Core-Shell Nanoparticles for Pulmonary Drug Delivery.

Nanoscale drug delivery systems have provoked interest for application in various therapies on account of their ability to elevate the intracellular concentration of drugs inside target cells, which leads to an increase in efficacy, a decrease in dose, and dose-associated adverse effects. There are several types of nanoparticles available; however, core-shell nanoparticles outperform bare nanoparticles in terms of their reduced cytotoxicity, high dispersibility and biocompatibility, and improved conjugation with drugs and biomolecules because of better surface characteristics. These nanoparticulate drug delivery systems are used for targeting a number of organs, such as the colon, brain, lung, etc. Pulmonary administration of medicines is a more appealing method as it is a noninvasive route for systemic and locally acting drugs as the pulmonary region has a wide surface area, delicate blood-alveolar barrier, and significant vascularization. A core-shell nano-particulate drug delivery system is more effective in the treatment of various pulmonary disorders. Thus, this review has discussed the potential of several types of core-shell nanoparticles in treating various diseases and synthesis methods of core-shell nanoparticles. The methods for synthesis of core-shell nanoparticles include solid phase reaction, liquid phase reaction, gas phase reaction, mechanical mixing, microwave- assisted synthesis, sono-synthesis, and non-thermal plasma technology. The basic types of core-shell nanoparticles are metallic, magnetic, polymeric, silica, upconversion, and carbon nanomaterial- based core-shell nanoparticles. With this special platform, it is possible to integrate the benefits of both core and shell materials, such as strong serum stability, effective drug loading, adjustable particle size, and immunocompatibility.

Design and development of donepezil hydrochloride loaded nanostructured lipid carriers for efficient management of Alzheimer's disease.

OBJECTIVE: The primary objective of this study was to develop nanostructured lipid carriers of donepezil hydrochloride (DNZ HCl) for effective management of Alzheimer's disease (AD). SIGNIFICANCE: Intranasal administration of DNZ NLC containing Nigella sativa (NS) oil as a liquid lipid may significantly improve nasal penetration and deliver the drug directly to the brain avoiding blood brain barrier (BBB). METHOD: High pressure homogenization was used to prepare nanostructured lipid carriers (NLCs), followed by ultrasonication. Glyceryl monostearate (GMS), Tween 80, and Poloxamer 407 were used as solid lipid, surfactant and co-surfactant respectively, whereas, Nigella sativa oil was used as a liquid lipid. RESULT: The particle size, polydispersity index and zeta potential were found to be 107.4 ± 2.64 nm, 0.25 ± 0.04 and -41.7 mV. The entrapment efficiency and drug content were found to be 70.20% and 89.05% respectively. After intranasal administration of Donepezil hydrochloride (DNZ HCl) loaded NLC's, the maximum concentrations (Cmax) of 4.597 µg/mL in brain and 2.2583 µg/mL in blood was achieved after 1 h (Tmax). CONCLUSION: The formulated DNZ HCl loaded NLCs significantly improved nasal penetration and enhanced drug distribution in brain resulting in a potentially effective intranasal drug delivery system for the effective management of Alzheimer's disease.

Nanostructured cubosomes in an in situ nasal gel system: an alternative approach for the controlled delivery of donepezil HCl to brain.

The purpose of this research was to develop cubosomal mucoadhesive in situ nasal gel to enhance the donepezil HCl delivery to the brain. Glycerol mono-oleate (GMO) and surfactant poloxamer 407 were used to prepare cubosomes. The developed formulations were characterized for particle size (PS), poly dispersity index (PDI), zeta potential (ZP), entrapment efficiency (EE), transmission electron microscopy (TEM), in vitro drug release and in vivo bio-distribution study in blood and brain tissue. Central composite design was used for the optimization purpose and the selected formulation (containing GMO 2 g and poloxamer 1.5%) was prepared in presence of gellan gum and konjac gum as gelling agent and mucoadhesive agent respectively. The optimal cubosomal dispersion and optimal cubosomal mucoadhesive in situ nasal gel were subjected to in vivo bio-distribution studies in rat model. It showed significantly higher transnasal permeation and better distribution to the brain, when compared to the drug solution. Thus, the formulated cubosomal mucoadhesive in situ gel could be considered as a promising carrier for brain targeting of CNS acting drugs through the transnasal route.

Solubility and bioavailability enhancement of poorly aqueous soluble atorvastatin: in vitro, ex vivo, and in vivo studies.

The objective of this investigation was to improve the solubility of the poorly water soluble drug atorvastatin (ATR), using solid dispersion (SD) techniques, with Neem Gum (NG) as a hydrophilic carrier. The effects of the polymer concentration and method of preparation on the solubility and dissolution rate were studied. The results showed that the solubility of ATR increases with increasing NG concentration. However, dissolution rate of ATR from its SD was dependent on the method used to prepare SD. An in vitro drug release study revealed that the solvent evaporation technique is a more convenient and effective method of preparing SD than kneading method. The SD was characterized using DSC, SEM, and XRD study. An in vivo study was performed in which the 3-hydroxy-3-methyl-glutaryl-coenzyme A (HMG CoA) reductase inhibition activity was measured. A significant reduction in HMG CoA reductase activity was observed with SD of ATR compared with the plain drug. An ex vivo absorption study was carried out using modified apparatus developed in our laboratory. The in vitro drug release and in vivo and ex vivo studies clearly demonstrated the potential of hydrophilic NG in enhancing the solubility, dissolution rate, and bioavailability of ATR.

Surface engineered nanostructured lipid carriers for efficient nose to brain delivery of ondansetron HCl using Delonix regia gum as a natural mucoadhesive polymer.

The objective of this investigation was to fabricate ondansetron hydrochloride [OND] loaded mucoadhesive nanostructured lipid carriers [NLCs] for efficient delivery to brain through nasal route. Mucoadhesive NLCs thereby sustaining drug release for longer time in nasal cavity. NLCs were prepared by high pressure homogenization [HPH] technique using glycerol monostearate [GMS]; as solid lipid, Capryol 90; as liquid lipid, soya lecithin; as surfactant and poloxamer 188; as cosurfactant. In the fabrication of NLCs, Delonix regia gum [DRG], isolated from seeds of D. regia belonging to family fabiaceae was used as a mucoadhesive polymer. The NLCs were evaluated for particle size, morphology, drug-entrapment efficiency [%EE], mucoadhesive strength, in vitro drug release, histological examination, ex vivo permeation study, in vivo biodistribution and pharmacokinetic studies in the brain/blood following intravenous [i.v.] and intranasal [i.n.] administration. Particle size, PDI, Zeta potential was observed in the range of 92.28-135nm, 0.32-0.46, and -11.5 to -36.2 respectively. Prepared NLCs achieved thermodynamic stability, control release pattern with minor histopathological changes in sheep nasal mucosa. The significantly [P<0.05] higher values for selected batch was observed, when administered by i.n. route showed higher drug targeting efficiency [506%] and direct transport percentage [97.14%] which confirms the development of promising OND-loaded NLC for efficient nose-to-brain delivery.

Graphene oxide based magnetic nanocomposites for efficient treatment of breast cancer.

The present work reports a simple one step synthesis of nanoscale graphene oxide magnetic composites (GO-IO) using ferrofluid (GO-IOF). The obtained GO-IO were compared with GO-IO obtained from in situ (GO-IOI) methods. Anastrozole (ANS) was loaded on the GO-IOI and GO-IOF via simple stirring method to form GO-IOA and GO-IOFA respectively. These GO-IO prepared by two techniques were characterized using spectroscopic techniques and vibrating sample magnetometer (VSM) analysis. Particle size and potential were measured using Malvern Zetasizer. Scanning electron microscopy (SEM) was used for studying the surface morphology of GO-IO, and in addition to this elemental analysis was also performed for confirming the presence of iron. The cell viability assay was carried out using the MCF-7 cell line. It revealed that GO-IOFA had reasonably high cytotoxicity (49.7%) compared to GO (13.1%), ANS (16.6), GO-IOI (13%), GO-IOF (13.6) and GO-IOIA (18.34%). Both, GO-IOIA and GO-IOFA showed improved cytotoxicity when compared with pure ANS. GO-IOF were found to exhibit superior magnetic activity due to higher iron content along with smaller particle size and higher loading efficiency compared to GO-IOI. The overall effect suggests that GO-IO can be utilized as efficient carriers for the loading of chemotherapeutic agents.

Novel surface modified polymer-lipid hybrid nanoparticles as intranasal carriers for ropinirole hydrochloride: in vitro, ex vivo and in vivo pharmacodynamic evaluation.

Here we report fabrication and evaluation of novel surface modified polymer-lipid hybrid nanoparticles (PLN) as robust carriers for intranasal delivery of ropinirole hydrochloride (ROPI HCl). Sustained release, avoidance of hepatic first pass metabolism, and improved therapeutic efficacy are the major objectives of this experiment. PLN were fabricated by emulsification-solvent diffusion technique and evaluated for physicochemical parameters, in vitro mucoadhesion, in vitro diffusion, ex vivo permeation, mucosal toxicity and stability studies. Box-Behnken experimental design approach has been employed to assess the influence of two independent variables, viz. surfactant (Pluronic F-68) and charge modifier (stearylamine) concentration on particle size, ζ-potential and entrapment efficiency of prepared PLN. Numerical optimization techniques were used for selecting optimized formulation sample, further confirmed by three dimensional response surface plots and regression equations. Results of ANOVA demonstrated the significance of suggested models. DSC and SEM analysis revealed the encapsulation of amorphous form of drug into PLN system, and spherical shape. PLN formulation had shown good retention with no severe signs of damage on integrity of nasal mucosa. Release pattern of drug-loaded sample was best fitted to zero order kinetic model with non-Fickian super case II diffusion mechanism. In vivo pharmacodynamic studies were executed to compare therapeutic efficacy of prepared nasal PLN formulation against marketed oral formulation of same drug. In summary, the PLN could be potentially used as safe and stable carrier for intranasal delivery of ROPI HCl, especially in treatment of Parkinson's disease.

Stimuli-sensitive layer-by-layer (LbL) self-assembly systems: targeting and biosensory applications.

Stimuli-sensitive layer-by-layer (LbL) self-assembly systems have generated much interest among researchers worldwide due to the simplicity of the process by which they are produced and their numerous applications in drug delivery. LbL self-assembly systems involve simple alternative adsorption of oppositely charged polyelectrolytes on core materials and are thus considered to be promising tools for drug delivery and biosensing. Here, we discuss the latest findings from research into LbL systems, with special emphasis on drug delivery systems. This review highlights various stimuli-responsive LbL systems and their targeting and biosensory applications. For the convenience of readers, these stimuli-responsive LbL systems are classified as exogenous stimuli-responsive LbL systems and endogenous stimuli-responsive LbL systems.

Novel surface modified solid lipid nanoparticles as intranasal carriers for ropinirole hydrochloride: application of factorial design approach.

Present investigation deals with intranasal delivery of ropinirole hydrochloride (ROPI HCl), loaded in solid lipid nanoparticles (SLNs). Prime objectives of this experiment are avoidance of hepatic first pass metabolism and to improve therapeutic efficacy in the treatment of Parkinson's disease. SLNs were fabricated by emulsification-solvent diffusion technique. A 3(2)-factorial design approach has been employed to assess the influence of two independent variables, namely Pluronic F-68 and stearylamine concentration on particle size, ζ-potential and entrapment efficiency of prepared SLNs. Prepared samples were further evaluated for in vitro drug diffusion, ex vivo drug permeation, histopathological and stability studies. Differential scanning calorimetry analysis revealed the encapsulation of amorphous form of drug into lipid matrix, while scanning electron microscopy studies indicated the spherical shape. Fabricated SLNs had shown no severe signs of damage on integrity of nasal mucosa. Release pattern of prepared drug-loaded sample was best fitted to zero-order kinetic model with non-Fickian super case II diffusion mechanism. In vivo pharmacodynamic studies were carried out to compare therapeutic efficacy of prepared nasal formulation against marketed oral formulation. Results of analysis of variance demonstrated the significance of suggested model. Three-dimensional response surface plots and regression equations confirmed the corresponding influence of selected independent variables on measured responses. Our findings suggested the feasibility of investigated system for intranasal administration.

Solid lipid nanoparticles of ondansetron HCl for intranasal delivery: development, optimization and evaluation.

The present investigation deals with the development and statistical optimization of solid lipid nanoparticles (SLNs) of ondansetron HCl (OND) for intranasal (i.n.) delivery. SLNs were prepared using the solvent diffusion technique and a 2(3) factorial design. The concentrations of lipid, surfactant and cosurfactant were independent variables in this design, whereas, particle size and entrapment efficiency (EE) were dependent variables. The particle size of the SLNs was found to be 320-498 nm, and the EE was between 32.89 and 56.56 %. The influence of the lipid, surfactant and cosurfactant on the particle size and EE was studied. A histological study revealed no adverse response of SLNs on sheep nasal mucosa. Transmission electron microscopic analysis showed spherical shape particles. Differential scanning calorimetry and X-ray diffraction studies indicated that the drug was completely encapsulated in a lipid matrix. In vitro drug release studies carried out in phosphate buffer (pH 6.6) indicated that the drug transport was of Fickian type. Gamma scintigraphic imaging in rabbits after i.n. administration showed rapid localization of the drug in the brain. Hence, OND SLNs is a promising nasal delivery system for rapid and direct nose-to-brain delivery.

Formulation, optimization and evaluation of spray-dried mucoadhesive microspheres as intranasal carriers for Valsartan.

This investigation deals with the intranasal delivery of Valsartan, encapsulated in HPMC-based spray-dried mucoadhesive microspheres, with an aim to provide rapid absorption and quick onset of action for treating hypertension. A 2³-factorial design has been employed for the assessment of influence of three independent variables, namely inlet temperature, feed-flow rate and drug-polymer ratio on production yield, particle size and in vitro drug diffusion of the prepared microspheres. Microspheres were evaluated for particle size, entrapment efficiency, swelling property, in vitro mucoadhesion, in vitro drug diffusion, ex vivo drug permeation, histopathological examination and stability studies. The results of differential scanning calorimetry, X-ray diffraction and scanning electron microscopy revealed molecular dispersion of Valsartan into microspheres with spherical shape and smooth surface. Optimized formulation indicated good mucoadhesion with no severe sign of damage on nasal mucosa. Results of the non-invasive animal studies in dexamethasone-induced hypertensive rat model suggested the suitability of investigated drug delivery system for intranasal administration.

Design and development of nasal mucoadhesive microspheres containing tramadol HCl for CNS targeting.

In the present study, tramadol HCl microspheres were designed in order to accomplish rapid delivery of drug to the brain. For this purpose, lower viscosity grade HPMC (E15) was chosen as mucoadhesive polymer and used at different drug/polymer ratios in the microspheres formulations. The spray-dried microspheres were evaluated with respect to the production yield, incorporation efficiency, particle size, mucoadhesive property, in vitro drug release, histopathological study, and radio imaging study in rabbits. DSC and XRD study showed molecular dispersion and conversion of the drug into amorphous form. Size and surface morphology of microspheres was analyzed by SEM and found to be spherical in shape with smooth surface. It was found that the particle size, swelling ability, and incorporation efficiency of microspheres increase with increasing drug-to-polymer ratio. Microspheres show adequate mucoadhesion and do not have any destructive effect on nasal mucosa. In vitro drug release of optimized formulation was found to be 94% after 90 min. The radio imaging study indicated localization of drug in the brain. Hence, tramadol HCl microspheres based on a HPMC E15 may be a promising nasal delivery system for CNS targeting.

Development and evaluation of a pulsatile drug delivery system using novel polymer. Part II: in vivo radio imaging study.

The objective of the present study was to correlate the results of the in vitro release of a previously reported pulsatile drug delivery system with the in vivo radio imaging study. The formulated drug delivery system containing pellets of barium sulphate was administered to rabbits after overnight fast. Formulated dosage form, previously evaluated for in vitro drug release study, showed drug release after 6-10 h of lag time depending on the hardness as well as the thickness of the plug. Radio imaging study also showed that the plug in the capsule drug delivery system remains intact for the period of 6 h. Thus, the formulated drug delivery system is capable of delaying release in vitro as well as in rabbits for 6 hours.

Formulation and evaluation of nasal mucoadhesive microspheres of sumatriptan succinate.

The purpose of present research work was to develop mucoadhesive microspheres for nasal delivery with the aim to avoid hepatic first-pass metabolism, improve therapeutic efficacy and enhance residence time. For the treatment of migraine, hydroxypropyl methylcellulose (HPMC) K4M and K15M based microspheres containing sumatriptan succinate (SS) were prepared by spray-drying technique. The microspheres were evaluated with respect to the yield, particle size, incorporation efficiency, swelling property, in vitro mucoadhesion, in vitro drug release, histological study and stability. Microspheres were characterized by differential scanning calorimetry, scanning electron microscopy and X-ray diffraction study. It was found that the particle size, swelling ability and incorporation efficiency of microspheres increases with increasing drug-to-polymer ratio. HPMC-based microspheres show adequate mucoadhesion and do not have any destructive effect on nasal mucosa. On the basis of these results, SS microspheres based on HPMC may be considered as a promising nasal delivery system.

Development and evaluation of pulsatile drug delivery system using novel polymer.

The aim of the present investigation was to develop a pulsatile drug delivery system based on an insoluble capsule body filled with theophylline microspheres and sealed with a swellable novel polymer plug isolated from the endosperm of seeds of higher plant Delonix regia family-Fabaceae. Theophylline microspheres were prepared by solvent evaporation method using Eudragit S 100. The swellable plugs of varying thickness and hardness were prepared by direct compression, which were then placed in the capsule opening. The drug delivery system was designed to deliver the drug at such a time when it was needed most to offer convenience to the chronic patients of asthma. Formulated dosage forms were evaluated for an in vitro drug release study, which showed that the release might be consistent with a release time expected to deliver the drug to the colon depending on the thickness and hardness of the hydrogel plug. Thus, thickness and hardness of the novel polymeric plug plays an important role in controlling the drug release from the formulated drug delivery system.