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BACKGROUND: The aim of this research was to engineer solid dispersion lipid particles (SD-SLs) in which a solid dispersion (SD) was encapsulated to form the core of solid lipid particles (SLs), thereby achieving an efficient enhancement in the dissolution of a poorly water-soluble drug. METHODS: Ultrasonication was introduced into the process to obtain micro/nanoscale SLs. The mechanism of dissolution enhancement was investigated by analysing the crystalline structure, molecular interactions, and particle size of the formulations. RESULTS: The drug release from the SD-SLs was significantly greater than that from the SD or SLs alone. This enhancement in drug release was dependent on the preparation method and the drug-to-polymer ratio of the SD. With an appropriate amount of polymer in the SD, the solidification method had the potential to alter the drug crystallinity to an amorphous state, resulting in particle uniformity and molecular interactions in the SD-SLs. CONCLUSIONS: The proposed system provides a new strategy for enhancing the dissolution rate of poorly water-soluble drugs and further improving their bioavailability.

A major hurdle in cancer treatment is the precise targeting of drugs to the cancer site. As many cancer cells overexpress the transferrin receptor (TfR), the transferrin (Tf)-TfR interaction is widely exploited to target cancer cells. In this study, novel amphiphilic apo-Tf stearic acid (TfS) conjugates were prepared and characterized by Fourier transform infrared (FTIR) spectroscopy, matrix-assisted laser desorption/ionization-time of flight (MALDI-TOF) mass spectrometry, and trinitrobenzenesulfonic acid (TNBS) assay. The prepared TfS conjugates were readily self-assembled in water to form nanoparticles (NPs), consisting of TfS as a core of NPs, whose sizes and zeta potentials were determined by scanning electron microscopy (SEM), transmission electron microscopy (TEM), and a particle size analyzer. Hydrophilic water-soluble doxorubicin (DOX) was chosen as a model drug. DOX-loaded TfS NPs (NP+DOX), prepared by the adsorption of DOX on the NP surface via the incubation method, were analyzed for their cell targeting and killing efficiencies in TfR-overexpressing A549 and HCT116 cell lines by MTT assay, confocal microscopy, and fluorescence assisted cell sorting (flow cytometry). The data showed that NP+DOX exhibited improved cancer cell targeting and killing properties compared to that reported for free DOX. Further, the cytotoxic efficiency of NP+DOX was comparable to that of PEGylated liposomal product, Doxil®, while its cellular uptake was higher than that of Doxil®. Thus, this novel receptor-based TfS NP drug delivery system has great potential to target TfR-overexpressing cancer cells without off-target effects.

Sonication-assisted nanoprecipitation provides an effective tool for nanomedicine engineering in therapeutic improvement. In the scope of this review, original works in interdisciplinary areas of using sonication with precipitation method for nanoparticulate drug delivery systems and its applications in management of different diseases are discussed. The use of sonication-assisted nanoprecipitation has been proved to improve drug bioavailability, which attracts tremendous interests as an effective strategy for drug delivery. However, many challenges still remain. To overcome these barriers, different approaches such as precipitation method, rational design, optimization and modification have been investigated. Accordingly, current knowledge of sonication-assisted nanoprecipitation proposes a broad perspective and optimization for the applications of nanotechnology in drug delivery.

Microemulsion has the potentials to enhance dissolution as well as facilitate absorption and permeation of poorly water-soluble drugs through biological membranes. However, its application to govern a controlled release buccal delivery for local treatment has not been discovered. The aim of this study is to develop microemulsion-based mucoadhesive wafers for buccal delivery based on an incorporation of the microemulsion with mucoadhesive agents and mannitol. Ratio of oil to surfactant to water in the microemulsion significantly impacted quality of the wafers. Furthermore, the combination of carbopol and mannitol played a key role in forming the desired buccal wafers. The addition of an extra 50% of water to the formulation was suitable for wafer formation by freeze-drying, which affected the appearance and distribution of carbopol in the wafers. The amount of carbopol was critical for the enhancement of mucoadhesive properties and the sustained drug release patterns. Release study presented a significant improvement of the drug release profile following sustained release for 6 h. Ex vivo mucoadhesive studies provided decisive evidence to the increased retention time of wafers along with the increased carbopol content. The success of this study indicates an encouraging strategy to formulate a controlled drug delivery system by incorporating microemulsions into mucoadhesive wafers.

The study aims to design and evaluate the ability of zein in solid dispersion (SD) system to enhance drug dissolution rate for a further application of colonic delivery of poorly water-soluble drug. The SD samples were prepared by solvent method and the investigation of drug release was performed at pH 7.4. The wettability, molecular interactions and drug’s crystal behaviours of SDs were studied by contact angle measurement, Fourier transform infrared spectroscopy (FTIR) and powder X-ray diffraction (PXRD), respectively. Zein-based SDs showed its potential in enhancing the rate of drug release. The PXRD results pointed out a rearrangement of drug’s crystalline structure in some SD samples through the appearance of new peaks on PXRD diffractogram, while a formation of a hydrogen bond between prednisolone (PRL) and zein was also confirmed by FTIR spectra. It was evident that a strong relationship between the amount of zein and the dissolution rate of PRL in SD system attributed to zein hydrophobicity, recrystallization and molecular interaction which were factors inducing the enhanced drug release rate. In conclusion, zein is a potential carrier for controlled release SD systems, especially further application for poorly water-soluble drugs in colonic delivery like PRL due to the resistance of zein at low pH environment.

Nanoparticles for a specific delivery are likely to be designed for cancer therapeutic effectiveness and improvement. In this study, a fucoidan-oleic acid conjugate was prepared and investigated in terms of loading capacity for poorly water-soluble anti-cancer drugs to maximize effectiveness of the treatment. Fucoidan was used as a hydrophilic portion of an amphiphilic structure for improving cancer therapeutic effects. Paclitaxel and curcumin were chosen as other model drugs loaded in the conjugates. The results showed that self-assembled nanoparticles with different sizes and morphologies could be prepared with two different concentrations of oleic acid as hydrophobic portion. Moreover, loading efficiency and release patterns of these drugs were mainly dependent on the hydrophobic interaction between drugs and oleic acid. It was also revealed that fucoidan and curcumin were released higher at pH 4.5 than at the physiological condition (pH 7.4), thus, facilitating the delivery and maximizing effects of the anticancer agents on cancer cells. On the contrary, paclitaxel from fucoidan nanoparticles was released faster at pH 7.4. The exploration of fucoidan-oleic acid conjugate could be considered as promising nanomedicines for cancer therapeutics.

This research aims to develop an iron oxide nanoparticle drug delivery system utilizing a recent material discovered from ocean, fucoidan. The material has drawn much interest due to many biomedical functions that have been proven for human health. One interesting point herein is that fucoidan is not only a sulfated polysaccharide, a polymer for stabilization of iron oxide nanoparticles, but plays a role of an anticancer agent also. Various approaches were investigated to optimize the high loading efficiency and explain the mechanism of nanoparticle formations. Fucoidan was functionalized on iron oxide nanoparticles by a direct coating or via amine groups. Also, a hydrophobic part of oleic acid was conjugated to the amine groups for a more favorable loading of poorly water-soluble anticancer drugs. This study proposed a novel system and an efficient method to functionalize fucoidan on iron oxide nanoparticle systems which will lead to a facilitation of a double strength treatment of cancer.

The evolution of polymer-based nanoparticle as a drug delivery carrier has greatly contributed to the development of advanced nano and micro-medicine in the past few decades. The polymer-based nanoparticles of biodegradable and biocompatible polymers such as poly (lactide-co-glycolide) and chitosan which have been approved by Food & Drug Administration and/or European Medicine Agency can particularly facilitate the maintaining of specific properties for a real transition from laboratory to the clinical oral and parental administration. This review presents an overview of the strategies of preparing polymeric nanoparticles and using them for targeting colorectal cancer. Theranostics and surface engineering aspects of nanoparticle design in colonic cancer delivery are also highlighted.

This study aimed to originally develop a new nanoparticulate drug delivery system of iron oxide nanoparticles (Fe 3 O 4 ) for biomedical applications. Oleic acid and bovine serum albumin were decorated on the surface of iron oxide nanoparticles in new pattern by conjugation. The decoration was kicked off by the functionalization of arginine on the surface of the iron oxide nanoparticles. It was then followed by the conjugation of oleic acid and bovine serum albumin through the amide bond. Scanning electron microscopy, transmission electron microscopy, powder X-ray diffraction and Fourier transform infrared spectroscopy were used to characterize and determine mechanism of the decorated nanoparticles. Paclitaxel was chosen as the model drug in the study. The nanoparticles demonstrated a potential utility in delivery of anticancer drugs.

The aim of this research was to investigate the effects of absorbents on solid dispersions (SDs) to improve the solubility of isradipine (IS). Polyethylene glycol 6000 (PEG 6000) was applied to investigate physical structure and improved dissolution rate of IS under SD form. Aerosil® 200 was used as a moisture absorbent to maintain the dryness and free-flow of powders and granules during storage. SDs were prepared by melting method at various ratios of drug and polymers. Dissolution rates of SDs were tested in simulated gastric fluid (buffer pH 1.2) and simulated intestinal fluid (buffer pH 6.8). High-performance liquid chromatography (HPLC) was utilized to determine concentration of IS after dissolution test. Structural behaviors of drugs and SDs were characterized by Power X-ray diffraction (PXRD) and molecular interactions between drug and carriers were analyzed by Fourier Transform Infrared spectroscopy (FTIR). A transformation of crystalline form into amorphous state of SDs and an intermolecular bonding were observed. Aerosil® could be considered as a pertinent absorbent to assist the carrier in increasing the dissolution rate of poorly water-soluble drugs.

Prednisolone, an anti-inflammatory drug with a very slight solubility (0.23 mg/mL at 25 °C), high permeability and short biological half-life (2–4 h) in oral administration was selected as the candidate drug for sustained drug release. The aim of this research is to formulate and evaluate the stable formation of oil-in-water microemulsion for enhancing the solubility of the model drug. Microemulsion containing oleic acid as oil component, Tween 20 and P188 as main surfactant and co-surfactant at different ratios were evaluated. The microemulsion was characterized by stability test, particle size, clarity, conductivity and pH value. A stable system at nano size (11.6 and 12.3 nm) which possibly enhanced drug solubility with no drug aggregation.

This research aims to enhance the dissolution rate of prednisolone using sonoprecipitation method and to elucidate the mechanism of drug release. The sonoprecipitated prednisolone were tested in both liquid and solid dosage forms transformed by enhancement of prednisolone in stimulated colonic fluid (pH 7.4) was observed in the amorphous zein-coated prednisolone in solid dosage form, compared to its identical formulation in liquid dosage form as well as the pure crystalline prednisolone. Power X-ray Diffraction and Fourier Transform Infrared spectroscopies implied that the decrease in crystallinity level of sonoprecipitated nanoparticles could be primary mechanism for this improvement.

This study was aimed at characterizing superparamagnetic nanoparticles surface-functionalized with gelatin-oleic acid (GOAS-MNPs) and loaded with paclitaxel by assessing the pharmacokinetics and biodistribution of paclitaxel in tissues and the in vivo efficacy of antitumor activity after the administration of the drug. Initially, instrumental analysis was performed to examine the particle size distribution, surface charge, and morphology of the paclitaxel-loaded GOAS-MNPs. Furthermore, we evaluated their magnetic properties and performed T2-weighted magnetic resonance imaging (MRI) on cells. We intravenously administered Taxol® and paclitaxel-loaded GOAS-MNPs and compared the pharmacokinetics, biodistribution, and antitumor efficacies of the two formulations. Determination of the pharmacokinetics and the biodistribution of paclitaxel-loaded NPs showed that this formulation increased the systemic circulation time of paclitaxel and regulated its transport to tissues. The in vivo antitumor efficacy of the paclitaxel-loaded NPs was better than that of Taxol® at the same dose. Furthermore, the paclitaxel-loaded GOAS-MNPs were found to be effective as contrast agents for enhanced MRI in cancer cells. Thus, GOAS-MNPs could be an effective diagnostic system for cancer and for the delivery of paclitaxel with better therapeutic effects and a significant reduction in toxicity.

The aims of this study are to increase and explain the mechanism of dissolution enhancement of isradipine using the sonoprecipitation method for stable nanosuspensions. There have been still few of published researches on formulation of isradipine using nanoparticle engineering. Nanosuspension systems were prepared upon various factors including amplitude and the time length of ultrasonication. The dissolution test was performed according to the USP paddle method in intestinal fluid (pH 6.8). The crystalline structure of drug, the molecular interaction, morphology and size of nanosuspension were also investigated to determine the mechanism of dissolution enhancement. The sonoprecipitation method with use of HPMC 6 showed its potential in enhancement of the drug release rate. Stable nanosuspension was significantly depended on amplitude and time of ultrasonication since these factors affected on the size of nanoparticles. The synergistic effects of reduction of drug crystallinity and particle size could increase the dissolution rate of isradipine by providing a stable nanosuspension. This work may contribute to a new strategy for improvement dissolution rate of isradipine.

The structure of polymeric amphiphiles with both hydrophilic and hydrophobic groups forming self-assembled nanoparticles have attracted increasing attention in studies of delivery systems of therapeutic agents. An amphiphilic carrier for self-assembly in an aqueous solution is preferable because of its structure with a hydrophobic core and hydrophilic outer shell, which can be applied to many biotechnological and pharmaceutical fields with numerous types of drugs. An amphiphilic carrier for self-assembly also represents the most appealing delivery system owing to its exceptional advantages in selectively delivering drugs to tumor cells and thus, reduction of side effects. This paper reviews two types of self-assembled nanoparticles/micelles of conjugated polymeric amphiphiles: (1) self-assembled micelles/nanoparticles of amphiphilic conjugates followed by drug loading and (2) self-assembled micelles/nanoparticles of polymer-drug conjugates where a conjugation reaction occurs between the polymer and drug. The development of the research has been addressed in this review with up-to-date references. In conclusion, the challenges and remaining difficulties for the future development are discussed.

The aim of this study was to investigate the pharmacokinetics and biodistribution in Sprague-Dawley rats, anti-tumor activity and acute toxicity in different tumor-bearing mice of novel biocompatible nanoparticles. Paclitaxel (PTX) was selected as a model drug and loaded on different tumor types and at various doses. The nanoparticles were prepared using a newly synthesized gelatin-oleic acid conjugate via self-assembly in an aqueous solution. The nanoparticles were further functionalized using folic acid (FA) as a targeting ligand for cancer. The in vivo effects of the nanoparticles were compared with the commercially available Taxol (a solution form of PTX) as a reference dosage form. The in vivo studies confirmed that nanoparticles showed improved therapeutic effects on tumors and significantly reduced the toxic effects associated with Taxol, even at the 50% lethal dose (LD50). The in vivo pharmacokinetic parameters and biodistribution of the nanoparticles containing PTX also indicated slower clearance, longer blood circulation and higher tumor selectivity. Furthermore, the functionalized nanoparticles with FA were more effective than the non-functionalized nanoparticles. Thus, the suitable properties of gelatin-oleic nanoparticles (GON) as a drug carrier and the effective targeting ligand could synergistically maximize the in vivo anti-tumor efficacy resulting in delayed tumor volume growth and hence, providing versatile strategies in cancer therapy and drug delivery.

In this work, a novel, biocompatible conjugates of gelatin and oleic acid (GOC) were synthesized by a novel aqueous solvent-based method that overcame challenges of completely contrary solubility between gelatin and oleic acid (OA). The GO nanoparticles (GONs) and Paclitaxel encapsulated nanoparticles (PTX-GON) were prepared by self-assembly in water. These nanoparticles (NPs) were then conjugated with folic acid (FA) for targeting cervical cancer cells (Hela cells) and were characterized for their various physicochemical and pharmaceutical properties. Fourier transform infrared spectroscopy (FT-IR) and 1H NMR studies indicated the successful synthesis of GOC which showed low critical aggregation concentration in water (0.015 mg/ml). All NPs were stable in human blood serum and their mean diameters were below 300 nm suitable for passive targeting. Powder X-ray diffraction (PXRD) diffractograms showed the reduction in drug crystallinity and hence, leading to the solubility enhancement of PTX. The release of PTX from both PTX-GON and FA conjugated PTX-GON (PTX-FA-GON) was controlled for a long time. The cytotoxicity results demonstrated great advantages of PTX-FA-GON and PTX-GON over the conventional dosage form of pacliaxel (Taxol). These results, therefore, indicate that GOC is a promising material to prepare drug encapsulated NP as a controlled delivery system and PTX-FA-GON is a potential targeted delivery system for cancer therapy.

The aim of the study was to press a synergistic act of a formulation: (1) enhancing the dissolution rate of a poorly water-soluble drug; (2) controlling the release rate of the drug. There is still little published research on such a formulation. The model drug used in the current study is isradipine (IS), a calcium channel blocker of the dihydropyridine class. To fulfill the expected target, solid dispersion containing IS was first prepared with the carrier polyethylene glycol 6000 (PEG 6000) with the melting method and then polyethylene oxide N-60K (PEO N-60K) was utilized to induce drug release in a controlled manner. Physicochemical properties of the solid dispersion and physical mixture were characterized by powder x-ray diffraction (PXRD) and Fourier transform infrared (FTIR) spectroscopy to investigate the structural behavior of drug and IS-PEG interactions, respectively. Preparation of such a formulation not only enhanced but also controlled the drug dissolution rate in both simulated gastric (pH 1.2) and intestinal (pH 6.8) media. This result should be a consideration for pharmaceutical scientists in maintaining the desired blood levels of drugs with narrow therapeutic fluctuation ranges for extended periods of time after a single administration.

A new conceptual nanoparticle consisting of a silica-coated iron oxide magnetic core and a fattigation-based biocompatible shell with oleic acid and hydrophilic protein (gelatin). The prepared particle can be a useful theranostics platform material for diagnostic imaging and as a drug delivery system. Oleic acid and gelatin were conjugated on the silica-coated magnetic nanoparticle surface to provide three primary functionalities: 1) enhancing biocompatibility and solubility in aqueous solution and providing the ability to incorporate hydrophobic chemical drugs into the shell for delivery, 2) improving treatment-response magnetic monitoring as a diagnostic agent with low nanotoxicity, and 3) increasing anticancer efficacy owing to the controlled release of the incorporated drug in cells and in an animal model. We prepared magnetic-silica nanoparticles with super-paramagnetic properties, which are utilized as a T2-weighted magnetic resonance imaging agent. After formation of an oleic acid-gelatin shell, the prepared materials exhibited high loading capacity for a hydrophobic anticancer drug (paclitaxel). Our particle platform system exhibited higher therapeutic efficacy and lower toxicological effects in vitro and in an in vivo cancer model than a clinically available chemo-drug (Taxol®). Our findings strongly suggest that this nanoparticle system can serve as a platform for cancer therapy by the incorporation of chemical drugs.

Background Neurodegenerative disorders (NDs) are typically referred to Alzheimer's disease, Parkinson's diseases, amyotrophic lateral sclerosis and prion disease. These are commonly debilitating and, unfortunately, have few therapeutic options. Objective In this review, we describe some emerging advances in nanoengineering strategies for the treatment of NDs. One of the main difficulties in fighting against NDs is to overcome the shielding of blood-brain barrier (BBB), which greatly limits the penetration of various therapeutic drugs, which sometimes leads to severe side effects. Nanotechnology, by engineering materials of a size scale usually within 1-100 nm, fortunately offers an alternative approach for novel, promising and innovative solutions. Nanoparticles are capable of not only penetrating the BBB but also releasing active ingredients at a specific site due to its surface functionalization. Therefore, nanoengineered delivery systems potentially facilitate the targeted delivery of neuronal therapeutic drugs and genes to the central nervous system. Furthermore, recently developed nanomaterials are considered as therapeutic agents themselves since they exhibit important roles in promoting the protection of healthy neurons or the regeneration of neurons to repair damaged tissues. Conclusion There have been a variety of innovative approaches to designing therapeutic nanoparticles for NDs, and each has been associated with certain pros and cons.

Rabeprazole sodium (RPN) is known to be very unstable at acidic condition or some acidic pharmaceutical excipients such as acrylic acid polymer (carbomer 934) with carboxylic acids. Thus, degradation mechanism of binary blends of rabeprazole with pharmaceutical excipients in a solid state without using solvents at three different ratios (3:1, 1:1 and 1:3) was investigated using Fourier transform infrad (FTIR) spectroscopy. Alkalizer (MgO), neutral hydroxypropymethylcellulose (HPMC 4000) were also tested for comparison. The binary blends were stored under accelerated conditions (40oC/75% relative humidity) for two weeks. The concentration of thioether rabeprazole from the binary blends with acidic carbomer 934 increased as the rabeprazole concentration decreased. In addition, the degradation half-life of rabeprazole as well as the relative peak area ratios obtained from FT-IR spectra of S=O stretching at 1094.1 cm1 decreased consistently as the fraction of carbomer 934 increased due to its sensitivity between the basic benzimidazole nitrogen and carboxylic acid group of carbomer 934. The physical appearance also turned into strong brown color in the presence of carbomer 934. In contrast, there were no significant changes in the degradation kinetics of rabeprazole with MgO and HPMC 4000 in a solid state. This present study demonstrated that the solid-state compatibility test with the aid of HPLC chromatographic and FTIR spectral analyses could offer a valuable methodology to select suitable pharmaceutical excipients and to elucidate the degradation mechanism of RPN for drug formulations at the early formulation stages.

Over the last 30 years, nanoparticle-based medicine has received tremendous attention due to its advances with smart therapeutics and less toxicity. Few nanomedicine products have been approved for commercial use in the clinic (such as Doxil(®), Ambraxane(®)..). Nanomedicine research is still at its early stage and the preparation of nanoparticles must be carefully considered. Systems involving further increased supersaturation, either via solvent evaporation, temperature reduction or anti-solvent mixture, were suggested to be capable of inducing nanoprecipitation (NPT). Since this technique is straight-forward, fast and easy to duplicate in practice, it is highly preferred and recommended. In this review, the process of NTP was described and discussed in detail. Factors that affect the encapsulation efficiency, the nanoparticle size, the morphology and the stability of nanoparticles prepared by NTP were described. This process is one of the most preferable processes for preparing solid nano-protein due to their elegant techniques that preserve the bioactivity of proteins. Although the production of nanoparticles by this process has not been applied in the pharmaceutical industry due to the organic solvent issue, the production equipment for large-scale has been marketed.

The aim of this study was to investigate the effect of modification processes on physical properties and explain the mechanism of sustained drug release from modified rice (MR). Various types of Vietnamese rice were introduced in the study as the matrices of sustained release dosage form. Rice was thermally modified in water for a determined temperature at different times with a simple process. Then tablets containing MR and isradipine, the model drug, were prepared to investigate the capability of sustained drug release. Scanning electron microscopy (SEM) was used to determine different morphologies between MR formulations. Flow property of MR was analyzed by Hausner ratio and Carr's indices. The dissolution rate and swelling/erosion behaviors of tablets were evaluated at pH 1.2 and pH6.8 at 37±0.5°C. The matrix tablet containing MR showed a sustained release as compared to the control. The SEM analyses and swelling/erosion studies indicated that the morphology as well as swelling/erosion rate of MR were modulated by modification time, drying method and incubation. It was found that the modification process was crucial because it could highly affect the granule morphologies and hence, leading to the change of flowability and swelling/erosion capacity for sustained release of drug.

This study is to design a sustained release solid dispersion using swellable polymer by melting method.Polyethylene glycol 6000 (PEG 6000) and hydroxypropyl methylcellulose 4000 (HPMC 4000) were used in solid dispersion for not only enhancing drug dissolution rate but also sustaining drug release. HPMC 4000 is a common swellable polymer in matrix sustained release dosage form, but could not be used in preparation of solid dispersion by melting method. However, the current study utilized the swelling capability of HPMC 4000 accompanied by the common carrier PEG 6000 in solid dispersion to accomplish the goal.While PEG 6000 acted as a releasing stimulant carrier and provided an environment to facilitate the swelling of HPMC 4000, this swellable polymer could act as a rate-controlling agent. This greatly assisted the dissolution enhancement by changing the crystalline structure of drug to more amorphous form and creating a molecular interaction.These results suggested that this useful technique can be applied in designing a sustained release solid dispersion with many advantages.

Marine environment exhibits an enormous diversity of organisms which contains an abundant source of polysaccharides. As polymer matrix carriers, marine-based polymers possess several valuable properties including high stability, non-toxicity, hydrophilicity, biodegradability, with low production cost. Despite notable biological activities of these natural polymers, there are certain limitations in exploring their functions in applications of nano-sized drug delivery systems. The review aims to demonstrate exceptional characteristics of marine-based polymers including fucoidan, alginate, carrageenan, hyaluronic acid, chondroitin sulfate, and chitosan as well as provide perspectives of current publications on their nanoparticle formulations for biomedical applications.

Curcumin, a polyphenolic compound derived from Curcuma longa, possesses diverse pharmacologic effects such as anti-inflammatory, antioxidant, antiproliferative and antiangiogenic activities. However, curcumin has poor bioavailability and low dissolution rate due to poor absorption, rapid metabolism, and rapid systemic elimination. The aim of the study was to improve the solubility and dissolution rate of curcumin by solid dispersions. Polyethylene glycol (PEG 6000) and swellable polymers such as hydroxylpropyl methylcelluloses (HPMCs) and polyethylene oxide (PEO), were applied to improve dissolution and oral absorption of curcumin. The solid dispersions (SDs) in different ratios were prepared by hot melting method. The dissolution rate of SDs was tested in simulated gastric fluid (buffer pH 1.2) and simulated intestinal fluid (buffer pH 6.8). Samples were collected at 10, 20, 30, 60, 90, 120 minutes and replaced with an equivalent amount of fresh medium to maintain a constant dissolution volume. High-performance liquid chromatography (HPLC) method was used to determine concentration of curcumin after dissolution test. The dissolution rate of curcumin was enhanced by the incorporation into hydrophilic carrier (e.g. PEG 6000, HPMC 4000, HPMC 6, and PEO). The best percentage of drug release was observed with curcumin: PEG 6000: HPMC 4000 in ratio 1:8:4. Through the selection of polymers with optimal ratio, the SDs could increase the dissolution rate of curcumin.

The aim of this study was to modify the rice starch to prolong the release of drug in gastric fluid. Various types of Vietnamese rice were introduced in the study as the matrix of sustained release dosage form. Rice was thermally modified in water for a determined time at different temperatures. The rice starch was first ground and sieved. Then the powder was physically modified by heat and finally dried in an oven. The modified rice starch appeared as an odorless fine white powder. The tablet containing modified rice starch and Paracetamol were prepared by the wet granulation method. The dissolution rate of tablets was evaluated in simulated gastric fluid without pepsin (buffer pH 1.2). HPLC method was used to determine the amount of drug release. The matrix tablet containing thermally modified starch showed sustained release as compared to the control. The thermally modified starch could be a novel pharmaceutical excipient for sustained release dosage form design.

The study aimed to investigate a new method of thermal modification which was microwave method for controlling drug release of rice starch. The Vibigaba sprouted rice starch (Vietnam) was selected as the model rice. The rice was thermally modified in water for a determined time at different power. The rice starch was first ground and sieved. Then, the powder was physically modified by heat via the microwave and finally dried in an oven. Tablets containing the modified sprouted rice starch of Paracetamol were prepared by the wet granulation method. The dissolution rate of tablets was evaluated in simulated gastric fluid without pepsin (buffer pH 1.2). The matrix tablet containing thermally modified sprouted rice starch showed a sustained release, indicating that the sprouted rice under microwave method could be a promising material for a sustained release dosage form.

Around current 40% of potential active agents are poorly water-soluble drugs. Solid dispersion (SD) technique is one of the most common techniques used to increase the dissolution rate of a poorly water-soluble drug. The aim of this research was to investigate a capability of SD in improving dissolution rate of curcumin, a poorly water-soluble drug in acidic and neutral media. SDs were prepared by melting and solvent methods. Hydroxypropyl methylcellulose 6, polyethylene glycol 6000, poloxamer 407 were used as carriers in the SDs. The dissolution rate of SDs was tested in simulated gastric fluid (buffer pH 1.2) and simulated intestinal fluid (buffer pH 6.8). The structural behaviors of drug were characterized by power X-ray diffraction (PXRD) and Fourier transform spectroscopy (FTIR). The presence of poloxamer 407 in SDs of curcumin improved dissolution rate of the drug. The crystalline structure of the drug was changed to amorphous form. The study indicated that the melting method with poloxamer 407 was the promising approach to enhance dissolution rate of curcumin and hence, suggesting further solutions to achieve the best product containing curcumin which could improve bioavailability of the drug.

Aim of present work was to originally elucidate the roles of ultrasonication method for modulating the size and molecular interactions in controlling release of poorly water-soluble drug. Curcumin was chosen as a model drug. Three types of polymers were investigated as carriers for preparation of polymeric nanoparticles under various ultrasonication conditions and polymer-drug ratios. Changes in drug crystallinity, particle size, and molecular interactions which would be factors enhancing drug dissolution rate were evaluated. Amorphous form of curcumin, size reduction of nanoparticles and interaction between drug and polymer in formulations were attributed to improved drug dissolution rate. Particle size was strongly affected by polymer type, polymer-drug ratio and ultrasonication conditions. Interestingly, control of those factors caused differences in molecular interactions of the hydroxyl groups and then, highly affected particle size of the nanoparticles. It was obvious that there was a reciprocal influence between the drug-polymer interactions and particle size of the nanoparticles. This relation could be modulated by polymers and ultrasonication processes for enhancing drug dissolution rate.

Recently, we synthesized novel amphiphilic gelatin-oleic acid (GO) conjugate to prepare self-assembled nanoparticles for drug delivery. The aim of this study was to investigate pharmaceutical potentialities of self-assembled GO nanoparticles for solubility enhancement and modified release of poorly water-soluble drugs. Three poorly water-soluble model drugs with different pH-dependent solubility (valsartan and aceclofenac, insoluble at pH 1.2; telmisartan, insoluble at pH 6.8) were chosen to investigate the potential contributions of self-assembled GO nanoparticles to solubility enhancement and controlled release. The particle size of the drug-loaded nanoparticles was 200-250 nm. Zeta potential was calculated, and instrumental analysis such as powder X-ray diffraction (PXRD) and Fourier transform infrared (FT-IR) spectroscopy were used to investigate the physicochemical properties of the drug-loaded nanoparticles. Compared to the drug alone, the drug-loaded nanoparticles showed enhanced solubility. Furthermore, the release profiles of the model drugs were modified in a controlled manner. The current self-assembled GO nanoparticles can provide a versatile potential in drug delivery and tumor targeting.

Poorly water-soluble drug with a short half-life such as isradipine (IDP) offer challenges in the controlled release formulation because of low dissolution rate and poor bioavailability. Self-emulsifying solid dispersions (SESD) of IDP consisted of surfactant and fatty acid in poloxamer 407 (POX 407) as a carrier and were manufactured by the melting method. Then, controlled release HPMC matrix tablet containing SESD were prepared via direct compression. The dissolution behaviors and in vivo bioavailability of controlled release matrix tablet in healthy human volunteers were investigated. The physical properties of solid dispersion were also examined using differential scanning calorimetry (DSC), powder X-ray diffraction (PXRD) and scanning electron microscopy (SEM). It was shown that structure of IDP was amorphous in the solid dispersion. The dissolution rate of IDP from SESD was markedly enhanced because of increased solubility and wetting effect. Controlled release HPMC matrix tablets containing SESD released drug in a controlled manner and were stable during storage over 3 months at 40 °C/75% RH. Furthermore, the tablet containing 5mg IDP SESD showed significantly increased oral bioavailability and extended plasma concentration compared with the marketed 5 mg Dynacirc(®) capsule. A combined method of solid dispersion and controlled release technology could provide versatile dosage formulations containing IDP with poor water solubility and short half-life.

For the past few decades biomedical engineering has imprinted its significant impact on the map of science through its wide applications on many other fields. An important example obviously proving this fact is the versatile application of magnetic nanoparticles in theranostics. Due to preferable properties such as biocompatibility, non-toxicity compared to other metal derivations, iron oxide-based magnetic nanoparticles was chosen to be addressed in this review. Aim of this review is to give the readers a whole working window of these magnetic nanoparticles in the current context of science. Thus, preparation of magnetic iron oxide nanoparticles with the so-far techniques, methods of characterizing the nanoparticles as well as their most recent biomedical applications will be stated.

Although the solid dispersion method has been known to increase the dissolution rate of poorly water-soluble drugs by dispersing them in hydrophilic carriers, one obstacle of the solid dispersion method is its limited solubilization capacity, especially for pH-dependent soluble drugs.pH-modified solid dispersion, in which pH modifiers are incorporated, may be a useful method for increasing the dissolution rate of weakly acidic or basic drugs. Sufficient research, including the most recent reports, was undertaken in this review.How could the inclusion of the pH the pH modifiers in the solid dispersion system change drug structural behaviors, molecular interactions, microenvironmental pH, and/or release rate of pH modifiers, relating with the enhanced dissolution of weakly acidic or weakly basic drugs with poor water solubility? These questions have been investigated to determine the dissolution-modulating mechanism of pH modifiers in solid dispersion containing weakly acidic or basic drugs.It is believed that step-by-step mechanistic approaches could provide the ultimate solution for solubilizing several poorly water-soluble drugs with pH-dependent solubility from a solid dispersion system, as well as provide ideas for developing future dosage systems.

The study introduced a new therapeutic agent, fucoidan, which can offer potential medical treatments including anti-inflammatory and anti-coagulant activities, as well as anti-proliferative effects on cancer cells. Fucoidan was included in sustained release formulations expected for an effective plasma drug concentration for approximately 24 h. The matrices based on the two polymers hydroxypropyl methycellulose (HPMC) and polyethylene oxide (PEO) were prepared with various ratios between the polymers and fucoidan. The dissolution profiles of various matrix tablets performed in enzyme-free simulated intestinal fluid (pH 6.8) for 24 h indicated a higher potential of PEO-based matrix tablets in sustaining release of fucoidan. The swelling and erosion of the tablets were also characterized to elucidate the difference among those dissolution profiles.

Many new drugs have been discovered in pharmaceutical industry and exposed their surprised potential therapeutic effects. Unfortunately, these drugs possess low absorption and bioavailability since their solubility limitation in water. Solid dispersion (SD) is the current technique gaining so many attractions from scientists due to its effect on improving solubility and dissolution rate of poorly water-soluble drugs. A number of patents including the most recent inventions have been undertaken in this review to address various respects of this strategy in solubilization of poorly watersoluble drugs including type of carriers, preparation methods and view of technologies used to detect SD properties and mechanisms with the aim to accomplish a SD not only effective on enhanced bioavailability but also overcome difficulties associated with stability and production. Future prospects are as well discussed with an only hope that many developments and researches in this field will be successfully reached and contributed to commercial use for treatment as much as possible.

In vitro intestinal uptake of non-soluble polystyrene microspheres (NPMS) was visualized with and without oleic acid using a fluorescence microscopy. Fluorescent polystyrene latex microspheres with 1m larger size were used as models for nonspecifically absorbed nonbiodegradable particulates. The NPMS could not penetrate the enterocytes but a few NPMS could be penetrated via Peyer's patches. When the oleic acid was mixed with NPMS, the transporting efficiency of NPMS through enterocytes as well as Peyer's patches was significantly enhanced. The modification of the intestinal membrane permeability and surface feature of the NPMS in the presence of oleic acid might be a clue to the transport of NSPM although the detailed mechanism is still under investigation.