Praful B. Deshpande

Silymarin liposomes improves oral bioavailability of silybin besides targeting hepatocytes, and immune cells

BACKGROUND Silymarin, a hepatoprotective agent, has poor oral bioavailability. However, the current dosage form of the drug does not target the liver and inflammatory cells selectively. The aim of the present study was to develop lecithin-based carrier system of silymarin by incorporating phytosomal-liposomal approach to increase its oral bioavailability and to make it target-specific to the liver for enhanced hepatoprotection. METHODS The formulation was prepared by film hydration method. Release of drug was assessed at pH 1.2 and 7.4. Formulation was assessed for in vitro hepatoprotection on Chang liver cells, lipopolysaccharide-induced reactive oxygen species (ROS) production by RAW 267.4 (murine macrophages), in vivo efficacy against paracetamol-induced hepatotoxicity and pharmacokinetic study by oral route in Wistar rat. RESULTS The formulation showed maximum entrapment (55%) for a lecithin-cholesterol ratio of 6:1. Comparative release profile of formulation was better than silymarin at pH 1.2 and pH 7.4. In vitro studies showed a better hepatoprotection efficacy for formulation (one and half times) and better prevention of ROS production (ten times) compared to silymarin. In in vivo model, paracetamol showed significant hepatotoxicity in Wistar rats assessed through LFT, antioxidant markers and inflammatory markers. The formulation was found more efficacious than silymarin suspension in protecting the liver against paracetamol toxicity and the associated inflammatory conditions. The liposomal formulation yielded a three and half fold higher bioavailability of silymarin as compared with silymarin suspension. CONCLUSIONS Incorporating the phytosomal form of silymarin in liposomal carrier system increased the oral bioavailability and showed better hepatoprotection and better anti-inflammatory effects compared with silymarin suspension.

Methotrexate-loaded Biodegradable Nanoparticles:Preparation, Characterization and Evaluation of its Cytotoxic Potential Against U-343 MGa Human Neuronal Glioblastoma Cells

Nanoparticles represent one of the attractive alternatives in the effective treatment of cancer chemotherapy. In the present work, formulation and development of a novel methotrexate (MTX)-loaded biodegradable nanoparticles using poly(D,L-lactide-co-glycolide) (PLGA) was carried out. The prepared nanoparticles were evaluated for physicochemical properties such as particle size, zeta potential, release studies, etc and also evaluated for its in vitro cytotoxic potential against U-343 MGa human neuronal glioblastoma cells. Particle size of optimized formulation was < 200 nm. There was a considerable decrease in cell viability and enhancement in cytotoxic activity of MTX-loaded nanoparticles compared to MTX alone when tested against U-343 MGa human neuronal glioblastoma cells.

Transdermal Delivery of Lercanidipine Hydrochloride: Effect of Chemical Enhancers and Ultrasound

The effects of permeation enhancers and sonophoresis on the transdermal permeation of lercanidipine hydrochloride (LRDP) across mouse skin were investigated. Parameters including drug solubility, partition coefficient, drug degradation and drug permeation in skin were determined. Tween-20, dimethyl formamide, propylene glycol, poly ethylene glycol (5% v/v) and different concentration of ethanol were used for permeation enhancement. Low frequency ultrasound was also applied in the presence and absence of permeation enhancers to assess its effect on augmenting the permeation of drug. All the permeation enhancers, except propylene glycol, increased the transdermal permeation of LRDP. Sonophoresis significantly increased the cumulative amount of LRDP permeating through the skin in comparison to passive diffusion. A synergistic effect was noted when sonophoresis was applied in presence of permeation enhancers. The results suggest that the formulation of LRDP with an appropriate penetration enhancer may be useful in the development of a therapeutic system to deliver LRDP across the skin for a prolonged period (i.e., 24 h). The application of ultrasound in association with permeation enhancers could further serve as non-oral and non-invasive drug delivery modality for the immediate therapeutic effect.

PEGylated liposomes of anastrozole for long-term treatment of breast cancer: in vitro and in vivo evaluation.

Abstract The aim of present study was to develop conventional and PEGylated (long circulating), liposomes containing anastrozole (ANS) for effective treatment of breast cancer. ANS is a third-generation non-steroidal aromatase inhibitor of the triazole class used for the treatment of advanced and late-stage breast cancer in post-menopausal women. Under such disease conditions the median duration of therapy should be prolonged until tumor regression ends (>31 months). Liposomes were prepared by the thin film hydration method by using ANS and various lipids such as soyaphosphatidyl choline, cholesterol and methoxy polyethylene glycol distearoyl ethanolamine in different concentration ratios and evaluated for physical characteristics, in vitro drug release and stability. Optimized formulations of liposome were studied for in vitro cytotoxic activity against the BT-549 and MCF-7 cell lines and in vivo behavior in Wistar rats. Preformulation studies, both Fourier transform infrared study and differential scanning calorimetry analysis showed no interaction between the drug and the excipients used in the formulations. The optimized formulations AL-07 and AL-09 liposomes showed encapsulation efficiencies in the range 65.12 ± 1.05% to 69.85 ± 3.2% with desired mean particle size distribution of 101.1 ± 5.9 and 120.2 ± 2.8 nm and zeta potentials of −43.7 ± 4.7 and −62.9 ± 3.5 mV. All the optimized formulations followed Higuchi-matrix release kinetics and when plotted in accordance with the Korsemeyer–Peppas method, the n-value 0.5 < n < 1.0 suggests an anomalous (non-Fickian) transport. Likewise, the PEGylated liposomes showed greater tumor growth inhibition on BT-549 and MCF-7 cell lines from in vitro cytotoxicity studies (p < 0.05). Pharmacokinetic study of conventional and PEGylated liposomes in Wistar rats demonstrated a 3.33- and 20.28-fold increase in AUC(0–∞) values when compared to pure drug (p < 0.001). Among the formulations, PEGylated liposomes showed encouraging results by way of their long circulation and sustained delivery properties for effective treatment of breast cancer.

Role of components in the formation of self-microemulsifying drug delivery systems

Pharmaceutical research is focused in designing novel drug delivery systems to improve the bioavailability of poorly water soluble drugs. Self-microemulsifying drug delivery systems, one among the lipid-based dosage forms were proven to be promising in improving the oral bioavailability of such drugs by enhancing solubility, permeability and avoiding first-pass metabolism via enhanced lymphatic transport. Further, they have been successful in avoiding both inter and intra individual variations as well as the dose disproportionality. Aqueous insoluble drugs, in general, show greater solubility in lipid based excipients, and hence they are formulated as lipid based drug delivery systems. The extent of solubility of a hydrophobic drug in lipid excipients i.e. oil, surfactant and co-surfactant (components of self-microemulsifying drug delivery systems) greatly affects the drug loading and in producing stable self-microemulsifying drug delivery systems. The present review highlighted the influence of physicochemical factors and structural features of the hydrophobic drug on its solubility in lipid excipients and an attempt was made to explore the role of each component of self-microemulsifying drug delivery systems in the formation of stable microemulsion upon dilution.

Nanomedicine of anastrozole for breast cancer: Physicochemical evaluation, in vitro cytotoxicity on BT-549 and MCF-7 cell lines and preclinical study on rat model

AIM Formulation and evaluation of anastrozole, an anti-cancer drug loaded in different biodegradable polymeric nanoparticles. MATERIALS AND METHODS Different carrier systems such as poly(lactide-co-glycolide) (PLGA 50:50), poly(lactic-acid) (PLA) and poly(ε-caprolactone) (PCL) are used to prepare nanoparticles by simple emulsion technique. The surfactants polyvinyl alcohol and sodium deoxycholate were studied for their use as stabilizing agents at varying concentrations. The formulations were studied for their particle size, zeta potential, entrapment efficiency and solid state characteristics, and also were tested for their in vitro cytotoxicity and in vivo behavior in rats. KEY FINDINGS The entrapment ranged from 35 to 85%, depending on the drug-polymer ratio used. Particle size ranged from 100 to 350nm with optimal zeta potential. Accordingly, discrete spherical nanoparticles with smooth surface were obtained as evidence from Field Emission Scanning Electron Microscopy (FESEM) study. The solid state characteristics revealed dispersion of drug at the molecular level in the polymeric matrix of nanoparticles. A non-Fickian transport with initial burst release followed by slow release was observed with nanoparticles. The remarkable decrease in cell viability at various time points was observed for PLGA nanoparticles compared to other polymer matrices. The AUC(0→∞) of PLGA, PLA and PCL nanoparticles were found to be 4.77, 19.31 and 19.81 fold higher than (p<0.05) anastrozole in solution, respectively. Also, pharmacokinetics study revealed the long time circulation of anastrozole loaded polymeric nanoparticles. SIGNIFICANCE The results suggest that developed nanoparticles could be used successfully for effective management of breast cancer chemotherapy.

Novel liquid chromatographic method for simultaneous estimation of pioglitazone and glimepiride in rat plasma by solid phase extraction: application to preclinical pharmacokinetic studies.

The need for a reliable bioanalytical method is of primary importance during preclinical studies. The aim of the present study was simultaneous determination of pioglitazone (CAS 111025-46-8) (PIO) and glimepiride (CAS 93479-97-1) (GLM) in plasma of rats. A high-performance liquid chromatographic method has been developed and validated using C18 column and UV detector. A mobile phase composed of acetonitrile and ammonium acetate buffer pH 4.5 in the ratio of 55:45%. The plasma samples clean-up was carried out using solid phase cartridges. The method was in the linear range of 50-8000 ng/mL for PIO and 50-2000 ng/mL for GLM. The coefficient of regression was found to be > or = 0.99. Precision and accuracy were within the acceptable limits, as indicated by relative standard deviation varying from 1.5 to 6.1% for PIO and 3.1 to 7.0% for GLM whereas the accuracy ranged from 97.0 to 106.4% for PIO and 96.5 to 106.4% for GLM. The mean extraction recovery was found to be 90.2 +/- 4.5, 76.8 +/- 2.8 and 85.2 +/- 5.2% for PIO, GLM and internal standard, respectively. Moreover, PIO and GLM were stable in plasma, up to 30 days of storage at -70 degrees C and after being subjected to bench top, auto-sampler, and three freeze-thaw cycles. The developed method was applied for preclinical pharmacokinetic studies.

A novel nanoproliposomes of lercanidipine: Development, in vitro and preclinical studies to support its effectiveness in hypertension therapy

AIM The aim of the present study was to develop nanoproliposomes of lercanidipine, in order to overcome its poor biopharmaceutical properties and to improve its therapeutic efficacy in treating hypertension. MAIN METHODS The nanoproliposomes were prepared using a modified thin-film hydration method, and the formula was optimized by varying the ratio of lipids and the types of cryoprotectants. This optimized formulation was characterized in terms of its particle size, solid-state, drug release, in-situ absorption, in-vivo pharmacokinetics, and in-vivo anti-hypertensive activity in DOCA-salt induced hypertensive rats. Finally, a PK-PD correlation was established in order to understand the clinical implications of the developed novel nanoproliposomes. KEY FINDINGS The nanoproliposomes showed a particle size of 174.7nm and an entrapment efficiency of 85.4%. The in-vitro release displayed initial rapid release (19.33%) followed by a sustained release profile, releasing 88.37% of the encapsulated drug. The in-situ studies showed a significant increase in absorption rate across the rat intestinal membrane. The pharmacokinetics of this novel form indicated a 2.75-fold increase in the absolute bioavailability as compared to pure lercanidipine. In addition, the nanoproliposomes were found to be efficient in treating hypertension in DOCA-salt induced hypertensive rats. The PK-PD correlation demonstrated no time lag between effect and exposure, indicating that a direct PK-PD relationship can be expected in the clinic. SIGNIFICANCE These findings suggest that nanoproliposomes are promising carriers in improving the oral bioavailability and bioactivity of lercanidipine, and can be an effective therapy in the management of hypertension.

Gastroretentive Pulsatile Release Tablets of Lercanidipine HCl: Development, Statistical Optimization, and In Vitro and In Vivo Evaluation

The present study was aimed at the development of gastroretentive floating pulsatile release tablets (FPRTs) of lercanidipine HCl to enhance the bioavailability and treat early morning surge in blood pressure. Immediate release core tablets containing lercanidipine HCl were prepared and optimized core tablets were compression-coated using buoyant layer containing polyethylene oxide (PEO) WSR coagulant, sodium bicarbonate, and directly compressible lactose. FPRTs were evaluated for various in vitro physicochemical parameters, drug-excipient compatibility, buoyancy, swelling, and release studies. The optimized FPRTs were tested in vivo in New Zealand white rabbits for buoyancy and pharmacokinetics. DoE optimization of data revealed FPRTs containing PEO (20% w/w) with coat weight 480 mg were promising systems exhibiting good floating behavior and lag time in drug release. Abdominal X-ray imaging of rabbits after oral administration of the tablets, confirmed the floating behavior and lag time. A quadratic model was suggested for release at 7th and 12th h and a linear model was suggested for release lag time. The FPRT formulation improved pharmacokinetic parameters compared to immediate release tablet formulation in terms of extent of absorption in rabbits. As the formulation showed delay in drug release both in vitro and in vivo, nighttime administration could be beneficial to reduce the cardiovascular complications due to early morning surge in blood pressure.