, S. TAMIZHARASI, T. SIVAKUMAR Nandha College of Pharmacy and Research Institute, Erode 630052, Tamilnadu, IndiaEmail: sumoraji@gmail.comObjective: The objective of this study was to formulate and evaluate the poorly soluble drug, naringenin (NAR) into nanosuspension to increase the solubility and enhance the dissolution rate and then improve its bioavailability.Methods: Nanosuspenion of naringenin (NARNS) was prepared using high-pressure homogenization method using Soya lecithin, Polaxamer-407, Polaxamer-188, Hydroxypropyl methyl cellulose (HPMC) and Tween-80. Ten formulations were prepared to show the effect of stabilizer and its ratio. D-α-Tocopheryl polyethene glycol succinate 1000 (TPGS) was added as a co-stabilizer. All these formulations were evaluated for their particle size, PDI, zeta potential, FT-IR study, drug content, saturation solubility studies, entrapment efficiency, in vitro permeability and in vitro drug release. The formulation was further evaluated for scanning electron microscope (SEM), differential scanning calorimetry (DSC) and Powder X-ray diffraction (P-XRD) and hemocompatibility assessment.Results: All the prepared formulations were in the nano size. The optimum concentration of the stabilizer was in the formulation was found 1:1.5:1 (drug: stabilizer: co-stabilizer ratio). Dramatic effect of the particle size reduction was found by the addition of the co-stabilizer (TPGS) in formulation N2 that has P. S 80.52±0.13 nm. The solubility and dissolution of NAR in the form of NARNS were significantly higher than those of pure NAR. SEM report shows that naringenin nanosuspension revealed a smooth texture. P-XRD crystallography diffraction and DSC studies indicated that the crystalline state of NAR was converted into amorphous nature. The safety evaluation showed that NARNS provided a lower rate of erythrocyte hemolysis.Keywords: Naringenin, High-Pressure Homogenization, Nanosuspenion, Solubility, Bioavailability Conclusion:In this study, (NARNS) was successfully carried out by high-pressure homogenization technique and characterized. The physiochemical characterization shown that crystalline naringenin was converted to a polymorphic form (DSC and P-XRD Study) which evidenced by enhanced dissolution rate in comparisons of the formulation with (NAR) pure drug. The NARNS has shown 7.5±0.4 fold increased relative bioavailability when compared to the NAR. The increased drug dissolution rate may have a significant impact in absorption which in turn the improved oral bioavailability of naringenin. Thus, this delivery system may prefer to improve the dissolution of poorly soluble drugs like NAR and thus enhanced oral bioavailability. The safety evaluation showed that nanoformulation (NF2) shows a lower rate of erythrocyte hemolysis. These findings suggest that the selected formulation may represent a promising new drug formulation for intravenous administration in the treatment of certain cancers.

Naringenin (NAR) is a naturally occurring plant flavonoid, found predominantly in citrus fruits, possesses a wide range of pharmacological properties. However, despite the therapeutic potential of NAR, its clinical development has been hindered due to low aqueous solubility and inefficient transport across biological membranes resulting in low bioavailability at tumor sites. In our previous studies, nanosuspension of naringenin (NARNS) was prepared using high pressure homogenization method using different polymers. D-α-Tocopheryl polyethylene glycol succinate 1000 (TPGS) was added as a co-stabilizer. All formulation characterization studies were performed. As a continuation of our previous research, current study has further evaluated the ability of the TPGS-coated NARNS, to reverse drug-resistance of P-gp-over expressing MCF-7 human breast adenocarcinoma cell line and animal model. MTT-based colorimetric assay revealed higher cytotoxic efficacy of NARNS than free NAR in MCF-7 cells. NARNS treatment significantly increased intracellular ROS level, mitochondrial membrane potential, caspase-3 activity, lipid peroxidation status (TBARS) and decreased GSH levels when compared to free NAR treatment in MCF-7 cells. It has been also noticed that the presence of apoptotic indices (membrane blebbing, nuclear fragmentation) in NARNS treated cancer cells. Further, NARNS exhibited dose-dependent in vitro antitumor activity with DLA cells. A significant increase in the life span and a decrease in the cancer cell number and tumor weight were noted in the tumor-induced mice after treatment with NARNS.

The objective of this study was to investigate the influence of type of cross-linking method used on the properties of ambroxol hydrochloride microspheres such as encapsulation efficiency, particle size, and drug release. Microspheres were prepared by solvent evaporation technique using chitosan as a matrix-forming agent and cross-linked using formaldehyde and heat treatment. Morphological and physicochemical properties of microspheres were then investigated by scanning electron microscopy (SEM), X-ray diffractometry (XRD), differential scanning calorimetry (DSC), and Fourier-transform infrared spectroscopy (FTIR) spectroscopy. The cross-linking of chitosan takes place at the free amino group because of formation of imine bond as evidenced by FTIR. The DSC, XRD, and FTIR analysis showed that chitosan microspheres cross linked by heating were superior in properties and performance as compared to the microspheres cross-linked using formaldehyde. SEM results revealed that heat-treated microspheres were spherical, discrete having smooth, and porous structure. The particle size and encapsulation efficiencies of the prepared chitosan microspheres ranged between 10.83–24.11 μm and 39.73μ80.56%, respectively. The drug release was extended up to 12 h, and the kinetics of the drug release was obeying Higuchi kinetic proving diffusion-controlled drug release.

Pentoxifylline-loaded poly(ε-caprolactone) microspheres were prepared by solvent evaporation technique with different drug to carrier ratio F1 (1:3), F2 (1:4), F3 (1:5) and F4 (1:6). The microspheres were characterized for particle size, scanning electron microscopy, FT-IR study, percentage yield, drug entrapment, stability studies and for in vitro release kinetics. The shape of microspheres was found to be spherical by SEM. The size of microspheres was found to be ranging 59.3±6.3μm to 86.22±4.23 μm. Among the four drug to carrier ratio, F3 (1:5) showed maximum percentage yield of 83.34±2.46% and F2 (1:4) showed highest drug entrapment of 76.92±3.24% w/w. It was found that there was no interaction between drug and polymer by FT-IR study. No appreciable difference was observed in the extent of degradation of product during 60 d in the microspheres, which were stored at various temperatures. In the in vitro release study formulation F2 (1:4) showed 90.34% drug release at 15 h and found to be sustained. The release followed Higuchi kinetics indicating diffusion controlled drug release.

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Background:Oral sustained release gastroretentive dosage forms offer many advantages for drugs having absorption from upper gastrointestinal tract and improve the bioavailability of medications that are characterized by narrow absorption window. The aim of current study was to design sustained release bioadhesive gastroretentive dosage form of ofloxacin.Materials and Methods:A 32 full factorial design was employed to systematically study the drug release profile and bioadhesive strength. Carbopol 934P and HPMC K100M were selected as the independent variables. Compatibility between drug and polymer was tested by fourier transform infrared (FTIR) and X-ray diffraction (XRD) techniques. Tablets were prepared by direct compression and were evaluated for tablet characteristics, swelling study, adhesion strength, percent drug released, radiographic imaging study and stability study. The optimized formulation was then compared with marketed formulation (Oflin OD®).Results:Tablets prepared showed good tablet characteristics, optimum swelling property, and good adhesion strength with high detachment force. Most of the formulations including the optimized formulation followed Higuchi kinetics and the drug release mechanism was found to be anomalous. Radiographic image proved that tablet remains intact in its structural integrity and shape in stomach up to 24 h. The short-term accelerated stability testing was carried out for the optimized formulation, and results revealed that drug content, in-vitro dissolution and all other parameters were within acceptable limits.Conclusion:Thus, the prepared bioadhesive gastroretentive ofloxacin tablet may prove to be a potential candidate which increases the bioavailability of ofloxacin for any intragastric condition.

A simple, specific, sensitive and rapid Reverse phase high performance liquid chromatographic (RP-HPLC) method has been developed and validated for the quantification of Metoprolol Tartrate in small volumes of rabbit plasma. The method was further extended for its pharmacokinetic studies in rabbit plasma samples after transdermal and oral administration. Biological sample preparation involving simple extraction with organic solvent, followed by dilution with mobile phase was adopted to eliminate any chromatographic solvent effects. The method was proven to be linear over a plasma concentration range of 20 ng/ml to100 ng/ml with a mean correlation coefficient of 0.99. The limit of detection and the limit of quantification of the newly developed method were determined to be 5.8ng/mL and 16.1ng/mL, respectively. The method was successfully applied to assess pharmacokinetic parameters of Metoprolol Tartrate in rabbit plasma and found out the comparative bioavailability of MT following oral and transdermal dosage forms. The developed method was established as a rapid analytical tool in a pharmacokinetic study as it required short retention time, high precision, sensitivity and small volumes of plasma for analysis.