Spontaneous Emulsification Solvent Diffusion Research Articles

Preparation, Process Optimization and Cytotoxicity Evaluation of Lyophilized Etoposide Loaded Nanoparticles

The purpose of this study was to develop freeze dried Polylactide-co-glycolide (PLGA) nanoparticles loaded with etoposide intended to be administered intravenously with improved therapeutic efficacy of the drug and thereby reduced dose related toxicity associated with it. The etoposide loaded nanoparticles were prepared using modified spontaneous emulsification solvent diffusion method (SESD).The in Vitro release study of etoposide loaded Polylactide-co-glycolide (PLGA)–Nanoparticles NP was carried by dialysis bag diffusion technique.The incorporation efficiency was found to be higher in modified SESD technique than emulsification solvent evaporation method. The release behavior of etoposide exhibited a biphasic pattern characterized by an initial burst release followed by a slow and continuous release. The nanoparticles were characterized by particle size, zeta potential, polydispersity index, DSC and FTIR. The long term stability was achieved by lyophilisation technique. The cell line study using XTT assay on LNCaP prostate tumor cell lines revealed that etoposide loaded nanoparticles showed greater cancer cell inhibition compared to plain nanoparticles and marketed conventional formulations.

Preparation of Silymarin–quercetin Loaded Nanoparticles by Spontaneous Emulsification Solvent Diffusion Method Using D-alpha-tocopheryl Poly (Ethylene Glycol) 1000 Succinate

Silymarin, a flavonolignan, derived from Silybum marianum, family Asteraceae has long been used as a hepatoprotective remedy. Silymarin has cytoprotective activities due to its antioxidant property and free radical scavenging activity. The pharmacokinetic studies of past three decades revealed that silymarin has poor absorption, rapid metabolism especially by Phase II metabolism and ultimately poor oral bioavailability. Quercetin, a flavonoid present in edible vegetables and fruits, It is a potent antioxidant and shows a wide range of biological functions. Quercetin improves blood levels and efficacy of number of drugs since it is P-Glycoprotein inhibitor and also inhibits drug metabolizing enzymes. Both silymarin and quercetin were, poorly soluble in the water shows low bioavailability. The advanced type of formulation like polymeric nanoparticles (PNPs) can be successfully utilised for bioavailability enhancement and targeting the Silymarin-quercetin to hepatocytes. A controlled release PNPs of silymarin-quercetin were prepared by spontaneous emulsification solvent diffusion (SESD) method using Poly Lactic-co-Glycolic Acid (PLGA) as biodegradable polymer, D-alpha-tocopheryl poly (ethylene glycol) 1000 succinate (TPGS) used as a solubilizer, as an emulsifier. TPGS as an emulsifier and further as a matrix material blended with PLGA was used to enhance the encapsulation efficiency and improve the drug release profile of nanoparticles. Different formulations with various drug: polymer ratios and volume and concentration of surfactant, centrifugation time were evaluated. The effect of formulation parameters such as drug/polymer ratio, volume and surfactant content were evaluated. The surface morphology and size of the nanoparticles were studied by scanning electron microscopy (SEM) Transmission electron microscopy (TEM). Drug encapsulation efficiency and in vitro drug release profiles of nanoparticles were determined using UV spectrophotometry. The nanoparticles prepared with combination of both the drugs in this study were spherical with size range of 100–200 nm. It was shown that TPGS was a good emulsifier for producing nanoparticles of hydrophobic drugs and improving the encapsulation efficiency and drug loading and drug release profile of nanoparticles. Although the amount of the TPGS used had a significant effect on the nanoparticle size and morphology, the drug loading and release profile of nanoparticles

Nanoencapsulation of Andrographolide Rich Extract for the Inhibition of Cervical and Neuroblastoma Cancer Cells.

Andrographis paniculata is traditionally used for many diseases and scientifically proven for anti-cancer property. Andrographolide which is the marker compound is believed to be the main contributor to the pharmacological activities. The poor solubility and bioavailability of this diterpenoid lactone could be overcome by nanoencapsulation. Reflux extraction, and followed by successive Soxhlet fractionation were used to obtain andrographolide rich extract from the herb. Spontaneous emulsion solvent diffusion was used to nanoencapsulate andrographolide using poly(lactic-co-glycolic acid) with 1% polyvinyl alcohol as emulsifier. Nanospheres loaded with andrographolide was found to have the particle size, 163 nm; polydispersity index, 0.26 and zeta potential, - 57.85 mV. The encapsulation efficiency and in vitro drug release were 80.0% and 84.2%, respectively. The andrographolide nanoparticles could inhibit the proliferation of cervical and neuroblastoma cells with no adverse effect on normal human skin cells. Andrographolide rich extract loaded nanoparticles could inhibit the proliferation of HeLa and SH-SY5Y cells, mainly through Bax-induced apoptosis. The result was consistent with the low expression of anti-apoptotic genes (Bcl-2 and Bcl-xL) and prognostic factor (Ki-67). The tumour size of HeLa bearing mice was significantly reduced (73%) after treated with andrographolide rich nanoparticles (10 mg/kg body weight) for a month.

Gastrointestinal Responsive Polymeric Nanoparticles for Oral Delivery of Insulin: Optimized Preparation, Characterization, and In Vivo Evaluation

Gastrointestinal responsive polymeric nanospheres (NPs) based on hydroxypropyl methylcellulose phthalate were prepared using spontaneous emulsification solvent diffusion method for improved oral administration of insulin. The NPs prepared under optimized conditions have an encapsulation efficiency of 90% and a particle size of about 200 nm. In vitro drug release experiments demonstrated that the NPs exhibited a gradient release profile of loaded drug when the pH value gradually increased from 3.0 to 7.4. Enzyme resistance experiments showed that under simulated gastrointestinal conditions, the NPs protected more than 60% of the drug from being degraded by trypsin. The oral hypoglycemic experiments revealed that insulin-loaded NPs could significantly reduce blood glucose levels in diabetic rats with a relative bioavailability of 8.6%. Ex vivo imaging investigation of rat tissues showed that the drug-loaded NPs could promote the absorption of insulin in the ileum and colon. The work described here suggests that the gastrointestinal responsive polymeric NPs may be promising candidates for improving gastrointestinal tract delivery of hydrophilic biomacromolecules. Accordingly, the results indicated that hydroxypropyl methylcellulose phthalate NPs with gastrointestinal stimuli responsiveness could be a promising candidate for oral insulin delivery.

Preparation and optimization of poly (lactic acid) nanoparticles loaded with fisetin to improve anti-cancer therapy

Fisetin is a natural flavonoid with promising antitumor activity, whereas its clinical application is limited by its hydrophobic property. In this study, we aimed to load fisetin into poly(lactic acid) (PLA) nanoparticles to increase fisetin's solubility and therapeutic efficacy. Based on spontaneous emulsification solvent diffusion (SESD) method, the formulation of PLA nanoparticles was optimized by two successive experimental designs. One-factor-at-a-time variation experiments were first applied to investigate the effects of four process variables on three responses, including drug encapsulation efficiency, average particles size and cumulative drug release ratio, followed by determining the possible ranges of these variables. Subsequently, the combinations of four variables at best levels were evaluated using a Taguchi orthogonal array design with regard to the same three responses. Eventually, the nanoparticle prepared by optimized procedure showed a narrow size distribution around 226.85 ± 4.78 nm with a high encapsulation efficiency of 90.35%. The incorporation of fisetin in nanoparticles was subsequently confirmed by FT-IR and DSC spectroscopy. Furthermore, cytotoxicity assay against HCT116 colon cancer cells in vitro and antitumor test in a xenograft 4T1 breast cancer model in vivo demonstrated that the antitumor effect of drug-loaded nanoparticles was superior to that of free drug solution.

Lamotrigine loaded poly-ɛ-(d,l-lactide-co-caprolactone) nanoparticles as brain delivery system

Management of epilepsy requires brain delivery therapy, therefore, this study was aimed to prepare lamotrigine loaded poly-ɛ-(d,l-lactide-co-caprolactone) (PLCL) nanoparticles using spontaneous emulsification solvent diffusion method. Nanoparticles for brain delivery required to have a particle size <200 nm, polydispesity index <0.2 and a sustained drug release properties. For such aim different factors were considered in preparing the nanoparticles as PLCL monomers' ratio, type of organic solvent used to prepare the nanoparticles, amount of PLCL and Pluronic®F127 in the nanoparticles. Prepared nanoparticles were characterized for their shape, particle size, polydispersity index, zeta potential, encapsulation efficiency, drug loading capacity, process yield and in-vitro drug release pattern. The in-vivo investigation for brain delivery of selected nanoparticles delivered by intravenous route was investigated in rats and compared to that for oral tablet. The obtained nanoparticles were spherical in shape. The amount of surfactant and PLCL affected the properties of the obtained nanoparticles. Using a mixture of organic solvent in preparing the nanoparticles improved its properties. The nanoparticles prepared using PLCL with monomers' ratio of 25:75, had particle size value of 125 nm, polydispersity index value of 0.184, zeta potential value of −39 mV and encapsulation efficiency value of 99%, was selected to study their efficacy to deliver the drug to the brain. The tested nanoparticles showed higher values of Tmax, Cmax, AUC, and MRT in homogenized rat brain, compared to oral lamotrigine tablet, while the bioavailability of the oral tablet was higher in rat plasma compared to that for the nanoparticles. This reflects that brain was the main distribution site for tested nanoparticles, and plasma was the main distribution site for oral tablets. This confirms the goal of the selected formulation as brain delivery nanoparticles.

Preparation and in vitro evaluation of rhein-loaded PEG-PCL-PEI nanoparticles

This study was aimed to synthesize the polyethyleneglycol-polycaprolactone-polyethyleneimine (PEG-PCL-PEI) three block polymer material, prepareRhein (RH)-loaded PEG-PCL-PEI nanoparticles(PPP-RH-NPS), and then evaluate their physical and chemical properties and biological characteristics in vitro. PEG-PCL-PEI polymer was obtained by adopting thering-opening polymerization and Michael addition reaction, and their physical and chemical properties were analyzed by using NMR and gel permeation chromatography. PEG-PCL-PEI was then used as the carriers to prepare PPP-RH-NPS by applying spontaneous emulsification solvent diffusion method. The results showed that molecular weight of PEG-PCL-PEI polymer was 9.5×103, and critical micelle concentration was 0.723 mmol•L⁻¹. PPP-RH-NPS had pale yellow, opalescence faade, round and smooth without aggregation, formed of (118.3±3.6) nm in particle size with PDI of (0.19±0.08), Zeta potential of (6.3±1.5) mV, entrapment efficiency of (93.64±5.28)%, and drug loading of (8.57±0.53)%. The accumulative release percentage of PPP-RH-NPS was 75.92% in 48h, and the release profiles in PBS conformed to the Higuchi equation： Q=0.121 6t1/2+0.069 5 (R²=0.887 4), presenting slow release characteristics. Within the scope of the 0-0.05 mmol•L⁻¹, the nanoparticles had no obvious hemolysis on rabbit red blood cells and toxicity on HK-2 cells. In the investigation of uptake efficiency by flow cytometry, nanoparticles can be absorbed into cells quickly and internalized within 30 minutes fully, with a high uptake efficiency. In confocal laser scanning microscope observation, the nanoparticles can escape from lysosome into cytoplasm. Herein, this study synthesized the PEG-PCL-PEI polymer and prepared PPP-RH-NPS successfully; the nanoparticles showed uniform particle size, higher encapsulation efficiency and drug-loading rate, slow release characteristics, quick uptake and internalization, lysosome escape property and good biocompatibility. PPP-RH-NPS will be a promising pharmaceutical formulation for further development.

Tamoxifen citrate-loaded poly(d,l) lactic acid nanoparticles: Evaluation for their anticancer activity in vitro and in vivo

The optimization of tamoxifen citrate entrapment and its release from biodegradable poly(d,l) lactic acid nanoparticles are prepared by modified spontaneous emulsification solvent diffusion method. Since the addition of tamoxifen citrate induces the formation of drug crystals from nanoparticle suspension the influence of several parameters on tamoxifen citrate encapsulation was investigated. In vitro studies for cytotoxicity, DNA ladder, and the expression of Bcl-2-Bax expression were also investigated for MCF-7 and MDA-MB-231 cells after the addition of tamoxifen citrate alone and tamoxifen citrate-poly(d,l) lactic acid-nanoparticles (encapsulated tamoxifen citrate). From results, it was noticed that the size and zeta potential of the drug loaded nanoparticles were not differed much in their physicochemical properties from drug free counterparts. The drug-loaded and drug-free nanoparticles exhibited size of in between 271.4 and 282.7 nm and zeta potential of -34 to -27.4 mV, respectively. There was significant increase in drug incorporation in the particles noticed in dichloromethane + methanol system in comparison to acetone + methanol and ethyl acetate + methanol systems. The drug was partly released from the nanoparticles after 48 h of incubation at 37℃. From Fourier transform infrared spectroscopy and differential scanning calorimetry data demonstrated drug-polymer characteristics within the nanoparticles and unincorporated drug that appeared in the form of crystals from polarized microscopic study. MCF-7 and MDA-MB-231 cells were more sensitive to tamoxifen citrate-poly(d,l) lactic acid-nanoparticles than tamoxifen citrate alone. DNA ladder and the expression of Bax to Bcl-2 ratio were much higher in tamoxifen citrate encapsulated in nanoparticles than that in tamoxifen citrate alone. These results demonstrated the feasibility of encapsulation of tamoxifen citrate and its enhanced efficiency in vitro and in vivo studies.

SN-38 active loading in poly(lactic-co-glycolic acid) nanoparticles and assessment of their anticancer properties on COLO-205 human colon adenocarcinoma cells

SN-38 is a highly effective drug against many cancers. The development of an optimal delivery system for SN-38 is extremely challenging due to its low solubility and labile lactone ring. Herein, SN-38 encapsulated in poly(d,l-lactide-co-glycolide) nanoparticles (NPs) is introduced to enhance its solubility, stability and cellular uptake. SN-38-loaded NPs prepared by spontaneous emulsification solvent diffusion (SESD) method had an average diameter of 310 nm, a zeta potential of −9.69 mV and a loading efficiency of 71%. They were able to protect the active lactone ring of SN-38 against inactivation under physiological condition. A colorectal adenocarcinoma cell line (COLO-205) was used to assess the NPs effects on cytotoxicity and cellular uptake. Result showed a significant decreased cell proliferation and cell apoptosis. These results suggest that these SN-38-loaded NPs can be an effective delivery system for the treatment of colon cancer and potentially for other types of cancers.

Natural Bioadhesive Biodegradable Nanoparticle-Based Topical Ophthalmic Formulations for Management of Glaucoma.

We prepared and characterized topical ophthalmic formulations containing brimonidine-loaded bioadhesive cationic chitosan or anionic alginate nanoparticles (NPs) for sustained release of brimonidine as once daily regimen for management of glaucoma. Nanoparticles were prepared using a spontaneous emulsification solvent diffusion method. Different concentrations of polymers, emulsifiers, and NPs stabilizers were used for formulation optimization. Nanoparticles were characterized regarding particle size, zeta potential, morphology, and drug content. Brimonidine-loaded NPs were incorporated into eye drops, a temperature-triggered in situ gelling system, and a preformed gel. They then were characterized regarding their pH, viscosity, uniformity of drug content, in vitro release characteristics, in vitro cytotoxicity, and in vivo intraocular pressure (IOP) lowering effects. Characteristics of optimized brimonidine-loaded chitosan and alginate NPs, respectively, are: particle size, 115.67 ± 3.58 and 157.67 ± 5.53 nm; zeta potential, +35.27 ± 3.39 and -37.8 ± 3.77 mV; encapsulation efficiency, 74.34% ± 2.05% and 70.40% ± 2.77%; drug loading, 11.81% ± 0.67% and 13.14% ± 0.90%; and yield, 87.91% ± 5.92% and 76.53% ± 3.32%. Transmission electron microscope (TEM) analyses revealed that NPs have spherical shapes with a dense core and distinct coat. Formulations possessed uniform drug content. Furthermore, pH and viscosity were compatible with the eye. Formulations showed a sustained release without any burst effect with a Higuchi non-Fickian diffusion mechanism. Cytotoxicity studies revealed that all formulations are biocompatible. Importantly, all formulations possessed a sustained IOP lowering effect compared to the marketed brimonidine tartrate eye drops. These formulations provide a great improvement in topical ocular brimonidine delivery. The application of a single drop is sufficient to provide extended IOP reduction, which should improve patient compliance. We have developed a novel biocompatible topical delivery system for brimonidine, a first line glaucoma medication. Once daily application should have positive effects on patient compliance and, therefore, preservation of vision.

Optimization of Curcuminoid-Loaded PLGA Nanoparticles Using Box-Behnken Statistical Design

Curcuminoids are a mixture of phenolic compounds isolated from Curcuma longa L. (turmeric) rhizomes that possess antioxidant, anti-inflammatory, anti-Alzheimer and anticancer activities. However, curcuminoids have poor solubility in acid and neutral solutions, rapid decomposition in neutral and alkaline solutions, and low bioavailability that limits their use as therapeutic agents. To overcome these problems, statistical design for preparation and characterization of poly(D,L-lactide-co-glycolide) (PLGA) nanoparticles as a carrier for curcuminoids was evaluated in this study. The curcuminoid-loaded PLGA nanoparticles were prepared by a modified spontaneous emulsification solvent diffusion method using polyvinyl alcohol (PVA) as a stabilizer. The formulations were optimized using three-factor, three-level Box-Behnken experimental design. The independent variables in the formulations were the lactide/glycolide (LA/GA) molar ratio of PLGA (50:50 to 85:15), the curcuminoid concentration (2%-10%, w/v), and the PVA concentration (3%-7%, w/v). The dependent variables were particle size, loading capacity and entrapment efficiency. Statistical evaluation showed that the LA/GA molar ratio of PLGA and the curcuminoid and PVA concentrations all affected the characteristics of the PLGA nanoparticles. To achieve a minimum particle size and maximum loading capacity and entrapment efficiency, the optimal formulation of the curcuminoid-loaded PLGA nanoparticles had a LA/GA molar ratio of PLGA of 50:50, 10% (w/v) curcuminoids, and 3% (w/v) PVA. A sustainable in vitro release profile of curcuminoids was obtained from this optimal formulation.

Preparation, characterization, and in vivo study of rhein-loaded poly(lactic-co-glycolic acid) nanoparticles for oral delivery

A novel rhein formulation based on poly(lactic-co-glycolic acid) (PLGA) nanoparticles (NPs) suitable for oral administration was developed in this study. The designed nanosystems were obtained by a modified spontaneous emulsification solvent diffusion method. The morphology of rhein-loaded PLGA NPs showed a spherical shape with a smooth surface, without any particle aggregation. Mean size of the NPs was 140.5±4.3 nm, and the zeta potential was −16.9±3.1 mV. The average drug loading was 3.9%±0.7%, and encapsulation efficiency was 84.5%±6.2%. Meanwhile, NPs are characterized by the slower release (only about 70% of rhein is released within 5 hours), and the model that fitted best for rhein released from the NPs was Higuchi kinetic model with correlation coefficient r=0.9993, revealing that rhein could be controlled released from the NPs. In vivo, NPs altered the distribution of rhein, and the half-life after oral administration was prolonged remarkably more than those of suspensions (22.6 hours vs 4.3 hours). The pharmacokinetic results indicated that the NPs had sustained-release efficacy. The area under the curve0–∞ of the NPs formulation was 3.07-fold higher than that of suspensions, suggesting that the encapsulated rhein had almost been absorbed in rats over the period of 12 hours. Although rhein-loaded PLGA NP formulations are hopefully used as a chemotherapeutic or adjuvant agent for human gastric cancer (SGC-7901), their in vivo antitumor effect and mechanisms at the molecular level still need further study.

A modified spontaneous emulsification solvent diffusion method for the preparation of curcumin-loaded PLGA nanoparticles with enhanced in vitro anti-tumor activity

To improve the anti-tumor activity of hydrophobic drug curcumin, we prepared curcumin-loaded PLGA nanoparticles (PLGA-Cur NPs) through a modified spontaneous emulsification solvent diffusion (modified-SESD) method. The influence of main preparation parameters was investigated, such as the volume ratio of binary organic solvents and the concentration of surfactant. Results indicated that the synthesized regular spherical PLGA NPs with the average diameter of 189.7 nm exhibited relatively higher yield (58.9%), drug loading (11.0% (w/w)) and encapsulation efficiency (33.5%), and also a controllable drug release profile. In order to evaluate the in vitro cytotoxicity of the prepared NPs, MTT assay was conducted, and results showed that the NPs could effectively inhibit HL60 and HepG2 cells with lower IC50 values compared with free curcumin. Furthermore, confocal microscopy together with flow cytometry analysis proved the enhanced apoptosis-inducing ability of PLGA-Cur NPs. Polymeric NP formulations are potential to be used for hydrophobic drug delivery systems in cancer therapy.

Novel Topical Ophthalmic Formulations for Management of Glaucoma

Preparation of topical ophthalmic formulations containing brimonidine-loaded nanoparticles prepared from various biodegradable polymers-PCL, PLA and PLGA-for sustained release of brimonidine as a once daily regimen for management of glaucoma. Nanoparticles were prepared using spontaneous emulsification solvent diffusion method then characterized regarding their particle size, zeta potential, morphology and drug contents. Brimonidine-loaded nanoparticles were incorporated into eye drops, temperature-triggered in situ gelling system and preformed gel and characterized regarding their pH, viscosity, uniformity of drug contents, in vitro release study, in vitro cytotoxicity and in vivo intraocular pressure (IOP) lowering effects. The results of optimized brimonidine-loaded PCL-, PLGA- and PLA-NPs respectively, are: particle sizes of 117.33 ± 4.58nm, 125.67 ± 5.15nm and 131.67 ± 3.79nm; zeta potentials of -18.5 ± 2.87mV, -21.82 ± 2.7mV and -28.11 ± 2.21mV; and encapsulation efficiencies of 77.97 ± 1.38%, 68.65 ± 3.35% and 73.52 ± 2.92%. TEM analyses revealed that all NPs have spherical shapes with dense core and distinct coat. In vitro release data showed a sustained release without any burst effect with Higuchi non-Fickian diffusion mechanism. Cytotoxicity studies revealed that all formulations are non-toxic. Also all formulations possessed a sustained IOP lowering effect compared to Alphagan® P eye drops. Our formulations showed prolonged management of glaucoma that should meet with better patient compliance as a once-daily formulation.

Pharmaceutical Nanotechnology Nanoparticle-Based Topical Ophthalmic Formulations for Sustained Celecoxib Release

Celecoxib-loaded NPs were prepared from biodegradable polymers such as poly-ε-caprolactone (PCL), poly(L-lactide) (PLA), and poly(D,L-lactide-co-glycolide) (PLGA) by spontaneous emulsification solvent diffusion method. Different concentrations of polymers, emulsifier, and cosurfactants were used for formulation optimization. Nanoparticles (NPs) were characterized regarding their particle size, PDI, zeta potential, shape, morphology, and drug content. Celecoxib-loaded NPs were incorporated into eye drops, in situ gelling system, and gel and characterized regarding their pH, viscosity, uniformity of drug content, in vitro release, and cytotoxicity. The results of optimized celecoxib-loaded PCL-, PLGA-, and PLA-NPs, respectively, are particle size 119 ± 4, 126.67 ± 7.08, and 135.33 ± 4.15 nm; zeta potential -22.43 ± 2.91, -25.46 ± 2.35, and -31.81 ± 2.54 mV; and encapsulation efficiency 93.44 ± 3.6%, 86.00 ± 1.67%, and 79.04 ± 2.6%. TEM analyses revealed that NPs have spherical shapes with dense core and distinct coat. Formulations possessed uniform drug content with pH and viscosity compatible with the eye. Formulations showed sustained release without any burst effect with the Higuchi non-fickian diffusion mechanism. Cytotoxicity studies revealed that all formulations are nontoxic. Our formulations provide a great deal of flexibility to formulation scientist whereby sizes and zeta potentials of our NPs can be tuned to suit the need using scalable and robust methodologies. These formulations can thus serve as a potential drug delivery system for both anterior and posterior eye diseases.

Schisandra lignans-loaded enteric nanoparticles: preparation, characterization, and in vitro–in vivo evaluation

Schisandrae lignans (SL) have been well proven to possess hepatoprotective effect against the hepatic dysfunction induced by various chemical hepatotoxins. Deoxyschisandrin (DA) and schisantherin A (SA) are both considered as the major active components in SL. The objective of the study was to prepare and evaluate Schisandra lignans (composed of DA and SA)-loaded enteric nanoparticles produced by a novel toxic solvent-free modified spontaneous emulsification solvent diffusion (SESD) method. An organic Schisandra lignans/Eudragit® S100 solution was injected into an aqueous poloxamer 188 solution under a agitation. The nanoparticles were characterized with respect to particle size distribution, morphology, encapsulation efficiency (EE) and physical stability of the drug, wettability, in vitro release and in vivo bioavailability. Nanoparticles with a smooth surface and dense structure were obtained with high EE (EEDA >90%; EESA >85%). The drug was in a noncrystalline state in the matrix and physically stable for 120 days at room temperature. In vitro drug release study, the drug dissolution rate from the nanoparticles was significantly enhanced compared to the physical mixture and to the pure drug; the release profile of the nanoparticles was stable after 120 days. The appropriate size of nanoparticles (~93 nm), the solubilization of the surfactant, the noncrystalline state of the drug in the matrix and the fast dissolution rate contributed to a significantly enhanced oral bioavailability from the nanoparticles when compared to pure drug suspension.

The development and scale-up of biodegradable polymeric nanoparticles loaded with ibuprofen

This study aims to ascertain the influence of variables in the production of blank and ibuprofen-loaded polymeric nanoparticles (IbNPs), as well as to scale up nanoparticle (NP) preparation 30-fold. Blank NP and IbNP with a matrix of poly (lactide-co-glycolide) (PLGA) were prepared by modified spontaneous emulsion solvent diffusion (SESD). The variables, organic solvent type, surfactant type and concentration, polymer concentration, aqueous phase volume, mixing speed, and manufacturing temperature, were investigated. Particle size, encapsulation efficiency (EE), drug loading and drug release were characterized. The smallest blank NP (175nm) was obtained using a dimethy sulfoxide (DMSO):ethanol (50:50) organic solvent system with poly (vinyl alcohol) (PVA, 0.5% (w/w)) under magnetic stirring. The smallest IbNP obtained was 152nm. The EE was highest at 30:100, drug:polymer ratio with a drug loading of 17.2%. Key NP characteristics, particle size, EE, drug loading and total drug release time of 30-fold scaled-up batch were not significantly different from lab-scale batch; however, 50% drug release for the scaled-up batch was significantly sooner (p<0.05) than the lab-scale batch.

Uptake and transport of furanodiene in Caco-2 cell monolayers: a comparison study between furanodiene and furanodiene loaded PLGA nanoparticles

AimFuranodiene (FDE) possesses diverse pharmacological activities with high lipophilicity and poor stability. This study prepared FDE loaded PLGA nanoparticles (FDE-PLGA-NPs) and PEGylated PLGA nanoparticles (FDE-PEG-PLGA-NPs) by the spontaneous emulsion solvent diffusion method to improve the stability and bioavailability of FDE. MethodsFDE-PLGA-NPs and FDE-PEG-PLGA-NPs were characterized for size and size distribution, surface morphology, zeta-potential and entrapment efficiency. The stability of FDE, FDE-PLGA-NPs and FDE-PEG-PLGA-NPs in physiological fluids (PBS and artificial gastrointestinal fluids) was evaluated. In vitro cellular uptake and transport studies were performed using Caco-2 cell monolayers. ResultsThe size of FDE-PLGA-NPs and FDE-PEG-PLGA-NPs ranged from 110-140 nm, the entrapment efficiencies were 87.3% and 89.2%, respectively, and the stabilities were enhanced significantly compared with FDE. FDE-PLGA-NPs and FDE-PEG-PLGA-NPs could be taken up by Caco-2 cells freely and transported across the monolayers. While FDE hardly reached to the receptor side, it could be taken up into Caco-2 cell monolayers. ConclusionsThese results indicated that FDE-PLGA-NPs, especially FDE-PEG-PLGA-NPs, could enhance the stability and hydrophilicity of FDE and increase the permeation of FDE across Caco-2 cell monolayers.

Design and evaluation of a novel nanoparticulate-based formulation encapsulating a HIP complex of lysozyme

Formulation development of protein therapeutics using polymeric nanoparticles has found very little success in recent years. Major formulation challenges include rapid denaturation, susceptibility to lose bioactivity in presence of organic solvents and poor encapsulation in polymeric matrix. In the present study, we have prepared hydrophobic ion pairing (HIP) complex of lysozyme, a model protein, using dextran sulfate (DS) as a complexing polymer. We have optimized the process of formation and dissociation of HIP complex between lysozyme and DS. The effect of HIP complexation on enzymatic activity of lysozyme was also studied. Nanoparticles were prepared and characterized using spontaneous emulsion solvent diffusion method. Furthermore, we have also investigated release of lysozyme from nanoparticles along with its enzymatic activity. Results of this study indicate that nanoparticles can sustain the release of lysozyme without compromising its enzymatic activity. HIP complexation using a polymer may also be employed to formulate sustained release dosage forms of other macromolecules with enhanced encapsulation efficiency.

LAB-EXPERIMENTAL (PRE-CLINICAL) THERAPEUTICS AND PHARMACOLOGY

Ginsenoside Rg3 is a natural active ingredient that is extracted from Korean red ginseng root. It elevates the therapeutic effect of radiotherapy and chemotherapy, but previous studies found that the application of Rg3 is heavily limited by its low bioavailability and poor absorption via oral administration. To overcome these problems, Rg3-loaded PEG-PLGA-NPs (Rg3-NPs) were prepared by the modified spontaneous emulsification solvent diffusion (SESD) method, and the physicochemical characteristics of Rg3-NPs were investigated. We treated primary glioblastoma with 50 mM Rg3-NPs for 48h. We then used gene expression arrays (Illumina) for genome-wide expression analysis and validated the results for genes of interest by means of real-time PCR. Functional annotations were then performed using the DAVID and KEGG online tools. The results showed that the Rg3-NPs are slick and uniform, the average diameter of the nanoparticles is 75-90 nm, and their entrapment efficiency is 89.7+1.7%. MTT showed that the growth of cells can be significantly inhibited by Rg3-NPs in a dose-dependent manner. FCM testing showed Rg3-NPs can be released from the conjugate nanoparticle and react with the genes in the cell nuclei, causing changes in the gene molecules. We also found that cancer cells treated with Rg3-NPs undergo cell-cycle arrest at different checkpoints. This arrest was associated with a decrease in the mRNA levels of core regulatory genes BUB1, CDC20, TTK, and CENPE, as determined by microarray analysis and verified by real-time PCR. Furthermore, Rg3-NPs induced the expression of the apoptotic and antimigratory protein p53 in cell lines. The results of the present study, together with the results of earlier studies, show that Rg3-NPs target genes involved in theprogressionoftheM-phaseofthecellcycle.Itisassociatedwithseveralimportant pathways, which include apoptosis (p53). Rg3-NPs may be a potent cell-cycle regulation drug targeting the M-phase in glioblastoma cell lines.