Ravi Shankar Pandey

Poly (ethylene)-glycol conjugated solid lipid nanoparticles of noscapine improve biological half-life, brain delivery and efficacy in glioblastoma cells

UNLABELLED Noscapine crosses blood-brain-barrier and inhibits proliferation of glioblastoma cells. However, short plasma half-life and rapid elimination necessitate the administration of multiple injections for successive chemotherapy. Noscapine bearing solid lipid nanoparticles, Nos-SLN and poly (ethylene)-glycol conjugated solid lipid nanoparticles of noscapine, Nos-PEG-SLN of 61.3 ± 9.3-nm and 80.5 ± 8.9-nm containing 80.4 ± 3.2% and 83.6 ± 1.2% of Nos, were constructed. First order kinetic and Higuchi equation were followed to release the Nos at intracellular pH~4.5. Further, a decrease in IC₅₀ (Nos; 40.5 μM>Nos-SLN; 27.2 μM>20.8 μM) and enhanced subG1 population were observed in U87cells. Plasma half-life was enhanced up to ~11-fold and ~5-fold by Nos-PEG-SLN and Nos-SLN which significantly (P<0.05) deposits 400.7 μg/g and 313.1 μg/g of Nos in comparison to 233.2 μg/g by drug solution. This is first report demonstrating a workable approach to regulate the administration of multiple injections of Nos, warranting further in vivo tumor regression study for superior management of brain cancer. FROM THE CLINICAL EDITOR This report describes a possible approach to regulate the administration of multiple injections of Noscapine using solid lipid nanoparticles. The data warrant further in vivo tumor regression studies for optimal management of glioblastoma, a generally very poorly treatable brain cancer.

Comparative study of transfersomes, liposomes, and niosomes for topical delivery of 5-fluorouracil to skin cancer cells: preparation, characterization, in-vitro release, and cytotoxicity analysis.

Topical 5-fluorouracil (5-FU) is used for the treatment of actinic keratosis and nonmelanoma skin cancer. Unfortunately, 5-FU per se shows a poor percutaneous permeation, thus reducing its anticancer effectiveness after topical administration. Therefore, we have constructed transfersomes, liposomes, and niosomes of 5-FU for topical applications in this investigation. Transfersomes were prepared by the solvent evaporation method, whereas liposomes and niosomes were constructed by reverse-phase evaporation method. The nanovesicles were characterized for particle size, shape, zeta potential, viscosity, entrapment efficiency, deformability, in-vitro permeation release, and kinetics and retention. Cytotoxicity study was carried out on HaCaT cells. Transfersomes (153.2±10.3 nm), liposomes (120.3±9.8 nm), and niosomes (250.4±8.6 nm) were produced with a maximum entrapment efficiency of 82.4±4.8, 45.4±3.3, and 43.4±3.2%, respectively. Moreover, transmission electron microscopy and atomic force microscopy assure the smooth and spherical shape of nanovesicles. Skin permeation and retention showed better permeability and retention than the nonvesiculized dosage form. The IC50 value of transfersomes (1.02 &mgr;mol/l), liposomes (6.83 &mgr;mol/l), and niosomes (9.91 &mgr;mol/l) was found to be far less than 5-FU (15.89 &mgr;mol/l) at 72 h. 5-FU-loaded transfersomes were found to be most cytotoxic on the HaCaT cell line in comparison with liposomes and niosomes. We concluded that vesiculization of 5-FU not only improves the topical delivery, but also enhances the cytotoxic effect of 5-FU. We have presented here a viable formulation of 5-FU for the management of actinic keratosis and nonmelanoma skin carcinoma.

Evaluation of neuropeptide loaded trimethyl chitosan nanoparticles for nose to brain delivery

Leucine-enkephalin (Leu-Enk) is a neurotransmitter or neuromodulator in pain transmission. Due to non-addictive opioid analgesic activity of this peptide, it might have great potential in pain management. Leu-Enk loaded N-trimethyl chitosan (TMC) nanoparticles were prepared and evaluated as a brain delivery vehicle via nasal route. TMC biopolymer was synthesized and analyzed by (1)H NMR spectroscopy. TMC nanoparticles were prepared by ionic gelation method. Mean peptide encapsulation efficiency and loading capacity were 78.28±3.8% and 14±1.3%, respectively. Mean particle size, polydispersity index and zeta potential were found to be 443±23 nm, 0.317±0.17 and +15±2 mV respectively for optimized formulations. Apparent permeability coefficient (Papp) of Leu-Enk released from nanoparticles across the porcine nasal mucosa was determined to be 7.45±0.30×10(-6) cm s(-1). Permeability of Leu-Enk released from nanoparticles was 35 fold improved from the nasal mucosa as compared to Leu-Enk solution. Fluorescent microscopy of brain sections of mice showed higher accumulation of fluorescent marker NBD-F labelled Leu-Enk, when administered nasally by TMC nanoparticles, while low brain uptake of marker solution was observed. Furthermore, enhancement in brain uptake resulted into significant improvement in the observed antinociceptive effect of Leu-Enk as evidenced by hot plate and acetic acid induced writhing assay.

Carbohydrate modified ultrafine ceramic nanoparticles for allergen immunotherapy

The uses of drug-delivery systems in allergen specific immunotherapy appear to be a promising approach due to their ability to act as adjuvants, transport the allergens to immune-competent cells and tissues and reduce the number of administrations. The aim of this work was to evaluate the carbohydrate modified ultrafine ceramic core based nanoparticles (aquasomes) as adjuvant/delivery vehicle in specific immunotherapy using ovalbumin (OVA) as an allergen model. Prepared nanoparticles were characterized for size, shape, zeta potential, antigen integrity, surface adsorption efficiency and in vitro release. The humoral and cellular-induced immune responses generated by OVA adsorbed aquasomes were studied by two intradermal immunizations in BALB/c mice. OVA sensitized mice were treated with OVA adsorbed aquasomes and OVA adsorbed aluminum hydroxide following established protocol. Fifteen days after therapy, animals were challenged with OVA and different signs of anaphylactic shock were evaluated. Developed aquasomes possessed a negative zeta potential (-11.3 mV) and an average size of 47 nm with OVA adsorption efficiency of ~60.2 μg mg(-1) of hydroxyapatite core. In vivo immune response after two intradermal injections with OVA adsorbed aquasomes resulted in a mixed Th1/Th2-type immune response. OVA-sensitized mice model, treatment with OVA adsorbed aquasomes elicited lower levels of IgE (p<0.05), serum histamine and higher survival rate in comparison with alum adsorbed OVA. Symptoms of anaphylactic shock in OVA aquasome-treated mice were weaker than the one induced in the alum adsorbed OVA group. Results from this study demonstrate the valuable use of aquasomes in allergen immunotherapy.

Sterically stabilized gelatin microassemblies of noscapine enhance cytotoxicity, apoptosis and drug delivery in lung cancer cells.

Noscapine, recently identified as anticancer due to its microtubule-modulating properties. It is presently in Phase I/II clinical trials. The therapeutic efficacy of noscapine has been established in several xenograft models. Its pharmacokinetic limitations such as low bioavailability and high ED50 impede development of clinically relevant treatment regimens. Here we present design, synthesis, in vitro and in vivo characterization of sterically stabilized gelatin microassemblies of noscapine (SSGMS) for targeting human non-small cell lung cancer A549 cells. The average size of the sterically stabilized gelatin microassemblies of noscapine, SSGMS was 10.0±5.1 μm in comparison to noscapine-loaded gelatin microassemblies, GMS that was 8.3±5.5 μm. The noscapine entrapment efficiency of SSGMS and GMS was 23.99±4.5% and 24.23±2.6%, respectively. Prepared microassemblies were spherical in shape and did not show any drug and polymer interaction as examined by FTIR, DSC and PXRD. In vitro release data indicated that SSGMS and GMS follow first-order release kinetics and exhibited an initial burst followed by slow release of the drug. In vitro cytotoxicity evaluated using A549 cells showed a low IC50 value of SSGMS (15.5 μM) compared to GMS (30.1 μM) and free noscapine (47.2 μM). The SSGMS can facilitate a sustained therapeutic effect in terms of prolonged release of noscapine as evident by caspase-3 activity in A549 cells. Concomitantly, pharmacokinetic and biodistribution analysis showed that SSGMS increased the plasma half-life of noscapine by ~9.57-fold with an accumulation of ~48% drug in the lungs. Our data provides evidence for the potential usefulness of SSGMS for noscapine delivery in lung cancer.

Inhalable nanostructured lipid particles of 9-bromo-noscapine, a tubulin-binding cytotoxic agent: in vitro and in vivo studies.

9-Bromo-noscapine (9-Br-Nos) alters tubulin polymerization in non-small cell lung cancer cells differently from noscapine. However, clinical applications of 9-Br-Nos are limited owing to poor aqueous solubility and high lipophilicity that eventually lead to suboptimal therapeutic efficacy at the site of action. Hence, 9-Br-Nos loaded nanostructured lipid particles (9-Br-Nos-NLPs) were prepared by nanoemulsion method to reduce the particle size below 100 nm. To impart the inhalable and rapid release (RR) attributes, 9-Br-Nos-NLPs were treated with spray dried lactose and effervescent excipients to generate, 9-Br-Nos-RR-NLPs. The mean particle and aerodynamic size of 9-Br-Nos-NLPs were measured to be 13.4±3.2 nm and 2.3±1.5 μm, significantly (P<0.05) lower than 19.4±6.1 nm and 3.1±1.8 μm of 9-Br-Nos-RR-NLPs. In addition, zeta-potential of 9-Br-Nos-NLPs was examined to be -9.54±0.16 mV, significantly (P<0.05) lower than -7.23±0.10 mV of 9-Br-Nos-RR-NLPs. Hence, both formulations were found to be optimum for pulmonary delivery through inhalation route of administration. Next, 9-Br-Nos-RR-NLPs exhibited enhanced cytotoxicity, apoptosis and cellular uptake in A549, lung cancer cells, as compared to 9-Br-Nos-NLPs and 9-Br-Nos suspension. This may be attributed to enhanced drug delivery and internalization character of 9-Br-Nos-RR-NLPs by energy-dependent endocytosis and passive diffusion mechanism. Pharmacokinetic and distribution analysis demonstrated the superiority of 9-Br-Nos-RR-NLPs that exhibited ∼1.12 and ∼1.75-folds enhancement in half-life of the drug as compared to 9-Br-Nos-NLPs and 9-Br-Nos powder following inhalation route. Continuation to this, 9-Br-Nos-RR-NLPs also displayed ∼3.75-fold increment in half-life of the drug in lungs, as compared to 9-Br-Nos suspension following intravenous route of administration. Furthermore, enhanced drug exposure was measured in terms of AUC(last) in lungs following administration of 9-Br-Nos-RR-NLPs, as compared to 9-Br-Nos-NLPs, 9-Br-Nos powder and 9-Br-Nos suspension. This may be attributed to rapid dispersion, enhanced dissolution and deep lung deposition of nanoparticles following inhalation route. Therefore, inhalable 9-Br-Nos-RR-NLPs claims further in depth in vivo tumor regression study to scale up the technology for clinical applications.

Evaluation of ISCOM matrices clearance from rabbit nasal cavity by gamma scintigraphy

Immune stimulating complexes and/or ISCOM matrices (adjuvant nanoparticles without antigen as a structural component) found potential applications as nasal vaccine adjuvant/delivery system owing to virus like particulate structure and saponin as potent Th1 adjuvant. One of important limiting factor for nasal vaccine delivery is the limited time available for absorption within the nasal cavity due to mucociliary clearance. In this report the clearance rate of ISCOM matrices from nasal cavity of rabbit was determined by gamma scintigraphy. ISCOM matrices were radiolabelled with (99m)Tc by direct labelling method using stannous chloride as a reducing agent. (99m)Tc labelled ISCOM matrices were administered into the nostril of female New Zealand rabbits and 1 min static views were repeated each 15 min until 4h. Clearance rate of ISCOM matrices from nasal cavity was calculated after applying the physical decay corrections. The mean labelling efficiency for ISCOM matrices were calculated as approximately 58.4%. ISCOM matrices showed slower clearance rate compared to sodium pertechnetate control solution (p<0.005) from nasal cavity that may be due to particulate and hydrophobic characters of ISCOM particles even though it was also cleared within 4h from nasal cavity. Mucoadhesive ISCOM formulations that retain in nasal cavity for longer duration of time may reduce the dose/frequency of vaccine for nasal immunization.

Inclusion complex of colchicine in hydroxypropyl-β-cyclodextrin tenders better solubility and improved pharmacokinetics

Context: Colchicine (CLC) causes cell death by destabilizing the tubulin unit. However, it ionizes at physiological pH resultant low bioavailability and therapeutic efficacy. Objectives: We have attempted to augment the bioavailability of CLC by fabricating the inclusion complex with hydroxypropyl-β-cyclodextrin (HP-β-CD). Materials and methods: CLC-HP-β-CD inclusion complex was prepared and evaluated with Fourier-transform infrared spectroscopy, differential scanning calorimetry, powder X-ray diffractometry, scanning electron microscopy, 1H nuclear magnetic resonance (1H NMR) spectroscopy and rotating frame overhauser enhancement spectroscopy (ROESY). Oral bioavailability of CLC-HP-β-CD inclusion complex was analyzed using high performance liquid chromatography method. Results and discussion: Our phase-solubility data indicated the formation of a stable complex with Kc ~0.31 mM−1 at pH 7.4. 1H NMR ascertains that NHCOCH3 moiety of CLC enters in the HP-β-CD cavity and deshielded the H-3 and H-5 protons. ROESY also correlates the Hf and Hg of CLC with H-3 and H-5 protons of HP-β-CD and indicates that Hf and Hg protons of CLC are present either as cis and/or trans form in CLC-HP-β-CD inclusion complex. Pharmacokinetic studies showed a 1.82-fold increase in absolute bioavailability of CLC upon complexation. Conclusion: CLC-HP-β-CD inclusion complex may potentially be used as a viable formulation of CLC.

Controlling release of metformin HCl through incorporation into stomach specific floating alginate beads.

The aim of present study was to develop stomach specific floating beads of metformin hydrochloride for effective management of type 2 diabetes mellitus. The beads were evaluated for surface morphology, particle size, tapped density, true density, percent porosity, drug entrapment efficiency, percent yield, differential scanning calorimetry, in vitro floating ability and in vitro drug release. Stability studies were performed at 25 and 40 °C up to 45 days. Effectiveness of the formulations was evaluated in vivo by hypoglycemic response in both normal and diabetic albino rats. The beads were grossly spherical in shape, and average particle diameter of beads was found to be in the size range of 861.34 to 991.75 μm. Percent entrapment was found to be in the range of 77.61 to 82.48%. Beads demonstrated favorable in vitro floating ability. All the formulations followed a non-Fickian release mechanism. It was found that there was no significant effect on floating ability of aged beads since it floated up to an 8 h study period. In vivo studies on diabetic rats showed that the hypoglycemic effect induced by the metformin hydrochloride loaded alginate beads was significantly greater (P < 0.05) and more prolonged than that induced by the nonfloating beads. The results clearly demonstrated the ability of the formulation to maintain blood glucose level and improved the patient compliance by enhancing, controlling and prolonging the systemic absorption of metformin hydrochloride.

Galactosylated gelatin nanovectors of doxorubicin inhibit cell proliferation and induce apoptosis in hepatocarcinoma cells.

We have synthesized and characterized doxorubicin (DOX)-loaded galactosylated gelatin nanovectors using in vitro and in vivo for targeting liver cells including hepatocarcinoma cells. Galactosylated and nongalactosylated gelatin nanovectors (GL-GN-DOX and GN-DOX) were spherical in shape and had mean sizes of about 95.1 and 88.3 nm, respectively. In-vitro release of DOX from nanovectors followed first-order kinetics and was pH dependent. Galactosylated formulation released 95.2% of DOX compared with 86.6% by nongalactosylated formulation at pH 5.8. However, the release rate was suppressed at pH 7.4. Further, we showed that GL-GN-DOX had greater growth inhibitory effect on HepG2 in terms of low inhibitory concentration (IC50; 0.35 µg/ml) compared with GN-DOX (0.75 µg/ml) and induced caspase-3-mediated apoptosis in HepG2 cells. This might be due to efficient internalization of galactosylated nanovectors by HepG2 cells compared with unmodified formulation. Pharmacokinetic and biodistribution analyses show that galactosylated formulation deposits 24.5 µg/g of DOX in targeted tissue (liver) in comparison with heart (0.3 µg/g) at a single dose of 10 mg/kg. These results suggest that DOX-loaded galactosylated gelatin nanovectors warrant future in-depth antitumor study to scale-up technology and may be used for the management of hepatocarcinoma.