Sarbani Dey Ray

Alginate/hydrophobic HPMC (60M) particulate systems: new matrix for site-specific and controlled drug delivery

This study aimed to obtain site-specific and controlled drug release particulate systems. Some particulates were prepared using different concentrations of sodium alginate (Na-Alg) alone and others were formulated using different proportions of Na-Alg with hydroxypropyl methylcellulose (HPMC) stearoxy ether (60M viscosity grade), a hydrophobic form of conventional HPMC, using diclofenac potassium (DP) by ion-exchange methods. Beads were characterized by encapsulation efficiency, release profile, swelling, and erosion rate. The suitability of common empirical (zero-order, first-order and Higuchi) and semi-empirical (Ritger-Peppas and Peppas-Sahlin) models was studied to describe the drug release profile. The Weibull model was also studied. Models were tested by non-linear least-square curve fitting. A general purpose mathematical software (MATLAB) was used as an analysis tool. In addition, instead of the widely used linear fitting of log-transformed data, direct fitting was used to avoid any sort of truncation or transformation errors. The release kinetics of the beads indicated a purely relaxation-controlled delivery, referred to as case II transport. Weibull distribution showed a close fit. The release of DP from Na-Alg particulates was complete in 5-6 hours, whereas from Na-Alg hydrophobic HPMC particulate systems, release was sustained up to 10 hours. Hydrophobic HPMC with Na-Alg is an excellent matrix to formulate site-specific and controlled drug release particulate systems.

Effect of cross-linked biodegradable polymers on sustained release of sodium diclofenac-loaded microspheres

O objetivo deste estudo foi elaborar um sistema de entrega de oral de liberacao sustentada de diclofenaco sodico (DS) com base em alginato de sodio (SA), como um transportador hidrofilico em combinacao com quitosana (CH) e carboximetilcelulose de sodio (SCMC) como modificadores de liberacao de farmaco para diminuir os efeitos adversos e melhorar a biodisponibilidade. Prepararam-se microesferas de DS usando um metodo facil de geleificacao ionotropica. Avaliaram-se os grânulos preparados quanto ao tamanho medio de particula, eficiencia de compressao, inchaco in vitro, erosao e capacidade de liberacao de farmacos. Estes tammbem foram submetidos a varios estudos, como espectrometria no infravermelho com transformada de Fourier (FTIR) para compatibilidade de farmaco e polimero, microscopia eletronica de varredura para morfologia de superficie, analise de difracao de raios-X (XRD) do pos e analise calorimetrica diferencial de varredura (DSC) para determinar o estado fisico do farmaco nos grânulos. A adicao de SCMC durante a preparacao de grânulos do polimero resultou em farmacos com menor carga de farmaco e liberacao prolongada do DS. O perfil de liberacao dos lotes F5 e F6 apresentou maximo de farmaco liberado de 96,97±0,356% apos 8 h apos o que a proporcao do farmaco no polimero foi diminuida. As microesferas de diclofenaco de sodio com os polimeros foram formuladas com sucesso. A analise dos perfis de liberacao mostrou que os dados correspondem ao mecanismo de difusao controlada, como sugerido por Higuchi.

Sterodin ® , a novel immunostimulating drug: Some toxicological and pharmacological evaluations in vivo, and drug-lipid interaction studies in vitro

Sterodin®, a novel immunostimulating drug: Some toxicological and pharmacological evaluations in vivo, and drug-lipid interaction studies in vitro Sterodin® is a novel non-specific immunostimulating drug produced by a combination of bile lipids and bacterial metabolites. In the present study, we investigated some of its (i) toxicological and (ii) pharmacological properties in vivo, and (iii) drug-lipid interaction (lipid peroxidation) in vitro. We also evaluated the possible (iv) Sterodin®-induced lipid peroxidation as well as the effect of ascorbic acid on this peroxidation. We found LD50 of Sterodin® to be 31.50 mL kg-1 body mass. In male albino mice, Sterodin® increased the total white blood cells and neutrophils count by 59 and 26%, respectively, on the 6th day, compared to day 0 after injection and stimulated phagocytic activity in vivo. We used goat liver as lipid source in drug-lipid interaction studies in vitro. Our experiments show that Sterodin® induces lipid peroxidation, which was prevented by ascorbic acid. Sterodin®, novi imunostimulator: neka toksikološka i farmakološka vrednovanja in vivo i interakcija lijek-lipid in vitro Sterodin® je novi nespecifični imunostimulator koji sadrži žučne lipide i bakterijske metabolite. U radu su opisana neka njegova toksikološka i farmakološka svojstva in vivo, te interakcija lijek-lipid in vitro. Nadalje, proučavana je moguća peroksidacija lipida inducirana Sterodinom® te učinak askorbinske kiseline na tu peroksidaciju. LD50 Sterodina® bio je 0,63 mL u mužjacima albino miševa mase 20 g (31,50 mL kg-1 tjelesne mase). U istim životinjama Sterodin® je povećao ukupan broj leukocita i neutrofila (59 odnosno 26% mjereno 6 dana nakon injekcije Sterodina®) i stimulirao aktivnost fagocita in vivo. U ispitivanjima interakcije lijek-lipid in vitro korištena je jetra koze kao izvor lipida. Rezultati ukazuju da Sterodin® inducira peroksidaciju lipida, koja se može spriječiti askorbinskom kiselinom.

Isolation of a new triterpene derivative and in vitro and in vivo anticancer activity of ethanolic extract from root bark of Zizyphus nummularia Aubrev.

The various parts of Zizyphus nummularia has been used traditionally in several disease conditions. However, its anticancer activity and mechanism of action remain to be elucidated. Considering this, the objective of this study was to isolate, identify and screen for possible anticancer activity in vitro and in vivo of the ethanolic extract (EE) and isolated identified compound (IC) from Z. nummularia root bark. The in vitro activity against human breast cancer, leukaemia, ovarian cancer, colon adenocarcinoma and human kidney carcinoma cell lines was determined. The in vivo activity in female Swiss albino mice against Ehrlich ascites carcinoma (EAC) was determined. The isolated compound is a new triterpene derivative. EE/IC showed cytotoxicity against different cell lines. The administration of EE/IC decreased tumour parameters such as tumour volume, viable tumour cell count and increased body weight, haematological parameters and life span in comparison to the EAC control mice.

DPPH RADICAL SCAVENGING ACTIVITY A NEW TRITERPENE DERIVATIVE ISOLATED FROM ROOT BARK OF ZIZIPHUS NUMMULARIA AUBREV

The study was designed with an aim to investigate the DPPH radical scavenging activity of the ethanolic extract (EE) and an identified lead compound (LC) which is a new triterpene derivative isolated from root bark of Ziziphus nummularia. The in vitro evaluation of antioxidant activities of ethanolic extract (EE) and an identified lead compound (LC) was done by measuring DPPH radical. The results indicate that EE and LC of Z. nummularia have potent DPPH radical scavenging activity.

EXPLORING THE PROETECTIVE ROLE OF WATER EXTRACT OF SPIRULINA PLATENSIS ON GEMCITABINE-INDUCED LIPID PEROXIDATION USING COMMON LABORATORY MARKERS

The present study was designed with an aim to explore the protective role of water extract of Spirulina platensis on gemcitabine-induced lipid peroxidation. The work was carried out in vitro and goat liver was used as model lipid source. Two common laboratory markers such as malondialdehyde and reduced glutathione were used for the model. The results showed that gemcitabine has the ability to induce lipid peroxidation to a significant extent and it was also found that water extract of the Spirulina platensis has the ability to suppress the gemcitabine-induced toxicity.

ROLE OF NARINGIN ON GEMCITABINE-INDUCED LIPID PEROXIDATION

Aim: The aim of the present study was to investigate the antiperoxidative property of naringin on gemcitabine-induced lipid peroxidation. Methods: The in vitro work was carried out using goat liver as model lipid source. Two common laboratory markers such as malondialdehyde and reduced glutathione were used for the model. Results: The data generated from the work showed that gemcitabine increase the MDA level and reduce the GSH level. But when gemcitabine was used in combination with naringin then there is decrease in MDA level and increase in GSH level. Conclusion: The results showed that gemcitabine has the ability to induce lipid peroxidation to a significant extent and it was also found that naringin has antiperoxidative potential to suppress the gemcitabine-induced toxicity.

PACLITAXEL INDUCED LIPID PEROXIDATION: ROLE OF WATER EXTRACT OF SPIRULINA PLATENSIS

The present study showed th e free radical scavenging activity of water extract of Spirulina platensis on paclitaxel - induced lipid peroxidation. This in vitro work was carried out with goat liver as lipid source using malondialdehyde and 4 - hydroxy - 2 - nonenal as model markers. The find ings suggest that paclitaxel could induce lipid peroxidation to a significant extent and it was also found that water extract of the Spirulina platensis has the ability to suppress the paclitaxel - induced toxicity.

EXPLORING PROTECTIVE ROLE OF MORIN ON PA CLITAXEL - INDUCED LIP ID PEROXIDATION USING MALONDIALDEHYD E AND 4 - HYDROXY - 2 - NO NENAL AS MODEL MARKE RS

The present in vitro study was designed to explore antiperoxidative potential of morin on paclitaxel - induced lipid peroxidation. Goat liver tissue homogenate was used as source of lipid. Estimation of malondialdehyde and 4 - hydroxy - 2 - nonenal in liver tissue homogenate was used as model markers for paclitaxel - induced lipid peroxidation. The results suggest that paclitaxel could induce lipid peroxidation to a significant extent and i t was also found that morin has the ability to suppress the pa clitaxel - induced toxicity.

Combined experimental and in silico approaches for exploring antiperoxidative potential of structurally diverse classes of antioxidants on docetaxel-induced lipid peroxidation using 4-HNE as the model marker

The objective of the present work was tantamount to explain the antiperoxidative potential and structural requirements of twenty-eight structurally diverse classes of antioxidants on docetaxel-induced lipid peroxidation. Both experimental and computational approaches were taken to the work. The experiments were performed in vitro and goat liver was used as a source of lipid. 4-hydroxy-2-nonenal was used as model marker for estimation of docetaxel-lipid interaction. The computational portion of the work was limited to QSAR analysis of those antioxidants for better understanding of the structural requirements of antioxidants on docetaxel-lipid interaction. The study was done with freely online available 2D descriptors available on PaDEL (open source). Stepwise regression analysis was used as chemometric tool. The experimental study showed the lipid peroxidation induction capacity of docetaxel. It was also noted that all twenty-eight antioxidants had the ability to suppress the lipid peroxidation. But among them butylated hydroxyl toluene showed the highest potential (-20.5%) and flavone showing lowest potential (-0.8%) to suppress the docetaxel-induced lipid peroxidation. The computational study indicates the importance of topology of the whole molecules, topological distances among atoms within a molecule and specific fragment pattern present in a molecule required for inhibition of lipid peroxidation.