Analysis of Liquid Crystalline Nanoparticles by Small Angle X-Ray Diffraction: Evaluation of Drug and Pharmaceutical Additives Influence on the Internal Structure

The goal of this work was to study the liquid crystalline structure of a nanodispersion delivery system intended to be used in photodynamic therapy after loading with photosensitizers (PSs) and additives such as preservatives and thickening polymers. Polarized light microscopy and light scattering were performed on a standard nanodispersion in order to determine the anisotropy of the liquid crystalline structure and the mean diameter of the nanoparticles, respectively. Small angle X-ray diffraction (SAXRD) was used to verify the influence of drug loading and additives on the liquid crystalline structure of the nanodispersions. The samples, before and after the addition of PSs and additives, were stable over 90 days, as verified by dynamic light scattering. SAXRD revealed that despite the alteration observed in some of the samples analyzed in the presence of photosensitizing drugs and additives, the hexagonal phase still remained in the crystalline phase. (C) 2011 Wiley-Liss, Inc. and the American Pharmacists Association J Pharm Sci 100: 2849-2857, 2011

Aditivos de formulação na formação de filmes isolados de etilcelulose. estudos físico-químicos e morfológicos

Formulation Additives on Formation of Films isolated from Ethylcellulose. Physicochemical and Morphological Studies. In this work were developed free films from Surelease (R), additives alpha-GOS (alfa-glucooligosaccharide) and/or Tween (R) 80 in aqueous solution. It was obtained by Teflon plates casting process. The free films were characterized by thermal analysis (DSC and TGA), infrared spectroscopy (FTIR-ATR) and scanning electron microscopy (SEM). DSC and TO analysis showed that the additives do not influenced in the thermal stability of Surelease (R) films. SEM analysis observed homogeneous morphological characteristics and phase detachment absence. FTIR-ATR spectra were used to confirm the physical mixture between the components of films.

Additives and Protein-DNA Combinations Modulate the Humoral Immune Response Elicited by a Hepatitis C Virus Core-encoding Plasmid in Mice

Humoral and cellular immune responses are currently induced against hepatitis C virus (HCV) core following vaccination with core-encoding plasmids. However, the anti-core antibody response is frequently weak or transient. In this paper, we evaluated the effect of different additives and DNA-protein combinations on the anti-core antibody response. BALB/c mice were intramuscularly injected with an expression plasmid (pIDKCo), encoding a C-terminal truncated variant of the HCV core protein, alone or combined with CaCl2, PEG 6000, Freund's adjuvant, sonicated calf thymus DNA and a recombinant core protein (Co.120). Mixture of pIDKCo with PEG 6000 and Freund's adjuvant accelerated the development of the anti-core Ab response. Combination with PEG 6000 also induced a bias to IgG2a subclass predominance among anti-core antibodies. The kinetics, IgG2a/IgG1 ratio and epitope specificity of the anti-core antibody response elicited by Co.120 alone or combined with pIDKCo was different regarding that induced by the pIDKCo alone. Our data indicate that the antibody response induced following DNA immunization can be modified by formulation strategies.

Water adsorption isotherms and isosteric sorption heat of spray-dried and freeze-dried dehydrated passion fruit pulp with additives and skimmed milk

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Synthesis of new calixarene-based lubricant additives

The lubricants are normally composed by base oils and a number of additives which are added to improve the performances of the final product. In this work, which is due to the collaboration between ENI S.p.A. and Prof. Casnati’s group, significant results in the application of calixarene structures to two classes of lubricant additives (viscosity index improvers and detergents) were shown. In particular, several calix[8]arene derivatives were synthesized to use as core precursors in the “arm-first" synthetic processes of star polymers for viscosity index improver applications. The use of calixarene derivatives enable the production of star polymers with a high and well-defined number of branches and endowed with a very low dispersivity of molecular weight which can originate better performances than the current commercially available viscosity index improvers of the major competitor. Several functional groups were considered to prepare reactive p-tert-butylcalix[8]arene cores to be used in living anionic polymerization. n-butyllithium was used as model of the living anionic polymer to test the outcome of the reaction of polymer insertion on the calixarene core, facilitating the analyses of the products. The calixarene derivative, which easier reacts with n-BuLi, was selected for the preparation of star polymers by using a isoprene/styrene living anionic polymer. Finally, the lubricant formulations, which include the calixarene-based star polymers or commercially available products as viscosity index improvers, were prepared and comparatively tested. In the last part of Thesis, the use of calixarenes as polycarboxylic acids to synthetize new sulfur-free detergents as lubricant additives was carried out. In this way, these calcium-based detergents can be used for the formulation of new automotive lubricants with low content of ash, phosphorus and sulfur (low SAPS). To increase the low deprotonation degree of OH groups and their capacity to complex calcium ions, a complete functionalization of the calixarene mixtures with acetic acid groups was required. Futhermore, the “one-step” synthesis of new calixarenes with alkyl chains in para positions longer than the ones already known was necessary to improve the oil solubility and stability of reverse micelles formed by the detergents. Moreover, the separation and characterization of the calixarenes were carried out to optimize their synthetic process, also on pilot scale. For our purpose, the use of p-tert-octylcalixarenes for the preparation of detergents was carried out to compare the properties of the final detergents respect to the use of the p-dodecyl calixarenes. Once achieved the functionalization of both calixarene mixtures with carboxylic acid groups, the syntheses of new calixarene-based detergents were carried out to identify the best calixarene derivative for our research goals. The synthetic process for the preparation of calixarene-based detergent having very high basicity (TBN 400) was also investigated for applications in lubricants for marine engines. In addition, with the aim of testing the calixarene-based detergents in automotive lubricants, several additive packages (concentrated mixture of additives) containing our detergents were prepared. Using these packages the corresponding automotive lubricants can be formulated. Besides, a lubricant containing commercial calcium alkylbenzene-sulfonates detergents was prepared to compare its detergency properties with those of the calixarene-based oils.

Formulation of immunomodulatory agents

Reversed-phase high-performance liquid chromatography procedures were developed for the analysis of pyrimidine-based drugs bropirimine and its derivatives (2-N-acetyl- and 2-N-propanoyl-) and for pyrimethamine and its 2/4- substituted derivatives (2, N-propanoyl and 2,4-N, N-dipropanoyl-) and its 6- substituted (methyl-, ethyl-, propyl- and isopropyl- carboxylates) analogues. Stability studies indicated that these derivatives were not sufficiently labile to act as potential prodrugs. Solubility-pH profiles were constructed from which the dissociation constants were calculated. The physicochemical properties of these compounds were studied and attempts were made to increase the poor aqueous solubility of bropirimine (35μg/mL) by prodrug synthesis, solvate formation (acetic acid, N, N-dimethylformamide and N-methylformamide) and the use of co-solvents and additives. The first two methods proved to be fruitless whereas the latter method resulted in an intravenous formulation incorporating 32mg/mL of bropirimine. An in-vitro method for the detection of precipitation was developed and the results suggested that by using low injection rates (< 0.24mL/min) and high mobile phase flow rates (> 500mL/hr) precipitation could be minimised. Differential scanning calorimetry showed that bropirimine debrominates in the presence of a number of additives commonly used in formulation work but the temperature at which this occurred were usually > 200oC. In-vitro work gave encouraging results for the possibility of rectal delivery of bropirimine but in-vivo work on rabbits showed considerable variations in the resulting plasma levels and pharmacokinetic parameters.

Effect of the Electrolyte Formulation on the Performances of Edlc and Li-Ion Batteries

One of the most important components in electrochemical storage devices (batteries and supercapacitors) is undoubtedly the electrolyte. The basic function of any electrolyte in these systems is the transport of ions between the positive and negative electrodes. In addition, electrochemical reactions occurring at each electrode/electrolyte interface are the origin of the current generated by storage devices. In other words, performances (capacity, power, efficiency and energy) of electrochemical storage devices are strongly related to the electrolyte properties, as well as, to the affinity for the electrolyte to selected electrode materials. Indeed, the formulation of electrolyte presenting good properties, such as high ionic conductivity and low viscosity, is then required to enhance the charge transfer reaction at electrode/electrolyte interface (e.g. charge accumulation in the case of Electrochemical Double Layer Capacitor, EDLC). For practical and safety considerations, the formulation of novel electrolytes presenting a low vapor pressure, a large liquid range temperature, a good thermal and chemical stabilities is also required.

This lecture will be focused on the effect of the electrolyte formulation on the performances of electrochemical storage devices (Li-ion batteries and supercapacitors). During which, a summary of the physical, thermal and electrochemical data obtained by our group, recently, on the formulation of novel electrolyte-based on the mixture of an ionic liquid (such as EmimNTf2 and Pyr14NTf2) and carbonate or dinitrile solvents will be presented and commented. The impact of the electrolyte formulation on the storage performances of EDLC and Li-ion batteries will be also discussed to further understand the relationship between electrolyte formulation and electrochemical performances. This talk will also be an opportunity to further discuss around the effects of additives (SEI builder: fluoroethylene carbonate and vinylene carbonate), ionic liquids, structure and nature of lithium salt (LiTFSI vs LiPF6) on the cyclability of negative electrode to then enhance the electrolyte formulation. For that, our recent results on TiSnSb and graphite negative electrodes will be presented and discussed, for example 1,2.

1-C. Marino, A. Darwiche1, N. Dupré, H.A. Wilhelm, B. Lestriez, H. Martinez, R. Dedryvère, W. Zhang, F. Ghamouss, D. Lemordant, L. Monconduit “ Study of the Electrode/Electrolyte Interface on Cycling of a Conversion Type Electrode Material in Li Batteries” J. Phys.chem. C, 2013, 117, 19302-19313

2- Mouad Dahbi, Fouad Ghamouss, Mérièm Anouti, Daniel Lemordant, François Tran-Van “Electrochemical lithiation and compatibility of graphite anode using glutaronitrile/dimethyl carbonate mixtures containing LiTFSI as electrolyte” 2013, 43, 4, 375-385.

Valorization of by-products from olive oil industry and their utilization for innovative food formulation

The purpose of this thesis work was the valorization of the main by-products obtained from olive oil production chain (wastewater and pomace) and their utilization in innovative food formulation. In the first part of the thesis, an olive mill wastewater extract rich in phenols were used in the formulation of 3 innovative meat products: beef hamburgers, cooked ham and würstels. These studies confirms that olive mill wastewaters extract rich in phenols could be an alternative for the reduction/total replacement of additives (i.e., nitrites) in ground and cooked meat preparations, which would promote the formulation of healthier clean label products and improve the sustainability of the olive oil industry with a circular economy approach, by further valorizing this olive by-product. In the second part of the thesis, the lipid composition and oxidative stability of a spreadable product obtained from a fermented and biologically de-bittered olive pomace, was assessed during a shelf-life study. This study confirmed that olive pomace represents an excellent ingredient for the formulation of functional foods In the third and last part of the thesis, carried out at the Universidad de Navarra (Pamplona, Spain), during a period abroad (3 months), three extracts obtained from purification of olive mill wastewaters, were subjected to in-vitro digestion and characterized. From the analysis of the three phenolic extracts, it emerged that the most promising extract to be used in the food field is the spry-dried one. Thanks to its formulation containing maltodextrins it manages to maintain its antioxidant capacity even after being underwent to in-vitro digestion. This thesis work is a part of the PRIN 2015 project (PROT: 20152LFKAT) "Olive phenols as multifunctional bioactives for healthier food: evaluation of simplified formulation to obtain safe meat products and new foods with higher functionality", coordinated by University of Perugia.

Influence of additives on the performance of a PVDF membrane

The field of use of membranes is wide and ranges from the automotive industry to biomedical uses. Many formulations and compositions find a niche where they are able to improve efficiency, running cost and quality of the product. The aim of this research is to expand GVS’s product portfolio introducing a new membrane formulation. A series of additives were researched and evaluated, adding them to the membrane solutions, which were then cast and characterised using techniques like Scanning Electron Microscopy (SEM), poroscopy, FT-IT ATR and measurements like Water Break Through (WBT), Air Flow (AF), thickness. This study ultimately focused on one additive, which effect on the membranes was studied in various compositions. Interesting insights were also collected on the stability of the polymer solutions over time, which was found to change the membrane properties significantly, mainly affecting airflow and water breakthrough. Properties of the membranes were studied to find possible correlations to the amount of additive. The additive seems however to change the membrane porometry considerably depending on the time of immersion in the water bath. A new procedure to yield uniform unsupported polymeric membranes for tensile tests was developed. The additive was found to reduce elongation at break and decrease tensile strength of the membranes, possibly hinting toward plasticization of the product.

Lawsonia Inermis-mediated Synthesis Of Silver Nanoparticles: Activity Against Human Pathogenic Fungi And Bacteria With Special Reference To Formulation Of An Antimicrobial Nanogel.

Lawsonia inermis mediated synthesis of silver nanoparticles (Ag-NPs) and its efficacy against Candida albicans, Microsporum canis, Propioniabacterium acne and Trichophyton mentagrophytes is reported. A two-step mechanism has been proposed for bioreduction and formation of an intermediate complex leading to the synthesis of capped nanoparticles was developed. In addition, antimicrobial gel for M. canis and T. mentagrophytes was also formulated. Ag-NPs were synthesized by challenging the leaft extract of L. inermis with 1 mM AgNO₃. The Ag-NPs were characterized by Ultraviolet-Visible (UV-Vis) spectrophotometer and Fourier transform infrared spectroscopy (FTIR). Transmission electron microscopy (TEM), nanoparticle tracking and analysis sytem (NTA) and zeta potential was measured to detect the size of Ag-NPs. The antimicrobial activity of Ag-NPs was evaluated by disc diffusion method against the test organisms. Thus these Ag-NPs may prove as a better candidate drug due to their biogenic nature. Moreover, Ag-NPs may be an answer to the drug-resistant microorganisms.

Pharmacokinetic And Pharmacodynamic Evaluation Of A Nanotechnological Topical Formulation Of Lidocaine/prilocaine (nanorap) In Healthy Volunteers.

Nanorap is a new nanotechnological formulation for topical anesthesia composed of lidocaine (2.5%) and prilocaine (2.5%). The present study evaluated the pharmacokinetics (PK) of Nanorap. For the determination of lidocaine and prilocaine in human plasma a new method using high-performance liquid-chromatography coupled to tandem mass spectrometry was developed. Nanorap pharmacodynamic (PD) and its physical proprieties were also evaluated. Nanorap was administered by topical application of 2g to healthy volunteers and blood samples were collected for the PK analysis. The drugs were extracted from plasma by liquid-liquid extraction with ether/hexane (80/20, v/v). The chromatography separation was performed on a Genesis C18 analytical column 4 µm (100 x 2.1 mm i.d.) with a mobile phase of methanol/acetonitrile/water (40/30/30, for lidocaine, and 50/30/20, for prilocaine, v/v/v) + 2 mM of ammonium acetate and ropivacaine as internal standard. The drugs were quantified using a mass spectrometer with an electrospray source in the ESI positive mode (ES+) configured for multiple reaction monitoring. The PD of Nanorap was evaluated with the use of a visual analogue scale. Nanorap was characterized by cryofracture. The chromatography run time was 5.5 min for lidocaine and 3.3 min for prilocaine and the lower limit of quantification was 0.05 ng/mL for both drugs. Mean Cmax was 6.62 and 1.72 ng/mL for lidocaine and prilocaine, respectively. Median Tmax was 6.5 hours for both drugs. Nanocapsules had a mean size of 88nm and mean drug association of 92.5% and 89% for lidocaine and prilocaine, respectively. The PD study showed that Nanorap has a sufficient analgesic effect (>30% reduction in pain) after 10 minutes of application. A new simple, selective and sensitive method for determination of lidocaine and prilocaine in human plasma was developed. Nanorap generated safe plasma levels of the drugs and satisfactory analgesic effect.

Determination Of Detergent And Dispensant Additives In Gasoline By Ring-oven And Near Infrared Hypespectral Imaging.

A method using the ring-oven technique for pre-concentration in filter paper discs and near infrared hyperspectral imaging is proposed to identify four detergent and dispersant additives, and to determine their concentration in gasoline. Different approaches were used to select the best image data processing in order to gather the relevant spectral information. This was attained by selecting the pixels of the region of interest (ROI), using a pre-calculated threshold value of the PCA scores arranged as histograms, to select the spectra set; summing up the selected spectra to achieve representativeness; and compensating for the superimposed filter paper spectral information, also supported by scores histograms for each individual sample. The best classification model was achieved using linear discriminant analysis and genetic algorithm (LDA/GA), whose correct classification rate in the external validation set was 92%. Previous classification of the type of additive present in the gasoline is necessary to define the PLS model required for its quantitative determination. Considering that two of the additives studied present high spectral similarity, a PLS regression model was constructed to predict their content in gasoline, while two additional models were used for the remaining additives. The results for the external validation of these regression models showed a mean percentage error of prediction varying from 5 to 15%.

Didanosine-loaded Chitosan Microspheres Optimized By Surface-response Methodology: A Modified Maximum Likelihood Classification" Approach Formulation For Reverse Transcriptase Inhibitors."

Didanosine-loaded chitosan microspheres were developed applying a surface-response methodology and using a modified Maximum Likelihood Classification. The operational conditions were optimized with the aim of maintaining the active form of didanosine (ddI), which is sensitive to acid pH, and to develop a modified and mucoadhesive formulation. The loading of the drug within the chitosan microspheres was carried out by ionotropic gelation technique with sodium tripolyphosphate (TPP) as cross-linking agent and magnesium hydroxide (Mg(OH)2) to assure the stability of ddI. The optimization conditions were set using a surface-response methodology and applying the Maximum Likelihood Classification, where the initial chitosan concentration, TPP and ddI concentration were set as the independent variables. The maximum ddI-loaded in microspheres (i.e. 1433mg of ddI/g chitosan), was obtained with 2% (w/v) chitosan and 10% TPP. The microspheres depicted an average diameter of 11.42μm and ddI was gradually released during 2h in simulated enteric fluid.

Impact Of Drug Formulation And Free Platinum/cisplatin Ratio On Hypersensitivity Reactions To Cisplatin: Formulation Matters.

Use of cisplatin can induce type I hypersensitivity reactions that may also be linked to the quality of the drug utilized. We observed cases of hypersensitivity that appeared to be associated with the brand of cisplatin used. The aim of this study was to compare two different brands of cisplatin in relation to type I hypersensitivity reactions. Brand A was used in a tertiary care teaching hospital until 2012, and use of brand B started from January 2013, when the first hypersensitivity cases were observed. Patients were categorized based on symptom. Cisplatin of both brands was analysed by high-performance liquid chromatography (HPLC) and high-resolution electrospray ionization mass spectrometry (ESI-(+)-MS) and characterized according to US Pharmacopeia. There were no cases of hypersensitivity associated with the use of cisplatin brand A, whereas four of 127 outpatients that used cisplatin brand B were affected. The two brands were in accordance with the US Pharmacopeia parameters, and there was no significant difference in the total platinum levels between the two brands when analysed by HPLC. However, high-resolution ESI-(+)-MS analyses show that brand B contains approximately 2.7 times more hydrolysed cisplatin than brand A. The increase in the hydrolysed form of cisplatin found in brand B may be the cause of the hypersensitivity reaction observed in a subset of patients. We present the first study of the quality of drugs by high-resolution ESI-(+)-MS. Drug regulatory agencies and manufacturers should consider including measurement of hydrolysed cisplatin as a quality criterion for cisplatin formulations.