Macrophage targeted polymeric curcumin nanoparticles limit intracellular survival of Mycobacterium tuberculosis through induction of autophagy and augment anti-TB activity of isoniazid in RAW 264.7 macrophages.

Rapid emergence of antibiotic resistance in tuberculosis has left us with limited resources to treat and manage multi drug resistant (MDR) cases of tuberculosis, prompting the development of novel therapeutics. Mycobacterium tuberculosis (MTB) perturbs the host protective pathways for its survival, therefore host directed therapeutic (HDT) interventions offer an attractive alternative strategy. Curcumin (CMN), the principle curcuminoid from Curcuma longa is known to have anti-TB activity against MDR strains of MTB in macrophages. We discovered that treatment of CMN induced autophagy in uninfected and MTB infected macrophages which was evident by conversion of LC3-I to LC3-II and degradation of p62. Inhibition of autophagy by a pharmacological inhibitor 3-MA resulted in significant inhibition of intracellular killing activity of CMN, suggesting the involvement of autophagy in intracellular clearance of MTB. Moreover, annexin v-FITC/PI staining data suggested induction of apoptosis in uninfected and MTB infected macrophages post CMN treatment. This finding was further corroborated by up-regulated expression of pro-apoptotic proteins, Bax, cleaved caspase-3 and PARP and diminished expression of anti-apoptotic protein Bcl-2 as evaluated by immunoblotting. Using GFP-MTB H37Rv and Lysotracker Red staining we demonstrated co-localization of GFP-MTB H37Rv containing phagosome to lysosome after CMN treatment, indicating enhanced phagosome lysosome fusion. Due to poor bioavailability of CMN, its clinical use is limited, therefore to overcome this issue, CMN was encapsulated in Poly(lactic-co-glycolic) acid (PLGA) shell, resulting in polymeric CMN nano particles (ISCurNP). Flow cytometric evaluation suggested >99% uptake of ISCurNP after 3h of treatment. In BALB/c mice, oral dose of ISCurNP resulted in 6.7-fold increase in the bioavailability compared to free CMN. Moreover, ISCurNP treatment resulted in significant decrease in the intracellular survival of MTB H37Rv through induction of autophagy. Adjunct action of ISCurNP and CMN in combination with isoniazid (INH) revealed >99% decrease in intracellular survival of MTB in macrophage as compared to ISCurNP, CMN or INH alone. In conclusion, our findings suggest the role of ISCurNP as novel host directed formulation to combat both sensitive and MDR strains of MTB by induction of autophagy.

Nano Drug Delivery Strategies for an Oral Bioenhanced Quercetin Formulation.

Quercetin, a naturally occurring flavonoid, has been credited with a wide spectrum of therapeutic properties. However, the oral use of quercetin is limited due to its poor water solubility, low bioavailability, rapid metabolism, and rapid plasma clearance. Quercetin has been studied extensively when used with various nanodelivery systems for enhancing quercetin bioavailability. To enhance its oral bioavailability and efficacy, various quercetin-loaded nanosystems such as nanosuspensions, polymer nanoparticles, metal nanoparticles, emulsions, liposomes or phytosomes, micelles, solid lipid nanoparticles, and other lipid-based nanoparticles have been investigated in in-vitro cells, in-vivo animal models, and humans. Among the aforementioned nanosystems, quercetin phytosomes are attracting more interest and are available on the market. The present review covers insights into the possibilities of harnessing quercetin for several therapeutic applications and a special focus on anticancer applications and the clinical benefits of nanoquercetin formulations.

Facile Technology for Extemporaneous Preparation of Long-Acting Injectable Microparticulate Suspensions at the Patient Side.

In this study, we present an innovative and facile in situ approach for extemporaneous preparation of sterile microparticles. An amazingly simple approach, in situ technology circumvents the stability, and scale up challenges as well as sterilization issues associated with long-acting particulate systems. Monophasic preconcentrates of donepezil base (DPZ), a model drug with a biodegradable polymer poly (DL-lactide-co-glycolide) (PLGA), with stabilizer were prepared by simple solution and sterilized by filtration (0.22 micron). The sterile preconcentrates when added to aqueous dextrose solution (total volume < 3 mL) generated ready-to-inject DPZ PLGA microparticles (DPZ-PLGA-MP) with high reproducibility, entrapment efficiency (> 80%), and size ~ 80 micron. DPZ micro suspension (DPZ-MS) with high precipitation efficiency (> 90%) and size ~ 80 micron was obtained in a similar manner omitting PLGA. XRD and DSC study confirmed decreased crystallinity in the presence of PLGA. No interaction between PLGA and DPZ was evident in the FTIR study. The microparticulate dispersions exhibited good in vitro injectability when tested using the texture analyzer (force < 5 N). When evaluated using the dialysis bag method (Himedia 12-14 kDa molecular weight cutoff), both microparticulate formulations exhibited controlled release up to 1 week in vitro. Further, low burst release of ~ 10% at the end of 6 h in the ex vivo chicken muscle study proposes great promise. Our data propose the facile extemporaneous generation of microparticles as a practical and promising approach for development of long-acting injectables. This facile approach could serve as platform technology for other drug candidates.

An innovative approach using microencapsulated turmeric oleoresin to develop ready-to-use turmeric milk powder with enhanced oral bioavailability.

The use of phytochemicals for nutritional wellness has attracted worldwide attention and resulted in development of innovative formulations. Turmeric latte is one such formulation. However, an in-depth study on its physicochemical properties and oral bioavailability has not been conducted as yet. We present a ready-to-use turmeric latte by microencapsulating turmeric oleoresin (TO) with a blend of gum acacia, maltodextrin, and dairy whitener (DW) with bioenhancers by spray drying. The microencapsulated powder obtained exhibited >95% encapsulation efficiency, desired curcumin content, of 539.98 ± 6.56 to 706.40 ± 5.25 mg/100 g, wettability time below 40 s, and dispersibility above 95%. Turmeric latte released >95% of curcumin at pH 1.2 HCl with 0.1% Tween 80, which was ascribed in part to curcumin amorphization as evidenced by DSC and XRD. Turmeric latte demonstrated superior antioxidant activity with 4.2-fold enhanced permeability through non-everted rat intestine and 4.9-fold higher oral bioavailability in rats confirming bioenhancement.

Innovative Betulin Nanosuspension exhibits enhanced anticancer activity in a Triple Negative Breast Cancer Cell line and Zebrafish angiogenesis model.

We present a nanosuspension of betulin, a BCS class II anticancer drug, particularly effective against resistant breast cancer. As anticancer efficacy of betulin is hampered by poor aqueous solubility, a nanosuspension with surface area was considered to enhance efficacy. An innovative approach wherein the betulin nanosuspension is generated instantaneously in situ, by adding a betulin preconcentrate (BeTPC) comprising drug and excipients, to aqueous medium, is successfully demonstrated. The optimal BeTPC when added to isotonic dextrose solution instantaneously generated an in situ nanosuspension (BeTNS-15) with high precipitation efficiency (92.7 ± 1.21%), average particle size (383.74 ± 7.24 nm) and good stability as per ICH guidelines. TEM revealed elongated particles while DSC and XRD indicated partial amorphization. Significantly higher cytotoxicity of BeTNS-15 (IC50 38.44 µg/ml) compared to betulin (BetS) (IC50 69.54 µg/ml) in the resistant triple negative human breast cancer cell line MDA-MB-231, was attributed to high intracellular uptake confirmed by HPLC and Imaging Flow cytometry (IFC). IFC confirmed superior anti-cancer efficacy of BeTNS-15 mediated by mitochondrial membrane disruption and inhibition of the G0/G1 phase. BeTNS-15 also exhibited significantly greater anti-angiogenic efficacy (p < 0.05) in the zebrafish model confirming superior efficacy. Simplicity of the innovative in situ approach coupled with superior efficacy proposes BeTNS as an innovative and highly promising anticancer formulation.

Pre-clinical evaluation of an innovative oral nano-formulation of baicalein for modulation of radiation responses.

There is an unmet medical need for non-toxic and effective radiation countermeasures for prevention of radiation toxicity during planned exposures. We have earlier shown that intraperitoneal administration of baicalein (BCL) offers significant survival benefit in animal model. Safety, tolerability, pharmacokinetics (PK) and pharmacodynamics of baicalein has been reported in pre-clinical model systems and also in healthy human volunteers. However, clinical translation of baicalein is hindered owing to poor bioavailability due to lipophilicity. In view of this, we fabricated and characterized in-situ solid lipid nanoparticles of baicalein (SLNB) with effective drug entrapment and release kinetics. SLNB offered significant protection to murine splenic lymphocytes against 4 Gy ionizing radiation (IR) induced apoptosis. Oral administration of SLNB exhibited ~70% protection to mice against whole body irradiation (WBI 7.5 Gy) induced mortality. Oral relative bioavailability of BCL was enhanced by over ~300% after entrapment in the SLNB as compared to BCL. Oral dosing of SLNB resulted in transient increase in neutrophil abundance in peripheral blood. Interestingly, we observed that treatment of human lung cancer cells (A549) with radioprotective dose of SLNB exhibited radio-sensitization as evinced by decrease in survival and clonogenic potential. Contrary to antioxidant nature of baicalein in normal cells, SLNB treatment induced significant increase in cellular ROS levels in A549 cells probably due to higher uptake and inhibition of TrxR. Thus, a pharmaceutically acceptable SLNB exhibited improved bioavailability, better radioprotection to normal cells and sensitized cancer cells to radiation induced killing as compared to BCL suggesting its possible utility as an adjuvant during cancer radiotherapy.

Asialoglycoprotein receptor targeted delivery of doxorubicin nanoparticles for hepatocellular carcinoma.

We report asialoglycoprotein receptor (ASGPR)-targeted doxorubicin hydrochloride (Dox) nanoparticles (NPs) for hepatocellular carcinoma (HCC). Polyethylene sebacate (PES)-Gantrez® AN 119 Dox NPs of average size 220 nm with PDI < 0.62 and ∼20% Dox loading were prepared by modified nanoprecipitation. ASGPR ligands, pullulan (Pul), arabinogalactan (AGn), and the combination (Pul-AGn), were anchored by adsorption. Ligand anchoring enabled high liver uptake with a remarkable hepatocyte:nonparenchymal cell ratio of 85:15. Furthermore, Pul-AGn NPs exhibited an additive effect implying incredibly high hepatocyte accumulation. Galactose-mediated competitive inhibition confirmed ASGPR-mediated uptake of ligand-anchored NPs in HepG2 cell lines. Subacute toxicity in rats confirmed the safety of the NP groups. However, histopathological evaluation suggested mild renal toxicity of AGn. Pul NPs revealed sustained reduction in tumor volume in PLC/PRF/5 liver tumor-bearing Nod/Scid mice up to 46 days. Extensive tumor necrosis, reduced collagen content, reduction in the HCC biomarker serum α-fetoprotein (p < 0.05), a mitotic index of 1.135 (day 46), and tumor treated/tumor control (T/C) values of <0.42 signified superior efficacy of Pul NPs. Furthermore, weight gain in the NP groups, and no histopathological alterations indicated that they were well tolerated by the mice. The high efficacy coupled with greater safety portrayed Pul Dox NPs as a promising nanocarrier for improved therapy of HCC.

Docosahexaenoic acid-mediated, targeted and sustained brain delivery of curcumin microemulsion.

We disclose microemulsions (ME) of curcumin (CUR) with docosahexaenoic acid (DHA)-rich oil (CUR DHA ME) for targeted delivery to the brain. MEs of CUR (5 mg/mL) with and without DHA-rich oil (CUR Capmul ME) suitable for intravenous and intranasal administration exhibited negative zeta potential, globule size <20 nm and good stability. Following intravenous delivery MEs exhibited high brain concentration with CUR DHA ME exhibiting a 2.8-fold higher Cmax than CUR solution. Furthermore, high and sustained concentration was demonstrated even at 24 h, which was 8- and 2-fold higher than CUR solution and CUR Capmul ME, respectively. Brain concentrations following intranasal administration were, however, substantially higher as evident from higher Cmax and AUC and sustained compared to corresponding intravenous formulations signifying nose to brain targeting. The high brain concentration of CUR DHA ME is ascribed to the targeting efficiency enabled by DHA-mediated transport across the blood-brain barrier (BBB). Histopathological and nasal toxicity confirmed safety of the MEs. Concentration-dependent cytotoxicity in vitro, on human glioblastoma U-87MG cell line was observed with CUR DHA MEs and with the blank DHA ME, implying anticancer potential of DHA. The dramatically low IC50 value of CUR DHA ME (3.755 ± 0.24 ng/mL) is therefore attributed to the synergistic effect of CUR and DHA in the ME. The CUR concentration achieved with CUR DHA ME at 24 h which translated to >66-fold(intranasal) and >21-fold (intravenous) the IC50 value in the U-87MG cell line suggests great promise of CUR DHA ME for therapy of brain cancer by both routes.

Design and Characterization of Metformin-Loaded Solid Lipid Nanoparticles for Colon Cancer.

Colorectal cancer is a global concern, and its treatment is fraught with non-selective effects including adverse side effects requiring hospital visits and palliative care. A relatively safe drug formulated in a bioavailability enhancing and targeting delivery platform will be of significance. Metformin-loaded solid lipid nanoparticles (SLN) were designed, optimized, and characterized for particle size, zeta potential, drug entrapment, structure, crystallinity, thermal behavior, morphology, and drug release. Optimized SLN were 195.01 ± 6.03 nm in size, -17.08 ± 0.95 mV with regard to surface charge, fibrous in shape, largely amorphous, and release of metformin was controlled. The optimized size, charge, and shape suggest the solid lipid nanoparticles will migrate and accumulate in the colon tumor preventing its proliferation and subsequently leading to tumor shrinkage and cell death.

Polyethylene sebacate doxorubicin nanoparticles: role of carbohydrate anchoring on in vitro and in vivo anticancer efficacy.

We report carbohydrate-anchored polyethylene sebacate (PES)-Gantrez® AN 119 Doxorubicin hydrochloride (Dox) nanoparticles (NPs) for enhanced anticancer efficacy. The carbohydrates Arabinogalactan (AGn), an adjuvant in anticancer chemotherapy and pullulan (Pul) reported to promote collagen synthesis, were selected as ligands. PES Dox NPs of an average size around 200 nm, greater than 20% w/w Dox loading and negative zeta potential were anchored with Pul, AGn, and Pul-AGn combination by simple incubation. Increase in particle size and zeta potential confirmed carbohydrate anchoring. FTIR confirmed ionic complexation of Dox and Gantrez® AN 119. DSC and XRD demonstrated amorphization of Dox. Higher Dox release in pH 5.5 as compared with pH 7.4 is beneficial for reduced systemic toxicity and enhanced drug release in tumors. Good in vitro serum stability and low hemolysis revealed suitability for intravenous administration. All NPs revealed circulation longevity in normal rats. Pul NPs revealed superior anticancer efficacy in vitro and an 11-fold enhancement in uptake in MCF-7 breast cancer cells. The greater efficacy in vivo is attributed to possible pullulan-mediated integrin receptor uptake and interaction with tumor collagen. Histopathology confirmed safety and suggested promise of Pul NPs in improved anticancer efficacy.

Nevirapine Loaded Core Shell Gold Nanoparticles by Double Emulsion Solvent Evaporation: In vitro and In vivo Evaluation.

BACKGROUND: HIV/AIDS is a macrophage resident infection localized in the reticuloendothelial system and remote locations of brain and bone marrow. We present core shell nanoparticles of gold(AuNPs) and nevirapine(NVP) for targeted delivery to the multiple HIV reservoirs. The aim of the study was to design core shell NVP loaded AuNPs with high drug loading and to evaluate biodistribution of the nanoparticles in possible HIV reservoirs in vivo. A specific objective was to assess the possible synergy of AuNPs with NVP on anti-HIV activity in vitro. METHOD: Core shell nanoparticles were prepared by double emulsion solvent evaporation method and characterized. RESULTS: Glyceryl monostearate-nevirapine-gold nanoparticles(GMS-NVP-AuNPs) revealed high entrapment efficiency (>70%), high loading (~40%), particle size <250 nm and zeta potential -35.9± 1.41mv and exhibited sustained release with good stability. Surface plasmon resonance indicated shell formation while SEM coupled EDAX confirmed the presence of Au. TEM confirmed formation of spherical core shell nanoparticles. GMS-NVP-AuNPs revealed low hemolysis (<10 %) and serum stability upto 6 h. GMS-NVP-AuNPs exhibited rapid, high and sustained accumulation in the possible HIV reservoir organs, including the major organs of liver, spleen, lymph nodes, thymus and also remote locations of brain, ovary and bone marrow. High cell viability and enhanced uptake in PBMC's and TZM-bl cells were observed. While uptake in PBMC's proposed monocytes/macrophages enabled brain delivery. GMS-NVP-AuNPs demonstrated synergistic anti-HIV activity. CONCLUSION: The superior anti-HIV activity in vitro coupled with extensive localization of the nanoparticles in multiple HIV reservoirs suggests great promise of the core shell GMS-NVP-AuNPs for improved therapy of HIV.

In Situ Lipidization as a New Approach for the Design of a Self Microemulsifying Drug Delivery System (SMEDDS) of Doxorubicin Hydrochloride for Oral Administration.

The present paper reports in situ lipidization as a novel approach for the design of Dox-self microemulsifying drug delivery system (SMEDDS). Dox-aerosol OT (AOT) ion pair complex (lipidized Dox), exhibited high log P value of 1.74, indicating lipophilic nature. The lipidized Dox revealed good solubility but limited stability in various oils. Rapid complex formation of Dox with AOT dissolved in oils, and the high partitioning of lipidized Dox (-90%) into the oily phase presented in situ lipidization as a strategy to overcome the limited chemical stability of lipidized Dox. SMEDDS was prepared by mixing the lipidizing agent AOT, the surfactant α-Tocopheryl-Polyethyleneglycol-1 000-Succinate (TPGS) and Capmul as the oil. Dox was suspended in the SMEDDS to obtain Dox-SMEDDS. Dox-SMEDDS on aqueous dilution, resulted in a microemulsion with globule size 196 ± 16.56 nm, and revealed slow release of Dox. Oral bioavailability study in rats revealed a 420% enhancement from Dox-SMEDDS compared to Dox solution. Dox-SMEDDS and control group revealed comparable superoxide dismutase (SOD), catalase (CAT) and malondialdehyde (MDA) levels in heart and kidneys suggesting safety of the Dox-SMEDDS. Efficacy study (tumor size reduction) in fibrosarcoma mouse model suggested Dox-SMEDDS as a promising oral delivery system for the treatment of cancer. In situ lipidization of Dox in SMEDDS presents a novel approach for the design of an orally bioavailable and promising formulation of Dox for oral administration.

Intranasal microemulsion for targeted nose to brain delivery in neurocysticercosis: Role of docosahexaenoic acid.

Intranasal Microemulsions (MEs) for nose to brain delivery of a novel combination of Albendazole sulfoxide (ABZ-SO) and Curcumin (CUR) for Neurocysticercosis (NCC), a brain infection are reported. MEs prepared by simple solution exhibited a globule size <20nm, negative zeta potential and good stability. The docosahexaenoic acid (DHA) ME revealed high and rapid ex vivo permeation of drugs through sheep nasal mucosa. Intranasal DHA ME resulted in high brain concentrations and 10.76 (ABZ-SO) and 3.24 (CUR) fold enhancement in brain area-under-the-curve (AUC) compared to intravenous DHA MEs at the same dose. Direct nose to brain transport (DTP) of >95% was seen for both drugs. High drug targeting efficiency (DTE) to the brain compared to Capmul ME and drug solution (P<0.05) suggested the role of DHA in aiding nose to brain delivery. Histopathology study confirmed no significant changes. High efficacy of ABZ-SO: CUR (100:10ng/mL) DHA ME in vitro on Taenia solium cysts was confirmed by complete ALP inhibition and disintegration of cysts at 96h. Considering that the brain concentration at 24h was 1400±160.1ng/g (ABZ-SO) and 120±35.2ng/g (CUR), the in vitro efficacy seen at a 10 fold lower concentration of the drugs strongly supports the assumption of clinical efficacy. The intranasal DHA ME is a promising delivery system for targeted nose to brain delivery.

Comparative evaluation of polymeric nanoparticles of rifampicin comprising Gantrez and poly(ethylene sebacate) on pharmacokinetics, biodistribution and lung uptake following oral administration.

The present study reports the comparative pharmacokinetic evaluation and biodistribution of rifampicin (RIF) following oral administration of nanoparticles of a bioadhesive polymer, Gantrez and a hydrophobic polymer poly(ethylene sebacate) (PES). A specific objective of the study was to evaluate lung uptake of the nanoparticles following oral administration. Nanoparticles were obtained in the size range 350-450 nm with rifampicin loading of 12-14% w/w. Zeta potential confirmed colloidal stability. PES nanoparticles revealed high macrophage uptake compared to Gantrez nanoparticles, and direct correlation was observed between hydrophobicity (contact angle) and macrophage uptake (r2 -0.940). Enhanced RIF uptake with folic acid anchoring suggested folate receptor mediated uptake. RIF nanoparticles exhibited significantly higher Cmax and AUC, delayed Tmax and sustained release compared to plain RIF. More importantly the plasma concentration of RIF with the nanoparticles was significantly greater than the MIC of RIF (0.25 microng/mL) over 24 h. While gamma scintigraphy revealed higher lung accumulation of nanoparticles, the concentration with Gantrez nanoparticles was significantly higher. HPLC evaluation of lung concentration correlated with scintigraphy data. The significantly higher bioavailability and lung accumulation with Gantrez nanoparticle over PES nanoparticles was attributed mucoadhesion and high affinity of Gantrez to the Peyer's patches. Our study suggests Gantrez nanoparticles as a promising carrier for enhancing lung accumulation of drugs.

Polyaspartic acid functionalized gold nanoparticles for tumor targeted doxorubicin delivery.

In this paper, we present polyaspartic acid, a biodegradable polymer as a reducing and functionalizing agent for the synthesis of doxorubicin loaded gold nanoparticles by a green process. Gold nanoparticles were stable to electrolytes and pH. Secondary amino groups of polyaspartic acid enabled reduction of gold chloride to form gold nanoparticles of size 55 +/-10 nm, with face centered cubic crystalline structure as confirmed by UV, TEM, SAED and XRD studies. Cationic doxorubicin was readily loaded onto anionic polyaspartic acid gold nanoparticles by ionic complexation. Fluorescence studies confirmed doxorubicin loading while FTIR spectra confirmed ionic complexation. Doxorubicin loading onto polyaspartic acid gold nanoparticles was studied at doxorubicin/polyaspartic acid molar ratios 1:10 to 1:1. As the molar ratio tended to unity, although loading up to 60% was achieved, colloidal instability resulted and is attributed to effective covering of negative charges of polyaspartic acid. Stable doxorubicin loaded polyaspartic acid gold nanoparticles of 105 +/- 15.1 nm with doxorubicin loading of 23.85% w/w and zeta potential value of -28 +/- 0.77 mV were obtained at doxorubicin/polyaspartic acid molar ratio 1:10. Higher doxorubicin release rate from the doxorubicin loaded polyaspartic acid gold nanoparticles in an acid medium (i.e., pH 5.5) as compared to that in pH 7.4 and deionized water is a desirable characteristic for tumor targeted delivery. Enhanced cytotoxicity and 3 fold higher uptake of doxorubicin loaded polyaspartic acid gold nanoparticles as compared to doxorubicin solution were seen in MCF-7 breast cancer cells while polyaspartic acid gold nanoparticles revealed no cytotoxicity confirming safety. Prominent regression in tumor size in-vivo in fibrosarcoma tumor induced mouse model was observed upto 59 days with doxorubicin loaded polyaspartic acid gold nanoparticles while doxorubicin solution treated mice showed regrowth beyond 23rd day. Moreover, a decrease of body weight of 35% indicating severe toxicity with doxorubicin solution as compared to only 20% with gradual recovery after day 30 in case of doxorubicin loaded polyaspartic acid gold nanoparticles confirmed their lower toxicity and enhanced efficacy.

Inorganic nanovectors for nucleic acid delivery.

Nucleic acids show immense potential to treat cancer, acquired immune deficiency syndrome, neurological diseases and other incurable human diseases. Upon systemic administration, they encounter a series of barriers and hence barely reach the site of action, the cell. Intracellular delivery of nucleic acids is facilitated by nanovectors, both viral and non-viral. A major advantage of non-viral vectors over viral vectors is safety. Nanovectors evaluated specifically for nucleic acid delivery include polyplexes, lipoplexes and other cationic carrier-based vectors. However, more recently there is an increased interest in inorganic nanovectors for nucleic acid delivery. Nevertheless, there is no comprehensive review on the subject. The present review would cover in detail specific properties and types of inorganic nanovectors, their preparation techniques and various biomedical applications as therapeutics, diagnostics and theranostics. Future prospects are also suggested.

Self nanoprecipitating preconcentrate of tamoxifen citrate for enhanced bioavailability.

We disclose a self nanoprecipitating preconcentrate (SNP) of tamoxifen citrate (TMX), which forms TMX loaded polymeric nanoparticles, on dilution with aqueous media. SNP comprised TMX, polymer (Kollidon SR) and surfactant/s dissolved in a pharmaceutically acceptable vehicle. Binary surfactant mixtures of Aerosol OT (AOT) with Tween 80 revealed synergistic reduction in surface tension to enable both high entrapment efficiency (EE) and low particle size (PS). Synergism of the surfactants was confirmed by molecular interaction parameter(ß(σ)). Combination of AOT and Tween 80 resulted in EE (∼85%) and PS (<250nm). Formation of TMX-KSR nanoparticles in situ was reproducible under most experimental conditions and exhibited pH independent behavior. Dilution volume (>80mL) influenced both PS and EE while dilution temperature influenced only PS. Marginal increase in size was evident at the end of 1h nevertheless was not of concern as TMX SNP exhibited near complete release in 1h. DSC and XRD studies revealed amorphous nature of TMX in nanoparticles. FTIR imaging confirmed uniform distribution of TMX in nanoparticles. ESEM and TEM revealed spherical nanoparticles. Biodistribution studies of (99m)Tc labeled TMX SNP in rats revealed no significant absorption however oral pharmacokinetics revealed enhanced oral bioavailability of TMX (165%) compared to TMX suspension. SNP presents a new in situ approach, for design of drug loaded polymeric nanoparticles.

Lipomer of doxorubicin hydrochloride for enhanced oral bioavailability.

The present study discusses design of doxorubicin hydrochloride (Dox) loaded lipid based nanocarrier (LIPOMER) for oral delivery. High entrapment (>90 %) and high loading (38.11 ± 0.37 %w/w) of hydrophilic Dox in lipid nanocarrier of polyglyceryl-6-distearate was achieved using poly(methyl vinyl ether-co-maleic anhydride) (Gantrez AN 119) and a modified nanoprecipitation method. Dox-LIPOMER revealed nanosize (314 ± 16.80 nm) and negative zeta potential (-25.00 ± 2.41 mV). Dox-LIPOMER exhibits sustained release in vitro and was influenced by ionic strength of dissolution medium. DSC and XRD studies suggested amorphous nature of Dox in LIPOMER. TEM revealed spherical morphology of Dox-LIPOMER. Dox-LIPOMER was stable up to 12 months at 25 °C/60 % RH. A 384 % enhancement in oral bioavailability compared to Dox solution was observed following Dox-LIPOMER administration at 10 mg/kg body weight. Superoxide dismutase (SOD), catalase (CAT) and malondialdehyde (MDA) assay data of heart and kidney tissues of rats treated with Dox-LIPOMER were comparable with untreated rats. Dox-LIPOMER represents a potential safe drug delivery system for oral administration.

Evaluation of pullulan-functionalized doxorubicin nanoparticles for asialoglycoprotein receptor-mediated uptake in Hep G2 cell line.

The present study discusses evaluation of pullulan-functionalized doxorubicin nanoparticles for asialoglycoprotein receptor-mediated uptake in the Hep G2 cell line. Doxorubicin hydrochloride (DOX) nanoparticles using polymers of different hydrophobic character, polyethylene sebacate (hydrophobic) and poly (lactic-co-glycolic acid) (intermediate hydrophobicity) with high entrapment efficiency and particle size were prepared by modified nanoprecipitation, using Gantrez AN 119 as complexing agent. Nanoparticles of Gantrez AN 119 were also prepared to represent a hydrophilic polymer. Cell uptake of DOX nanoparticles was found to be comparable to DOX solution irrespective of DOX concentration, nanoparticles size, and pullulan concentration. Furthermore, uptake of nanoparticles functionalized with or without pullulan prepared with polymers of different hydrophobic character revealed comparable uptake. Comparable uptake of DOX solution and DOX nanoparticles functionalized with or without pullulan suggest extracellular release of DOX as the mechanism of uptake from the nanoparticles. In vivo evaluation in hepatic cancer model is therefore essential to confirm the role of pullulan as asialoglycoprotein receptors ligand.

Polyethylene sebacate-doxorubicin nanoparticles for hepatic targeting.

The present study discusses polyethylene sebacate (PES)-doxorubicin (DOX) nanoparticles (PES-DOX NP) using pullulan as asialoglycoprotein receptor (ASGPR) ligand for hepatic targeting. Pullulan, a hydrophilic polymer served as ligand and as stealth agent. PES-DOX NP were prepared by modified nanoprecipitation using PES and Gantrez AN 119 (Gantrez), as complexing agent in the organic phase, while DOX was dissolved in the aqueous phase. Pullulan was adsorbed on the formed nanoparticles (PES-DOX-PUL). Intimate association of PES and Gantrez, and ionic complexation of DOX with Gantrez (confirmed by FTIR), coupled with rapidity of nanoprecipitation resulted in nanoparticles with high entrapment efficiency and high drug loading. Nanoparticles were successfully freeze dried. Drug release from PES NP followed zero order kinetics. PES-DOX NP and PES-DOX-PUL exhibited low hemolytic potential and good serum stability. Comparative biodistribution study in rats using (99m)Tc labeled formulations revealed higher blood concentration and lower liver concentration of PES-DOX-PUL, confirming the long circulating nature of PES-DOX-PUL, and thereby the possibility of improved targeting to hepatocytes. Nanoparticles revealed lower DOX concentration in the heart suggestive of low cardiotoxicity. Our study presents a radically different yet simple approach for the design of PES-DOX nanoparticles with high drug loading for improved therapy in hepatic cancer.