Achint Jain

Assessment of solubilization characteristics of different surfactants for carvedilol phosphate as a function of pH.

The effect of surfactants on the solubility of a new phosphate salt of carvedilol was investigated at different biorelevent pH to evaluate their solubilization capacity. Solutions of different classes of surfactants viz., anionic-sodium dodecyl sulfate (SDS) and sodium taurocholate (STC), cationic-cetyltrimethylammonium bromide (CTAB) and non-ionic-Tween 80 (T80) were prepared in the concentration range of 5-35 mmol dm(-3) in buffer solutions of pH 1.2, 3.0, 4.5, 5.8, 6.8 and 7.2. The solubility data were used to calculate the solubilization characteristics viz. molar solubilization capacity, water micelle partition coefficient, free energy of solubilization and binding constant. Solubility enhancement in basic pH was in following order: CTAB>T80>SDS>STC. CTAB and T80 showed remarkable solubility enhancement in acidic pH as well. Among the anionic surfactants, solubility in acidic medium was retarded except at pH 1.2 in case of SDS. Cationic and non-ionic surfactants were found to be suitable for enhancing the solubility of CP which can be employed for maintaining the in vitro sink condition in the basic dissolution medium. While anionic surfactants showed solubility retardant behavior which may be exploited in increasing the drug entrapment efficiency of a colloidal drug delivery system formulated by emulsification technique.

Studies on Binary Lipid Matrix Based Solid Lipid Nanoparticles of Repaglinide: in Vitro and in Vivo Evaluation

The purpose of present study is to examine effect of binary lipid matrix (combination of lipids) on the entrapment and storage stability of repaglinide (RG) loaded solid lipid nanoparticles (SLN). Solid lipid nanoparticles were prepared by modified solvent injection method for oral delivery to improve the bioavailability of RG, an antidiabetic drug. The stearic acid and tristearin were used to form lipid core materials, and Pluronic-F68 was used as a stabilizer. Nanoparticles were characterized by evaluating their particle size, zeta potential, entrapment efficiency, drug loading, solid-state studies (differential scanning calorimetry, X-ray diffraction), in vitro drug release, particle surface (transmission electron microscopy analysis with electron diffraction pattern), stability study in gastrointestinal fluids (GIFs) and storage stability at 30 °C/65% RH for 3 months. The characterization of SLN suggested that binary lipid matrix based nanoparticles had better drug entrapment and loading, desired release characteristics, stable in GIFs and significantly higher storage stability compared with single lipid formulations. Pharmacodynamic (blood glucose, blood cholesterol, blood triglyceride levels) and pharmacokinetic (AUC, T(max), peak plasma concentrations, K, t(1/2), mean residence time and relative bioavailabilities) studies were performed for the selected formulations. These studies indicate that the formulation based on binary lipid matrix significantly improves the oral bioavailability of RG.

In Vivo and Cytotoxicity Evaluation of Repaglinide-Loaded Binary Solid Lipid Nanoparticles After Oral Administration to Rats

The purpose of this work was to develop prolonged release binary lipid matrix-based solid lipid nanoparticles (SLN) of repaglinide (RG) for oral intestinal delivery and to improve the bioavailability of RG. SLN were designed by using glycerol monostearate and tristearin as lipid core materials and Pluronic-F68 as stabilizer. SLN were characterised by their particle size, zeta potential, entrapment efficiency, solid-state studies, in vitro drug release, particle surface and storage stability at 30 °C/65% relative humidity for 3 months. Pharmacodynamic (PD) and pharmacokinetic (PK) studies were also performed in diabetes-induced rat. Moreover, an in vitro toxicity study was performed in rat macrophage cells to establish the safety of the prepared SLN. It was observed that binary lipid matrix-based SLN had better drug entrapment, desired release characteristics, spherical shape and maximum storage stability. Pharmacodynamic study indicated that RG delivered through binary SLN significantly reduces blood glucose, blood cholesterol and blood triglycerides level. The area under the curves after oral administration of optimised RG-SLN formulation and RG control were 113.36 ± 3.01 and 08.08 ± 1.98 h/(ng · mL), respectively. The relative bioavailability of RG was enhanced with optimised SLN formulation when compared with RG control. There was a direct correlation found between the plasma drug level (drug concentration) and the peak response (% blood glucose inhibition) in optimised RG-SLN batch. The in vitro toxicity study indicated that the SLN were well tolerated.

Electrocatalytic activity of high specific surface area Perovskite-type LaNiO3 via sol-gel route for electrolytic oxygen evolution in alkaline solution

Abstract Lanthanum nickelate was synthesized by a sol-gel method at low temperature (500 °C) and its interfacial electrochemical and electrocatalytic properties in 1 M KOH were investigated in film form on Ni. The oxide film was obtained by painting a slurry of oxide powder and Triton X-100 and subsequent sintering at 400 °C. The cyclic voltammetry of the oxide electrode in 1 M KOH indicated the formation of the diffusion-controlled quasi-reversible Ni(II)-Ni(III) redox couple, prior to the onset of O 2 evolution. The oxygen evolution reaction followed approximately first order kinetics in OH − concentration. The Tafel slope was 65 mV decade −1 . The electrocatalytic activities of LaNiO 3 prepared by different methods have been compared.

Targeting of diacerein loaded lipid nanoparticles to intra-articular cartilage using chondroitin sulfate as homing carrier for treatment of osteoarthritis in rats

UNLABELLED Targeted delivery of antiosteoarthritic drug diacerein to articular tissue could be a major achievement and soluble polysaccharide chondroitin sulfate (ChS) may be a suitable agent for this. Therefore, diacerein loaded solid lipid nanoparticles modified with ChS (ChS-DC-SLN) were prepared for synergistic effect of these agents to combat multidimensional pathology of osteoarthritis (OA). Prepared formulation were of size range 396±2.7nm, showed extended release up to 16h and increased bioavailability of diacerein by 2.8 times. ChS-DC-SLN were evaluated for their effect on histopathology of femoro-tibial joint of rat knee and amount of ChS and rhein (an active metabolite of diacerein) at targeted site. Concentration of rhein was significantly higher in case of ChS-DC-SLN (7.8±1.23μg/ml) than that of drug dispersion (2.9±0.45μg/ml). It can be stated that ChS served as homing to articular cartilage for targeting of drug. Thus, ChS-DC-SLN have great potential to enhance the overall efficacy of treatment for OA. FROM THE CLINICAL EDITOR This study demonstrates the feasibility of targeted delivery of diacerein to articular tissue using soluble polysaccharide chondroitin sulfate as the targeting vector. This approach has the potential to significantly increase anti-arthritic drug concentration in joints without leading to systemic toxicity.

Physicochemical and electrocatalytic properties of LaNiO3 prepared by a low-temperature route for anode application in alkaline water electrolysis

LaNi1−xFexO3 (x = 0, 0.25, 0.5) has been synthesized by the hydroxide solid solution precursor method for electrochemical characterization as oxygen anode in strongly alkaline medium. Studies were made at the oxide film, which was obtained by the oxide-slurry painting technique. The cyclic voltammetric study showed the formation of a diffusion-controlled quasireversible redox couple, Ni(ii)/Ni(iii), (E0 ∼- 430 ± 10 mV) at the oxide surface in 1 m KOH. The reaction was observed to follow approximately first-order kinetics in OH− concentration. Values of the Tafel slope ranged between 59 and 86 mV decade−1 with all the oxide film electrodes. The electrocatalytic activity was found to be greatest with the Ni/LaNi0.75Fe0.25O3 electrode. A comparison was made between the electrocatalytic activities of LaNiO3 prepared by the hydroxide solid solution precursor and by the hydroxide coprecipitation technique.

Development of repaglinide loaded solid lipid nanocarrier: selection of fabrication method.

Repaglinide solid lipid nanoparticles (RG-SLN) were fabricated using stearic acid as lipid. Pluronic F68 (PLF68) and soya lecithin were used as a stabilizer. SLNs were prepared by modified solvent injection and ultrasonication methods. SLNs prepared with modified solvent injection method have larger particle size (360+/-2.5nm) than prepared with ultrasonication method (281+/-5.3nm). The zeta potential of the prepared formulations by these two methods varied from - 23.10 +/-1.23 to -26.01 +/-0.89 mV. The maximum entrapment efficiency (62.14 +/-1.29%) was obtained in modified solvent injection method. The total drug content was nearly same (98%) in both the methods. In vitro release studies were performed in phosphate buffer (pH 6.8) with 0.5% sodium lauryl sulphate (SLS) using dialysis bag diffusion technique. The cumulative drug release was 30% and 50% within 2 hrs in modified solvent injection and ultrasonication method, respectively. This indicates that RG-SLN prepared from modified injection method released the drug more slowly than SLNs prepared with ultrasonication method. Differential scanning calorimetry indicates that repaglinide (RG) entrapped in the solid lipid nanoparticles (SLN) exist in an amorphous or molecular state. Repaglinide loaded solid lipid nanoparticles prepared with both methods were of spherical shape as observed by transmission electron microscopy (TEM). These results suggest that modified solvent injection method is more suitable for preparation of repaglinide SLNs using stearic acid.

Medicinal significance, pharmacological activities, and analytical aspects of anthocyanidins ‘delphinidin’: A concise report

Abstract Herbal medicines have been used for the treatment of various disorders in the world since a very early age due to easily available and less side effect. A large number of phytochemicals have been derived directly or indirectly from natural sources in the form of oils, food supplement, neutraceuticals, and colour pigments. Anthocyanins are classes of phytoconstituents mainly responsible for the different colors of plants material. Literature report revealed the presence of different anthocyanidins such as cyanidin, delphinidin, petunidin, peonidin, pelargonidin, malvidin, cyaniding etc. These anthocyanidins showed a wide range of pharmacological activities. Anthocyanins have an attractive profile in the food industry as natural colorants due to its possible health benefits and safety issues compared to the synthetic dye. Delphinidin is an important anthocyanidins mainly present in the epidermal tissues of flowers and fruits. Delphinidin showed various pharmacological activities such as antioxidant, antimutagenesis, anti-inflammatory and antiangiogenic etc. This review was aimed to elaborate the medicinal importance, pharmacological activities and analytical aspects of anthocyanidins ‘delphinidin’. This review will be benificial to the scientist, manufacturer and consumers in order to explore the potential health benefits of delphinidin.

Mucoadhesive gel containing immunotherapeutic nanoparticulate satranidazole for treatment of periodontitis: development and its clinical implications

The aim of this study was to alleviate shortcomings in periodontal treatment by utilizing a mucoadhesive gel containing immunotherapeutic ganglioside coated polymeric nanoparticles (G-PNP) bearing satranidazole (SZ). Nanoprecipitation was used to fabricate SZ loaded G-PNP. In our previous deliberations aqueous dispersibility of conventional SZ had raised dose consistency issues. Usage of G-PNP allayed those fears as DSC and XRD data showed that SZ was rendered amorphous (more water dispersible than crystalline SZ) when captured in a polymeric matrix of nanoparticles. G-PNP were added to sodium carboxy methyl cellulose (SCMC 30 NP) gels and compared against SCMC 30 (gel containing conventional SZ) for texture, mucoadhesion, drug release and inhibitory susceptibility of Aggregatibacter actinomycetomicans. Subsequently a 21 day single blind clinical trial comparing the efficacy of SCMC 30 NP and SCMC 30 was conducted. SCMC 30 NP showed a maximum mucoadhesion force (43.27 ± 4.10 gf), low hardness (12.28 ± 0.17 N), moderate gel strength (8.53 ± 0.21 N) and elasticity (5.50 ± 0.03 mm). ‘Well’ diffusion data revealed qualitatively greater antibacterial activity of SCMC 30 NP. Dissolution studies demonstrated diffusion controlled release of SZ at concentrations above MIC. SCMC 30 NP caused a significant (P < 0.05) decrease in clinical markers of periodontitis, i.e. gingival index and pocket depth as compared to SCMC 30. Also reduction in the plaque index produced by SCMC 30 NP was highly significant (P < 0.01) as compared to SCMC 30 at the end of the 21st day of clinical study. Amelioration of disease was improved due to Th-2 biased immuno shifting mediated by G-PNPs, which increased secretion of anti-inflammatory cytokines like IL-4 and TGF-β from J774 macrophages. Clinical benefits incurred along with ease of application calls for a scaled up investigation of SCMC 30 NP.

Pharmacokinetic and Tissue Distribution Study of Solid Lipid Nanoparticles of Zidovudine in Rats

Zidovudine-loaded solid lipid nanoparticles (AZT-SLNs) and zidovudine in solution were prepared and administered in rats. The aim of this research was to study whether the bioavailability of zidovudine can be improved by AZT-SLNs perorally to rats as compared to oral administration of zidovudine. Zidovudine was determined in plasma and tissues by reverse phase high performance liquid chromatography. The pharmacokinetic parameters of zidovudine were determined after peroral administration: area under curve of concentration versus time (AUC) for AZT-SLNs was 31.25% greater than AZT solution; meanwhile mean resident time (MRT) was found to be 1.83 times higher for AZT-SLNs than AZT solution. Elimination half life of zidovudine was also increased for SLN formulation. Tissue distribution pattern of zidovudine was changed in case of AZT-SLNs. AUC of zidovudine in brain and liver was found to be approximately 2.73 and 1.77 times higher in AZT-SLNs than AZT solution, respectively, indicating that AZT-SLNs could cross blood brain barrier. Distribution of zidovudine was approximately 0.95 and 0.86 times lesser in heart and kidney, respectively. It can be concluded from the study that oral administration of AZT-SLNs modifies the plasma pharmacokinetic parameters and biodistribution of zidovudine.