Varsha Pokharkar

Porphyran capped gold nanoparticles as a novel carrier for delivery of anticancer drug: In vitro cytotoxicity study

In the present study, we have explored porphyran as a reducing agent for one pot size controlled green synthesis of gold nanoparticles (AuNps) and further investigated its application as a carrier for the delivery of an anticancer drug. The prepared AuNps showed surface plasmon resonance centered at 520 nm with average particle size of 13±5 nm. FTIR spectra suggested that the sulfate moiety is mainly responsible for reduction of chloroauric acid. The capping of the AuNps with porphyran was evident from the negative zeta potential value responsible for the electrostatic stability. Thus, porphyran acts as reducing as well as capping agent. These AuNps are highly stable in a wide range of pH and electrolyte concentration. Porphyran capped AuNps exhibited enhanced cytotoxicity on human glioma cell line (LN-229) as compared to native porphyran. Consequently, these AuNps have been utilized as a carrier for delivery of the anticancer drug doxorubicin hydrochloride (DOX). Spectroscopic examination revealed that DOX conjugated onto AuNps via hydrogen bonding. The release of DOX from DOX loaded AuNps was found to be sixfold higher in acetate buffer (pH 4.5) as compared to physiological buffer (pH 7.4). Further, the DOX loaded AuNps demonstrated higher cytotoxicity on LN-229 cell line as compared with an equal dose of native DOX solution. This established the potential of these AuNps as a carrier for anticancer drug delivery.

Biocompatible gellan gum-reduced gold nanoparticles: cellular uptake and subacute oral toxicity studies.

Currently gold nanoparticles are being explored for drug delivery and other biomedical applications; therefore it is necessary to study the fate of such nanoparticles inside the body. The objective of the present study was to investigate the cellular uptake and toxicity of the gold nanoparticles synthesized using a microbial polysaccharide, gellan gum, as a capping and reducing agent. The cellular uptake of gold nanoparticles was studied on mouse embryonic fibroblast cells, NIH3T3 and human glioma cell line, LN‐229. The cellular uptake study indicated that the gellan gum‐reduced gold nanoparticles were located in cancer cells (LN‐229) while no uptake was observed in normal mouse embryonic fibroblast cells (NIH3T3). The toxicity of the gold nanoparticles was evaluated by carrying out subacute 28 day oral toxicity studies in rats. Subacute administration of gum‐reduced gold nanoparticles to the rats did not show any hematological or biochemical abnormalities. The weight and normal architecture of various organs did not change compared with control. The current findings, while establishing the specific uptake of nanoparticles into cancerous cells, also demonstrates that the gellan gum‐reduced gold nanoparticles are devoid of toxicity in animals following oral administration. Copyright

Montelukast-loaded nanostructured lipid carriers: part I oral bioavailability improvement.

The purpose of the study was to formulate montelukast-loaded nanostructured lipid carrier (MNLC) to improve its systemic bioavailability, avoid hepatic metabolism and reduce hepatic cellular toxicity due to metabolites. MNLC was prepared using melt-emulsification-homogenization method. Preformulation study was carried out to evaluate drug-excipient compatibility. MNLCs were prepared using spatially different solid and liquid lipid triglycerides. CAE (DL-Pyrrolidonecarboxylic acid salt of L-cocyl arginine ethyl ester), a cationic, biodegradable, biocompatible surfactant was used to stabilize the system. MNLCs were characterized by FTIR, XRPD and DSC to evaluate physicochemical properties. MNLCs having a particle size of 181.4 ± 6.5 nm with encapsulation efficiency of 96.13 ± 0.98% were prepared. FTIR findings demonstrated no interaction between the drug and excipients of the formulation which could lead to asymmetric vibrations. DSC and XRPD study confirmed stable amorphous form of the montelukast in lipid matrix. In vitro release study revealed sustained release over a period of 24 h. In vivo single dose oral pharmacokinetic study demonstrated 143-fold improvement in bioavailability as compared to montelukast-aqueous solution. Thus, the result of this study implies that developed MNLC formulation be suitable to sustain the drug release with improvement in the bioavailability.

Ternary complexation of carvedilol, β-cyclodextrin and citric acid for mouth-dissolving tablet formulation

The objective of the present investigation was to study the effect of polyethylene glycol 4000 (PEG 4000) on in vitro dissolution of gliclazide from solid dispersions. Initial studies were carried out using physical mixtures of the drug and carrier. Solid dispersions were prepared by the melting or fusion method.Phase and saturation solubility study, in vitro dissolution of pure drug, physical mixtures and solid dispersions were carried out. PEG was found to be effective in increasing the dissolution of gliclazide in solid dispersions when compared to pure drug. FT-IR spectroscopy, differential scanning calorimetry and X-ray diffractometry studies were carried out in order to characterize the drug in the physical mixtures and solid dispersions. Dissolution enhancement was attributed to decreased crystallinity of the drug and to the wetting and solubilizing effect of the carrier from the solid dispersions of gliclazide. In conclusion, dissolution of gliclazide can be enhanced by the use of hydrophilic carrier.Ternary complexation of carvedilol, β-cyclodextrin and citric acid for mouth-dissolving tablet formulation The purpose of this study was to improve the solubility and dissolution rate of carvedilol by forming a ternary complex with β-cyclodextrin and citric acid and to formulate its mouth-dissolving tablets. The rationale for preparing mouth-dissolving tablet of carvedilol was to make the drug available in a soluble form in the mouth, which would facilitate its absorption from the buccal cavity. This would help to overcome its first-pass metabolism and thereby improve bioavailability. Phase solubility studies revealed the ability of β-cyclodextrin and citric acid to complex with carvedilol and significantly increase its solubility. Ternary complexation of carvedilol was carried out with β-cyclodextrin and citric acid by physical mixing, kneading and spray drying methods and the prepared complexes were characterized by Fourier transform infra red spectroscopy, differential scanning calorimetry, powder X-ray diffractometry, scanning electron microscopy and complexation efficiency. The complex obtained by the spray drying method resulted in highest complexation efficiency and a 110-fold increase in the solubility of carvedilol. The mouth-dissolving tablets formulated using the spray dried complex with suitable excipients showed 100 % dissolution within five minutes. Accelerated stability studies of mouth-dissolving tablets carried out as per ICH guidelines revealed that the tablets were stable. Ternarna kompleksacija karvedilola, β-ciklodekstrina i limunske kiseline za razvoj tableta topljivih u ustima Cilj rada bio je poboljšati topljivost i oslobađanje karvedilola stvaranjem ternarnog kompleksa s β-ciklodekstrinom i limunskom kiselinom i razvoj tableta topljivih u ustima. Takve tablete su napravljene s ciljem da se poboljša apsorpcija iz usta i izbjegne efekt prvog prolaza, što bi moglo imati za posljedicu poboljšanu bioraspoloživost. Testovi topljivosti pokazali su da β-ciklodekstrin i limunska kiselina stvaraju kompleks s karvedilolom i značajno povećavaju njegovu topljivost. Ternarna kompleksacija karvedilola s β-ciklodekstrinom i limunskom kiselinom provedena je fizičkim miješanjem, gnječenjem i sušenjem raspršivanjem. Pripravljeni kompleksi karakterizirani su infracrvenom spektroskopijom, diferencijalnom pretražnom kalorimetrijom, rendgenskom difraktometrijom praha, pretražnom elektronskom mikroskopijom i testovima učinkovitosti kompleksacije. Metodom sušenja raspršivanjem topljivost karvenidola povećala se 110 puta, a kompleksacija je bila najučinkovitija. Tablete pripravljene iz tog kompleksa i odgovarajućih pomoćnih tvari potpuno su se otopile unutar pet minuta. Testovi ubrzanog starenja provedeni prema ICH smjernicama pokazali su da su tablete stabilne.

Quillaja saponaria extract as mucosal adjuvant with chitosan functionalized gold nanoparticles for mucosal vaccine delivery: Stability and immunoefficiency studies

Carrier mediated delivery of vaccines along with adjuvants can possibly address the issue related to oral vaccines like inadequate immune potentiation. In this study, chitosan functionalized gold nanoparticles (CsAuNPs) were used as a carrier for the model antigen tetanus toxoid (TT) along with immunostimulant Quillaja saponaria extract (QS). Physicochemical properties (size, zeta potential, pH value) of formulation were investigated as stability indicating parameters. The synthesized CsAuNPs were spherical in shape, around 40 nm in size, positively charged (around +35 mV) and had TT and QS payload of 65% and 0.01%, respectively. Formulation parameters did not alter the secondary structure of TT, as determined by FTIR, fluorescence and CD spectroscopy. Antigen specificity, determined by an ELISA, was also not compromised. The CsAuNPs conferred protection to TT against gastric hydrolysis as studied in vitro. TT-QS-CsAuNPs induced up to 28-fold immune responses compared to control formulations (TT, TT-QS) after oral administration of formulations in BALB/c mice. The immune responses were quantified by measuring the TT-specific IgG and IgA titers using ELISA. Findings herein demonstrate that co-delivery of TT and QS with functionalized CsAuNPs promotes better systemic and local immune responses and hence can be considered as a sound approach for oral vaccine delivery.

Enhanced Mucosal Immune Responses Against Tetanus Toxoid Using Novel Delivery System Comprised of Chitosan-Functionalized Gold Nanoparticles and Botanical Adjuvant: Characterization, Immunogenicity, and Stability Assessment

Approaches based on combined use of delivery systems and adjuvants are being favored to maximize efficient mucosal delivery of antigens. Here, we describe a novel delivery system comprised of chitosan-functionalized gold nanoparticles (CsAuNPs) and saponin-containing botanical adjuvant; Asparagus racemosus extract (ARE) for oral delivery of tetanus toxoid (TT). A significant increase in TT-specific IgG (34.53-fold) and IgA (43.75-fold) was observed when TT-CsAuNPs were formulated with ARE (TT-ARE-CsAuNPs). The local IgA immune responses for TT also showed a significant increase (106.5-fold in intestine washes and 99.74-fold in feces) with ARE-based formulations as compared with plain TT group. No effect of ARE was observed on size, charge, and loading properties of CsAuNPs. Additionally, no effect of ARE and CsAuNPs was observed on antigenicity and secondary structure of TT as determined by fluorescence, circular dichroism, and Fourier transform infrared spectroscopy. The stability studies demonstrated excellent stability profile of formulation at recommended storage conditions. The study establishes the possible role of immunomodulatory adjuvants in particulate delivery systems for mucosal delivery of vaccines.

Montelukast-loaded nanostructured lipid carriers: Part II Pulmonary drug delivery and in vitro–in vivo aerosol performance

The aim of the present study was to establish the potential of montelukast loaded nanostructured lipid carrier (MNLC) for pulmonary application. The formulated nanoparticles were evaluated in vitro for aerodynamic characterization and in vivo for pulmokinetics in Wistar rats. The in vitro cytotoxicity was performed on A549 cell line and compared with montelukast-aqueous solution. MNLC was prepared with montelukast (0.2%), Precirol ATO5 (solid lipid), and Capryol-90 (liquid lipid) in the ratio of 7:3 using melt-emulsification-homogenization method. dl-Pyrrolidonecarboxylic acid salt of l-cocyl arginine ethyl ester (CAE), a biodegradable surfactant in the concentration of 1% was used to stabilize the nanoparticles. The particle size and encapsulation efficiency (EE) were 184.6 ± 2.7 nm and >95%, respectively. MNLC-Dry powder for inhalation (DPI) was prepared by lyophilization using 3% mannitol as cryoprotectant and carrier. MNLC-DPI was evaluated for flow, crystallographic and thermal properties. Mass median diameters (MMD) and density for MNLC-DPI were found to be 15.1 ± 1.4 μm and 0.051 ± 0.002 g/cc, respectively. In vitro aerosol performance study indicated more than 95% of the emitted dose (ED) at both the flow rates studied. Mass median aerodynamic diameters (MMAD) of 3.24 ± 0.67 μm with 69.98 ± 1.9% fine particle fraction (FPF) were obtained at 30 L/min flow rate, whereas at 60 L/min MMAD and FPF were found to be 2.83 ± 0.46 μm and 90.22 ± 2.6%, respectively. In vitro cytotoxicity study on A549 cells revealed higher safety of MNLC than pure drug. The pulmonary pharmacokinetic study demonstrated improved bioavailability, longer residence of drug in the lung and targeting factor of 11.76 for MNLC as compared to montelukast-aqueous solution. Thus, the results of the study demonstrated the potential of montelukast lipidic nanoparticulate formulation to improve the efficacy with reduced toxicity leading to better performance of drug as MNLC-DPI for inhalation use.

Quality by design approach to understand the process of optimization of iloperidone nanostructured lipid carriers for oral bioavailability enhancement

Abstract Context: The current work was carried out by exploring the principles of quality by design approach to develop an optimized nanostructured lipid carrier (NLC) formulation of poorly water soluble active iloperidone (ILO) through systematic statistical study. The potential of NLC for improving the oral bioavailability of ILO was also evaluated. Objective: To understand the effect of formulation variables (critical parameters) on the performance characteristics (critical quality attributes) of NLC. Materials and methods: A 3-factor, 3-level Box–Behnken factorial design was explored to predict the responses such as particle size (Y1) and % entrapment efficiency (EE) (Y2) when concentration of lipid (X1), concentration of drug (X2) and concentration of surfactant (X3) were selected as independent variables. Results and discussion: Particle size analysis revealed that all the batches were within the nanometer range. The % EE was found to be between 63% and 96%. In-vitro release study demonstrated sustained release profile of ILO NLC. The pharmacokinetic study in Wistar rats over the period of 24 h demonstrated 8.30-fold increase in oral bioavailability of ILO NLC as compared with ILO pure drug suspension. Conclusion: The NLC formulation remarkably improved the oral bioavailability of ILO and demonstrated a promising perspective for oral delivery of poorly water-soluble drugs.

Engineering of a hybrid polymer–lipid nanocarrier for the nasal delivery of tenofovir disoproxil fumarate: Physicochemical, molecular, microstructural, and stability evaluation

PURPOSE To engineer a hybrid nanocarrier system based on lipid and polymer for the nasal delivery of tenofovir disoproxil fumarate (TDF), and further to investigate its physicochemical, molecular, microstructural, and stability aspects. METHODS Nanoparticles were prepared by melt emulsification-probe sonication technique. A 3(2) factorial design was used to identify key formulation variables influencing the characteristics of drug-loaded carrier. FT-IR, mass spectroscopy (MS) and (1)H NMR was used to probe molecular interactions among the components of the system, while the surface morphology was imagined through electron microscopy (TEM and SEM). Thermal analysis and powder X-ray diffraction (PXRD) was used to explore melting and crystallization behavior of drug and the carrier lipid. PLN-9 GEL was studied for its rheology, drug release, ex-vivo permeation, histopathology, and stability. RESULTS Batch PLN-9 had size of 239 nm, drug encapsulation of 87.14% and revealed spherical morphology. MS, FT-IR and (1)H NMR established compatibility between the drug (TDF) and the carrier lipid (Lauric acid), while, a strong H-bonding was identified between the amino (-NH2) group of drug and the carboxyl (-COOH) group of pemulen polymer. Thermal analysis confirmed an amorphous TDF within the carrier matrix. PXRD analysis indicated substantial change in the molecular packing and subcell structure of carrier lipid during the PLN processing. PLN-9 GEL had shear thinning rheology, an anomalous type (n>0.5) of drug release and possessed potential to transport TDF across the nasal mucosa with an average flux of 135.36 μg/cm(2)/h. CONCLUSION The designed carrier can encapsulate TDF and accentuates its transnasal flux, thus could be used as a carrier for an effective nasal delivery of TDF.

Bicalutamide nanocrystals with improved oral bioavailability: in vitro and in vivo evaluation.

Context: Bicalutamide (BCT) is an antiandrogenic compound belonging to Biopharmaceutics Classification System (BCS) class II drug. Thus it has limited aqueous solubility and hence limited oral bioavailability. Objective: The purpose of the present investigation was to obtain stable nanocrystals of BCT with improved kinetic solubility, dissolution and pharmacokinetic profiling. Materials and methods: BCT nanocrystals were prepared by antisolvent precipitation method using Soluplus, a novel amphiphilic polymer. Nanocrystals were characterized for particle size, powder X-ray diffraction analysis (PXRD), in vitro dissolution, in vivo pharmacokinetic profile and stability. Results and discussion: The obtained nanocrystals had particle size of 168 nm and were spherical in shape. The nanocrystals exhibited fivefold increase in kinetic solubility as compared to pure drug and 85% dissolution in 60 min. PXRD studies established the retention of crystalline polymorphic form II. The in vivo pharmacokinetic study demonstrated that the Cmax and AUC of nanosized BCT were about 3.5 times higher as compared to pure drug. Conclusion: Nanosizing of BCT significantly improved the pharmacokinetic profile of the drug administered to rats. Prepared nanocrystals were found to be stable over the entire stability period. Thus the use of amphiphilic polymer like Soluplus singularly helped in efficient size reduction and stabilization of the drug.