Particulate Drug Delivery Research Articles

Theoretical study on the stability of insulin within poly-isobutyl cyanoacrylate (PIBCA) nanocapsule

ABSTRACTTo study the physical stability of insulin in drug delivery particles, we developed a coarse-grained (CG) model for insulin based on dissipative particle dynamics (DPD). Three insulin modelling schemes were considered: each amino acid as a bead (IM1), each amino acid being separated into one to three beads (IM2), and adding secondary structural information of insulin to IM2 (IM3). The best possible bead-bead interaction parameters were obtained from Hildebrand and Hansen solubility parameters by performing the constant-temperature DPD simulation with insulin models in 20% acetic acid solution. IM3 showed good results in terms of RMSF, RMSD and A1B30 distance compared to those of all-atom models from the literature. Then, the IM3 model was considered in an oil-filled poly (isobutyl cyanoacrylate) (PIBCA) nanocapsule. Two crucial factors were found that mainly influence the stability of insulin in oil: the PIBCA shell thickness and the amount of ethanol in the oil droplet. An appropriate PIBCA shell thickness is necessary to block the interaction between insulin and water outside, and ethanol could stabilise insulin with its good affinity for both insulin and oil.

Combining activatable nanodelivery with immunotherapy in a murine breast cancer model

A successful chemotherapy-immunotherapy solid-tumor protocol should accomplish the following goals: debulk large tumors, release tumor antigen for cross-presentation and cross-priming, release cancer-suppressive cytokines and enhance anti-tumor immune cell populations. Thermally-activated drug delivery particles have the potential to synergize with immunotherapeutics to accomplish these goals; activation can release chemotherapy within bulky solid tumors and can enhance response when combined with immunotherapy. We set out to determine whether a single protocol, combining locally-activated chemotherapy and agonist immunotherapy, could accomplish these goals and yield a potentially translational therapy. For effective delivery of free doxorubicin to tumors with minimal toxicity, we stabilized doxorubicin with copper in temperature-sensitive liposomes that rapidly release free drug in the vasculature of cancer lesions upon exposure to ultrasound-mediated hyperthermia. We found that in vitro exposure of tumor cells to hyperthermia and doxorubicin resulted in immunogenic cell death and the local release of type I interferons across murine cancer cell lines. Following intravenous injection, local activation of the liposomes within a single tumor released doxorubicin and enhanced cross-presentation of a model antigen at distant tumor sites. While a variety of protocols achieved a complete response in >50% of treated mice, the complete response rate was greatest (90%) when 1 week of immunotherapy priming preceded a single activatable chemotherapeutic administration. While repeated chemotherapeutic delivery reduced local viable tumor, the complete response rate and a subset of tumor immune cells were also reduced. Taken together, the results suggest that activatable chemotherapy can enhance adjuvant immunotherapy; however, in a murine model the systemic adaptive immune response was greatest with a single administration of chemotherapy.

Feasibility Study of Mesoporous Silica Particles for Pulmonary Drug Delivery: Therapeutic Treatment with Dexamethasone in a Mouse Model of Airway Inflammation.

Diseases in the respiratory tract rank among the leading causes of death in the world, and thus novel and optimized treatments are needed. The lungs offer a large surface for drug absorption, and the inhalation of aerosolized drugs are a well-established therapeutic modality for local treatment of lung conditions. Nanoparticle-based drug delivery platforms are gaining importance for use through the pulmonary route. By using porous carrier matrices, higher doses of especially poorly soluble drugs can be administered locally, reducing their side effects and improving their biodistribution. In this study, the feasibility of mesoporous silica particles (MSPs) as carriers for anti-inflammatory drugs in the treatment of airway inflammation was investigated. Two different sizes of particles on the micron and nanoscale (1 µm and 200 nm) were produced, and were loaded with dexamethasone (DEX) to a loading degree of 1:1 DEX:MSP. These particles were further surface-functionalized with a polyethylene glycol–polyethylene imine (PEG–PEI) copolymer for optimal aqueous dispersibility. The drug-loaded particles were administered as an aerosol, through inhalation to two different mice models of neutrophil-induced (by melphalan or lipopolysaccharide) airway inflammation. The mice received treatment with either DEX-loaded MSPs or, as controls, empty MSPs or DEX only; and were evaluated for treatment effects 24 h after exposure. The results show that the MEL-induced airway inflammation could be treated by the DEX-loaded MSPs to the same extent as free DEX. Interestingly, in the case of LPS-induced inflammation, even the empty MSPs significantly down-modulated the inflammatory response. This study highlights the potential of MSPs as drug carriers for the treatment of diseases in the airways.

Magnetic nano-particles retrievable biodegradable hydrogel microrobot

Drug therapy using cancer-targeted drug delivery particles is widely adopted as a general anti-cancer therapy. In this approach, anticancer drug particles target mainly cancer cells, thereby reducing the side effects caused by anticancer drug particles against normal cells. However, these cancer-targeted drug delivery particles still have many risks due to uncertainty in their ability to target cancer cells. Microrobots may overcome this problem by delivering therapeutic drugs to a cancer cell target lesion via electromagnetic actuation. Generally, microrobots include an anti-cancer drug and magnetic nanoparticles (MNPs) for their electromagnetic actuation. However, the MNPs may remain and cause toxicity in the body after the drug delivery. To remedy this, we propose a new type of microrobot that can deliver an anti-cancer drug to cancer target lesion and retrieve the problematic MNPs. The proposed microrobot consists of a gelatin/poly vinyl alcohol (PVA) based hydrogel, MNPs and poly lactic-co-glycolic acid particles carrying doxorubicin (PLGA–DOX particles). The targeting and the retrieval of MNPs from the hydrogel microrobot is accomplished by a fabricated customized electromagnetic actuation (EMA) and near-infra red (NIR) integrated system. First, the hydrogel microrobot reaches a pre-determined target lesion by the magnetic field of the EMA system. Next, after NIR irradiation, the gelatin/PVA of the hydrogel microrobot is decomposed and the MNPs and PLGA–DOX drug particles are left in the target area. After the disassembled MNPs are recovered out of the target lesion by the magnetic field of the EMA system, only the PLGA–DOX particles remain in the target area. Finally, the anti-cancer drug can be released from the remaining PLGA–DOX particles and can generate a therapeutic effect in the target lesion. In this study, we fabricated the hydrogel microrobot, analyzed its characteristics (shape, size, magnetization, and drug encapsulation), verified the possibilities of targeting and disassembly of the hydrogel microrobot, and proved the retrieval of MNPs and the drug delivery from the remaining PLGA–DOX particles. Additionally, we executed the drug-releasing experiment using PLGA–DOX particles and confirmed the therapeutic effect of the hydrogel microrobot through an in vitro test using Hep3B cancer cell. We conclude that the proposed hydrogel microrobot is a new type of biocompatible microrobot with the capability of active targeting as well as toxic MNP retrieval.

Time scale based analysis of in-situ crystal formation in droplet undergoing rapid dehydration

The surface structure of crystalline particles affects the functionality of the particles in drug delivery. Prediction of the final structure of particles that crystallize easily within the spray drying process is of interests for many applications. A theoretical framework was developed for the prediction of crystal structure precipitating on the surface of the particle. This model was based on the dimensionless Damkohler number (Da), to be an indicator of final particle morphology. Timescales of evaporation and reaction were required for calculation of the Damkohler number. The modified evaporation time scale was estimated based on the time that is available for the crystal to precipitate after supersaturation. The reaction time scale was estimated based on the time scale for induction time. Mannitol was produced under different processing conditions in order to validate the theoretical model. Results showed for the high Damkohler numbers, the surface structure of the particle was rough, while smaller Damkohler numbers led to relatively smooth particle surfaces. Additionally, although the beta polymorph was dominant in all of the experiments, alpha polymorph was precipitated in the experiments with a large Damkohler number. The theoretical framework developed will be a useful predictive tool to guide the manipulation of particle crystallization in spray dryers.

Impact of Nanoparticulate Drug Delivery System of Herbal Drug in Control of Diabetes Mellitus

Aim: The main objective of the current study is to organize and evaluate polymeric nanoparticles for the selected drug Gymnemic acid, improve the bioavailability of poorly bioavailable gymnemic acid, enhance the anti-diabetic activity of Gymnemic acid, reduce the dose size of Gymnemic acid by reducing the particle size. Method and procedure: Gymnemic acid nanoparticles was prepared through emulsion-droplet coalescence method, by using chitosan polymer (GNP1-GNP5). Based on the invitro drug release profile of Gymnemic acid nanoparticles formulations (GNP1-GNP5) formulation GNP3 is selected as the best preparation in which the particle size was 195 nm[1]. Since from ancient times the naturopathic treatment for diseases has been explored widely and in advance momentum in the present situation, and has several pharmacological significance. Nano particulate drug delivery systems symbolize a promising drug delivery system[2] in recent years for its prescribed and targeted drug release. They exists as with a size choice of 10-1000nm, in which the drug or dissolved active ingredient, encapsulated, entrapped, absorbed or attached to the matrix system. The present research is a development of nanoparticulate[3,4] drug delivery system for Gymnema sylvestre by ionic gelation method. The formulation is characterized by particle size, zeta potential, particle morphology and best formulation was selected for the further studies. Result: The Gymnemic acid nanoparticles [1] were formulated and evaluated for its invitro drug release profile. The results showed that the in vitro drug release for GNP1, GNP2, GNP3, GNP4 and GNP5 were found 99.55± 0.89, 99.51± 0.34, 99.57± 0.31,78.82± 0.82 and 65.73± 0.62 respectively at the end of 24hrs. Conclusion: It can be concluded that the newly formulated controlled release nanoparticulate drug delivery[32] systems of Gymnemic acid may be ideal and effective in the treatment of diabetes mellitus by allowing the drug to release continuously for 24 hrs.

Neuroprotective efficacy of a multi‐loaded micro particulate drug delivery system in an ocular hypertension model of glaucoma

Neuroprotective efficacy of a multi‐loaded micro particulate drug delivery system in an ocular hypertension model of glaucoma

Multifunctional magnetic ZnFe2O4-hydroxyapatite nanocomposite particles for local anti-cancer drug delivery and bacterial infection inhibition: An in vitro study

Abstract In this study, a co-precipitation method was applied to synthesize the ZnFe2O4 and ZnFe2O4 Hydrxoapatite (HAp) nanostructures. The microstructure and morphological characteristics of the nanoparticles were studied and well discussed. A dose-dependent biological evaluation comprising of their minimum inhibitory concentration (MIC) antibacterial features as well as their magnetic characteristics were analyzed. The results of vibrating-sample magnetometer (VSM) showed nanoscaled ZnFe2O4 HAp had lower saturation magnetization as well as higher coercive field than ZnFe2O4, which enables the ZnFe2O4 HAp nanoparticles to stimulate cell proliferation, differentiation and adhesion. A remarkable inhibitory effect of the nanoscaled ZnFe2O4 HAp was recognized on bacterial proliferation and growth in the optimal dose, 0.078 mg/L. Besides, a dose-dependent cytocompatibility tests of the nanoparticles on the HEK normal cell and G292 cancer cell was assessed by 3-(4,5-Dimethylthiazol-2-Yl)-2,5-Diphenyltetrazolium Bromide assay (MTT). All nanoparticles were cytocompatible and no cytotoxicity effect on normal and cancer cells was observed in the dose-dependent test. In addition, an in vitro test of the drug release from drug-loaded ZnFe2O4-HAp nanocarrier were investigated and well described. The Inhibitory effect of the drug-loaded ZnFe2O4-HAp nanoparticles was investigated in-vitro so that the nanoparticle possessed the ability for inhibiting cancer cell proliferation and growth. By the increment of the nanoparticles concentrations, G292 cancer cell proliferation was inhibited, while, HEK normal cell proliferation was stimulated. Conclusively for the first time, a robust composite based nanostructure as a promising material was developed for multiple applications of bone filler, drug delivery and cancer treatment.

Fabricated porous silk fibroin particles for pH-responsive drug delivery and targeting of tumor cells

To improve the roles of tumor drug, porous silk fibroin particles have been designed as drug carriers. Doxorubicin (DOX) is encapsulated during the fabrication process of the silk fibroin particles to form DOX loaded silk fibroin particles (SFPs-DOX). Folic acid (FA) is covalently grafted to the surface of the silk fibroin particles (FA-SFPs-DOX) as a target group to the folate receptor of tumor cells. The experimental results showed that under the conditions of low pH, high ionic strength and high enzyme concentration, the release of loaded drugs in particles has stimulus response under various conditions. The synthesized silk fibroin particles have good biocompatibility. The specific binding of fibroin particles to folate receptors provides the particles to with target functions to the tumor cells. The job develops potential application of silk fibroin particles as smart drug carriers for the targeted therapy of tumor.

Mechanosensitive Endocytosis of High-Stiffness, Submicron Microgels in Macrophage and Hepatocarcinoma Cell Lines.

The mechanical properties of submicron particles offer a unique design space for advanced drug-delivery particle engineering. However, the recognition of this potential is limited by a poor consensus about both the specificity and sensitivity of mechanosensitive endocytosis over a broad particle stiffness range. In this report, our model series of polystyrene-co-poly(N-isopropylacrylamide) (pS-co-NIPAM) microgels have been prepared with a nominally constant monomer composition (50 mol % styrene and 50 mol % NIPAM) with varied bis-acrylamide cross-linking densities to introduce a tuned spectrum of particle mechanics without significant variation in particle size and surface charge. While previous mechanosensitive studies use particles with moduli ranging from 15 kPa to 20 MPa, the pS-co-NIPAM particles have Young's moduli (E) ranging from 300 to 700 MPa, which is drastically stiffer than these previous studies as well as pure pNIPAM. Despite this elevated stiffness, particle uptake in RAW264.7 murine macrophages displays a clear stiffness dependence, with a significant increase in particle uptake for our softest microgels after a 4 h incubation. Preferential uptake of the softest microgel, pS-co-NIPAM-1 (E = 310 kPa), was similarly observed with nonphagocytic HepG2 hepatoma cells; however, the uptake kinetics were distinct relative to that observed for RAW264.7 cells. Pharmacological inhibitors, used to probe for specific routes of particle internalization, identify actin- and microtubule-dependent pathways in RAW264.7 cells as sensitive particle mechanics. For our pS-co-NIPAM particles at nominally 300-400 nm in size, this microtubule-dependent pathway was interpreted as a phagocytic route. For our high-stiffness microgel series, this study provides evidence of cell-specific, mechanosensitive endocytosis in a distinctly new stiffness regime that will further broaden the functional landscape of mechanics as a design space for particle engineering.

Light-Scattering Sizing of Single Submicron Particles by High-Sensitivity Flow Cytometry.

Rapid and reliable size measurement of single submicron particles (100-1000 nm) is important for quality control of particulate matter, biomedical research, environmental study, and drug delivery system development. Though direct measurement of the elastically scattered light from individual submicron particles represents the simplest method for particle size measurement, the inadequate instrument sensitivity and complicated relationship between scattering intensity and particle size render it a great challenge. Combining the superior sensitivity of a laboratory-built high-sensitivity flow cytometer (HSFCM) in the side scattering (SSC) detection of single nanoparticles and the great efforts in synthesizing 38 highly monodisperse silica spheres ranging from 180 to 880 nm with small size intervals, here we report the first comprehensive comparison between the experimentally measured and Mie theory calculated intensities of light scattered by single submicron particles. Good agreements were observed for both the silica spheres and polystyrene beads at both the perpendicular and the parallel polarizations of the incident laser beam. Compared with perpendicular polarization, parallel polarization can resolve differently sized beads better due to the continuously increased scattering intensity with particle size. The predictive capability of the simple numerical model constructed in present work can be exploited to allow us to foresee scattering behavior on flow cytometers. More importantly, the linear correlation between the measured and the calculated scattering intensities enables us to develop a method that can measure the particle size of submicron particles with the precision and accuracy of Mie theory rather than a calibration curve fitted by several sparsely separated size reference standards. Comparable sizing resolution and accuracy to those of electron microscopy were demonstrated for Gram-positive bacteria Staphylococcus aureus. The as-developed method shows great potential in guiding the accurate size measurement of submicron particles.

PEGylation of model drug carriers enhances phagocytosis by primary human neutrophils

Targeted drug carriers are attractive for the delivery of therapeutics directly to the site of a disease, reducing systemic side effects and enhancing the efficacy of therapeutic molecules. However, the use of particulate carriers for drug delivery comes with its own set of challenges and barriers. Among these, a great deal of research effort has focused on protecting carriers from clearance by phagocytes via altering carrier surface chemistry, mostly with the use of polyethylene glycol (PEG) chain coatings. However, few papers have explored the effects of PEGylation on uptake by freshly-obtained primary human phagocytes in physiological conditions. In this work, we investigate the effect of PEGylation on particle uptake by primary human neutrophils in vitro and compare these effects to several cell lines and other model phagocytic cells systems. We find that human neutrophils in whole blood preferentially phagocytose PEGylated particles (e.g., ∼40% particle positive neutrophils for PEGylated versus ∼20% for carboxylated polystyrene microspheres) and that this effect is linked to factors present in human plasma. Model phagocytes internalized PEGylated particles less efficiently or equivalently to carboxylated particles in culture medium but preferentially phagocytosed PEGylated particles in the human plasma (e.g., ∼86% versus ∼63% PEGylated versus carboxylated particle positive cells, respectively). These findings have significant implications for the efficacy of PEGylation in designing long-circulating drug carriers, as well as the need for thorough characterization of drug carrier platforms in a wide array of in vitro and in vivo assays. Statement of SignificanceThe work in this manuscript is highly significant to the field of drug delivery, as it explores in-depth the effects of polyethylene glycol (PEG) coatings, which are frequently used to prevent phagocytic clearance of particulate drug carriers, on the phagocytosis of such carriers by neutrophils, the most abundant leukocyte in blood circulation. Surprisingly, we find that PEGylation enhances uptake by primary human neutrophils, specifically in the presence of human plasma. This result suggests that PEGylation may not confer the benefits in humans once thought, and may help to explain why PEG has not become the “magic bullet” it was once thought to be in the field of particulate drug delivery.

Morphological Modification of Carbon Nanoparticles after Interacting with Methotrexate as a Potential Anticancer Agent.

Production of highly penetrable and targetable drug delivery particles is mainly focused by current therapy and such focus is achieved in our present study. The carbon nanoparticle (CNP) prepared from purely natural source was modified from spherical shape to cylindrical floral like structure after treatment with the anticancer drug methotrexate (CM). The physiochemical properties of the CNP and CM was characterized using FT-IR/Raman Spectrometer, XRD, SEM, AFM, particle size analyzer and its biological evaluation using haemolysis and MTT assay. The shift in FT-IR peaks at 1592, 1120cm-1 and peaks of raman spectra observed at 1303, 1300cm-1 represents ordered carbon nanotubes. The morphological change from spherical to cylindrical floral like structure was observed using SEM and AFM and its particle size distribution analysis shows an average diameter of 269nm for CM. XRD peak at 2θ = 23.86° (002) indicates the presence of large amount of amorphous material that corresponds to multi-walled carbon nanotubes. Haemocompatibility studies proved the safety level usage as 100μg/ml and MTT assay shows viability rate of 85-98% with mouse embryonic fibroblast (NIH/3T3) and 30-45% with pancreatic carcinoma (MIA PaCa-2) and gastric cancer cell lines (SNU- 484) respectively.These results are also supported by phase contrast microscope images observed after staining with calcein AM and EthD-1. The morphologically modified CNPs has shown good anticancer, biocompatibility and haemocompatibility property which is an important criterion to be satisfied by a biomedical product.

Calcium phosphate particles stimulate exosome secretion from phagocytes for the enhancement of drug delivery.

Exosomes are attractive potential carriers for drug delivery because of their natural function of transferring biomolecules among cells without eliciting immune responses. However, an obstacle to the application of exosomes for drug delivery is the difficulty in collecting sufficient numbers of these vesicles. In this study, we demonstrate treatment with calcium phosphate (CaP) particles could increase over two-fold the number of exosomes secreted from macrophage-like RAW264.7 cells and monocyte-like THP-1 cells. CaP particles were easily internalized into cells and dissolved in acidic late-endosomes or lysosomes, resulting in the rupture of their membranes followed by the release of Ca2+ into cytosol. Moreover, we found that exosomes secreted from cells treated with CaP particles are not contaminated by the Ca2+ released from CaP; the Ca2+ contents in exosomes secreted from CaP particle-treated cells were similar to that in exosomes from untreated control cells. This study highlights the potential for the efficient production of exosomes using CaP particles for drug delivery.

Current trends and concepts in the design and development of nanogel carrier systems

Nanotechnology, a relatively novel technique, has much potential in smart drug delivery. Development of novel nanosized particulate drug delivery systems (DDS) may help in disease prevention, diagnosis, and treatment of many of the important diseases. Nanogels have particle sizes in the 0–100 nm range, and the three-dimensional network is maintained by varying the solvent quality. This review article describes concisely the current trends and concepts involved in the design and development of nanogel DDS. This review also explores the various approaches of drug loading, release mechanisms, characterization, and biomedical applications. Optimized nanogel systems can be developed on the basis of the site of action and pattern of drug release desired for improved therapeutic benefits. This can be achieved by using the appropriate method of preparation (physical or chemical) and drug loading mechanism by modifying the geometry and surface of the nanogels. The properties of nanogels are dependent on the constituent materials/components (synthetic or natural) and on external stimuli (pH, temperature, ionic strength or incorporation of hydrophilic residues) in the case of stimuli-sensitive nanogels. Due to the high stability, biodegradability, biocompatibility, large surface area, and minimal resources required for manufacture of nanogels, their applications (such as in oral, pulmonary, nasal, ocular, and topical routes) have gained special attention in the development of pharmaceutical drug carriers.

Parameter Optimization Of Injectable Polycaprolactone Microspheres Containing Curcumin Using Response Surface Methodology.

The achievement of desirable pharmacokinetic parameters from particulate drug delivery systems are dependent on the physical characteristics of the systems namely, particle dimension, loading of therapeutic agent, encapsulation efficiency, in vitro release kinetics. This study aimed to evaluate the main and interaction effects of the formulation variables on those physical characteristics and also to optimize the best combination of the variables to formulate small size particles with high encapsulation efficiency. The results showed that all the process variables (amount of polycaprolactone and stirring speed) except the amount of surfactant contributed significantly to the parameters previously mentioned. The best optimized formulation was experimentally validated for the closeness to the theoretical estimates.

Enhancing Passive Transport of Micro/Nano Particles into Cells by Oxidized Carbon Black.

Uses of micro-/nano-sized particles to deliver biologically active entities into cells are common for medical therapeutics and prophylactics and also for cellular experiments. Enhancing cellular uptake and avoiding destruction by lysosomes are desirable for general particulate drug delivery systems. Here, we show that the relatively nontoxic, negatively charged oxidized carbon black particles (OCBs) can enhance cellular penetration of micro- and nano-particles. Experiments with retinal-grafted chitosan particles (PRPs) with hydrodynamic sizes of 1200 ± 51.5, 540 ± 29.0, and 430 ± 11.0 nm (three-sized model particles) indicate that only the sub-micron-sized particles can penetrate the first layer of multilayered liposomes. However, in the presence of OCBs, the micron-sized PRPs and the two submicron-sized PRPs can rapidly enter the interiors of all layers of the multilayered liposomes. Very low cellular uptakes of micro- and submicron-sized PRPs into keratinocytes cells are usually observed. However, in the presence of OCBs, faster and higher cellular uptakes of all of the three-sized PRPs are clearly noticed. Intracellular traffic monitoring of PRP uptake into HepG2 cells in the presence of OCBs revealed that the PRPs did not co-localize with endosomes, suggesting a nonendocytic uptake process. This demonstration of OCB’s ability to enhance cellular uptake of micro- and submicron-particles should open up an easy strategy to effectively send various carriers into cells.

Formulation and Development of Particulate Mucoadhesive Drug Delivery System of Venlafaxine Hydrochloride.

Formulation and Development of Particulate Mucoadhesive Drug Delivery System of Venlafaxine Hydrochloride.

Egg Component-Composited Inverse Opal Particles for Synergistic Drug Delivery.

Microparticles have a demonstrated value in drug delivery systems. The attempts to develop this technology focus on the generation of functional microparticles by using innovative but accessible materials. Here, we present egg component-composited microparticles with a hybrid inverse opal structure for synergistic drug delivery. The egg component inverse opal particles were produced by using egg yolk to negatively replicate colloid crystal bead templates. Because of their huge specific surface areas, abundant nanopores, and complex nanochannels of the inverse opal structure, the resultant egg yolk particles could be loaded with different kinds of drugs, such as hydrophobic camptothecin (CPT), by simply immersing them into the corresponding drug solutions. Attractively, additional drugs, such as the hydrophilic doxorubicin (DOX), could also be encapsulated into the particles through the secondary filling of the drug-doped egg white hydrogel into the egg yolk inverse opal scaffolds, which realized the synergistic drug delivery for the particles. It was demonstrated that the egg-derived inverse opal particles were with large quantity and lasting releasing for the CPT and DOX codelivery, and thus could significantly reduce cell viability, and enhance therapeutic efficacy in treating cancer cells. These features of the egg component-composited inverse opal microparticles indicated that they are ideal microcarriers for drug delivery.

Preparation and Evaluation of Micro particulate Drug Delivery Systems of Gliclazide Employing Starch Acetate

Recently much emphasis is being laid on the development of micro particulate DDS in preference to single unit systems because of their potential benefits such as increased bioavailability, reduced risk of systemic toxicity, reduced risk of local irritation and predictable gastric emptying. The objective of the present study is to prepare and evaluate micro particulate drug delivery systems of Gliclazide using starch acetate, a new modified starch for oral controlled release. The starch acetate (DS 2.75) was freely soluble in chloroform and insoluble in several aqueous fluids and organic solvents. Chloroform could be used as solvent for starch acetate in the preparation of micro particles, microcapsules and in film coating Spherical starch acetate- Gliclazide micro particles could be prepared by the emulsification-solvent evaporation method. The method is industrially feasible as it involves emulsification and removal of the solvent, which can be controlled precisely. The emulsification solvent evaporation method was reproducible with regard to size and size distribution of the micro particles. About 65-70% of micro particles in each batch were in the size range 35/50 mesh (398.5I¼m) Encapsulation efficiency was in the range 96.0-99.3 % in the preparation of micro particles.