Anekant Jain

Transferrin‐conjugated solid lipid nanoparticles for enhanced delivery of quinine dihydrochloride to the brain

Transferrin (Tf)‐conjugated solid lipid nanoparticles (SLNs) were investigated for their ability to deliver quinine dihydrochloride to the brain, for the management of cerebral malaria. SLNs were prepared by an ethanol injection method using hydrogenated soya phosphatidyl choline (HSPC), triolein, cholesterol and distearylphosphatidylethanolamine (DSPE). Coupling of SLNs with Tf was achieved by incubation of Tf with quinine‐loaded SLNs in the presence of 1‐ethyl‐3‐(3‐dimethylaminopropyl) carbodiimide (EDC) hydrochloride in phosphate buffered saline (pH 7.4) as a cross‐linker. SLNs were characterized for shape, particle size, polydispersity and percentage drug entrapment. The SLNs were 108–126 nm in size, and maximum drug entrapment was 38.4–42.7%. Average size increased on coupling with Tf but percentage drug entrapment was reduced. The in‐vitro release profile was determined using a dialysis technique; non‐conjugated SLNs released comparatively more drug than Tf‐SLNs. Fluorescence studies revealed enhanced uptake of Tf‐SLNs in brain tissue compared with unconjugated SLNs. In in‐vivo performance studies, quinine plasma level and tissue distribution after intravenous administration of drug‐loaded Tf‐SLNs and unconjugated SLNs was compared with that of free drug. Intravenous administration of quinine dihydrochloride solution resulted in much higher concentrations of drug in the serum than with SLNs. Conjugation of SLNs with Tf significantly enhanced the brain uptake of quinine which was shown by the recovery of a higher percentage of the dose from the brain following administration of Tf‐coupled SLNs compared with unconjugated SLNs or drug solution.

Design and development of ligand-appended polysaccharidic nanoparticles for the delivery of oxaliplatin in colorectal cancer

UNLABELLED Hyaluronic acid-coupled chitosan nanoparticles bearing oxaliplatin (L-OHP) encapsulated in Eudragit S100-coated pellets were developed for effective delivery to colon tumors. The in vitro drug release was investigated using a USP dissolution rate test paddle-type apparatus in different simulated gastrointestinal tract fluids. In therapeutic experiments the pellets of free drug, and hyaluronic acid-coupled and uncoupled chitosan nanoparticles bearing L-OHP were administered orally at the dose of 10 mg L-OHP/kg body weight to tumor-bearing Balb/c mice. In vivo data showed that hyaluronic acid-coupled chitosan nanoparticles delivered 1.99 +/- 0.82 and 9.36 +/- 1.10 microg of L-OHP/g of tissue in the colon and tumor, respectively after 12 hours, reflecting its targeting potential to the colon and tumor. These drug delivery systems show relatively high local drug concentration in the colonic milieu and colonic tumors with prolonged exposure time, which provides a potential to enhance antitumor efficacy with low systemic toxicity for the treatment of colon cancer. FROM THE CLINICAL EDITOR In this study, a nanoparticle system was developed to deliver oxaliplatin to colorectal tumors. In murine models, the drug delivery system showed relatively high local drug concentration in colonic tumors with prolonged exposure time, which provides a potential for enhanced antitumor efficacy with low systematic toxicity.

In vitro and cell uptake studies for targeting of ligand anchored nanoparticles for colon tumors

Hyaluronic acid (HA) coupled chitosan nanoparticles (HACTNP) bearing 5-flurouracil (5FU) were prepared, by ionotropic gelation method, for the effective delivery of drug to the colon tumors. HACTNP appeared to be spherical in shape and mean size was found to be around 150+/-3.4nm with low polydispersity index. The in vitro drug release was investigated using USP dissolution test (paddle type) apparatus in different simulated GIT fluids. The biocompatibility of NPs formulations were evaluated for in vitro cytotoxicity by MTT assay using HT-29 cell lines and cell uptake was assessed by fluorescent microscopy. Cellular uptake of HACTNP was determined by incorporating calcein as a fluorescent marker. The cellular uptake of fluorescent HACTNP was clearly evidenced by fluorescence microscopy. HACTNP nanoparticles showed significant higher uptake by cancer cells as compared to uncoupled nanoparticles and the uptake of HA coupled CTNPs by HT-29 colon cancer cells were observed to be 7.9 times more as compared to uncoupled CTNPs at the end of 4h. The cytotoxicity of 5FU incorporated in HACTNP was higher compared to the conventional 5FU solution, even at the lower concentrations. 5FU in HACTNP was about 2.60-folds more effective than free 5FU on HT-29 cells.

Mannosylated gelatin nanoparticles bearing an anti-HIV drug didanosine for site-specific delivery

The present investigation was aimed at developing and exploring the use of mannosylated gelatin nanoparticles for the selective delivery of an anti-HIV drug, didanosine, to the target organs. The mannosylated gelatin nanoparticles (MN-G-NPs) were prepared using a two-step desolvation technique and coupled with mannose using the amino group of gelatin present on the surface of nanoparticles. The mannosylation was confirmed using infrared and nuclear magnetic resonance spectroscopy. MN-G-NPs were characterized for shape, particle size, zeta potential, and percentage drug entrapment. The size of nanoparticles was found to be in range of 248-325 nm, and maximum drug payload was found to be 40.2% to 48.5%. Average size was found to be more, but drug payload was less in the case of MN-G-NPs as compared with unconjugated nanoparticles (G-NPs). The results of the in vitro release profile demonstrated that G-NPs release a comparatively higher percentage of drug than MN-G-NPs. Cellular uptake by MN-G-NPs was 2.7 times more as compared with G-NPs. Fluorescence studies revealed the enhanced uptake of MN-G-NPs in the macrophage tissues when compared with unmodified G-NPs. Intravenous administration of free-drug solution resulted in a high concentration of drug in serum, whereas it was much less in the case of G-NPs. Coupling of the nanoparticles with mannose significantly enhanced the lung, liver, and lymph nodes uptake of drug, which is reflected in the recovery of a higher percentage of the dose from these organs following administration of MN-G-NPs in comparison to noncoupled G-NPs or free drug.

Design and development of hydrogel beads for targeted drug delivery to the colon.

The purpose of this research was to develop and evaluate a multiparticulate system of chitosan hydrogel beads exploiting pH-sensitive property and specific biodegradability for colon-targeted delivery of satranidazole. Chitosan hydrogel beads were prepared by the cross-linking method followed by enteric coating with Eudragit S100. All formulations were evaluated for particle size, encapsulation efficiency, swellability, and in vitro drug release. The size of the beads was found to range from 1.04±0.82 mm to 1.95±0.05 mm. The amount of the drug released after 24 hours from the formulation was found to be 97.67%±1.25% in the presence of extracellular enzymes as compared with 64.71%±1.91% and 96.52%±1.81% release of drug after 3 and 6 days of enzyme induction, respectively, in the presence of 4% cecal content. Degradation of the chitosan hydrogel beads in the presence of extracellular enzymes as compared with rat cecal and colonic enzymes indicates the potential of this multiparticulate system to serve as a carrier to deliver macromolecules specifically to the colon and can be offered as a substitute in vitro system for performing degradation studies. Studies demonstrated that orally administered chitosan hydrogel beads can be used effectively for the delivery of drug to the colon.

Design and development of folate appended liposomes for enhanced delivery of 5-FU to tumor cells

Folate appended sterically-stabilized liposomes (FA–SL) were investigated for tumor targeting. Liposomes were prepared using HSPC, cholesterol and FA–polyethylene glycol (PEG)–SA. The liposomes with polyethylene glycol (PEG) without folic acid which has similar lipid composition were used for comparison. Liposomal preparations were characterized for shape, size and percent entrapment. The average size of liposomes was found to be in range 124–163 nm and maximum drug entrapment was found to be 34.2–40.3%. In vitro drug release from the formulations is obeying fickian release kinetics. Cellular uptake and IC50 values of the FR-targeted formulation were determined in vitro in FR (+) B16F10 melanoma cells. In vitro cell binding of FA–SL exhibits 11-folds higher binding to B16F10 melanoma cells in comparison to SL. In vivo cytotoxicy assay on FR targeted liposomes gave IC50 of 1.87 μM and non-targeted liposomes gave IC50 of 4.02 μM. In therapeutic experiments 5-fluorouracil (5-FU), SL and FA–SL were administered at the dose of 10 mg 5-FU/kg body weight to B16F10 tumor bearing Balb/c mice. Administration of FA–SL formulation results in effective reduction in tumor growth as compared with free 5-FU and SL. Results indicate that folic acid appended SL bearing 5-FU are significantly (P < 0.01) active against primary tumor and metastasis than non-targeted sterically-SL. Thus, it could be concluded that folate coupled liposomal formulations enhanced drug uptake by tumor cells.

Development and characterization of 5-FU bearing ferritin appended solid lipid nanoparticles for tumour targeting

Ferritin coupled solid lipid nanoparticles were investigated for tumour targeting. Solid lipid nanoparticles were prepared using HSPC, cholesterol, DSPE and triolien. The SLNs without ferritin which has similar lipid composition were used for comparison. SLNs preparations were characterized for shape, size and percentage entrapment. The average size of SLNs was found to be in the range 110–152 nm and maximum drug entrapment was found to be 34.6–39.1%. In vitro drug release from the formulations is obeying fickian release kinetics. Cellular uptake and IC50 values of the formulation were determined in vitro in MDA-MB-468 breast cancer cells. In vitro cell binding of Fr-SLN exhibits 7.7-folds higher binding to MDA-MB-468 breast cancer cells in comparison to plain SLNs. Ex-vivo cytotoxicity assay on targeted nanoparticles gave IC50 of 1.28 µM and non-targeted nanoparticles gave IC50 of 3.56 µM. In therapeutic experiments, 5-FU, SLNs and Fr-SLNs were administered at the dose of 10 mg 5-FU/kg body weight to MDA-MB-468 tumour bearing Balb/c mice. Administration of Fr-SLNs formulation results in effective reduction in tumour growth as compared with free 5-FU and plain SLNs. The result demonstrates that this delivery system possessed an enhanced anti-tumour activity. The results warrant further evaluation of this delivery system.

Potential of calcium pectinate beads for target specific drug release to colon

A pectin-based colon specific delivery system bearing 5-fluorouracil (5-FU) was developed for effective delivery of drug to the colon. Calcium pectinate gel (CPG) beads were prepared by ionotropic gelation method followed by enteric coating with Eudragit S-100. The CPG beads formed were spherical with smooth surfaces. CPG beads size was found to be in the range of 1.32 ± 0.12–1.88 ± 0.08 mm. The in vitro drug release was investigated using USP dissolution rate test paddle type apparatus in different simulated mediums. Release in PBS (pH 7.4) and simulated gastric fluid showed almost similar pattern and rate, whereas a significant increase in percent cumulative drug release (58.3 ± 1.36%) was observed in medium containing rat caecal content, i.e. the amount of the drug released from the formulation was found to be 49.2 ± 2.29 and 58.3 ± 1.36% of drug with 2 and 4% w/v caecal matter after 24 h whereas in control study 33.2 ± 1.19% of drug was released. Moreover, to induce the enzymes that specifically act on pectin, the rats were treated with 1 ml of 1% w/v dispersion of pectin for 2 and 4 days and release rate studies were repeated in SCF in the presence of 2 and 4% w/v of caecal matter. A marked improvement in the drug release was observed in presence of caecal matter obtained after induction when compared to those without induction. The percentage of drug released after 24 h release was observed to be 69.3 ± 2.81 and 86.7 ± 3.15%, respectively, with 2 and 4% w/v rat caecal matter obtained after 2 days of enzyme induction, and 82.4 ± 3.15 and 98.7 ± 4.26%, respectively, after 4 days of enzyme induction. In vivo data showed that Eudragit S-100 coated calcium pectinate beads delivered most of its drug load (93.2 ± 3.67%) to the colon after 9 h, which reflects its targeting potential to the colon. It is concluded that orally-ssadministered 5-FU loaded Eudragit S-100 coated calcium pectinate beads can be used effectively for the specific delivery of drug to the colon.

Target-specific drug release to the colon

Background: The ability to deliver drugs to the human colon in a specific manner has become feasible over the years. Targeting pharmaceutical drugs to the colon makes it possible to achieve local or systemic drug delivery to this site. Objective: To deliver the compounds in a non-degraded form to the lower part of the gastrointestinal tract, they must first pass through the stomach and the upper part of the intestine before releasing the contents in the colon. Methods: This review provides an overview of the various approaches to targeted drug delivery to the colon using different drug delivery systems, their limitations and the future developments in this field. Results/conclusions: A microbially controlled system, which is a well-accepted approach, based on natural polymers, has the greatest potential for colonic delivery, particularly in terms of site specificity and safety. However, close attention should be paid to the performance of these products in the heterogeneous environment of the human gastrointestinal tract.

Multivesicular Liposomes Bearing Celecoxib-β-Cyclodextrin Complex for Transdermal Delivery

In our work depot delivery systems of celecoxib were developed using multivesicular liposomes. Moreover, the solubility of celecoxib was enhanced by complexing drug with cyclodextrin to overcome the limitation of conventional therapy. The multivesicular liposomes (MVLs) bearing celecoxib-β -cyclodextrin inclusion complex were prepared by reverse phase evaporation method, and multilamellar vesicles (MLVs)-bearing drug complex was prepared by the cast film method. The formulations were characterized for vesicle size, encapsulation efficiency, and in vitro drug release. In vivo performance of multivesicular liposomes bearing celecoxib-β -cyclodextrin inclusion complex was evaluated by assessing anti-inflammatory activity using carrageenan-induced rat paw edema volume method. The results were compared with that of celecoxib-cyclodextrin complex and MLVs containing celecoxib-β -cyclodextrin inclusion complex in equal amounts. Phase solubility studies for the celecoxib-β -cyclodextrin inclusion complex clearly indicated an increase in aqueous solubility of celecoxib with an increase in β –CD concentration. The in vitro release studies reveal that MLVs release more than 80% drug within 48 hr whereas MVL formulations release nearly the same amount of drug in 120 hr. In vivo data reveal that reduction in paw volume with MVL formulation was not rapid and fast, but the effect was maintained for prolonged periods, and even after 24 hr there was 40.7 ± 3.40% reduction in paw volume. MVL formulation showed more sustained and prolonged anti-inflammatory effect compared with plain drug and MLVs. We concluded that multivesicular liposome can be successfully utilized for the sustained delivery of celecoxib.