Entrapment and release kinetics of furosemide from pegylated nanocarriers

Preparation and characterization of flexible furosemide-loaded biodegradable microneedles for intradermal drug delivery

Transdermal drug delivery systems are a useful and minimally invasive alternative to other drug administration routes. Biodegradable polymeric microneedles (MNs) are widely used in controlled-release drug delivery due to their tunable properties and ease of patient self-administration. Polylactic-co-glycolic acid (PLGA) is often used for sustained drug release owing to special intrinsic properties including biocompatibility and biodegradability, which offer excellent applicability in preparing MNs. Congestive heart failure (CHF) is characterized by fluid overload during acute exacerbation, necessitating frequent patient hospitalization for continuous intravenous (i.v.) diuretic therapy. In the present study, we incorporated furosemide (FUR) as a model drug into flexible PLGA MN skin patches for potential intradermal delivery to overcome the limitations associated with i.v. diuresis. The MNs were fabricated by a casting-mold technique and consisted of two main parts, PLGA needle tips loaded with varying concentrations of FUR and a flexible backing layer comprising sodium alginate and glycerol. MN formulations were characterized by SEM and exhibited a uniform pyramidal shape. The measured surface pH of all samples suggested that no skin irritation is expected upon application. High encapsulation efficiency was obtained for FUR-MN formulations in which a decrease was noted as the FUR/PLGA ratio decreased. Drug loading content ranged from 19.1 ± 1% to 28.9 ± 1.4%. Successful insertion of MNs into a Parafilm® skin simulant model suggested that MNs will easily penetrate the skin's outermost layer, the stratum corneum, and will permit intradermal delivery of FUR. The MNs were further characterized by analytical methods. Finally, the MNs exhibited an initial burst release followed by a sustained release of FUR. Self-administered FUR-MNs can open new avenues to overcome i.v. drip limitations and increase patient compliance.

Formulation of drug-loaded oligodepsipeptide particles with submicron size

The size of particulate carriers is key to their transport and distribution in biological systems, and needs to be tailored in the higher submicron range to enable follicular uptake for dermal treatment. Oligodepsipeptides are promising nanoparticulate carrier systems as they can be designed to exhibit enhanced interaction with drug molecules. Here, a fabrication scheme for drug-loaded submicron particles from oligo[3-(S)-sec-butylmorpholine-2,5-dione]diol (OBMD) is presented based on an emulsion solvent evaporation method with cosolvent, surfactant, and polymer concentration as variable process parameters. The particle size (300-950 nm) increased with lower surfactant concentration and higher oligomer concentration. The addition of acetone increased the particle size at low surfactant concentration. Particle size remained stable upon the encapsulation of models compounds dexamethasone (DXM) and Nile red (NR), having different physicochemical properties. DXM was released faster compared to NR due to its higher water solubility. Overall, the results indicated that both drug-loading and size control of OBMD submicron particles can be achieved. When applied on porcine ear skin samples, the NR-loaded particles have been shown to allow NR penetration into the hair follicle and the depth reached with the 300 nm particles was comparable to the one reached with the cream formulation. A potential benefit of the particles compared to a cream is their sustained release profile.

Cisplatin and farnesol co-encapsulated PLGA nano-particles demonstrate enhanced anti-cancer potential against hepatocellular carcinoma cells in vitro

Cisplatin (CDDP) is a potent chemotherapeutic drug, but its severe side-effects often prohibit its use. Combined treatment with CDDP plus Farnesol (FAR) and their co-encapsulated nano form were investigated in in vitro to examine if synergistic cytotoxicity of this combination could reduce unwanted side-effects of CDDP chemotherapy and potentiate CDDP anticancer activity against hepatocellular carcinoma (HCC) cells. After finding combination therapy of CDDP and FAR successfully combat HCC we formulated co-encapsulation of CDDP and FAR within poly(lactic-co-glycolic acid) copolymer (NCDDPFAR) by following the standardized solvent displacement method. NCDDPFAR treatment caused faster drug mobility, sustained particle release, site-specific action and higher percentage of apoptotic death compared with single drug treatment even at relatively low concentrations. Co-encapsulation of two drugs exhibited additive effects against HCC; FAR reduced CDDP-induced glutathione level by increasing expression of CYP2E1 while CDDP directly interacted with DNA; FAR up-regulated the expression of TopII, thereby promoting DNA breaks and escaping DNA repair machinery. Expression pattern of apoptotic genes like p53, Bax, cytochrome c and caspase-3 suggested that NCDDPFAR induced HCC cell death through mitochondrial intrinsic pathway. Administration of NCDDPFAR had better ability of drug carriage and enhanced anticancer potentials against HCC cells.

Oral Treatment of Spontaneously Hypertensive Rats with Captopril-Surface Functionalized Furosemide-Loaded Multi-Wall Lipid-Core Nanocapsules

Multi-wall lipid-core nanocapsule (MLNC) functionalized with captopril and nanoencapsulating furosemide within the core was developed as a liquid formulation for oral administration. The nanocapsules had mean particle size below 200 nm, showing unimodal and narrow size distributions with moderate dispersity (laser diffraction and dynamic light scattering). Zeta potential was inverted from −14.3 mV [LNC-Fur(0,5)] to +18.3 mV after chitosan coating. Transmission electron microscopy and atomic force microscopy showed spherical structures corroborating the nanometric diameter of the nanocapsules. Regarding the systolic pressure, on the first day, the formulations showed antihypertensive effect and a longer effect than the respective drug solutions. When both drugs were associated, the anti-hypertensive effect was prolonged. On the fifth day, a time effect reduction was observed for all treatments, except for the nanocapsule formulation containing both drugs [Capt(0.5)-Zn(25)-MLNC-Fur(0.45)]. For diastolic pressure, only Capt(0.5)-Zn(25)-MLNC-Fur(0.45) presented a significant difference (p < 0.05) on the first day. On the fifth day, both Capt(0.5)-MLNC-Fur(0.45) and Capt(0.5)-Zn(25)-MLNC-Fur(0.45) had an effect lasting up to 24 h. The analysis of early kidney damage marker showed a potential protection in renal function by Capt(0.5)-Zn(25)-MLNC-Fur(0.45). In conclusion, the formulation Capt(0.5)-Zn(25)-MLNC-Fur(0.45) proved to be suitable for hypertension treatment envisaging an important innovation.

Enhanced sustained release of furosemide in long circulating chitosan-conjugated PLGA nanoparticles

Furosemide (FSM) is commonly used in the treatment of edema associated with congestive cardiac failure, cirrhosis of the liver, renal disease, including the nephrotic syndrome and hypertension. However, in ascites, it is clinically limited due to its frequent dosing and short biological half-life and its prolonged-release preparations are not available. Therefore, the main objective behind the present research work is to develop chitosan coated and conjugated poly (lactic-co-glycolic acid) (PLGA) nanocarriers, to sustain the delivery of FSM with improved systemic circulation. Emulsion-solvent evaporation technique was used for the preparation of nanoparticles. In-vivo pharmacokinetic study showed 2.6, 3.10, and 4.30 folds enhancement in relative availability of FSM for FSM-PLGA, FSM-chitosan-coated-PLGA and FSM-chitosan-conjugated- PLGA nanoparticles, respectively than FSM. The present research work concluded that FSM loaded chitosan conjugated PLGA nanoparticles could enhance the systemic circulation of FSM with improved pharmacokinetics parameters.

Hybrid Hydrogel Composed of Polymeric Nanocapsules Co-Loading Lidocaine and Prilocaine for Topical Intraoral Anesthesia

This study reports the development of nanostructured hydrogels for the sustained release of the eutectic mixture of lidocaine and prilocaine (both at 2.5%) for intraoral topical use. The local anesthetics, free or encapsulated in poly(ε-caprolactone) nanocapsules, were incorporated into CARBOPOL hydrogel. The nanoparticle suspensions were characterized in vitro in terms of particle size, polydispersity, and surface charge, using dynamic light scattering measurements. The nanoparticle concentrations were determined by nanoparticle tracking analysis. Evaluation was made of physicochemical stability, structural features, encapsulation efficiency, and in vitro release kinetics. The CARBOPOL hydrogels were submitted to rheological, accelerated stability, and in vitro release tests, as well as determination of mechanical and mucoadhesive properties, in vitro cytotoxicity towards FGH and HaCaT cells, and in vitro permeation across buccal and palatal mucosa. Anesthetic efficacy was evaluated using Wistar rats. Nanocapsules were successfully developed that presented desirable physicochemical properties and a sustained release profile. The hydrogel formulations were stable for up to 6 months under critical conditions and exhibited non-Newtonian pseudoplastic flows, satisfactory mucoadhesive strength, non-cytotoxicity, and slow permeation across oral mucosa. In vivo assays revealed higher anesthetic efficacy in tail-flick tests, compared to a commercially available product. In conclusion, the proposed hydrogel has potential for provision of effective and longer-lasting superficial anesthesia at oral mucosa during medical and dental procedures. These results open perspectives for future clinical trials.

Strategic Pentablock Copolymer Nanomicellar Formulation for Paclitaxel Delivery System

Nanomicelles (NM) enhance solubility and absorption of active pharmaceutical ingredients (APIs). Various polymers and non-polymers are utilized to prepare nanomicellar formulations to achieve high absorption and delivery of drugs. The main purpose of this study was to develop drug-loaded nanomicelles with pentablock copolymers for paclitaxel delivery. Monomers of lactide, ε-caprolactone, and polyethylene-glycol were utilized to prepare pentablock copolymer by ring opening technique. The pentablock nanomicelles (PBNM) were formulated by evaporation and rehydration. Both copolymers and nanomicelles were analyzed by H-NMR, FTIR, and XRD. Nanomicelles were further analyzed for size and zeta potential using dynamic light scattering (DLS) and by H-NMR and TEM. The XRD, FTIR, and H-NMR analyses confirmed the structures of the pentablock copolymers. Average size was 20 nm ± 5.00 nm, and ζ-potential is around zero. H-NMR and FTIR analyses for Paclitaxel-PBNM indicated peaks of paclitaxel and the polymer, confirming successful encapsulation. TEM showed spherical morphology and size range similar to that obtained by DLS. In vitro release studies revealed slow first-order paclitaxel release rate from pentablock nanomicelles in phosphate buffer solution (PBS). Confocal laser scanning microscopy analysis with coumarin-6-loaded in PBNM indicated that pentablock nanomicelles were efficiently taken into prostate cancer (PC-3) cells. Cell proliferation assay showed that nanomicelles were able to ferry adequate amounts of paclitaxel drug into PC-3 cells and subsequently inhibiting PC-3 cell proliferation significantly. Results confirmed that pentablock copolymer can generate drug-loaded nanomicelles with desirable sizes and zeta potential. These demonstrate potentiality of pentablock nanomicelles as carrier for anticancer delivery.

Efficiency of resveratrol-loaded sericin nanoparticles: Promising bionanocarriers for drug delivery

Sericin protein nanoparticles are a biocompatible, bio-viable class of nanocarriers gaining prominence in drug delivery system. This research aimed to investigate the suitability fabrication of silk protein (SP) nanoparticles for loading with resveratrol (RSV) via a solventless precipitation technique. The addition of 0.5% (w/v) pluronic surfactant proved optimal for SP nanoparticle fabrication, with obtained nanoparticles being spherical, mono-dispersed and having mean size of approximately 200-400 nm. All exhibited negative surface charges, the extent of which being dependent on the SP concentration, and were non-toxic to normal skin fibroblasts (CRL-2522). Loading of RSV, a promising which poorly soluble multi-targeted anti-oxidative and anti-inflammatory natural polyphenol, into SP nanoparticles proved feasible, with encapsulation levels of 71-75% for 0.6% and 1.0% (w/v) nanoparticle formulations, respectively. Resveratrol-loaded SP nanoparticles strongly inhibited growth of colorectal adenocarcinoma (Caco-2) cells although proved non-cytotoxic to skin fibroblasts, as indicated by cell viability assays. Cellular internalization of SP nanoparticles proved facile and dependent on incubation time; transfection of these carriers, in vitro results indicating sustained release of RSV (over 72 h), and drug solubility enhancements on encapsulation highlight their potential in therapeutic and pharmaceutical applications. Thus, SP nanoparticles is a promising approach to be potential bio-nanocarrier for drug delivery system.

Label-Free Ferrocene-Loaded Nanocarrier Engineering for In Vivo Cochlear Drug Delivery and Imaging

It is hypothesized that ferrocene (FC)-loaded nanocarriers (FC-NCs) are safe label-free contrast agents for cochlear biodistribution study by transmission electron microscopy (TEM). To test this hypothesis, after engineering, the poly(epsilon-caprolactone)/polyglycolide NCs are tested for stability with various types and ratios of sugar cryoprotectants during freeze-drying. Their physicochemical properties are characterized by UV-visible spectroscopy, dynamic light scattering, Fourier transform infrared spectroscopy, and scanning electron microscopy coupled with energy dispersive X-ray spectroscopy (SEM/EDS). The biodistribution of the FC-NCs in the cochlear tissue after intratympanic injection in guinea pigs is visualized by TEM. Auditory brainstem responses are measured before and after 4-day treatments. These FC-NCs have 153.4 ± 8.7 nm, 85.5 ± 11.2%, and -22.1 ± 1.1 mV as mean diameters, percent drug association efficiency, and zeta potential, respectively (n = 3). The incorporation of FC into the NCs is confirmed by Fourier transform infrared spectroscopy and SEM/EDS spectra. Lactose (3:1 ratio, v/v) is the most effective stabilizer after a 12-day study. The administered NCs are visible by TEM in the scala media cells of the cochlea. Based on auditory brainstem response data, FC-NCs do not adversely affect hearing. Considering the electrondense, radioactive, and magnetic properties of iron inside FC, FC-NCs are promising nanotemplate for future inner ear theranostics.

Resveratrol-loaded nanocarriers: formulation, optimization, characterization and in vitro toxicity on cochlear cells

The present work aimed to investigate the suitability of polymeric nanoparticles (NPs) loaded with resveratrol (RES) for drug delivery to cochlear cells. RES-loaded NPs were prepared by a solvent-diffusion method without surfactant. The Box-Behnken design was used to study the effect of the formulation variables on the particle mean diameter (PMD), polydispersity index (PDI), zeta-potential (ζ), percent drug encapsulation efficiency (EE%), and ratio between NP size before and after freeze-drying (Sf/Si). The physicochemical stability of the RES-loaded NPs during freeze-drying was investigated using four well-known cryoprotectants (i.e., lactose, mannitol, sucrose, and trehalose) at different concentrations. The RES-loaded NPs were also characterized by powder X-ray diffraction (PXRD) and in vitro drug release studies. Finally, the in vitro toxicity of the synthesized NPs was evaluated on two cochlear cell lines: HEI-OC1 and SVK-1 cells. The optimal formulation (desirability: 0.86) had 135.5±37.3nm as PMD, 0.126±0.080 as PDI, -26.84±3.31mV as ζ, 99.83±17.59% as EE%, and 3.30±0.92 as Sf/Si ratio. The PMD and PDI of the RES-loaded NPs were maintained within the model space only when trehalose was used at concentrations higher than 15% (w/v). Results from the in vitro cytotoxicity studies showed that blank NPs did not alter the viability of both cells lines, except for concentrations higher than 600μg/mL. However, the cell viability was significantly decreased at high concentrations of native RES (>50μM, p<0.05) in both cell lines. Overall, the results suggested that the RES-loaded polymeric NPs could be a suitable template for cochlea antioxidant delivery and otoproctection.

Uptake and cytotoxicity of docetaxel-loaded hyaluronic acid-grafted oily core nanocapsules in MDA-MB 231 cancer cells

PURPOSE

It is hypothesized that docetaxel (Doc)-loaded hyaluronic acid (HA)-polyethylene glycol/poly(ε-caprolactone)-grafted oily core nanocapsules (NCs) can enhance the drug cytotoxicity and uptake in CD44 expressing breast cancer (BC) cells (MDA-MB 231).

METHODS

NCs were prepared, optimized and characterized by dynamic light scattering, transmission electron microscopy (TEM), and powder X-ray diffraction (PXRD). In vitro cytotoxicity tests [MTS, level of reactive oxygen species (ROS) and level of reduced glutathione (GSH)] were performed in BC cells. The contribution of CD44 to the NCs cellular uptake was elucidated using an anti CD44 antibody blockage and a CD44 negative NIH3T3 cell line.

RESULTS

The optimum formulation of Doc-loaded HA oily core NCs had respective mean diameter, polydispersity, and drug encapsulation efficiency of 224.18 nm, 0.32, and 60.38%. The NCs appeared spherical with low drug crystallinity, while the drug release data fitted to first order equation. Compared to that of ungrafted NCs, the cytotoxicity of Doc-loaded HA-grafted NCs was significantly enhanced (p<0.05). A decrease of the intracellular level of ROS was reversely correlated with that of GSH. Interestingly, the cellular internalization of HA-grafted NCs mediated CD44 was dramatically enhanced (3 to 4-fold) with respect to the absence of specific biomarker or targeting ligand.

CONCLUSIONS

The use of HA-grafted NCs enhanced the selective drug payload, cytotoxicity and uptake in MDA-MB 231 cells. Therefore, it could be a promising template for safe and effective delivery of Doc and similar chemotherapeutic agents in cancer cells.

Validated reverse-phase high-performance liquid chromatography for quantification of furosemide in tablets and nanoparticles

A simple, sensitive, and specific method for furosemide (FUR) analysis by reverse-phase-HPLC was developed using a Spherisorb C18 ODS 2 column. A chromatographic analysis was carried out using a mobile phase consisting of acetonitrile and 10 mM potassium phosphate buffer solution: 70 : 30 (v/v) at pH 3.85, at a flow rate of 1 mL·min(-1). The UV-detection method was carried out at 233 nm at room temperature. Validation parameters including limit of detection (LOD), limit of quantitation (LOQ), linearity range, precision, accuracy, robustness, and specificity were investigated. Results indicated that the calibration curve was linear (r (2) = 0.9997) in the range of 5.2 to 25,000 ng·mL(-1), with ε value equal to 3.74 × 10(4) L·M(-1) ·cm(-1). The LOD and LOQ were found to be 5.2 and 15.8 ng·mL(-1), respectively. The developed method was found to be accurate (RSD less than 2%), precise, and specific with an intraday and interday RSD range of 1.233-1.509 and 1.615 to 1.963%. The stability of native FUR has also been performed in simulated perilymph and endolymph media (with respective potency in each medium of 99.8 ± 2.3% and 96.68 ± 0.7%, n = 3) after 6 hours. This method may be routinely used for the quantitative analysis of FUR from nanocarriers, USP tablets and release media related to hearing research.

Novel insights into appropriate encapsulation methods for bioactive compounds into polymers: a study with peptides and HDAC inhibitors

The use of different nanoparticles (NPs) for successful encapsulation of bioactive substances is discussed. The inclusion efficiency into liposomes, acetalated dextran (Ac-Dex), and variants of poly[(lactic acid)-co-(glycolic acid)] (PLGA) NPs is analyzed after chemical degradation. Efficient inclusion of SIRT1 inhibitor Ex527 in liposomes, Ac-Dex- and PLGA-NPs is observed for all procedures used. Activity of Ex527 is demonstrated by monitoring the acetylation status of SIRT1-target p53. In contrast, small peptides are only incorporated into acid-terminated PLGA-NPs and marginally into Ac-Dex-NPs. The yield depends on peptide sequence and terminal modifications. Activity is exemplified for angiotensin II using the dynamic mass redistribution technology.