Thermosensitive PLA based nanodispersion for targeting brain tumor via intranasal route.

Delivery of drugs to the brain via nasal route has been studied by many researchers. However, low residence time, mucociliary clearance and enzymatically active environment of nasal cavity pose many challenges to successful nasal delivery of drugs. We aim to deliver methotrexate by designing thermosensitive nanodispersion exhibiting enhanced residence time in nasal cavity and bypassing the blood brain barrier (BBB). PLA nanoparticles were developed using solvent evaporation technique. The developed nanoparticles were further dispersed in prepared thermosensitive vehicle of poloxamer 188 and Carbopol 934 to impart the property of increased residence time. The formulated nanoparticles demonstrated no interaction with the simulated nasal fluids (SNF), mucin, serum proteins and erythrocytes which demonstrate the safety of developed formulation for nasal administration. The penetration property of nanoparticles though the nasal mucosa was higher than the pure drug due to low mucociliary clearance. The developed nanoparticles diffused though the membrane pores and rapidly distributed into the brain portions compared to the pure drug. There was detectable and quantifiable amount of drug seen in the brain as demonstrated by in vivo brain distribution studies with considerably low amount of drug deposition in the lungs. The pharmacokinetic parameters demonstrated the enhancement in circulation half life, area under curve (AUC) and Cmax of the drug when administered intranasal in encapsulated form. Thus, the thermosensitive nanodispersions are surely promising delivery systems for delivering anticancer agents though the nasal route for potential treatment of brain tumors.

Surface-coated PLA nanoparticles loaded with temozolomide for improved brain deposition and potential treatment of gliomas: development, characterization and in vivo studies.

Hydrophobicity of PLA nanoparticles makes them a good substrate for macrophageal and reticulo-endothelial system uptake. Long-circulating properties can be imparted to these particles by coating them with hydrophilic stabilizers. Surface-modified PLA nanoparticles loaded with anti-cancer agent temozolomide were fabricated by solvent evaporation method and coated with surface modifiers. Selection of the surface modifier was based upon uptake of nanoparticles by K9 cells (liver cells). The particles were prepared and characterized for various physicochemical properties using transmission electron microscopy, differential scanning calorimetry, powder X-ray diffraction and in vitro dissolution studies. In vitro BBB permeation studies were performed using the co-culture model developed by using Madin-Darby canine kidney and C6 glioma cells as endothelial and glial cells, respectively. In vitro C6 glioma cell cytotoxicity, cellular proliferation, cellular migration and cellular uptake studies due to developed nanoparticles was assessed. In vivo studies such as pharmacokinetics, qualitative and quantitative biodistribution studies were performed for the developed nanoparticles. Drug-loaded nanoparticles with entrapment efficiency of 50% were developed. PEG-1000 and polysorbate-80 coated nanoparticles were least taken up by the liver cells. Characterization of the nanoparticles revealed formation of spherical shape nanoparticles, with no drug and excipient interaction. In vivo pharmacokinetics of developed nanoparticles depicted enhancement of half-life, area under the curve and mean residence time of the drug. Qualitative and quantitative biodistribution studies confirmed enhanced permeation of the drug into the brain upon loading into nanoparticles with less deposition in the highly perfused organs like lung, liver, spleen, heart and kidney.

Evaluation of anti-metastatic potential of Cisplatin polymeric nanocarriers on B16F10 melanoma cells.

Nanoparticles are being increasingly used in the field of cancer treatment due to their unique properties and advantages. The aim of the present research work was to prepare and characterize a polymeric albumin nanosystem for Cisplatin and evaluate its in-vitro efficacy against B16F10 melanoma. The developed nanoparticles were almost spherical in shape with a particle size in the range of 150-300 nm, low polydispersity values and about 80% drug entrapment efficiency. Albumin nanocarriers sustained the release of Cisplatin for more than 48 h, suggesting the reduction in dosing schedule for this drug. The results from in-vitro cell line studies indicated the dose dependent cytotoxic potential of drug loaded albumin nanoparticles, their potential to inhibit cell proliferation and induce morphological changes. In addition, these nanoparticles exhibited superiority to Cisplatin in hampering the cell migration. Developed nanoparticles caused cell cycle arrest along with time and concentration dependent cellular uptake in B16F10 cell line. These results signify that the prepared Cisplatin albumin nanoparticles could serve as a promising approach for B16F10 melanoma treatment.

Double-salting out assisted liquid-liquid extraction (SALLE) HPLC method for estimation of temozolomide from biological samples.

The role of temozolomide (TMZ) in treatment of high grade gliomas, melanomas and other malignancies is being defined by the current clinical developmental trials. Temozolomide belongs to the group of alkylating agents and is prescribed to patients suffering from most aggressive forms of brain tumors. The estimation techniques for temozolomide from the extracted plasma or biological samples includes high-performance liquid chromatography with UV detection (HPLC-UV), micellar electrokinetic capillary chromatography (MKEC) and liquid chromatography coupled to mass spectroscopy (LC-MS). These methods suffer from disadvantages like low resolution, low sensitivity, low recovery or cost involvement. An analytical method possessing capacity to estimate low quantities of TMZ in plasma samples with high extraction efficiency (%) and high resolution with cost effectiveness needs to be developed. Cost effective, robust and low plasma component interfering HPLC method using salting out liquid-liquid extraction (SALLE) technique was developed and validated for estimation of drug from plasma samples. The extraction efficiency (%) with conventional LLE technique with methanol, ethyl acetate, dichloromethane and acetonitrile was found to be 5.99±2.45, 45.39±4.56, 46.04±1.14 and 46.23±3.67 respectively. Extraction efficiency (%) improved with SALLE where sodium chloride was used as an electrolyte and was found to be 6.80±5.56, 52.01±3.13, 62.69±2.11 and 69.20±1.18 with methanol, ethyl acetate, dichloromethane and acetonitrile as organic solvent. Upon utilization of two salts for extraction (double salting liquid-liquid extraction) the extraction efficiency (%) was further improved and was twice of LLE. It was found that double salting liquid-liquid extraction technique yielded extraction efficiency (%) of 11.71±5.66, 55.62±3.44, 77.28±2.89 and 87.75±0.89. Hence a method based on double SALLE was developed for quantification of TMZ demonstrating linearity in the range of 0.47-20 µg/ml. The LOQ and LOD for the developed method were 0.4 µg/ml and 0.1 µg/ml, respectively. Thus, plasma non-interfering SALLE-HPLC method that is precise, robust, accurate, specific and cost effective for estimation of temozolomide from plasma samples was developed and validated.

Novel strategies for effective transdermal drug delivery: a review.

Skin is the largest and easily accessible organ of the body and therefore can be extensively used as a prominent route of delivery for local and systemic effects. Though it presents a multifunctional barrier between body and surrounding particles, there are chances to deliver therapeutic nanocarrier, particularly in diseased skin. Both for dermal and transdermal drug delivery, the horny layer, i.e., the uppermost layer of the skin serve as the most resistant layer to be crossed and for this purpose, different perforation techniques are used that relatively widen the skin opening and allow the passage of drug (≤ 10 mg) and micromolecules, but this amateur disruption of the skin can be avoided in order to preserve this barrier against cutaneous microbiota by using deformable nanocarriers. In this review, we discuss the nanosized aggregates and microneedle technology for the advanced delivery of vaccines, protein, peptides, nucleic acid, and hormone across the skin.

Etoposide loaded solid lipid nanoparticles for curtailing B16F10 melanoma colonization in lung.

Poor solubility of etoposide and associated poor bioavailability of the drug was circumvented by developing solid lipid nanocarrier system. The objective of the research work was to prepare etoposide loaded solid lipid nanoparticles (SLN) for improved efficacy and therapy of metastasized cancers. Entrapment of drug into nanoparticulate system modifies the pharmacokinetic and biodistribution profile of the drug with improved therapeutic efficacy. Solid lipid nanoparticles of various triglycerides were prepared using hot homogenization technique. Further, the process and formulation parameters viz. homogenization cycle and pressure, type of lipid were optimized. Developed nanoparticles were characterised for particle size, in vitro dissolution studies, DSC thermogram, surface morphology and cytotoxicity assay. Pharmacokinetic and biodistribution study were performed to assess the distribution of the drug in vivo. Modulation of the therapeutic activity of the drug was studied by performing antimetastatic activity on a B16F10 melanoma mouse model. The obtained results exhibited suitability of trimysristin for fabrication of nanoparticles. Characterisation of nanoparticles depicted formation of homogenous, spherical particles entrapping approximately 50% of the drug. The results for the performed MTT assay suggested that the developed nanoparticles exhibited cytotoxicity in a time- and concentration-dependent fashion. These findings concord with the results of the in vitro dissolution profile. Pharmacokinetic parameters demonstrated increase in area under curve (AUC), t1/2 and mean residence time (MRT) for drug in plasma. Further there is enhancement in the ratio of the drug that reaches to the highly perfused organs (upon encapsulation into solid lipid nanoparticles). Generally, cancer cells metastasized through the blood or lymphatic system. Accumulation of the drug in the highly perfused organ suggests suitability of the developed nanoparticles for targeting metastasized tumors. This was proved by the findings of the in vivo B16F10 mouse melanoma model. Improvement in the tumoricidal activity and survival rate of the animals substantiates the application of nanoparticles for improved therapeutic activity of etoposide.

Unraveling the cytotoxic potential of Temozolomide loaded into PLGA nanoparticles.

BACKGROUND: Nanotechnology has received great attention since a decade for the treatment of different varieties of cancer. However, there is a limited data available on the cytotoxic potential of Temozolomide (TMZ) formulations. In the current research work, an attempt has been made to understand the anti-metastatic effect of the drug after loading into PLGA nanoparticles against C6 glioma cells.Nanoparticles were prepared using solvent diffusion method and were characterized for size and morphology. Diffusion of the drug from the nanoparticles was studied by dialysis method. The designed nanoparticles were also assessed for cellular uptake using confocal microscopy and flow cytometry. RESULTS: PLGA nanoparticles caused a sustained release of the drug and showed a higher cellular uptake. The drug formulations also affected the cellular proliferation and motility. CONCLUSION: PLGA coated nanoparticles prolong the activity of the loaded drug while retaining the anti-metastatic activity.

Studies on stabilization mechanism and stealth effect of poloxamer 188 onto PLGA nanoparticles.

In nanoparticulate engineering for drug delivery systems, poloxamers tri block copolymers are employed as adsorbing molecules to modify the aggregation state and impart stability to products. The aim was to prepare nanoparticles using poloxamer188 as stabiliser and investigate the mechanism of stabilisation of the prepared particles. Nanoparticles were prepared by solvent diffusion method with poloxamer 188 as stabiliser. Hydrodynamic thickness and zeta potential of the prepared nanoparticles were determined by photon correlation spectroscopy. To study the extent of adsorption of poloxamer onto the prepared nanoparticles, adsorption isotherms were constructed. The adsorbed amount of poloxamer 188 onto the particles was determined by depletion method. Macrophageal uptake study was performed to assess the uptake of the prepared nanoparticles using RAW 264.7 cell lines. Nanoparticles were prepared with slight increase in particle size and in absolute value of zeta potential compared to uncoated particles suggesting that this effect was due to adsorption of poloxamer 188. TEM studies and surface area analysis supported the results obtained from particle size analysis indicating preparation of particles with a thin layer of adsorbed poloxamer 188. Adsorption kinetics modeling suggested that at low concentrations (0.001-0.010 g/L), Langmuir monolayer equation fits quite well and at higher concentrations (above 0.010 g/L) multilayer adsorption of poloxamer 188 onto the prepared particles occurred. Thus the nanoparticles had multilayer of poloxamer 188 adsorbed onto the non uniform surface of PLGA. Results of macrophageal uptake and liver cell study exhibits adsorbed concentration dependent bypass of RES uptake of nanoparticles. Hence, results substantiate the application of adsorption isotherms for designing nanoparticles possessing potential to exhibit prolonged circulation when administered in vivo.