Subheet Kumar Jain

Nanoethosomal formulation for skin targeting of amphotericin B: an in vitro and in vivo assessment

Abstract The present study is envisaged to develop nanoethosomal formulation for enhanced topical delivery of amphotericin B (AmB) for the treatment of cutaneous fungal infections. AmB encapsulated nanoethosomes were prepared using mechanical dispersion method in a strength of 0.1% w/w similar to the strength of marketed topical formulation. Vesicle size of nanoethosomal formulations was found to be in the range of 186 ± 2 to 298 ± 4 nm. The optimized nanoethosomal formulation was further incorporated in gel base to form AmB nanoethogel formulation. Rheological characterization study of nanoethogel demonstrated its viscoelastic nature with high elasticity and resistance to deformation at 37 °C. The yield stress value was found to be 108.05 ± 2.4 and 52.15 ± 0.9 Pa for nanoethogel and marketed gel formulation, respectively. The nanoethogel formulation exhibited 2.7- and 3.5-fold higher steady state transdermal flux and skin deposition of AmB, respectively, in comparison to marketed formulation. Confocal laser scanning microscopy (CLSM) study also revealed enhanced skin permeation and deposition with nanoethogel formulation. In vivo study showed that topical application of nanoethogel does not exhibit any skin irritation as tested by Draize test. The developed formulation, in comparison to the marketed gel, demonstrated a remarkable increase in the antifungal activity against Candida albicans. It is thus corroborated from the above results that nanoethosomal formulation represents an efficacious carrier for effective topical delivery of AmB.

Sonochemical synthesis, characterization, antimicrobial activity and textile dyeing behavior of nano-sized cobalt(III) complexes.

Using ultrasonic irradiations, nano-sized cobalt(III) coordination complexes, [Co(NH3)6]Cl3·2H2O (A), [Co(en)3]Cl3·3H2O (B) (en-ethylenediamine) and [Co(dien)2]Cl3·3.5H2O (C) (dien-diethylenetriamine) were synthesized. These complexes were characterized by spectroscopic studies like IR, UV/Visible and NMR. Morphology of these complexes was determined by SEM and particle size with the help of TEM & Zeta-sizer. The comparative thermal stability along with phase difference between nano structures and their respective bulk complexes has been studied by thermal gravimetric analysis (TGA) and X-ray powder diffraction (XRD) study respectively. The dyeing behavior of nano-sized Co(III) complexes and their respective bulks has also been studied (using both exhaust and pad dyeing methods) on cotton and wool fabrics and results shown rationalized dyeing behavior. All these complexes were further tested for antimicrobial activity (against B. subtilis, E. coli, K. pneumoniae, F. oxysporum and A. alternate) and it was observed that nano sized complexes enhanced the activity further.

Self-nanoemulsifying drug delivery system of docosahexanoic acid: development, in vitro, in vivo characterization.

Abstract Context: Docosahexanoic acid (DHA) is an essential omega-3 fatty acid for normal brain development and its use has increased considerably in recent years. Objective: The aim of this study is to develop and evaluate self-nanoemulsifying drug delivery systems (SNEDDS) of DHA for improved palatability, dispersibility and bioavailability. Methods: The SNEDDS were prepared and evaluated for miscibility, employing different combinations of olive oil and soyabean oil as oil phase, Span 80, Span 20, soya phosphatidylcholine, Labrafil M 1944 CS as surfactants while Tween 80, PEG 400, Cremophor RH40 and propylene glycol as cosurfactants. Thermodynamically stable SNEDDS were characterized for dispersibility, self-emulsification time, droplet size, zeta potential along with sensory analysis. The optimized formulation was subjected to ex vivo and in vivo evaluation such as intestinal permeability, memory performance test, brain concentration and histopathology studies. Results: The optimized SNEDDS formulation showed emulsification time of 27 ± 4.7 s with droplet size of 17.6 ± 3.5 nm and zeta potential of −37.6 ± 0.5 mV. Intestinal absorption study depicted 18.3%, 21.5%, 41.5%, 98.7% absorption of DHA with SNEDDS-based formulation in comparison to 8.2%, 15.1%, 28.8%, 46.1% absorption of DHA with oil-based marketed formulation after 0.5, 1, 2 and 4 h. DHA concentration in brain homogenate was found to be increased to 2.6-fold in comparison to DHA-marketed formulation. This could be ascribed to enhanced dispersibility and bioavailability of DHA from nanosized formulation. Conclusion: The developed formulation led to enhanced dispersibility and bioavailability of DHA due to the formation of nanodroplets.

Vitamin E TPGS based nanogel for the skin targeting of high molecular weight anti-fungal drug: development and in vitro and in vivo assessment

The molecules having a molecular weight greater than 500 Da are considered to be ineffective in the treatment of skin diseases due to their low skin permeation. The present study entails the development of a Vitamin E TPGS nanoemulsion based nanogel formulation for the high molecular weight drug, amphotericin B (AmB 923 Da), intended for the effective treatment of cutaneous fungal infections. The nanoemulsion formulations were prepared in strengths similar to the marketed topical formulation and optimized with respect to the Smix ratio (surfactant:co-surfactant), type of surfactant, co-surfactant, globule size, size distribution, percent transmittance, dispersibility, viscosity and rheology. The optimized nanoemulsion formulation was further incorporated into a gel base to form the AmB nanogel formulation. When compared to the marketed topical formulation, the optimized nanogel exhibited a 3.9 fold higher skin deposition through porcine ear skin. Confocal laser scanning microscopy studies (CLSM) showed the specific distribution of AmB in different parts of the skin and confirmed the permeation of the nanogel to the deeper layers of the skin. The antifungal activity of the optimized nanogel formulation was tested using microdilution method and found to be 2.0 fold higher against Aspergillus niger and Candida albicans in contrast to the marketed formulation. The results show that the prepared nanogel formulation is a better alternative for effective topical delivery of AmB.

4-aryl/heteroaryl-4H-fused Pyrans as Anti-proliferative Agents: Design, Synthesis and Biological Evaluation

AIMS The current study is focused on the design and synthesis of 4-aryl/heteroaryl-4H-fused pyrans as anti-proliferative agents. All the synthesized molecules were screened against a panel of human carcinoma cell lines. DESCRIPTION Significant inhibition was exhibited by the compounds against HCT-116 (Colon) and PC-3 (Prostate) cell lines while A-549 (Lung) cell lines, MiaPaCa-2 (Pancreatic) cell lines and HL-60 (Leukemia Cancer) cell lines were almost resistant to the exposure of the test compounds. Compound FP-(v)n displayed noteworthy cytotoxicity towards HCT-116 malignant cells with the IC50 value of 0.67 µM. It induces apoptosis as revealed by several biological endpoints like apoptotic body formation, through DAPI staining, phase contrast microscopy and mitochondrial membrane potential loss. Moreover FP-(v)n is a potent apoptotic inducer confirmed by cell cycle arrest and ROS generation. The cell phase distribution studies indicate an augment from 4.94 % (control sample) to 39.68 % (sample treated with 1.5 µM compound FP-(v)n) in the apoptotic population. Compound FP-(v)n inhibits the tumor growth in Ehrlich ascites carcinoma (EAC), Ehrlich Tumor (ET, solid) and sarcoma-180 (solid) mice models. Additionally, it was established to be non-toxic at maximum tolerated dose of 1000 mg/kg in acute oral toxicity in Swiss-albino mice. CONCLUSION The current study provides an insight into anti-cancer potential of FP-(v)n, which might be valuable in the treatment of tumor.

Antitumour, acute toxicity and molecular modeling studies of 4-(pyridin-4-yl)-6-(thiophen-2-yl) pyrimidin-2(1H)-one against Ehrlich ascites carcinoma and sarcoma-180

In an effort to discover an effective and selective antitumour agent, synthesis and anti-cancer potential of 4-(pyridin-4-yl)-6-(thiophen-2-yl) pyrimidin-2(1H)-one (SK-25), which has been reported earlier by us with significant cytotoxicity towards MiaPaCa-2 malignant cells, with an IC50 value of 1.95 μM and was found to instigate apoptosis. In the present study, the antitumour efficacy of SK-25 was investigated on Ehrlich ascites tumour (EAT, solid), Sarcoma 180 (solid) tumour and Ehrlich ascites carcinoma. The compound was found to inhibit tumour development by 94.71% in Ehrlich ascites carcinoma (EAC), 59.06% in Ehrlich tumour (ET, solid) and 45.68% in Sarcoma-180 (solid) at 30 mg/kg dose. Additionally, SK-25 was established to be non-toxic at a maximum tolerated dose of 1000 mg/kg in acute oral toxicity in Swiss-albino mice. Computer-based predictions also show that the compounds could have an interesting DMPK profile since all 51 computed physicochemical parameters fall within the recommended range for 95% of known drugs. The current study provides insight for further investigation of the antitumour potential of the molecule.

Nanoencapsulation of docosahexaenoic acid (DHA) using a combination of food grade polymeric wall materials and its application for improvement in bioavailability and oxidative stability

Docosahexaenoic acid (DHA) is a vital structural component of neuronal tissue, which is critically required during pre- and post-natal brain development. Its liquid nature, fishy odor, poor bioavailability and oxidative stability are the major challenges in the development of a pharmaceutically elegant and stable formulation. In the present study, nanocapsules of DHA from microalgae oil were prepared using different combinations of wall materials (carbohydrates, polymers, gum and proteins). The encapsulation using spray drying was done to prepare a pharmaceutically stable DHA formulation. The optimized formulation had a nanometric particle size (780 nm), spherical shape, an encapsulation efficacy of 98.46 ± 1.1% and good oxidative stability, both under refrigerated and accelerated storage conditions. Brunauer-Emmett-Teller (BET) analysis of the powder depicted a higher surface area and pore diameter and a lower particle size range. An ex vivo intestinal permeability study demonstrated a two fold increase in absorption in comparison with a commercial DHA formulation. Furthermore, an in vivo biodistribution study demonstrated a 2.9 fold increase in brain DHA concentration in comparison with pure DHA oil. In vivo testing for memory enhancement effects using Normal Object Recognition (NOR) and Morris water maze models with histopathological studies demonstrated memory enhancement with an increase in the proliferation of neurons in the hippocampus area. Thus, this study indicated that combinations of wall materials were better for the effective encapsulation of DHA oil for improving its bioavailability, shelf life and oxidative stability.

Impact of various solid carriers and spray drying on pre/post compression properties of solid SNEDDS loaded with glimepiride: in vitro-ex vivo evaluation and cytotoxicity assessment

Abstract Development of self-nanoemulsifying drug delivery systems (SNEDDS) of glimepiride is reported with the aim to achieve its oral delivery. Lauroglycol FCC, Tween-80, and ethanol were used as oil, surfactant, and co-surfactant, respectively as independent variables. The optimized composition of SNEDDS formulation (F1) was 10% v/v Lauroglycol FCC, 45% v/v Tween 80, 45% v/v ethanol, and 0.005% w/v glimepiride. Further, the optimized liquid SNEDDS were solidified through spray drying using various hydrophilic and hydrophobic carriers. Among the various carriers, Aerosil 200 was found to provide desirable flow, compression, dissolution, and diffusion. Both, liquid and solid-SNEDDS have shown release of more than 90% within 10 min. Results of permeation studies performed on Caco-2 cell showed that optimized SNEDDS exhibited 1.54 times higher drug permeation amount and 0.57 times lower drug excretion amount than that of market tablets at 4 hours (p < .01). Further, the cytotoxicity study performed on Caco-2 cell revealed that the cell viability was lower in SNEDDS (92.22% ± 4.18%) compared with the market tablets (95.54% ± 3.22%; p > .05, i.e. 0.74). The formulation was found stable with temperature variation and freeze thaw cycles in terms of droplet size, zeta potential, drug precipitation and phase separation. Crystalline glimepiride was observed in amorphous state in solid SNEDDS when characterized through DSC, PXRD, and FT-IR studies. The study revealed successful formulation of SNEDDS for glimepiride.

Pathological Perturbations in Diabetic Retinopathy: Hyperglycemia, AGEs, Oxidative Stress and Inflammatory Pathways

Diabetic retinopathy (DR) remains the leading cause of blindness in working-aged adults around the world. The proliferative diabetic retinopathy (PDR) and diabetic macular edema (DME) are the severe vision threatening stages of the disorder. Although, a huge body of research exists in elaborating the pathological mechanisms that lead to the development of DR, the certainty and the correlation amongst these pathways remain ambiguous. The complexity of DR lies in the multifactorial pathological perturbations that are instrumental in both the disease development and its progression. Therefore, a holistic perspective with an understanding of these pathways and their correlation may explain the pathogenesis of DR as a unifying mechanism. Hyperglycemia, oxidative stress and inflammatory pathways are the crucial components that are implicated in the pathogenesis of DR. Of these, hyperglycemia appears to be the initiating central component around which other pathological processes operate. Thus, this review discusses the role of hyperglycemia, oxidative stress and inflammation in the pathogenesis of DR, and highlights the cross-talk amongst these pathways in an attempt to understand the complex interplay of these mechanisms. Further, an effort has been made to identify the knowledge gap and the key players in each pathway that may serve as potential therapeutic drug targets.

A Mechanistic Study to Determine the Structural Similarities Between Artificial Membrane Strat-M™ and Biological Membranes and Its Application to Carry Out Skin Permeation Study of Amphotericin B Nanoformulations

Type of biological membrane used in skin permeation experiment significantly affects skin permeation and deposition potential of tested formulations. In this study, a comparative study has been carried out to evaluate the potential of a synthetic membrane (Strat-M™) with rat, human, and porcine ear skin to carry out skin permeation study of nanoformulations of a high molecular weight drug, amphotericin B. Results demonstrated that the permeation of this high molecular weight drug through Strat-M™ showed close similitude to human skin. Value of correlation coefficient (R2) of log diffusion between Strat-M™ and human skin was found to be 0.99 which demonstrated the similarities of Strat-M™ membrane to the human skin. In similarity factor analysis, the value of f2 was also found to be 85, which further demonstrated the similarities of Strat-M™ membrane to human skin. Moreover, scanning electron microscopy (SEM), transmission electron microscopy (TEM), and Brunauer-Emmett-Teller (BET) analysis of synthetic and biological membranes depicted almost similar morphological features (thickness, pore size, surface morphology, and diameter) of synthetic membrane with human skin. The results of the study demonstrated Strat-M™ as a better alternative to carry out skin permeation experiment due to the consistent results, reproducibility, easy availability, and minimum variability with human skin.