Double Emulsion Solvent Evaporation Technique Research Articles

In vitro evaluation of chloroquine-loaded and heparin surface-functionalized solid lipid nanoparticles

BackgroundUse of chloroquine, an otherwise safe and relatively affordable anti-malarial drug, was discontinued due to widespread prevalence of resistant parasites. Many entrant anti-malarial drugs for treatment of chloroquine resistant malaria raises the concerns of cost and safety among other challenges. Innovative ways of circumventing chloroquine resistance is of paramount importance. Such may include nanoparticulate delivery strategies and targeting. This study evaluated physicochemical properties and in vitro antiplasmodial activity of chloroquine encapsulated heparin functionalized solid lipid nanoparticles (CQ-Hep-SLNs) and non-heparin functionalized SLNs (CQ-SLN) against Plasmodium falciparum.MethodsThe modified double-emulsion solvent evaporation technique was used to prepare the nanoparticles. HPLC/UV was used to determine the in vitro drug release. The semi-automated micro-dilution technique was adapted in assessing the in vitro antiplasmodial activity to give drug concentration capable of inhibiting 50% of the P. falciparum (IC50), as a function of antiplasmodial efficacy.ResultsPrepared nanoparticles were below 500 nm in size with % drug loading (%DL) between 21 and 25% and encapsulation efficiency (%EE) of 78–90%. The drug-loaded SLN exhibited a biphasic drug release profile at pH 7.4, with an initial burst release during the first 24 h followed by sustained release in both formulations. Nanoformulated CQ-SLN (4.72 ± 0.14 ng/mL) and CQ-Hep-SLN (2.41 ± 0.27 ng/mL), showed enhanced in vitro antiplasmodial activities against chloroquine sensitive (D6) strain of P. falciparum, albeit with no activity against the chloroquine resistant W2 strain, compared to free CQ standard (5.81 ± 0.18 ng/mL).ConclusionsThese findings suggest that the nanoformulated drugs displayed enhanced anti-malarial activities against chloroquine sensitive (D6) strains of P. falciparum compared to the free CQ standard. There is some form of potential dual synergistic effect of CQ-loaded heparinized solid lipid nanoparticles (Hep-SLN), meaning that combining heparin and CQ in SLNs has beneficial effects, including potential for specific targeting of parasitized red blood cells as afforded by heparin. Thus, the study has produced SLNs nanoparticles that have superior in vitro activities than CQ on CQ-sensitive parasites.

Development of a polymer system for the delivery of daunorubicin to tumor cells to overcome drug resistance

Method for the synthesis of polymeric nanoparticles (NP) with encapsulated daunorubicin (DNR) was developed on the basis of double emulsion solvent evaporation technique using biodegradable poly(lactide-co-glycolide) (PLGA), which is aimed at customization of pharmacokinetic properties of the preparation, enhanced accumulation of DNR in tumor cells and prolongation of its action. The obtained polymer nanoparticles (DNR-PLGA) had average size ranging around 138±36 nm, with zeta-potential of –25.3 mV and the polydispersity index (PDI) of 0.072. The release kinetics of DNR from polymer nanoparticles at pH 7.4 and 5.0 has been studied. In vitro studies showed similar specific activity of DNR- PLGA in K562 and MCF-7 cancer cell lines together with an increase in activity in K562 Adr and MCF-7 Adr cell lines, which are anthracycline resistant, by 1.6 and 3.4 times. The study demonstrated the efficacy of the developed PLGA-based DNR delivery system in the improvement of antitumor effect of DNR, overcoming multidrug resistance in cancer cells, and also in the decrease in nonspecific toxicity of the preparation.

Targeted Delivery of Amantadine-loaded Methacrylate Nanosphere-ligands for the Potential Treatment of Amyotrophic Lateral Sclerosis.

This study aimed to develop and analyse poly(DL-lactic acid)-methacrylic acid nanospheres bound to the chelating ligand diethylenetriaminepentaacetic acid (DTPA) for the targeted delivery of amantadine in Amyotrophic Lateral Sclerosis (ALS). The nanospheres were prepared by a double emulsion solvent evaporation technique statistically optimized employing a 3-Factor Box-Behnken experimental design. Analysis of the particle size, zeta potential, polydispersity (Pdl), morphology, drug entrapment and drug release kinetics were carried out. The prepared nanospheres were determined to have particle sizes ranging from 68.31 to 113.6 nm (Pdl ≤ 0.5). An initial burst release (50% of amantadine released in 24 hr) was also obtained, followed by a prolonged release phase of amantadine over 72 hr. Successful conjugation of the chelating ligand onto the surface of the optimised nanospheres was thereafter achieved and confirmed by TEM. The synthesized modified nanospheres were spherical in shape, 105.6 nm in size, with a PdI of 0.24 and zeta potential of -28.0 mV. Conjugation efficiency was determined to be 74%. In vitro and ex vivo cell study results confirmed the intracellular uptake of the modified nanospheres by the NSC-34 cell line and the non-cytotoxicity of the synthesized nanospheres. Biocompatible amantadine-loaded nanospheres were successfully designed, characterized and optimized employing the randomized Box-Behnken statistical design. Delivery of amantadine over 72 hrs was achieved, with the nanospheres being of a size capable of internalization by the NSC- 34 cells.This article is open to POST-PUBLICATION REVIEW. Registered readers (see "For Readers") may comment by clicking on ABSTRACT on the issue's contents page.

Development of Novel Octanoyl Chitosan Nanoparticles for Improved Rifampicin Pulmonary Delivery: Optimization by Factorial Design.

A novel hydrophobic chitosan derivative, octanoyl chitosan (OC) with improved organic solubility was synthesized, characterized, and employed for the preparation of rifampicin (Rif) encapsulated nanoparticle formulations for pulmonary delivery. OC was characterized to confirm acyl group substitution and cytotoxicity in A549 epithelial lung cells. OC nanoparticles were produced by the double emulsion solvent evaporation technique without cross-linking and characterized for particle size distribution, morphology, crystallinity, thermal stability, aerosol delivery, and drug release rate. OC was successfully synthesized with substitution degree of 44.05 ± 1.75%, and solubility in a range of organic solvents. Preliminary cytotoxicity studies of OC showed no effect on cell viability over a period of 24h on A549 cell lines. OC nanoparticles were optimized using a 32 full factorial design. An optimized batch of OC nanoparticles, smooth and spherical in morphology, had mean hydrodynamic diameter of 253 ± 19.06nm (PDI 0.323 ± 0.059) and entrapment efficiency of 64.86 ± 7.73% for rifampicin. Pulmonary deposition studies in a two-stage impinger following aerosolization of nanoparticles from a jet nebulizer gave a fine particle fraction of 43.27 ± 4.24%. In vitro release studies indicated sustained release (73.14 ± 3.17%) of rifampicin from OC nanoparticles over 72h, with particles demonstrating physical stability over 2months. In summary, the results confirmed the suitability of the developed systems for pulmonary delivery of drugs with excellent aerosolization properties and sustained-release characteristics.

Targeted Delivery of GP5 Antigen of PRRSV to M Cells Enhances the Antigen-Specific Systemic and Mucosal Immune Responses.

Efficient delivery of antigens through oral immunization is a first and critical step for successful induction of mucosal immunity, which can provide protection against pathogens invading the mucosa. Membranous/microfold cells (M cells) within the mucosa can transcytose internalized antigen without degradation and thus play an important role in initiating antigen-specific mucosal immune responses through inducing secretory IgA production. In this research, we modified poly (D, L-lactide-co-glycolide) (PLGA) nanoparticles (NPs) with Ulex europaeus agglutinin 1 (UEA-1) and successfully prepared an oral vaccine delivery system, UEA-1/PLGA NPs. PLGA NPs were prepared using a standard double emulsion solvent evaporation technique, which can protect the entrapped PRRSV DNA vaccine [pcDNA3.1-SynORF5 (synthetic ORF5)] or subunit vaccine ORF5-encoded glycoprotein (GP5) from exposure to the gastrointestinal (GI) tract and release the plasmids in a controlled manner. With UEA-1 modification, the UEA-1/PLGA NPs can be effectively transported by M-cells. We investigated immune response induced by UEA-1/PLGA-SynORF5 or UEA-1/PLGA-GP5 following inoculation in mice and piglets. Compared with PLGA-SynORF5 or PLGA-GP5 NPs, UEA-1/PLGA-SynORF5, or UEA-1/PLGA-GP5 NPs stimulated significantly increased serum IgG levels and augmented intestinal IgA levels in mice and piglets (P < 0.05). Our findings indicate UEA-1/PLGA NPs can be applied as a promising and universally robust oral vaccine delivery system.

Rational design and evaluation of HBsAg polymeric nanoparticles as antigen delivery carriers

The present work is focused on the development and evaluation of single dose sustained-release Hepatitis B surface antigen (HBsAg) loaded nanovaccine for Hepatitis B. The conventional treatment suffers from repeated administration and hence requires a booster dose. Therefore, polymeric nanovaccine of HBsAg was developed by double emulsion solvent evaporation technique, utilizing central composite design for formulation optimization. The effects of independent variables (like polymer amount, stabilizer concentration, aqueous/organic phase ratio and homogenizer speed) were also studied on critical quality attributes like particle size and entrapment efficiency. Nanovaccine was characterized in terms of physicochemical parameters, release, internalization and in vivo immunological evaluation in BALB/c mice after administration by different routes such as oral, sub-cutaneous, nasal and intramuscular. The designed nanovaccine demonstrated nanometric size with smooth surface, negative zeta potential, maximum entrapment, sustained release and better internalization in macrophage and MRC-5 cell line. The immune-stimulating activity of nanovaccine administered by different routes was evaluated by measuring anti-HBsAg titre like specific immunoglobulin IgG and IgA response and cytokine level (interleukin-2, interferon-Y) measurement. The results indicated that the nanovaccine administered by intramuscular route produced better humoral as well as cellular responses and potential carriers for antigen delivery at single dose administration via intramuscular route.

Recombinant Human Insulin- PLGA NP Administered Orally after Combination with a Protease Inhibitor (N-Ethylmaleimide) in vivo Results

Based on our published results, insulin PLGA NP composed from human insulin (5 mg) encapsulated in PLGA 2.5% (w/v) mixed with PEG (2 kDa, 5% w/w) and the external aqueous phase contained 1.25% of PVA (%w/v) were prepared by the modified double emulsion solvent evaporation technique [1,2]. The resulting NP have been investigated for oral administration of recombinant human insulin (100 IU/kg) in diabetic rats [3]. Our animal model, Male Sprague–Dawley rats (12-week-old, obtained from National researches center, Cairo, Egypt.) weighing 250-300 gm were fasted for 6 hours prior to the induction of type I diabetes via i.p injection of streptozotocin (50-60 mg.kg-1, pH=4.5). Rats with blood glucose levels >250 mg dl-1 were considered to be in a diabetic state. Three percent sodium bicarbonate solution (500 μL) in phosphate buffer saline (PBS) was administered through an oral gavage to neutralize gastric acid, a protease inhibitor -PI-(NEthylmaleimide, 2 mM) was physically mixed with free insulin or insulin PLGA-NP before oral administration [4,5]. To investigate the effect of PI, other two animal groups of rats were utilized for free insulin and insulin PLGA-NP without PI (Figure 1) [6,7].

Abstract B51: Targeted nanoparticle approach to treating metastatic prostate cancer

Abstract Introduction: Treatment outcomes of bone metastatic prostate cancer remain poor despite an increasing number of therapeutic options approved in recent years. Limitations exist in the drugs that are approved, such as no overall survival benefits or serious dose-limiting toxicities. We have engineered a targeted nanoparticle (NP) system to deliver cabazitaxel to bone lesions. The amino-bisphosphonate, alendronate, was used as the bone-targeting moiety on the surface of the NP. The objective of this approach is to increase therapeutic payload at the site of bone metastasis to achieve an improved therapeutic index. Methods: Poly(lactic-co-glycolic acid) NPs were synthesized using a modified water-in-oil-in-water double-emulsion solvent evaporation technique followed by binding of alendronate to the surface of the NP. We characterized NPs for size and zeta potential using dynamic light scattering. Cabazitaxel encapsulation efficiency, drug loading, and release kinetics were optimized by quantification with HPLC analysis. In vitro cell viability studies were performed on C4-2B and PC3 prostate cancer cell lines. 3D prostate cancer spheroids were utilized as well to test cell viability and NP penetration. Ex vivo bone binding studies were used to test nanoparticle affinity for hydroxyapatite structure. In vivo tumor efficacy studies were carried out with male athymic nude mice implanted with intraosseous tumors consisting of PC3-luciferase cells. After bone tumors were established for 1 week, mice were treated via tail vein injection with either saline, free cabazitaxel, non-targeted NPs, or targeted NPs for one month (starting n=6 per group). Response was measured with in vivo bioluminescence imaging, tumor limb weight at conclusion of experiment, and mouse x-ray monitoring. In addition, animal behavior experiments were performed on all treatment groups to assess functional status through gait analysis and pain through von Frey filament assay. Results: NPs were successfully synthesized to mean size of 236 nm with a PDI of .120. Highest encapsulation of cabazitaxel into nanoparticle was 55.8% with a drug loading of 3.7%. Release kinetics showed a strong burst phase release over the first 8 hours and subsequent sustained release up to 72 hours. In vitro cell viability and 3D spheroid experiments showed targeted and nontargeted NP to be equivalent to free drug. Ex vivo bone binding experiment showed targeted NP had a 4-fold increase in binding to bone at 6 hours and an 8-fold increase in bone binding at 72 hours compared to nontargeted NP. Tumor efficacy experiment showed targeted NP and nontargeted NP had a statistically significant overall reduction in tumor measured by bioluminescence (P value &amp;lt; 0.005). Interestingly, mice treated with targeted NP had no bone lesions on x-ray, whereas 100% of mice in saline group, 100% of mice in cabazitaxel group, and 33% of mice in nontargeted NP group had bone lesions. Gait analysis did not show a statistically significant difference between groups. However, von Frey assay showed a significant reduction in relative response in the targeted NP group (P value &amp;lt; 0.005). Conclusion: We have successfully synthesized a bone-targeted NP system. In this project, we have shown that targeted NPs help maintain bone structure in tumor-burdened limbs as well as decrease tumor size. We have also shown that these targeted NPs reduce the relative response to von Frey filament pain stimulation in the tumor limb. This bone-targeted NP system is a promising potential therapeutic in developing improved treatments for bone-metastatic prostate cancer patients. Note: This abstract was not presented at the conference. Citation Format: Andrew Gdowski, Amalendu Ranjan, Marjana Sarker, Jamboor Vishwanatha. Targeted nanoparticle approach to treating metastatic prostate cancer [abstract]. In: Proceedings of the AACR International Conference held in cooperation with the Latin American Cooperative Oncology Group (LACOG) on Translational Cancer Medicine; May 4-6, 2017; São Paulo, Brazil. Philadelphia (PA): AACR; Clin Cancer Res 2018;24(1_Suppl):Abstract nr B51.

Preparation, statistical optimization and in vitro evaluation of pramipexole prolonged delivery system based on poly (3-hydroxybutyrate-co-3-hydroxyvalerate) nanoparticles

The purpose of the current study was to prepare and optimize a long acting formulation for pramipexole based on poly (3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) nanoparticles (NPs). Pramipexole loaded PHBV NPs were prepared by double emulsion solvent evaporation technique. Box-behnken response surface methodology was utilized to assess the effect of independent variables including PVA concentration, polymer percentage and drug concentration on important properties of NPs. The optimized NPs was shown 228 nm size with 85.43% and 5.68% entrapment efficiency and loading capacity, respectively. The spherical structure of the pramipexole loaded PHBV NPs was proved by scanning electron microscope (SEM). Differential scanning calorimetry (DSC) testified both the absence of undesirable chemical interactions between pramipexole and NPs and the incorporation of pramipexole within the matrix of polymer. In vitro release studies demonstrated that 89.9% of pramipexole was gradually released within 30 days based on quasi-fickian diffusion mechanism.

Relationship between polarities of antibiotic and polymer matrix on nanoparticle formulations based on aliphatic polyesters

In the field of nanomedicine, nanoparticles are developed to target antibiotics to sites of bacterial infection thus enabling adequate drug exposure and decrease development of resistant bacteria. In the present study, we investigated the encapsulation of two antibiotics with different polarity into different PEGylated polymeric nanoparticles based on aliphatic polyesters, to obtain a better understanding of critical factors determining encapsulation and release. The nanoparticles were prepared from diblock copolymers comprising of a poly(ethylene glycol) block attached to an aliphatic polyester block of varying polarity: poly(lactic-co-glycolic acid) (mPEG-PLGA), poly(lactic-co-hydroxymethyl glycolic acid) (mPEG-PLHMGA) and poly(lactic-co-benzyloxymethyl glycolic acid) (mPEG-PLBMGA). Hydrophobic bedaquiline and hydrophilic vancomycin were encapsulated via single and double-emulsion solvent evaporation techniques, respectively. Encapsulation, degradation and release studies at physiological simulating conditions were performed. Drug polarity and preparation techniques influenced encapsulation efficiency into polymer nanoparticles, giving almost complete encapsulation of bedaquiline and approx. 30% for vancomycin independent of the polymer type. The nonpolar bedaquiline showed a predominantly diffusion-controlled release independent of polymer composition. However, polar vancomycin was released by a combination of diffusion and polymer degradation, which was significantly affected by polymer composition, the most hydrophilic polymer displaying the fastest release.

Targeted delivery and thermo/pH-controlled release of doxorubicin by novel nanocapsules

The ideal drug delivery system (DDS) should be able to deliver a therapeutic dose of drug to the target site in the body and maintain appropriate concentration over a desired period of time. Thermo/pH-responsive targeted polymeric nanocapsules (p(NIPA-co-AAc-co-GAA)) for delivery of anticancer drug (doxorubicin, DOX) were fabricated by W/O/W double emulsion solvent evaporation technique. The morphology, hydrodynamic diameter, size distribution, thermo/pH responsiveness, targeted property, anti-tumor efficacy, encapsulation efficiency, drug loading and controlled release of drug were systematically investigated. The results demonstrated that p(NIPA-co-AAc-co-GAA) nanocapsules minimized the drug leakage and reduced the toxic and side effects on normal tissues, while triggered and accelerated the release of drug in tumor tissues. It is very interesting for the site-specific release of drug to improve curative effects and reduce side effects, implying that p(NIPA-co-AAc-co-GAA) nanocapsule is a attractive candidate for DDS.

Effect of process variables on formulation, in-vitro characterisation and subcutaneous delivery of insulin PLGA nanoparticles: An optimisation study

This study was initiated to investigate the effect of PLGA concentration, PVA concentration, internal to external phase ratio (IEPR), PEG molecular weight and concentration on mean particle size, zeta potential, polydispersity index (PDI), percentage drug entrapment and in vitro release profile. Using PLGA (50:50) as the carrier, insulin nanoparticles (NP) were prepared using double emulsion solvent evaporation technique. The particle size was analysed by dynamic light scattering (DLS) and the geometrical shape was examined using scanning electron microscopy (SEM). Mean particle size was highly dependent on the combined effect of PLGA and PVA concentrations. Drug entrapment would be greatly controlled by PLGA concentration and internal to external phase ratio. Addition of PEG could modulate in vitro release behavior of insulin with initial burst at the first 12 h and sustain the drug release for 6 days. Insulin integrity was assessed in vitro using MALDI-TOF mass spectroscopy. The optimised NP formulation, had particle size of 202.60 nm and percent entrapment efficiency (EE) equal to 67.72%, was tested in vivo to examine its hypoglycemic effect after subcutaneous injection. Insulin NP had a significant hypoglycemic effect comparing to free insulin (p < 0.01) and insulin zinc suspension (p < 0.05).

Ultrasound-triggered PLGA microparticle destruction and degradation for controlled delivery of local cytotoxicity and drug release

In this study, we investigated the low intensity ultrasound (US)-controlled delivery of local cytotoxicity and drug release via induced destruction and degradation of microparticles (MPs) made of poly(lactic-co-glycolic acid) (PLGA). This study was conducted in vitro with potential application towards tumor treatment in conjunction with direct injection. MPs, either loaded with or without doxorubicin (DOX), were prepared using a double-emulsion solvent-evaporation technique. First, the MPs were exposed to US with duty cycle (DC)-modulation. The destruction and degradation of MPs were evaluated using light and scanning electron microscopy. Second, the effects of US-mediated destruction/degradation of MPs on the local cytotoxicity as well as DOX release were evaluated. US-triggered MP destruction/degradation significantly enhanced nearby cell death and DOX release. These affects occurred in proportion to the DC. Our findings indicate that controlled cytotoxicity and DOX release by US could be useful in developing the minimally invasive therapeutic applications for tumor treatment.

Sustained-releasing hollow microparticles with dual-anticancer drugs elicit greater shrinkage of tumor spheroids.

Polymeric particulate delivery systems are vastly explored for the delivery of chemotherapeutic agents. However, the preparation of polymeric particulate systems with the capability of providing sustained release of two or more drugs is still a challenge. Herein, poly (D, L-lactic-co-glycolic acid, 50:50) hollow microparticles co-loaded with doxorubicin and paclitaxel were developed through double-emulsion solvent evaporation technique. Hollow microparticles were formed through the addition of an osmolyte into the fabrication process. The benefits of hollow over solid microparticles were found to be higher encapsulation efficiency and a more rapid drug release rate. Further modification of the hollow microparticles was accomplished through the introduction of methyl-β-cyclodextrin. With this, a higher encapsulation efficiency of both drugs and an enhanced cumulative release were achieved. Spheroid study further demonstrated that the controlled release of the drugs from the methyl-β-cyclodextrin -loaded hollow microparticles exhibited enhanced tumor regressions of MCF-7 tumor spheroids. Such hollow dual-drug-loaded hollow microparticles with sustained releasing capabilities may have a potential for future applications in cancer therapy.

Dual delivery nanosystem for biomolecules. Formulation, characterization, and in vitro release

Because of the biocompatible and biodegradable properties of poly (lactic-co-glycolic acid) (PLGA), nanoparticles (NPs) based on this polymer have been widely studied for drug/biomolecule delivery and long-term sustained-release. In this work, two different formulation methods for lysozyme-loaded PLGA NPs have been developed and optimized based on the double-emulsion (water/oil/water, W/O/W) solvent evaporation technique. They differ mainly in the phase in which the surfactant (Pluronic® F68) is added: water (W-F68) and oil (O-F68). The colloidal properties of these systems (morphology by SEM and STEM, hydrodynamic size by DLS and NTA, electrophoretic mobility, temporal stability in different media, protein encapsulation, release, and bioactivity) have been analyzed. The interaction surfactant-protein depending on the formulation procedure has been characterized by surface tension and dilatational rheology. Finally, cellular uptake by human mesenchymal stromal cells and cytotoxicity for both systems have been analyzed.Spherical hard NPs are made by the two methods However, in one case, they are monodisperse with diameters of around 120nm (O-F68), and in the other case, a polydisperse system of NPs with diameters between 100 and 500nm is found (W-F68). Protein encapsulation efficiency, release and bioactivity are maintained better by the W-F68 formulation method. This multimodal system is found to be a promising “dual delivery” system for encapsulating hydrophilic proteins with strong biological activity at the cell-surface and cytoplasmic levels.

Antioxidant polymeric nanoparticles containing standardized extract of Ilex paraguariensis A. St.-Hil. for topical use

Although various compounds from Ilex paraguariensis present high antioxidant activity, limitations in terms of chemical stability may be found, impacting on the formulation step. In this context, nanotechnology may be alternatively used to provide an additional protection for these compounds, avoiding degradative reactions. Different formulation parameters (eg. particle size, zeta potential, internal phase fraction) were assayed to maximize a local antioxidant action. Firstly, the extraction procedure for obtaining increased concentrations of antioxidant compounds was optimized. High stirring speed and ethanol as extractor liquid were defined as key parameters. Nanoparticles were prepared by double emulsion solvent evaporation technique. Polycaprolactone-based nanoparticles showed to be more stable than poly(lactic-co-glycolic acid)-based nanoparticles. Instead of poly(vinyl alcohol), Pluronic® was selected as surfactant because it avoids aggregate formation and provides smaller particle size. While higher polymer content contributes positively to maintaining both reduced size particle and distribution, an increased extract concentration impacted negatively on these parameters. Stability studies were also performed using skin extracts and homogenates and confirmed that nanostructures provide an additional protection. Moreover, the incorporation of Ilex extract in nanoparticles significantly reduced the amount of chlorogenic acid permeated through the skin (no ex vivo permeation until 12h for this system), extending its topical antioxidant effect.

Manufacture and characterization of chitosan/PLGA nanoparticles nanocomposite buccal films

Oral bioavailability of C-glycosyl flavonoid enriched fraction of Cecropia glaziovii (EFF-Cg) is limited due to its chemical complexity. The purpose of this study is the prospective evaluation of chitosan buccal films impregnated with EFF-Cg-loaded nanospheres as a drug delivery system for labial herpes treatment or for buccal administration. EFF-Cg-loaded PLGA nanospheres were prepared by double emulsion solvent evaporation technique. Nanoparticles were embedded into buccoadhesive chitosan films in different concentrations in order to obtain nanocomposite films. Films were characterized in term of morphology, mechanical properties and water absorption test. Furthermore a cytotoxicity assay was analyzed to evaluate the biocompatibility of systems. The results obtained from these analyses revealed that nanocomposite films present transparent appearance in all composition and Scanning Electron Microscopy (SEM) images show a continuous and compact section structure. Compared to the control film, mechanical responses of nanocomposites presented lower tensile strength values and no significant effect on the elongation at break. Dynamic Mechanical Analysis (DMA) tests indicated that increasing of NP concentration caused decreased stiffness and an increased of glass transition temperature values. Direct cytotoxicity test shows that nanoparticles and chitosan films not induce cytotoxic effect. Given the promising results, the study concludes that the developed buccal film impregnated with EFF-Cg-loaded nanospheres could be a promising approach for effective delivery of EFF-Cg.

Prolonged injectable formulation of Nafarelin using in situ gel combination delivery system

The principal purpose of the present study was to prepare and characterize a complex drug delivery system consisting of Nafarelin-poly (3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) nanoparticles (NPs) in combination with sodium alginate/poloxamer 407 in situ gel. Nafarelin-loaded PHBV NPs were prepared via double emulsion solvent evaporation technique. Box–Behnken Response Surface Methodology was utilized to optimize NPs. Mean particle size, polydispersity index (PDI), entrapment efficiency (EE), and drug loading (DL) of the optimized NPs were measured. Incorporation of Nafarelin within NPs was proven by differential scanning calorimetry (DSC). The combination delivery system (CDS) was prepared by adding Nafarelin-loaded PHBV NPs to sodium alginate/poloxamer 407 solution followed by physical mixing. Morphological properties of Nafarelin-loaded PHBV NPs and CDS were evaluated by SEM. Rheological properties were employed to investigate the effects of alginate concentration on sol–gel transition temperature. The release profile of Nafarelin from both PHBV NPs and CDS were individually assessed. The cumulative release percentage from CDS was significantly lower than Nafarelin released from PHBV NPs. Based on the favorable results in this study, the CDS consisting of sodium alginate/poloxamer 407 loaded with PHBV NPs could be a promising candidate for designing a long-lasting formulation of Nafarelin.

NANO FORMULATION ANALYSIS: ANALYTICAL METHOD DEVELOPMENT OF ISONIAZID AND SIMULTANEOUS ESTIMATION OF ANTI-TUBERCULAR DRUGS ISONIAZID AND RIFAMPICIN BY RP-HPLC

Objective: The objective of the study was to develop and validate a simple and reproducible reverse phase high pressure liquid chromatography (RPHPLC) method for hydrophilic drug isoniazid (INH) to apply for the analysis of the INH in nanoparticle drug formulations. Furthermore, to estimate simultaneously rifampicin (RIF) and INH in combined form.Methods: Isocratic elution with 10 minutes runtime on a C-18 Luna, 5 μ, 100Å, 150 mm column, methanol, and water as mobile phase with detection wavelength at 268 nm was used. INH nanoformulations were prepared by double emulsion solvent evaporation technique. Quantitative analysis of encapsulated drug was estimated via developed RP-HPLC method. Simultaneous estimation for the two drugs was carried out by gradient elution. All chromatographic separation and estimations were obtained on Shimadzu HPLC system.Results: INH eluted with a short retention time (RT) of 4.06 minutes. Method showed good linearity in the range of concentrations 0.01-100 μg/ml. The limit of detection (LOD) and quantification (LOQ) for INH was 0.03 and 0.12 μg/mL, respectively, and developed method has been successfully applied for the analysis of drugs in nanoparticle formulations. Simultaneous estimation of antitubercular drugs INH and RIF showed two separate peaks within specified runtime.Conclusion: Developed method showed good resolved peaks. Since the RT is short, in a shorter duration more samples could be completed and developed method will be easy for analyzing greater number of samples. Analysis of nanoformulation results have shown that this method is simple, reliable, reproducible, hence can be applied for drug delivery analysis.Keywords: Antitubercular drugs, Reverse phase high performance liquid chromatography, Analytical method development.

Visualization of hybrid gold-loaded polymeric nanoparticles in cells using scanning electron microscopy

Nanotechnology is growing quickly, with great advances in the area of nanomedicine. Opening the door to personalized medicine, a considerable number of nanosystems have been synthetized for the diagnosis, treatment and monitoring of diseases. Specifically, gold nanoparticles (AuNPs) have been shown to be good contrast agents. However, they have a limited surface area for the transport of active molecules. In this paper, polymeric nanoparticles encapsulating AuNPs have been synthetized by the double emulsion method (w/o/w) and solvent evaporation technique. This approach opens up the possibility of encapsulating hydrophilic and/or lipophilic thermostable biomolecules. The nanoparticles could be monitored in macrophage cells by simple scanning electron microscopy (SEM). Nevertheless, a micro computed tomography (micro-CT) study revealed that they would not be detected in future in vivo studies. In short, this paper explains the difficulty of obtaining nanovehicles that are trackable from early investigation stages to their clinical use, and discusses the controversy surrounding the concentration of AuNPs needed to obtain enough X-ray attenuation with safe doses.