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Bioavailability enhancement of sulpiride by self-microemulsifying drug delivery system

Bioavailability enhancement of sulpiride by self-microemulsifying drug delivery system

SUMMARY . The self-microemulsifying drug delivery system (SMEDDS) was employed to improve the bioavailability of sulpiride, a drug which is poorly soluble. The mean droplet size and emulsification time of the test formulation used for in vivo study were 9.27 ± 2.02 nm and 87 ± 5 s, respectively. When com- pared with Reference (Dogmatil®), the test formulation exhibited faster in-vitro drug release rate. The C max and AUC values of the test formulation were significantly higher than those of Reference, with an

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Hyaluronic acid-coated gold nanoparticles as an anticancer drug delivery system - Biological characterization and efficacy

Hyaluronic acid-coated gold nanoparticles as an anticancer drug delivery system - Biological characterization and efficacy

Our physico-chemical characterization strategy for the NM used in this study included various techniques established in the NCL cascade (http://ncl.cancer.gov/). When bare AuNPs were conjugated to HA, TEM showed no change in the shape or size of the gold core, AuNPs remained spherical with a low size distribution. Also the surface charge remained unchanged at around -38 mV. The hydrodynamic radius of AuNPs turned from 12 nm to 98 nm after HA conjugation. ICP-MS analysis confirmed the theoretical concentration resulting from the AuNP synthesis and showed that EDS could be concentrated up to 100X. Through elemental analysis we could analyze the amount of HA after conjugation and determine the number of HA chains surrounding each AuNP core of the drug delivery system (approximately 2000 HA chains per NP).
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Gastroretentive drug delivery system of captopril and hydrochlorothiazide bilayer tablet: formulation, optimization and in vivo evaluation

Gastroretentive drug delivery system of captopril and hydrochlorothiazide bilayer tablet: formulation, optimization and in vivo evaluation

SUMMARY . The purpose of the present study was to develop and optimize floating-bioadhesive bilayer gastroretentive drug delivery system (GRDDS) exhibiting a unique combination of floatation and bioadhe- sion to prolong residence in the stomach using captopril (CP) and hydrochlorothiazide (HCTZ) as a model drug. Captopril being unstable in intestinal pH and HCTZ has specific absorption from duodenum and the first part of the jejunum and to a small extent in the stomach are suitable candidate for GRDDS. 3 2

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Self Regulatory Drug Transport: An Intelligent Drug Delivery System

Self Regulatory Drug Transport: An Intelligent Drug Delivery System

As the traditional drug delivery systems (DDSs) often as- sociated with many side effects, there as an always require- ment of approaches to develop new formulations for trans- porting medicine at required level when it needed. This type of on demand basis drug delivery also called smart drug delivery or intelligent drug delivery. These novel techniques enhance the therapeutic values and also reduce various side effects. In comparison to the conventional DDSs, the smart controlled DDSs can effectively reduce the dosage frequency, while maintaining the drug concentra- tion in targeted organs/tissues for a longer period of time. In this sense, the controlled DDSs provide broad insights and fascinating properties for decreasing drug concentra- tion fluctuation, reducing drug toxicities and improving therapeutic efficacy. 1
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Development of gastro retentive drug delivery system of cephalexin by using factorial design

Development of gastro retentive drug delivery system of cephalexin by using factorial design

The linear model for R3 (% drug release at 12 hr) found to be significant with F-value of 81.11 and P value 0.0022. In this case A, B are significant model terms with P value of 0.0235 and 0.0001 respectively. Figure 8 represents the observed response values compared to that of predicted values. The effect of factors A, B and C can be further elucidated with the help of response surface plot (Figure 9). The high level of factor B gave high value of R3 at all the levels of factor A where in case of figure 9(b), high level of factor B gave high value of R3 at all the levels of factor C which indicates that the factors A and B have significant positive effect on 12 hr drug release. Similar effect was observed in case R2. The factor B showed higher value indicating xanthan gum releases the drug at faster rate than guar gum.
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A novel controlled drug delivery system for growth hormone applied to healing skin wounds in diabetic rats

A novel controlled drug delivery system for growth hormone applied to healing skin wounds in diabetic rats

Abstract—Controlled release systems for drugs, hormones and growth factors can be particularly useful in tissue repair processes. These systems act as a biodegradable support containing the substance to be delivered, allowing their gradual release. In the past years, the local application of growth factors has acquired special relevance as a therapeutic option for use in subjects who show deŽ cient tissue scarring, the hormone dose being the limiting factor for its success. In this study, the in vitro biocompatibility of a copolymer formed by vinylpyrrolidone and 2-hydroxyethyl methacrylate, used as an administration vehicle for hGH, was evaluated. The system was then tested in vivo in terms of its capacity for healing incisional wounds in healthy and diabetic rats. For the in vitro studies, polymer and hormone degradation rates were determined, and polymer biocompatibility was evaluated in Ž broblast cultures. In the in vivo experiments, an incision was made in the back of the animals, and polymers discs with/ without hGH, were introduced in the aperture. Morphological, immunohistochemical and morphometric evaluations were performed on wound tissue specimens 3– 10 days after surgery. In vitro, the polymer was found to be biodegradable and showed no toxic effects on Ž broblasts, the hormone being slowly released to the culture medium. In untreated diabetic rats, a delayed skin scarring and cell response were observed, compared to that noted in healthy animals. Skin closure, keratinisation and Ž brosis occurred earlier in the presence of the polymer-hGH system. The use of this co-polymer as an administration vehicle for hGH improves the wound scarring process in the pathological setting of diabetes.
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Formulation and evaluation of a bilayer floating drug delivery system of nizatidine for nocturnal acid breakthrough

Formulation and evaluation of a bilayer floating drug delivery system of nizatidine for nocturnal acid breakthrough

All the formulations contain equal amount of gas generating agent (sodium bicarbonate and citric acid). The formulation F1-F3 containing (Carbopol 934p, 70-90 mg) tablets could not bear their matrix shape until 8 h and release the drug within 4 h. The drug release from HPMC K100M and HPMC K15M (F4-F9) was about (89-91%). A significantly higher rate and extent of drug release (98%) was observed from the formulations based on HPMC K4M (F10-F12).Varying amount of HPMC K4M affect the drug release 4 . The formulations containing Carbopol 934p
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Formulation and evaluation of osmotic drug delivery system of ibuprofen

Formulation and evaluation of osmotic drug delivery system of ibuprofen

therapeutic agent at a predetermined, zero order delivery rate based on the principle of Osmosis, which is movement of a solvent from lower concentration of solute towards higher concentration of solute across a semi-permeable membrane. After administration of osmotic system, water is imbibed into the core osmotically through semi-permeable membrane resulting in development of hydrostatic pressure that pumps drug containing solution or suspensions out of the core through one or more delivery ports. The delivery from the system is controlled by the water influx through semi-permeable membrane. 3 one of the most rate
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Elastin like recombinamers as smart drug delivery systems

Elastin like recombinamers as smart drug delivery systems

The fibronectin type III domain (Fn3), which binds the integrin αvβ3, has also been fused to ELR diblocks [90]. The self-assembly behaviour of the resulting constructs was studied through the bioproduction of ELRs with different hydrophilic and hydrophobic block lengths. The result was an increase in the uptake of ELR with Fn3 in comparison with the unimers in a transfected human leukaemia cell line overexpressing the integrin αvβ3 (K562/αvβ3). In a later study, a qualitative breakthrough in the design of ELR diblocks fused to functional peptides was accomplished. Thus, Chilkoti’s group constructed an ELR-based drug carrier termed nanopeptifier, that was able to improve cellular uptake by controlled exposure of CPPs, which toggled in response to the application of external mild hyperthermia (Figure 3) [91]. The construct (Arg8-ELRBC- cBH3) was genetically engineered to possess a CPP (Arg8) at the N-terminus and the therapeutic payload peptide cBH3 (derived from the proapoptotic Bak protein) located at the C- terminus. The therapeutic cBH3 peptide was separated by an RVRR peptide linker cleavable by furin and cathepsin B proteases. The nanopeptifiers are soluble at physiological temperature (37 °C), whereas under of mild hyperthermia conditions (42 °C) they self-assemble into spherical micelles displaying a high density of CPP on their corona and with cBH3 located in the micelle core. Although some uptake of the nanopeptifier occurs at 37 °C, when the temperature is increased to 42 °C this cell uptake increases dramatically. Once the complex is internalized, the action of either furin (localized in the trans-Golgi) or cathepsin B (early and late endosomes and lysosomes) favours release of the cBH3 load. Increases of up to 130 arbitrary cell fluorescence units were found to induce the therapeutic effect of cBH3. Its therapeutic action was assessed by activation of caspase-3, which is involved in apoptotic processes. Thus, the nanopeptifier was able to create a cytotoxic switch that induces apoptosis only when it is in the micelle conformation.
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Drug delivery systems based on poly(e caprolactone) for cancer treatment

Drug delivery systems based on poly(e caprolactone) for cancer treatment

As can be concluded, taking into account these very interesting results, the potential of PCL particles loaded with anticancer drugs is evident. However, the majority of the research efforts have been focussed on the use of copolymers due to their better drug loading and release properties, and to a more suitable biodegradation profile 10 . As an example, MePEG/PCL amphiphilic block copolymers (nanoparticle diameter ≈ 100 nm) proved to be able to encapsulate doxorubicin (DOX) in aqueous solutions. Confocal laser scanning microscopy (CLSM) demonstrated that drug-loaded micelles accumulated mostly in cytoplasm instead of cell nuclei, in contrast to free DOX. Furthermore, these drug-loaded particles exhibited time-delayed cytotoxicity in human MCF-7 breast cancer cells 47 . This biodegradable block copolymer has also been surface-functionalized with folic acid to target a folate-binding protein that is overexpressed on the surface of many tumor cells. With this aim, PTX-loaded folate-conjugated MePEG/PCL micelles (50 – 130 nm) were prepared by micelle formation in aqueous medium. The in vitro PTX release profile from the micelles showed no initial burst release but a clear sustained release. Interestingly, these PTX-loaded micelles proved much higher cytotoxicity for cancer cells (e.g., MCF-7 and HeLa cells) than MePEG/PCL micelles non-conjugated to folate. A confocal image analysis revealed that fluorescent PTX-loaded folate-conjugated micelles were endocytosed into MCF-7 cells through the interaction with overexpressed folate receptors on the surface of cancer cells 48 . Furthermore, PEG/PCL nanoparticles were prepared by a dialysis method and further surface- functionalized with folate moieties (via a coupling reaction between the –OH groups of PEG and the –COOH group of folic acid) for the active targeting of 5-FU and PTX to tumors. It was observed an enhanced cytotoxicity of these drug-loaded nanoparticles against folate receptor expressing tumor cells 49 . MePEG/PCL nanoparticles loaded with taxol were prepared by a dialysis procedure 26 . This copolymer was also used in the vehiculization of geldanamycin. In this case, the pharmacokinetic profile of the drug was improved (enhancement in the AUC ≈ 72-fold) and this formulation exhibited a lower systemic toxicity 50 . Finally, MePEG/PCL nanoparticles loaded with cisplatin (entrapment efficiency ≥ 75 %) have shown a significant less toxicity and an enhanced circulation time, compared to the free drug. Cisplatin release occurred in a sustained manner. In vitro cytotoxicity studies proved the efficacy of cisplatin-loaded nanoparticles against BGC823 and H 22 cancer cell
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Development and Evaluation of Isoniazid Loaded Silk Fibroin Microsphere

Development and Evaluation of Isoniazid Loaded Silk Fibroin Microsphere

of TB cases were of pulmonary TB unaided and soaring drug dose has essential to be managed since merely little slice of the entire dose reaches the lungs. Anti Tubercular drugs delivery system which could be delivered using the respiratory route alongside with canister evade the daily dosing since they can help out in: (i) Express drug deliv- ery to the unhealthy person; (ii) The targeting of alveolar macrophages which have uses via the mycobacteria while a secure place for their extended survival; (iii) reduced sys- temic toxicity of the drugs; and (iv) improved patient com- pliance .Furthermore in distinction the oral route of admin- istration and inhaled drugs were not subjected to first pass metabolism.It is not gratified for the reason that could not steadily reside in the lung. 10-12 Silk fibroin show advanced
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Gold Nanoparticles as Drug Delivery Agents. Detoxifying the Chemotherapeutic Drug Cisplatin

Gold Nanoparticles as Drug Delivery Agents. Detoxifying the Chemotherapeutic Drug Cisplatin

incubated 48 hours before performing the assay. Then EZ4U assay was performed as indicated by the manufacturer, but adding a previous washing step with PBS to remove the AuNPs in the media to avoid optical interferences with the absorption of formazan. Briefly, cells were washed with 200 L of PBS, and then 180 L of fresh media was added. Finally, 20 L of tetrazolium were added to every well and cells were incubated 1.5 hours. In this EZ4U 24h assay, no significant decrease of cell viability in A549 cells treated with AuNPs-cisplatin for any of the assayed concentrations was observed. This has not to be necessarily a problem since our system has been designed to show the benefits in in vivo experiments. Note that in the organism, free cisplatin is rapidly cleared by the kidneys having a blood half-life of less than 30 minutes and most of the remaining drug is deactivated by plasma proteins before reaching the target. 20 These losses, which have
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Elastin like polypeptides in drug delivery

Elastin like polypeptides in drug delivery

physiological conditions to form a local delivery depot [53]. The half-life of the resulting ELR-based coacervate at the administration site is at least 25-fold longer than for the soluble version [54]. Finally, ELRs are extremely non-inflammatory and biocompatible materials [55] and the removal of ELR-based devices when their payload is exhausted is not necessary as the biodegradation of these protein-based scaffolds follows the same natural routes as those found for structural proteins[56-58], whose degradation products, namely simple amino acids, do no present any toxicity or adverse responses[33]. Although no systematic studies on the biodegradability of ELR-based hydrogels are yet available, several parameters related to the requirements and characteristics of the body site should be taken into consideration when designing a drug-delivery device. As is the case in vitro [31], the in vivo half-life of the ELR-based hydrogel mainly depends on both enzymatic digestion and dissolution, therefore factors such as porosity, recombinamer sequence (in terms of presence of protease-sensitive sequences), and the cross-linking rate can be modified to tune their stability. For instance, the biodegradability of hydrogels obtained by coacervation may be markedly lower than that for their crosslinked counterparts as a result of dissolution. Moreover, in an environment in which ELR-based depots are exposed to a prolonged nonspecific proteolytic action, the ELRs, like all protein molecules, will be digested in a short time, whereas in less aggressive environment the half-life of such depots can exceed twelve months [33].
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Nanomaterials and Nanosystems for Biomedical Applications – M. Reza Mozafari

Nanomaterials and Nanosystems for Biomedical Applications – M. Reza Mozafari

uptake in vivo, showed high and rapid internalization into hepatocytes. Okuda et al (2004) also studied non-viral gene delivery systems and showed that dendritic poly (L-lysine) of the 6th generation (KG6) had high transfection efficiency into several cultivated cells with low cytotoxicity. They synthesized KGR6 and KGH6, in which terminal amino acids were replaced by arginines and histidines, respectively. DNA- binding analysis showed that KGR6 could bind to the plasmid DNA as strongly as KG6, whereas KGH6 showed decreased binding ability. Wada et al (2005) studied in vitro and in vivo gene delivery efficiency of polyamidoamine starburst dendrimer (generation 2) conjugate with -cyclodextrin bearing mannose with various degrees of substitution of the mannose moiety as a novel non-viral vector in a variety of cells. Sampathkumar et al (2005) described bifunctional PAMAM-based dendrimers that selectively target cancer cells. The targeting moiety for the folate receptor was complexed to an imaging or therapeutic agent by a DNA zipper. Choi et al (2005) produced amine-terminated, generation 5 polyamidoamine dendrimers conjugated to different biofunctional moieties (fluorescein and folic acid), and then linked them together using complementary DNA oligonucleotides to produce clustered molecules that target cancer cells that over express the high-affinity folate receptor. Kolhe et al (2003) studied the interaction between the drug and polyamidoamine dendrimers (generations 3 and 4 with − NH 2 functionality) and Perstrop Polyol (generation 5, hyperbranched polyester with –OH functionality) by using ibuprofen as a model drug. They found that hyperbranched Polyol (with 128 –OH end groups) appears to encapsulate approximately 24 drug molecules.
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Nanopartículas poliméricas de administración intranasal para la liberación de activos en el sistema nervioso central

Nanopartículas poliméricas de administración intranasal para la liberación de activos en el sistema nervioso central

Results. Many of the drugs employed for the treatment of neurodegenerative diseases are not capable of going through the blood-brain-barrier (BBB) and reach the brain with enough concentration, being unable to apply their therapeutic effect. That is why the idea of developing polymeric nanoparticles to be delivered through nasal delivery come out. Thanks to the use of this system, many researches have shown an improvement in the clinical utility of the drug, reducing the dose and the frequency of dosing as well as the side effects.

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