Sunil K. Jain

A PEGylated dendritic nanoparticulate carrier of fluorouracil

The present study was aimed at developing and exploring the use of uncoated and PEGylated newer PAMAM dendrimers for delivery of anti-cancer drug 5-fluorouracil. For this study, successive Michael addition and exhaustive amidation reactions were used to synthesize 4.0 G PAMAM dendrimers, using ethylenediamine as core and methylmethacrylate as propagating agent. The dendrimer was PEGylated using N-hydroxysuccinimide-activated carboxymethyl MPEG-5000. IR and NMR data proved the synthesis. Various physicochemical parameters, SEM, TEM, lambda(max) values, hemolytic toxicity, drug entrapment, drug release and blood-level studies of both PEGylated and non-PEGylated systems were determined and compared. The PEGylation of the systems was found to have increased their drug-loading capacity, reduced their drug release rate and hemolytic toxicity. TEM study revealed surface properties of the systems. Stability studies had shown its stability at room temperature in dark. The systems were found suitable for prolonged delivery of an anti-cancer drug by in vitro and blood-level studies in albino rats, without producing any significant hematological disturbances. PEGylation has been found to be suitable for modification of PAMAM dendrimers for reduction of drug leakage and hemolytic toxicity. This, in turn, could improve drug-loading capacity and stabilize such systems in body. The study suggests use of such PEGylated dendrimeric systems as nanoparticulate depot type of system for drug administration.

Eudragit-coated pectin microspheres of 5-fluorouracil for colon targeting.

An objective of the present investigation was to prepare and evaluate Eudragit-coated pectin microspheres for colon targeting of 5-fluorouracil (FU). Pectin microspheres were prepared by emulsion dehydration method using different ratios of FU and pectin (1:3 to 1:6), stirring speeds (500–2000 rpm) and emulsifier concentrations (0.75%–1.5% wt/vol). The yield of preparation and the encapsulation efficiencies were high for all pectin microspheres. Microspheres prepared by using drug:polymer ratio 1:4, stirring speed 1000 rpm, and 1.25% wt/vol concentration of emulsifying agent were selected as an optimized formulation. Eudragit-coating of pectin microspheres was performed by oil-in-oil solvent evaporation method using coat: core ratio (5:1). Pectin microspheres and Eudragit-coated pectin microspheres were evaluated for surface morphology, particle size and size distribution, swellability, percentage drug entrapment, and in vitro drug release in simulated gastrointestinal fluids (SGF). The in vitro drug release study of optimized formulation was also performed in simulated colonic fluid in the presence of 2% rat cecal content. Organ distribution study in albino rats was performed to establish the targeting potential of optimized formulation in the colon. The release profile of FU from Eudragit-coated pectin microspheres was pH dependent. In acidic medium, the release rate was much slower; however, the drug was released quickly at pH 7.4. It is concluded from the present investigation that Eudragit-coated pectin microspheres are promising controlled release carriers for colon-targeted delivery of FU.

Evaluation of porous carrier-based floating orlistat microspheres for gastric delivery

The purpose of this research was to prepare floating microspheres consisting of (1) calcium silicate as porous carrier; (2) orlistat, an oral anti-obesity agent; and (3) Eudragit S as polymer, by solvent evaporation method and to evaluate their gastro-retentive and controlled-release properties. The effect of various formulation and process variables on the particle morphology, micromeritic properties, in vitro floating behavior, percentage drug entrapment, and in vitro drug release was studied. The gamma scintigraphy of the optimized formulation was performed in albino rabbits to monitor the transit of floating microspheres in the gastrointestinal tract. The orlistat-loaded optimized formulation was orally administered to albino rabbits, and blood samples collected were used to determine pharmacokinetic parameters of orlistat from floating microspheres. The microspheres were found to be regular in sphae and highly porous. Microsphere formulation CS4, containing 200 mg calcium silicate, showed the best floating ability (88%±4% buoyancy) in simulated gastric fluid as compared with other formulations. Release pattern of orlistat in simulated gastric fluid from all floating microspheres followed Higuchi matrix model and Peppas-Korsmeyer model. Prolonged gastric residence time of over 6 hours was achieved in all rabbits for calcium silicate-based floating microspheres of orlistat. The enhanced elimination half-life observed after pharmacokinetic investigations in the present study is due to the floating nature of the designed formulations.

Evaluation of neuropeptide loaded trimethyl chitosan nanoparticles for nose to brain delivery

Leucine-enkephalin (Leu-Enk) is a neurotransmitter or neuromodulator in pain transmission. Due to non-addictive opioid analgesic activity of this peptide, it might have great potential in pain management. Leu-Enk loaded N-trimethyl chitosan (TMC) nanoparticles were prepared and evaluated as a brain delivery vehicle via nasal route. TMC biopolymer was synthesized and analyzed by (1)H NMR spectroscopy. TMC nanoparticles were prepared by ionic gelation method. Mean peptide encapsulation efficiency and loading capacity were 78.28±3.8% and 14±1.3%, respectively. Mean particle size, polydispersity index and zeta potential were found to be 443±23 nm, 0.317±0.17 and +15±2 mV respectively for optimized formulations. Apparent permeability coefficient (Papp) of Leu-Enk released from nanoparticles across the porcine nasal mucosa was determined to be 7.45±0.30×10(-6) cm s(-1). Permeability of Leu-Enk released from nanoparticles was 35 fold improved from the nasal mucosa as compared to Leu-Enk solution. Fluorescent microscopy of brain sections of mice showed higher accumulation of fluorescent marker NBD-F labelled Leu-Enk, when administered nasally by TMC nanoparticles, while low brain uptake of marker solution was observed. Furthermore, enhancement in brain uptake resulted into significant improvement in the observed antinociceptive effect of Leu-Enk as evidenced by hot plate and acetic acid induced writhing assay.

Nasal-nanotechnology: revolution for efficient therapeutics delivery

Abstract Context: In recent years, nanotechnology-based delivery systems have gained interest to overcome the problems of restricted absorption of therapeutic agents from the nasal cavity, depending upon the physicochemical properties of the drug and physiological properties of the human nose. Objective: The well-tolerated and non-invasive nasal drug delivery when combined with the nanotechnology-based novel formulations and carriers, opens the way for the effective systemic and brain targeting delivery of various therapeutic agents. To accomplish competent drug delivery, it is imperative to recognize the interactions among the nanomaterials and the nasal biological environment, targeting cell-surface receptors, drug release, multiple drug administration, stability of therapeutic agents and molecular mechanisms of cell signaling involved in patho-biology of the disease under consideration. Methods: Quite a few systems have been successfully formulated using nanomaterials for intranasal (IN) delivery. Carbon nanotubes (CNTs), chitosan, polylactic-co-glycolic acid (PLGA) and PLGA-based nanosystems have also been studied in vitro and in vivo for the delivery of several therapeutic agents which shown promising concentrations in the brain after nasal administration. Results and conclusion: The use of nanomaterials including peptide-based nanotubes and nanogels (NGs) for vaccine delivery via nasal route is a new approach to control the disease progression. In this review, the recent developments in nanotechnology utilized for nasal drug delivery have been discussed.

Con-A conjugated mucoadhesive microspheres for the colonic delivery of diloxanide furoate

The aim of the research work was to develop cyst-targeted novel concanavalin-A (Con-A) conjugated mucoadhesive microspheres of diloxanide furoate (DF) for the effective treatment of amoebiasis. Eudragit microspheres of DF were prepared using emulsification-solvent evaporation method. Formulations were characterized for particle size and size distribution, % drug entrapment, surface morphology and in vitro drug release in simulated gastrointestinal (GI) fluids. Eudragit microspheres of DF were conjugated with Con-A. IR spectroscopy and DSC were used to confirm successful conjugation of Con-A to Eudragit microspheres while Con-A conjugated microspheres were further characterized using the parameters of zeta potential, mucoadhesiveness to colonic mucosa and Con-A conjugation efficiency with microspheres. IR studies confirmed the attachment of Con-A with Eudragit microspheres. All the microsphere formulations showed good % drug entrapment (78+/-5%). Zeta potential of Eudragit microspheres and Con-A conjugated Eudragit microspheres were found to be 3.12+/-0.7mV and 16.12+/-0.5mV, respectively. Attachment of lectin to the Eudragit microspheres significantly increases the mucoadhesiveness and also controls the release of DF in simulated GI fluids. Gamma scintigraphy study suggested that Eudragit S100 coated gelatin capsule retarded the release of Con-A conjugated microspheres at low pH and released microspheres slowly at pH 7.4 in the colon.

Porous Carrier Based Floating Granular Delivery System of Repaglinide

ABSTRACT A floating granular delivery system consisting of calcium silicate (CS) as porous carrier; repaglinide (Rg), an oral hypoglycemic agent; and hydroxypropyl methylcellulose K4M (HPMC K4M), ethyl cellulose (EC) and carbopol 940 (CP940) as matrix forming polymers was prepared and evaluated for its gastro-retentive and controlled release properties. The effect of various formulation and process variables on the particle morphology, micromeritic properties, in vitro floating behavior, drug content (%) and in vitro drug release was studied. The transit of floating granules of optimized formulation in the gastrointestinal (GI) tract was monitored by gamma scintigraphy in albino rabbits. The optimized formulation was compared in vivo with lactose granules (RgSCLG) prepared from identical polymers with their optimized composition ratio. Repaglinide-loaded optimized formulation was orally administered to albino rabbits and blood samples collected were used to determine pharmacokinetic parameters of Rg from floating granular formulation. Results were compared with pharmacokinetic parameters of marketed tablet formulation of Rg. The optimized formulation (RgSCG4) demonstrated favorable in vitro floating and release characteristics. Prolonged gastric residence time (GRT) of over 6 hr was achieved in all subjects for calcium silicate based floating granules of Rg. The relative bioavailability of Rg-loaded floating granules increased 3.8-fold in comparison to that of its marketed capsule. The designed system, combining excellent buoyant ability and suitable drug release pattern, offered clear advantages in terms of increased bioavailability of repaglinide.

Controlling release of metformin HCl through incorporation into stomach specific floating alginate beads.

The aim of present study was to develop stomach specific floating beads of metformin hydrochloride for effective management of type 2 diabetes mellitus. The beads were evaluated for surface morphology, particle size, tapped density, true density, percent porosity, drug entrapment efficiency, percent yield, differential scanning calorimetry, in vitro floating ability and in vitro drug release. Stability studies were performed at 25 and 40 °C up to 45 days. Effectiveness of the formulations was evaluated in vivo by hypoglycemic response in both normal and diabetic albino rats. The beads were grossly spherical in shape, and average particle diameter of beads was found to be in the size range of 861.34 to 991.75 μm. Percent entrapment was found to be in the range of 77.61 to 82.48%. Beads demonstrated favorable in vitro floating ability. All the formulations followed a non-Fickian release mechanism. It was found that there was no significant effect on floating ability of aged beads since it floated up to an 8 h study period. In vivo studies on diabetic rats showed that the hypoglycemic effect induced by the metformin hydrochloride loaded alginate beads was significantly greater (P < 0.05) and more prolonged than that induced by the nonfloating beads. The results clearly demonstrated the ability of the formulation to maintain blood glucose level and improved the patient compliance by enhancing, controlling and prolonging the systemic absorption of metformin hydrochloride.

Colorectal cancer-targeted delivery of oxaliplatin via folic acid-grafted solid lipid nanoparticles: preparation, optimization, and in vitro evaluation

Abstract Objective: Colorectal cancer (CRC) ranked second in females and third in males among all type of cancers diagnosed. About 1.4 million cases took place with 693,900 deaths in 2012. It can occur either in colon or rectum. Thus, we aimed to develop and optimize oxaliplatin (OP) loaded solid lipid nanoparticles (SLNs). Materials and methods: SLNs containing tristearin, 1,2-distearoyl-sn-glycero-3-phosphoethanolamine (DSPE), Lipoid S75, and Tween 80 was developed. Box–Behnken design was applied for optimization of SLNs and optimized formulation was selected for conjugation with folic acid (FA). Optimized formulations were evaluated for various physiochemical parameters viz., particle size (PS), zeta potential, %entrapment efficiency (EE), morphology, X-ray diffraction (XRD), and differential scanning calorimetry (DSC). Results and discussion: OP loaded uncoupled SLNs (OPSLNs) and OP loaded FA coupled SLNs (OPSLNFs) formulations revealed good EE, 49.2 ± 0.38% and 43.5 ± 0.59%, respectively and small PS, 146.2 ± 4.4 nm, and 158.8 ± 5.6 nm, respectively. XRD pattern and DSC results confirmed that OP was uniformly distributed in amorphous form within SLNs. In vitro drug release study of OPSLNs and OPSLNFs formulation revealed sustained drug release pattern of OP for up to 6 d. Anticancer activity on HT-29 cell line indicated the highest potency of OPSLNFs as compared to OPSLNs and OP solution. Conclusion: The present work illustrated the higher sensitivity of HT-29 cells to the drug entrapped in OPSLNFs as compared to OPSLNs and OP solution. Hence, this novel strategy might be a promising approach for the management of CRC.

Preliminary studies for the development of intranasal nanoemulsion containing CNS agent: emphasizing the utilization of cut and weigh method

Abstract Context: The selection of excipients and preformulation strategy plays a vital role for the development of nanoemulsion, due to anatomical and physiological challenges posed by nasal cavity. Objective: This attempt is focused on the selection and optimization of excipients for the development of a nanoemulsion system for intranasal delivery. Materials and methods: Excipients were selected on the basis of solubility of active drug, compatibility interactions and nasal irritancy. Surfactant and co-surfactant combination and their ratio were finalized on the basis of nanoemulsion region obtained from constructed phase diagrams with Capmul MCM as oil phase. A validated cut and weigh method was employed for the optimization of different phase diagrams with respect to nanoemulsion region. Results and discussion: The solubility of drug in Capmul MCM, Labrasol, and Transcutol-P was found to be superior with numeric values of 79.50 ± 1.68 mg/ml, 51.10 ± 1.39 mg/ml, and 36.60 ± 0.85 mg/ml, respectively. On the basis of phase diagram analysis, Labrasol and Transcutol-P in 3:1 ratio provides greater nanoemulsion region of 65.28 ± 0.18%. The validation of cut and weigh method revealed that there was no significant statistical difference (P > 0.05) with a %RSD value of 2.38 for intersheet variation. Conclusion: The results of validation studies for cut and weigh method suggests that it can be effectively used as an optimization method for the selection of nanoemulsion composition.