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1.
Using an interactive multiobjective optimization method called NIMBUS and an approximation method called PAINT, preferable solutions to a five-objective problem of operating a wastewater treatment plant are found. The decision maker giving preference information is an expert in wastewater treatment plant design at the engineering company Pöyry Finland Ltd. The wastewater treatment problem is computationally expensive and requires running a simulator to evaluate the values of the objective functions. This often leads to problems with interactive methods as the decision maker may get frustrated while waiting for new solutions to be computed. Thus, a newly developed PAINT method is used to speed up the iterations of the NIMBUS method. The PAINT method interpolates between a given set of Pareto optimal outcomes and constructs a computationally inexpensive mixed integer linear surrogate problem for the original wastewater treatment problem. With the mixed integer surrogate problem, the time required from the decision maker is comparatively short. In addition, a new IND-NIMBUS® PAINT module is developed to allow the smooth interoperability of the NIMBUS method and the PAINT method.  相似文献   

2.
Context: Patient compliance can be reduced when bitter-tasting compounds, such as propiverine hydrochloride, are administered orally. Propiverine hydrochloride is an example of a drug with a bitter taste, used for the treatment of overactive bladders.

Objective: This study tested whether propiverine free base palatability and aqueous solubility could be improved by crystalline complex formation.

Materials and methods: We used 42 compounds, and found 9 new propiverine crystalline complexes. The properties and solubility of these complexes were studied using a range of techniques. A taste perception study was carried out using a taste sensor to evaluate the taste masking ability of the crystalline complex formation.

Results: The melting points of the crystalline complexes were higher than that of propiverine. The dissolution rates of the crystalline complexes in aqueous buffer solution (pH 6.8) and in purified water were much faster than that of propiverine. Propiverine salicylic acid crystalline complex had substantially less bitterness than propiverine hydrochloride, which was extremely bitter.

Discussion: The present findings indicated that crystalline complex formation provided an effective approach to enhancing propiverine solubility, and to masking its bitter taste.

Conclusion: Crystalline complex formation represents a useful and valuable technique for the preparation of orally disintegrating tablets and improving patient compliance, even for substances with bitter tastes.  相似文献   


3.
Electrospun polyvinylidene fluoride (PVDF)-containing carbon nanotubes (CNT) were prepared for use in fabricating actuator materials. Actuating displacement was measured in an electrochemical environment. The electrospun nanofibers were arranged using a drum-type collector, and morphology was investigated using a field emission-scanning electron microscope. The uniformity of dispersion of CNT in the PVDF nanofibers was monitored by electron probe X-ray micro-analysis. Tensile strength and electrical resistivity results were used as an indication of the state of alignment. The electrospun CNT/PVDF nanofiber sheets exhibited better mechanical and electrical properties in the arranged direction. The efficiency and electrical capacities of electrospun CNT/PVDF nanofiber sheet were compared with those of cast PVDF sheets for use in actuator applications in electrochemical environments. The electrospun CNT/PVDF nanofiber sheets exhibited much better actuator performance than PVDF sheets, which are attributed to their superior electrical properties.

Highlights

(1) The interfacial durability of CNT/PVDF nanofibers was enhanced to increase contact area by reinforcing CNT.

(2) The efficiency of CNT/PVDF actuators was improved due to interfacial properties.

(3) Thin thickness drum-type collector was made to enhance nanofiber alignment.

(4) The arranged CNT/PVDF nanofibers exhibited better mechanical and actuating displacements.  相似文献   


4.
Context: Although several methods have been investigated to measure the film thickness of tablets and its correlation with the dissolution behavior, much fewer such investigations exist for pharmaceutical pellets.

Objective: To study the possibility of measuring the film thickness and predicting the dissolution behavior of pellets produced in different fluid bed equipments with Raman spectroscopy.

Materials and methods: Pyridoxine hydrochloride-layered pellets were produced and coated in two different Strea-1 equipments. Raman spectra were collected and analysed to set up a calibration model based on the film thickness data calculated from Camsizer analysis results. Dissolution tests were done according to Ph. Eur. standards.

Results: Raman spectroscopy proved to be a good tool in the measurement of film thickness. Polymer weight gain showed a linear correlation with film thickness but was a poor predictor of dissolution results below a threshold value.

Conclusion: The Raman spectroscopic measurement of a small sample can provide accurate data of the film thickness. The investigation suggests that a threshold value might exist for the film thickness above which it can be used to judge future dissolution results.  相似文献   


5.
Context: Cilnidipine (CN) is a novel dihydropyridine calcium antagonist that is practically insoluble in aqueous media and exhibits a low oral bioavailability or limited clinical efficacy.

Objective: This study investigated the effects of three commercial and chemically diverse polymers – PVP, PVP/VA and Soluplus – on crystallization tendency and in vitro dissolution profiles of CN in order to determine an optimum carrier for composing the preferred solid dispersion (SD) of CN.

Methods: All these co-evaporated systems were characterized up to 3 months by thermoanalytical (DSC), crystallographic (POM, PXRD), microscopic (SEM) and spectroscopic (FTIR) techniques.

Results: The results showed that the polymers could be sorted by their effects of inhibiting CN crystallization in the ascending order: Soluplus, PVP/VA, PVP. The sequence was in accordance with that of the strength of drug–polymer hydrogen bonds revealed by FTIR spectra. It could be ascribed to relative hydrogen-bonding acceptor strengths of N-vinylpyrrolidone moiety in the polymer molecules. On the other hand, all the SDs showed enhanced dissolution profiles compared to pure CN alone. On their effects of enhancing CN dissolution, the polymers could be sorted in the descending order: Soluplus, PVP, PVP/VA.

Conclusions: It implied that the dissolution behavior of CN could bear a close relationship to both hydration capacity and hydrogen-bonding interaction tendency of moieties of the polymers. It might suggest an optimal formulation for CN comprising both PVP and Soluplus.  相似文献   


6.
Objective: To establish a new osmotic pressure measuring method with a wide measuring range.

Method: The osmotic pressure of drug solutions is determined by measuring the relative air humidity in equilibrium with the solution. The freezing point osmometry is used as a control.

Results: The data obtained by the proposed method are comparable to those by the control method, and the measuring range of the proposed method is significantly wider than that of the control method.

Conclusion: The proposed method is performed in an isothermal and equilibrium state, so it overcomes the defects of the freezing point and dew point osmometries which result from the heterothermal process in the measurement, and therefore is not limited to diluted solutions.  相似文献   


7.
Context: The advantage of solid nanocarriers like solid lipid nanoparticles (SLN) or nanostructured lipid carriers (NLC) is related to some degree of crystalline characteristics of the lipid. However, the detection of tiny content of crystalline structure in such nanoparticles is difficult.

Objective: The aim of this study was to explore a potential method for detection of low degree of crystalline characteristics of lycopene-loaded SLN and NLC.

Methods: Crystalline characteristics investigation was done by polarized light microscope (PLM), differential scanning calorimeter (DSC), X-ray diffractometer (XRD) and transmission electron microscope (TEM).

Results and discussion: It was found that high crystalline characteristics as anisotropic molecular organization crystal of pure orange wax and lycopene could be investigated by PLM, DSC and WAXS. Low crystallinity of lycopene-loaded SLN and NLC could not be detected by those techniques. Electron diffraction mode of TEM showed potential detection of tiny crystalline characteristics of such systems. The diffraction pattern of lycopene-loaded SLN and NLC exhibited obvious zero order laue zone indicating an isotropic fine grained polycrystalline of the nanoparticles.

Conclusion: It could be concluded that TEM is a promising method for detection of low-level crystallinity of solid nanocarriers.  相似文献   


8.
Context: Electrospraying was used in drug particle production.

Objective: The aim of the research was to evaluate the possibilities to produce drug particles with desired pharmaceutical properties by electrospraying. In particular, the effect of drying pressure on particle properties was studied.

Materials and methods: A poorly water soluble model drug (budesonide) was dissolved in chloroform, and the solution was atomized by electrospraying. Following this, the charged droplets were neutralized and dried in a drying chamber. The pressure in the drying chamber was varied. The dried particles were collected and analyzed.

Results: The pressure reduction had a slight impact on particle size distribution. The particles produced in reduced pressure turned out to be notably more porous than the particles produced in atmospheric pressure. The pressure reduction also affects the degree of crystallinity of the product. The dissolution of the particles produced in reduced pressures was faster to a certain extent than that of the particles produced in atmospheric pressure.

Discussion and conclusions: A setup for electrospraying materials in a reduced pressure was presented. The pressure reduction had a notable impact on particle morphology. The possibilities to tailor the particle properties during electrospraying were studied.  相似文献   


9.
Context: Combination therapies provide a potential solution to address the tumor heterogeneity and drug resistance issues by taking advantage of distinct mechanisms of action of the multiple therapeutics.

Objective: To design arginine-glycineaspartic acid (RGD) modified lipid-coated nanoparticles (NPs) for the co-delivery of the hydrophobic drugs against hepatocellular carcinoma (HCC).

Materials and methods: RGD modified lipid-coated PLGA NPs were developed for the targeted delivery of both sorafenib (SRF) and quercetin (QT) (RGD-SRF-QT NPs). Chemical–physical characteristics and release profiles were evaluated. In vitro cell viability assays were carried out on HCC cells. In vivo antitumor efficacies were evaluated in HCC animal model.

Results and discussion: The combination of SRF and QT formulations was more effective than the single drug formulations in both NPs and solution groups. RGD-SRF-QT NPs achieved the most significant tumor growth inhibition effect in vitro and in vivo.

Conclusion: The resulting NPs could provide a promising platform for co-delivery of multiple anticancer drugs for achievement of combinational therapy and could offer potential for enhancing the therapeutic efficacy on HCC.  相似文献   


10.
Context: Advancement in technology has transformed the conventional dosage forms to intelligent drug delivery systems. Such systems are helpful for targeted and efficient drug delivery with minimum side effects. Drug release from these systems is governed and controlled by external stimuli (pH, enzymes, ions, glucose, etc.). Polymeric biomaterial having stimuli-responsive properties has opened a new area in drug delivery approach.

Objective: Potential of a polysaccharide (rhamnogalacturonan)-based hydrogel from Linseeds (Linum usitatissimum L.) was investigated as an intelligent drug delivery material.

Materials and methods: Different concentrations of Linseed hydrogel (LSH) were used to prepare caffeine and diacerein tablets and further investigated for pH and salt solution-responsive swelling, pH-dependent drug release, and release kinetics. Morphology of tablets was observed using SEM.

Results: LSH tablets exhibited dynamic swelling–deswelling behavior with tendency to swell at pH 7.4 and in deionized water while deswell at pH 1.2, in normal saline and ethanol. Consequently, pH controlled release of the drugs was observed from tablets with lower release (<10%) at pH 1.2 and higher release at pH 6.8 and 7.4. SEM showed elongated channels in swollen then freeze-dried tablets.

Discussion: The drug release was greatly influenced by the amount of LSH in the tablets. Drug release from LSH tablets was governed by the non-Fickian diffusion.

Conclusions: These finding indicates that LSH holds potential to be developed as sustained release material for tablet.  相似文献   


11.
Context: Abuse potential of extended-release (ER) opioid tablets increases if tampering causes rapid opioid release.

Objective: To evaluate the susceptibility to tampering of biphasic immediate-release (IR)/ER oxycodone (OC)/acetaminophen (APAP) tablets compared with IR OC/APAP tablets.

Materials and methods: IR/ER OC/APAP and IR OC/APAP tablets were tested at room temperature and after heating, freezing and microwaving. Resistance to crushing was tested using manual and powered tools (e.g. spoons, mortar and pestle, blender, coffee grinder). Tampered tablets were tested for suitability for snorting, OC extraction in solvents and ease of drawing into a syringe. Dissolution of IR/ER OC/APAP in gastric fluid with and without ethanol was tested to determine the potential for facilitating precipitous release of opioid from the tablet.

Results: IR/ER OC/APAP tablets were more crush resistant than IR OC/APAP tablets. Heating, freezing and microwaving had no effect on crush resistance of IR/ER OC/APAP tablets. Although a mortar and pestle pulverized IR/ER OC/APAP tablets, upon contact with solvent, the powder formed a thick gel judged unsuitable for absorption through the nasal mucosa and could not be drawn into a syringe. In contrast, powder from crushed IR OC/APAP tablets dissolved readily, was judged suitable for snorting, and was easily drawn into a syringe. Dissolution of IR/ER OC/APAP tablets in gastric fluid was slowed by the addition of ethanol.

Discussion: IR/ER OC/APAP tablets are resistant to crushing and dissolution compared with IR OC/APAP tablets.

Conclusion: IR/ER OC/APAP tablets may have less potential for abuse involving tampering compared with IR OC/APAP tablets.  相似文献   


12.
Context: Benznidazole (BNZ) is an antiparasitic with trypanocidal properties for the etiological treatment of Chagas disease since 1973. Monitoring the stability of this drug is one of the most effective methods of assessment, forecasting and prevention of problems related to quality product.

Objective: To investigate the direct and indirect photodegradation of BNZ and to evaluate the interference of the excipients used in the forms dosage solid as well as to shed light on the chemical structure of the degradation products obtained.

Materials and methods: To perform this work we adopted the “ICH Harmonised Tripartite Guideline: Photostability Testing of New Drug Substances and Products Q1B” (Guideline Q1B). We used benzonidazole (BNZ) (N-benzil-2-(2-nitroimidazol-1-il) acetamide) (LAFEPE®, Recife, Brazil) and various excipients; beyond high-performance liquid chromatography (HPLC), differential scanning calorimetry (DSC), infrared spectroscopy (IR) and mass spectrometry/mass spectrometry (MS/MS). The indirect photodegradation of BNZ was carried out using physical mixtures with 13 pharmaceutical excipients commonly used in the preparation of solid dosage forms.

Results: HPLC and MS/MS techniques were selected for the identification of two photoproducts (PPs) and photoreactions found in direct and indirect tests with the microcrystalline cellulose, considered a critical excipient.

Discussion: Despite variations in the infrared spectrometry, differential scanning calorimetry and differential thermogravimetry curves, these techniques are not conclusive since the study of photodegradation of the drug caused decay of 30%, according to the ICH.

Conclusions: The results show that BNZ only undergoes direct photodegradation, since no new PPs were found for a combination of the drug and excipients.  相似文献   


13.
Background: In the system of the iontophoresis, the external electric field made the ions in the system moving directly, then, the current was generated. Because the current was contributed by all ions in the system, and the small ions with large amount often had higher conductibility than the drug ions, the fraction of the total current contributed by the drug ions was often low. It was the main reason for the generally low efficiency of the transdermal iontophoretic drug delivery.

Objectives: The objective of this study was to find a novel method to increase the fraction of the total current contributed by the drug ions so as to enhance the drug's iontophoretic delivery.

Method: Iontophoretic transport of nefopam hydrochloride solution and iontophoretic transport of nefopam assisted by ion-exchange materials, including ion-exchange resin, ion-exchange membrane and ion-exchange fiber, across the rat skin were investigated.

Results: Both in vitro and in vivo iontophoretic transport experiments showed that the efficiency of the nefopam-fiber iontophoretic system for nefopam permeating across rat skin was the highest among four iontophoretic systems (nefopam solution, nefopam-resin, nefopam-membrane and nefopam-fiber).

Conclusion: The results of this study suggested that there was an enhancement of nefopam across rat skin by ion-exchange fibers in ion-exchange fibers assisted iontophoresis. The present study has demonstrated the potential of a new approach of using ion-exchange fibers to improve the efficiency of the transdermal iontophoresis for cationizable drugs.  相似文献   


14.
Context: A stable topical ophthalmic curcumin formulation with high solubility, stability, and efficacy is needed for pharmaceutical use in clinics.

Objectives: The objective of this article was to describe a novel curcumin containing a nanomicelle formulation using a polyvinyl caprolactam–polyvinyl acetate–polyethylene glycol (PVCL–PVA–PEG) graft copolymer.

Methods: Nanomicelle curcumin was formulated and optimized and then further evaluated for in vitro cytotoxicity/in vivo ocular irritation, in vitro cellular uptake/in vivo corneal permeation, and in vitro antioxidant activity/in vivo anti-inflammatory efficacy.

Results: The solubility, chemical stability, and antioxidant activity were greatly improved after the encapsulation of the PVCL–PVA–PEG nanomicelles. The nanomicelle curcumin ophthalmic solution was simple to prepare and the nanomicelles are stable to the storage conditions, and it had good cellular tolerance. Nanomicelle curcumin also had excellent ocular tolerance in rabbits. The use of nanomicelles significantly improved in vitro cellular uptake and in vivo corneal permeation as well as improved anti-inflammatory efficacy when compared with a free curcumin solution.

Conclusions: These findings indicate that nanomicelles could be promising topical delivery systems for the ocular administration of curcumin.  相似文献   


15.
Objective: Preparation of magnolol-loaded amorphous solid dispersion was investigated for improving the bioavailability.

Materials and methods: A solid dispersion of magnolol was prepared with polyvinylpyrrolidone K-30 (PVP) by melting method, and the physical properties were characterized by using differential scanning calorimetry, powder X-ray diffractometry, Fourier transformation-infrared spectroscopy and scanning electron microscope. In addition, dissolution test was also performed. Subsequently, the bioavailability of magnolol pure compound, its physical mixture and solid dispersion were compared in rabbits. The blood samples withdrawn via marginal ear vein at specific time points were assayed by HPLC method.

Results: Oral administration of the solid dispersion of magnolol with PVP significantly increased the systemic exposures of magnolol and magnolol sulfates/glucuronides by 80.1% and 142.8%, respectively, compared to those given with magnolol pure compound.

Conclusion: Magnolol-loaded amorphous solid dispersion with PVP has demonstrated enhanced bioavailability of magnolol in rabbits.  相似文献   


16.
Objective: This work aimed to develop and characterize a topical emulgel of amphotericin B (AmB) with bacuri butter (Platonia insignis Mart.) and evaluate its antileishmanial activity using in vitro assays.

Significance: Leishmaniasis is considered an infectious disease, with high incidence and capacity to produce deformities. The first-line treatment recommended by WHO, with pentavalent antimonials, is aggressive and very toxic. Therefore, the development of topical treatments can emerge as a promising and less offensive alternative.

Methods: The developed formulations were evaluated for organoleptic characteristics, centrifugation resistance, globule size, pH, electrical conductivity, viscosity, spreadability, drug content, preliminary stability, in vitro release profile, evaluation of antileishmanial activity using promastigotes forms of Leishmania major as infecting agents, macrophage cytotoxicity and selectivity index (IS).

Results: Formulated emulsions presented organoleptic characteristics compatible with its constituents; pH values were suitable for topical application, ranging from 4.73 to 5.02; introduced non-Newtonian shear thinning system; drug content was within the established standards, and the most suitable kinetic model of release was the first order. Regarding the in vitro assays, formulations containing both 1% and 3% of AmB presented similar outcomes, indicating a synergism between the bacuri butter and the drug, possibly showing a reduction on cytotoxicity to host cells.

Conclusions: It was concluded that the formulations developed showed promising antileishmanial action and high potential for topical use.  相似文献   


17.
Objective: The aim of this study is to evaluate the relative stability of pharmaceutical cocrystals consisting of paracetamol (APAP) and oxalic acid (OXA) or maleic acid (MLA).

Significance: These observations of cocrystal stability under various conditions are useful coformer criteria when cocrystals are selected as the active pharmaceutical ingredient in drug development.

Method: The relative stability was determined from the preferentially formed cocrystals under various conditions.

Result: Cocrystal of APAP–OXA was more stable than that of APAP–MLA in a ternary cogrinding system and possessed thermodynamical stability. On the other hand, when grinding with moisture or maintaining at high temperatures and relative humidity conditions, APAP–MLA was more stable, and OXA converted to OXA dihydrate. In the slurry method, APAP–OXA was more stable in aprotic solvents because the APAP–OXA with low-solubility product precipitated.

Conclusions: The relative stability order was affected by preparing conditions of presence of moisture. This order might attribute to the small difference of crystal structure in the extension of the hydrogen bond network.  相似文献   


18.
Context: Teicoplanin is a fermentative antibiotic consisting of several active components that contribute similarly to the antibacterial activity, but exhibit different pharmacokinetic properties. Differences in systemic exposure between batches of teicoplanin are possible within pharmacopeial specifications as the proportion of subcomponents may vary from batch to batch.

Objective: The aim of this paper is to study the possible modification of the present pharmacopeial specification for teicoplanin composition to ensure an a priori pharmacokinetic equivalence between all pharmacopoeial-compliant batches.

Methods: The expectable whole Area Under the Curve (AUC) of plasma levels of teicoplanin was predicted for different experimental batches and also for the theoretical extreme batches within pharmacopeial specifications. Calculations were done based on the AUC of each teicoplanin active subcomponent. Subsequently, the equivalence between a generic teicoplanin and a reference drug product was investigated by means of the ratio of AUCs.

Results: Batches under study, complying with current pharmacopoeial specifications, showed a maximum predicted difference in AUC slightly larger than 40%. The observed variability in teicoplanin compositions surpasses the conventional ±5% specification used for drugs obtained by chemical synthesis, but no 5% differences have been observed for any of the AUC means of the reference product when compared with the whole pooled data.

Discussion and conclusion: Alternative specifications of actives composition can be defined to ensure that all batches complying with the pharmacopoeia are inside ±10% interval between them.  相似文献   


19.
Context: Combination anticancer therapy is promising to generate synergistic anticancer effects, to maximize the treatment effect and to overcome multi-drug resistance. Nanostructured lipid carriers (NLCs), composed of solid and liquid lipids, and surfactants are potentially good colloidal drug carriers.

Objective: The aim of this study is to construct novel NLCs as nanocarriers for co-delivery of doxorubicin (DOX) and cisplatin (CDDP) to treat breast cancer.

Methods: DOX and CDDP loaded NLCs (D–C-NLCs) were prepared by the solvent diffusion method. The in vitro cytotoxicity and synergistic studies of different formulations were evaluated on human breast cancer cells (doxorubicin resistant) (MCF-7/ADR cells). In vivo anti-tumor effects were observed on the murine bearing MCF-7/ADR cells model.

Results: D–C-NLCs showed the highest cytotoxicity and synergistic effect of two drugs in tumor cells in vitro. The in vivo study revealed the greatest anti-tumor activity than the other formulations in the breast cancer model.

Conclusion: The constructed NLCs could be used as a novel carrier for co-delivery of DOX and CDDP for breast cancer therapy. D–C-NLCs could be a promising targeted and combinational therapy nanomedicine.  相似文献   


20.
Context: The SeDeM expert system is based on the experimental study and quantitative determination of the characterization parameters of powdered substances, the aim being to determine whether a substance is suitable for producing tablets by means of direct compression (DC) technology, thereby reducing the lead time for pre-formulation studies. Additionally, this expert system also provides formulations with a minimum number of excipients.

Objective: We used this system to analyze suitable formulas for the production of orodispersible ibuprofen tablets.

Method: Twenty-one disintegrants and ibuprophen were characterized using SeDeM methodology.

Results: The results indicated that production of ibuprofen tablets by DC would require improvements in the dimension and compressibility factors of the active pharmaceutical ingredient. The expert system analysis provided the specific percentage of disintegrant needed to blend with ibuprofen and a standardized formula of lubricants in order to obtain a powder mix that would successfully produce tablets by DC. The eight formulas proposed by SeDeM were produced and tested in the laboratory.

Conclusion: All eight formulas successfully produced tablets by DC, but only four of them could be considered suitable for use as an orodispersible tablet and accomplishes all the pharmaceutical quality parameters. So, in fact, the use of the SeDeM system reduced the time of medicine’s development and therefore the cost of the activity.  相似文献   


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