delivery of cyclosporine A (CsA) is the preferred method for CsA delivery as a treatment for ocular inflammatory diseases such as uveitis, corneal healing, vernal keratoconjunctivitis and dry eye disease. However, due to the large molecular weight and hydrophobic nature of CsA and the natural protective mechanisms of the eye, achieving therapeutic levels of CsA in ocular tissues can be difficult. This review gives a comprehensive overview of the current products available to clinicians as well as emerging drug delivery solutions that have been developed at both the academic and industry levels.

Filgrastim (G-CSF) loaded liposomes: mathematical modeling and optimization of encapsulation efficiency and particle size

Introduction: Optimization of filgrastim (G-CSF) (granulocyte colony stimulating factor) liposomes formulation prepared by the method of film hydration was the aim of this research.

Methods: To study the independent variables effects in the development of filgrastim (G-CSF) liposomes, method of factorial design was applied. The molar ratio of dipalmitoyl phophatidylcholine (DPPC) per cholesterol (Chol.) and hydration time were chosen as two independent factors. The dependent variables were encapsulation efficiency percent (EE %) and particle size (PS). Ultrafiltration method was applied for separation of un-encapsulated protein. RP-HPLC method was employed for analysis of G-CSF.

Results: Application of response surface methodology (RSM) in formulation of filgrastim liposomes and the obtained results for responses including particle size and EE % showed that the main effective independent variable was DPPC/Chol molar ratio. Different impacts of influencing parameters including interaction and individual effects were checked employing a mathematical method for obtaining desired liposomes. Optimum liposomal formulations were established using this method for enhancing their characteristics. Average percent errors (APEs) were 3.86% and 3.27% for predicting EE % and PS, respectively which reflect high model ability in this regard.

Conclusion: It is concluded that observed and predicted values regarding PS and EE % were consistent and this model is efficient enough in prediction of the mentioned characteristics while preparing filgrastim (G-CSF) liposomes.

Formulation and In Vitro Evaluation of Cyclosporine-A Inserts Prepared Using Hydroxypropyl Methylcellulose for Treating Dry Eye Disease

PURPOSE

The aim of this study was to develop and characterize a novel sustained-release drug delivery system of cyclosporine-A (CsA) using hydroxypropyl methylcellulose (HPMC) and xanthan gum (XG) for treating dry eye disease (DED).

METHODS

Polymeric inserts of CsA were prepared using the solvent casting technique with a 2(3) full factorial design to evaluate the effect of HPMC and XG ratios and drug content on thickness, folding endurance, wettability, and in vitro drug release. Inserts were also evaluated for drug content, moisture absorption and loss, and surface pH. Inserts with an optimized ratio of HPMC and XG were sterilized with UV light and evaluated for morphology, thermal analysis, Fourier transform infrared spectroscopy, stability at 4°C, 25°C, and 40°C, cytotoxicity in cultured bovine corneal endothelial cells, and anti-inflammatory effect in Jurkat T cells.

RESULTS

The addition of XG increased the CsA release duration and enhanced the folding endurance of films. All films showed uniformity in drug content and thickness. Formulation F4 composed of 1% HPMC and 0.25% XG exhibited good folding endurance and sustained CsA release for up to 20 h. Sterility testing of F4 using plate and direct inoculation confirmed the formulation sterility and validated the sterilization method. The formulation was stable for at least 3 months at 4°C, 25°C, and 40°C. No cytotoxicity was observed in cultured bovine corneal endothelial cells for up to 24 h. The anti-inflammatory effect of CsA was intact in ophthalmic inserts.

CONCLUSION

In conclusion, combination therapy with HPMC and CsA can be a potential once-a-day formulation for treating DED.

Reformulating cyclosporine A (CsA): More than just a life cycle management strategy

Cyclosporine A (CsA) is a well-known immunosuppressive agent that gained considerable importance in transplant medicine in the late 1970s due to its selective and reversible inhibition of T-lymphocytes. While CsA has been widely used to prevent graft rejection in patients undergoing organ transplant it was also used to treat several systemic and local autoimmune disorders. Currently, the neuro- and cardio-protective effects of CsA (CiCloMulsion®; NeuroSTAT®) are being tested in phase II and III trials respectively and NeuroSTAT® received orphan drug status from US FDA and Europe in 2010. The reformulation strategies focused on developing Cremophor® EL free formulations and address variable bioavailability and toxicity issues of CsA. This review is an attempt to highlight the progress made so far and the room available for further improvements to realize the maximum benefits of CsA.

Polymeric nanoparticles for oral delivery of 5-fluorouracil: Formulation optimization, cytotoxicity assay and pre-clinical pharmacokinetics study

Poly(lactic acid) (PLA) or poly(lactic acid)-poly(ethylene glycol) (PLA-PEG) blend nanoparticles were developed loading 5-fluorouracil (5-FU), an antitumor agent broadly used in therapy. A 2(3) factorial experimental design was conducted to indicate an optimal formulation and demonstrate the influence of the interactions of components on the mean particle size and drug encapsulation efficiency. Optimized PLA nanoparticles presented 294nm and 51% of 5-FU encapsulation efficiency and PLA-PEG blend nanoparticles presented 283nm and 55% of 5-FU encapsulation efficiency. In vitro release assay demonstrated after 320h about 50% of 5-FU was released from PLA and PLA-PEG blend nanoparticles. Release kinetics of 5-FU from nanoparticles followed second order and the release mechanism calculated by Korsmeyer-Peppas model was diffusion and erosion. In the assessment of cytotoxicity over Hep-2 tumor cells, PLA or PLA-PEG blend nanoparticles presented similar IC50 value than free 5-FU. Pharmacokinetic parameters after oral administration of 5-FU were improved by nanoencapsulation. Bioavailability, Cmax, Tmax, t1/2 and distribution volume were significantly improved, while clearance were decreased. PEG presence in nanoparticles didn't influence physicochemical and biological parameters evaluated. PLA and PLA-PEG nanoparticles can be potential carriers for oral delivery of 5-FU.

Preparation and characterization of nanoparticles composed of methylated N-(4-N,N-dimethyl aminobenzyl) chitosan for oral delivery of cyclosporine A

Cyclosporine is considered a highly lypophilic compound meaning low bioavailability through oral administration. In this study, cyclosporine was entrapped in a novel aromatic, quaternized derivative of chitosan (i.e. methylated N-(4-N,N-dimethyl aminobenzyl) chitosan) in order to improve solubility and bioavailability. Methylated N-(4,N,N-dimethyl aminobenzyl) chitosan was synthesized by the Schiff base reaction method. Polymeric nanoparticles containing cyclosporine was prepared and the physico-chemical properties of prepared nanoparticles were determined. The nanoparticles were studied morphologically using transmission electron microscopy (TEM). Finally, the release of cyclosporine from nanoparticles was studied in vitro using simulated intestinal fluid adjusted to pH of 6.8. For the preparation of nanoparticles, different formulations were studied and it was found that proper nanoparticles were prepared in equal concentration (1 mg/mL) of polymer and sodium tri-poly phosphate (TPP). The size, zeta potential, PdI, EE% and LE% of the prepared nanoparticles were reported as 173±36 nm, 23.1±4.18 mV, 0.243±0.05, 97.1±4.38% and 3.2±0.21%, respectively. The TEM images of nanoparticles revealed spherical to sub-spherical nanoparticles with no sign of agglomeration. This study suggests that preparations of nanoparticles composed of methylated N-(4,N,N-dimethyl aminobenzyl) chitosan can be a good candidate for improving the oral bioavailability of cyclosporine.

Investigation and optimization of formulation parameters on preparation of targeted anti-CD205 tailored PLGA nanoparticles

The purpose of this study was to assess the effect of various formulation parameters on anti-CD205 antibody decorated poly(d, l-lactide co-glycolide) (PLGA) nanoparticles (NPs) in terms of their ability to target dendritic cells (DCs). In brief, emulsification solvent evaporation technique was adapted to design NP formulations using two different viscosity grades (low and high) of both ester and carboxylic acid terminated PLGA. Incorporation of ligand was achieved following physical adsorption or chemical conjugation processes. The physicochemical characterizations of formulations were executed to assess the effects of different solvents (chloroform and ethyl acetate), stabilizer percentage, polymer types, polymer viscosities, ligand-NP bonding types, cross-linkers, and cryoprotectants (sucrose and trehalose). Modification of any of these parameters shows significant improvement of physicochemical properties of NPs. Ethyl acetate was the solvent of choice for the formulations to ensure better emulsion formation. Infrared spectroscopy confirmed the presence of anti-CD205 antibody in the NP formulation. Finally, cytotoxicity assay confirmed the safety profile of the NPs for DCs. Thus, ligand modified structurally concealed PLGA NPs is a promising delivery tool for targeting DCs in vivo.

Lipid nanoparticles for cyclosporine A administration: development, characterization, and in vitro evaluation of their immunosuppression activity

Cyclosporine A (CsA) is an immunosuppressant commonly used in transplantation for prevention of organ rejection as well as in the treatment of several autoimmune disorders. Although commercial formulations are available, they have some stability, bioavailability, and toxicity related problems. Some of these issues are associated with the drug or excipients and others with the dosage forms. With the aim of overcoming these drawbacks, lipid nanoparticles (LN) have been proposed as an alternative, since excipients are biocompatible and also a large amount of surfactants and organic solvents can be avoided. CsA was successfully incorporated into LN using the method of hot homogenization followed by ultrasonication. Three different formulations were optimized for CsA oral administration, using different surfactants: Tween(®) 80, phosphatidylcholine, taurocholate and Pluronic(®) F127 (either alone or mixtures). Freshly prepared Precirol nanoparticles showed mean sizes with a narrow size distribution ranging from 121 to 202 nm, and after freeze-drying were between 163 and 270 nm, depending on the stabilizer used. Surface charge was negative in all LN developed. High CsA entrapment efficiency of approximately 100% was achieved. Transmission electron microscopy was used to study the morphology of the optimized LN. Also, the crystallinity of the nanoparticles was studied by X-ray powder diffraction and differential scanning calorimetry. The presence of the drug in LN surfaces was confirmed by X-ray photoelectron spectroscopy. The CsA LN developed preserved their physicochemical properties for 3 months when stored at 4°C. Moreover, when the stabilizer system was composed of two surfactants, the LN formulations were also stable at room temperature. Finally, the new CsA formulations showed in vitro dose-dependent immuno-suppressive effects caused by the inhibition of IL-2 levels secreted from stimulated Jurkat cells. The findings obtained in this paper suggest that new lipid nanosystems are a good alternative to produce physicochemically stable CsA formulations for oral administration.

Amphotericin B-loaded polymeric nanoparticles: formulation optimization by factorial design

In this study, PLGA or PLGA-PEG blend nanoparticles were developed loading amphotericin B (AmB), an antifungal agent broadly used in therapy. A 2(2) × 3(1) factorial experimental design was conducted to indicate an optimal formulation of nanoparticles containing AmB and demonstrate the influence of the interactions of components on the mean particle size and drug encapsulation efficiency. The independent variables analyzed were polymer amount (two levels) and organic phase (three factors in one level). The parameters methanol as cosolvent and higher polymer amount originated from the higher AmB encapsulation, but with the larger particle size. The selected optimized parameters were set as the lower polymer amount and ethyl acetate as cosolvent in organic phase, for both PLGA and PLGA-PEG nanoparticles. These parameters originated from nanoparticles with the size of 189.5 ± 90 nm and 169 ± 6.9 nm and AmB encapsulation efficiency of 94.0 ± 1.3% and 92.8 ± 2.9% for PLGA and PLGA-PEG nanoparticles, respectively. Additionally, these formulations showed a narrow size distribution indicating homogeneity in the particle size. PLGA and PLGA-PEG nanoparticles are potential carrier for AmB delivery and the factorial design presented an important tool in optimizing nanoparticles formulations.

Application of response surface methodology in development of sirolimus liposomes prepared by thin film hydration technique

Introduction : The present investigation was aimed to optimize the formulating process of sirolimus liposomes by thin film hydration method. Methods : In this study, a 3(2) factorial design method was used to investigate the influence of two independent variables in the preparation of sirolimus liposomes. The dipalmitoylphosphatidylcholine (DPPC) /Cholesterol (Chol) and dioleoyl phosphoethanolamine(DOPE) /DPPC molar ratios were selected as the independent variables. Particle size (PS) and Encapsulation Efficiency (EE %) were selected as the dependent variables. To separate the un-encapsulated drug, dialysis method was used. Drug analysis was performed with a validated RP-HPLC method. Results : Using response surface methodology and based on the coefficient values obtained for independent variables in the regression equations, it was clear that the DPPC/Chol molar ratio was the major contributing variable in particle size and EE %. The use of a statistical approach allowed us to see individual and/or interaction effects of influencing parameters in order to obtain liposomes with desired properties and to determine the optimum experimental conditions that lead to the enhancement of characteristics. In the prediction of PS and EE % values, the average percent errors are found to be as 3.59 and 4.09%. This value is sufficiently low to confirm the high predictive power of model. Conclusion : Experimental results show that the observed responses were in close agreement with the predicted values and this demonstrates the reliability of the optimization procedure in prediction of PS and EE % in sirolimus liposomes preparation.