Active Principle Ingredient Research Articles

Using synchrotron high-resolution powder X-ray diffraction for the structure determination of a new cocrystal formed by two active principle ingredients.

The crystal structure of a new 1:1 cocrystal of carbamazepine and S-naproxen (C15H12N2O·C14H14O3) was solved from powder X-ray diffraction (PXRD). The PXRD pattern was measured at the high-resolution beamline CRISTAL at synchrotron SOLEIL (France). The structure was solved using Monte Carlo simulated annealing, then refined with Rietveld refinement. The positions of the H atoms were obtained from density functional theory (DFT) ground-state calculations. The symmetry is orthorhombic with the space group P212121 (No. 19) and the following lattice parameters: a = 33.5486 (9), b = 26.4223 (6), c = 5.3651 (10) Å and V = 4755.83 (19) Å3.

Production of inclusion complexes containing corticosteroids by SAA process

Slightly water-soluble drugs are frequently coprecipitated with a suitable carrier to speed up active principle ingredient (API) dissolution, improving its bioavailability. In this work, combined systems constituted by a corticosteroid and a cyclodextrin were micronized by Supercritical Assisted Atomization (SAA). When SAA processes corticosteroids alone, it is impossible to obtain micronized powders. The selected corticosteroids were prednisolone and dexamethasone, and a derivative of β-cyclodextrin was chosen as the carrier. The drug:cyclodextrin molar ratio and the initial solution concentration were varied to verify their influence on the powders’ particle size and particle size distribution. At all ratios and concentrations assessed, spherical micrometric particles were obtained. Under the optimized process conditions, compared to the unprocessed material, the dissolution time decreases from 18 h to 4 h in the case of prednisolone and from 22 h to 5 h in the case of dexamethasone.

Crushing riluzole tablets: evaluation of loss of powder and active principle in a home-simulation experiment

Objective Swallowing difficulties cause patients with amyotrophic lateral sclerosis (ALS) to crush oral medications, falling outside the labeling instructions and entailing some risks. To date, there is no evidence about consequences of crushing riluzole tablets in a home setting. This simulation experiment evaluated the loss of powder and active principle ingredient (API) mimicking the home setting with two alternative crushing methods (A and B). Methods The tests were carried out by 15 volunteers without experience in the preparation of medication. Each volunteer manually crushed 5 tablets with a meat tenderizer (method A) or two spoons pressed against each other (method B). Riluzole was weighed before (W1) and after crushing (W2). Then, a subsample of crushed tablets was analyzed by HPLC to measure API content. The loss of powder was calculated as a percentage of the intact tablet weight, and the loss of API as a percentage of the labeled API content. Results The quantitative analysis showed a mean percentage loss of 6.27% corresponding to a mean (SD) loss of powder of 13(±13) mg. The API loss was directly related to the powder loss: overall the mean percentage of API loss was 8.53% (corresponding to a mean API loss of 4.27 ± 4.50 mg). The difference in powder and API loss was highly statistically significant. Conclusion Crushing riluzole tablets in a simulated home setting determined a significant loss of powder and API. These results support neurologists to evaluate formulations that minimize the need to alter the product and can improve ALS patient journey.

Exploiting phase inversion for penta-amine impregnation of ultrafiltration support matrix for rapid fabrication of a hyper-cross-linked polyamide membrane for organic solvent nanofiltration

For the sake of recovery of precious organic solvents from industrial organic solvent waste stream or alternatively for recovery of active principle ingredient (API) synthesized in pharmaceutical companies, organic solvent nanofiltration (OSN) membranes have recently been emerged. A thin film composite (TFC) membrane was fabricated by using rapid membrane fabrication technique. The PA(TEPA-TCL)@PSU/PETP membrane was fabricated by penta-amine (TEPA) impregnation of polysulfone (PSU) matrix during phase inversion which in turn was reacted with terephthaloyl chloride (TCL) through interfacial polymerization (IP). The PA(TEPA-TCL)@PSU/PETP membrane was characterized by scanning electron microscopy (SEM), water contact angle (WCA), energy dispersive X-ray (EDX) analysis, ATR-FTIR and elemental mapping. The PA(TEPA-TCL)@PSU/PETP membrane was applied for OSN by using water, methanol, ethanol and isopropanol as solvents. When methanol was used as feed, it showed a permeate flux of 28 L m−2 h−1 (LMH) at 20 bar. An inverse relationship was found between viscosity and flux of the solvents. A feed composed of methanol and dyes (dyes were used as model pollutants) was used to evaluate the OSN performance of the membrane. Apparently, size exclusion mechanism was found to be responsible for rejection of dyes as EBT was rejected up to > 92 % and Congo red (CR; M.W. = 696.6 g mol−1) rejection reached > 96% while it stayed at ≈ 88 % for Methylene blue (MB; M.W. = 319.8 g mol−1). The UV-Visible analysis of feed and permeate was conducted which confirmed the rejection of CR and MB. Hence, the PA(TEPA-TCL)@PSU/PETP membrane was found to be efficient for the purification of organic solvents contaminated with organic dyes.

Supercritical Fluids and Nanoparticles in Cancer Therapy.

Nanoparticles are widely used in the pharmaceutical industry due to their high surface-to-volume ratio. Among the many techniques used to obtain nanoparticles, those based on supercritical fluids ensure reduced dimensions, narrow particle size distributions, and a very low or zero solvent residue in the powders. This review focuses on using supercritical carbon dioxide-based processes to obtain the nanoparticles of compounds used for the treatment or prevention of cancer. The scientific literature papers have been classified into two groups: nanoparticles consisting of a single active principle ingredient (API) and carrier/API nanopowders. Various supercritical carbon dioxide (scCO2) based techniques for obtaining the nanoparticles were considered, along with the operating conditions and advantages and disadvantages of each process.

A Simplified Direct O2 Consumption-Based Assay to Test COX Inhibition

Background: Cyclooxygenase is a well-known oxidoreductase that catalyzes the uptake of two moles of O2 by arachidonic acid (AA), producing the hydroperoxide Prostaglandin G2 (PGG2), then reduced to the prostaglandin precursor Prostaglandin H2 (PGH2). O2 consumption during such reactions is a measure of cyclooxygenase activity. O2 involved is generally measured by indirect methods, accomplished in the presence of the substrate AA and/or inhibitors. Methods: We developed a new simplified and easy to be carried out protocol for O2 consumption measurement by using disrupted HEK293-derived adherent cells, stably transfected either with COX-1 or COX-2 genes, as a source of the COX enzymes. The Clark electrode is used to measure the O2 concentration variation during the enzyme-catalyzed reactions. Results and Discussion: The novel assay was validated by determining the IC50 values of the known inhibitors such as indomethacin, ibuprofen, SC560, and celecoxib. Indomethacin and ibuprofen are two traditional non-steroidal anti-inflammatory drugs (tNSAIDs). SC560 is a commercially available reference compound used for COX-1 inhibition investigations. Celecoxib is a clinically used COXIBs. The assay was also applied to measure the kinetics and IC50 of mofezolac and P6. Mofezolac is the most potent selective COX-1 inhibitor, and active principle ingredient of Disopain® used to treat rheumatoid arthritis in Japan. P6, uncovered by us, is used together with mofezolac as a reference in in vitro and in vivo COX inhibition investigations and as a scaffold for structure-inhibition activity relationship studies. Conclusion: The obtained results showed the suitability of the newly developed assay to measure COXs activity in the presence of inhibitors as well as the kinetics of the inhibition (i.e., Vmax and Km).

Melanochrome-based colorimetric assay for quantitative detection of levodopa in co-presence of carbidopa and its application to relevant anti-Parkinson drugs.

In this paper is reported the selective detection and quantification of levodopa in co-presence of carbidopa. The method took advantage of the spontaneous oxidation and color development of levodopa at basic pH here driven by alkaline earth cations and co-solvent in solution. We have shown for the first time the generation and stabilization of the purple melanochrome from levodopa, by using magnesium acetate and dimethyl sulfoxide, which was here exploited for the development of a quantitative colorimetric assay for the active principle ingredient in commercial drugs for the treatment of Parkinson's disease. The calibration curves of levodopa in the two tablet formulations, containing carbidopa as decarboxylase inhibitor, showed a common linear trend between 10 mg L-1 and 40 mg L-1 with levodopa alone or in combination with carbidopa in standard solutions, with very good reproducibility (CVav%, 3.3% for both brand and generic drug) and very good sensitivity, with limit of quantification about 0.6 mg L-1 in any case. The colorimetric method here developed is very simple and effective, appearing as a rapid and low-cost alternative to other methodologies, involving large and expensive instrumentations, for drug estimation and quality control of pharmaceutical formulations.

Pure cellulose nanofibrils membranes loaded with ciprofloxacin for drug release and antibacterial activity

The biocompatibility and very high specific area of cellulose nanofibrils (CNF) are properties of high interest for the development of active substrates for new medical device development. Enzyme pretreated CNF (CNF-e) can be self-organized into nanostructured membranes that are suitable for active principle ingredients (API) encapsulation through adsorption phenomena. In addition, tunable surface chemistry of CNF-e, allow for covalent immobilization of API. In this work, ciprofloxacin is integrated to CNF-e membranes according to two different strategies. The first one relies only on adsorption mechanisms; ciprofloxacin is encapsulated in the bulk before the membrane formation by solvent casting. The influence of the membrane properties and preparation parameters such as grammage, thickness and drying technique, are assessed with water uptake measurements and API release experiments. The second strategy deals with the covalent immobilization of ciprofloxacin directly onto CNF-e membrane. The two kinds of membranes are then compared in terms of antibacterial activity, in both static and dynamic conditions. Thick CNF-e membranes loaded with adsorbed ciprofloxacin that were overdried (2 h, 150 °C) prove to be more resistant in liquid medium and present a more prolonged drug release. However, these membranes rapidly lost their antibacterial activity, while CNF-e membranes with covalently immobilized ciprofloxacin remain contact active for several days. These 100% CNF active nanostructured membranes can be used as new wound dressing for topical application.

Production and Mechanical Characterisation of TEMPO-Oxidised Cellulose Nanofibrils/β-Cyclodextrin Films and Cryogels.

Wood-based TEMPO-oxidised cellulose nanofibrils (toCNF) are promising materials for biomedical applications. Cyclodextrins have ability to form inclusion complexes with hydrophobic molecules and are considered as a method to bring new functionalities to these materials. Water sorption and mechanical properties are also key properties for biomedical applications such as drug delivery and tissue engineering. In this work, we report the modification with β-cyclodextrin (βCD) of toCNF samples with different carboxyl contents viz. 756 ± 4 µmol/g and 1048 ± 32 µmol/g. The modification was carried out at neutral and acidic pH (2.5) to study the effect of dissociation of the carboxylic acid group. Films processed by casting/evaporation at 40 °C and cryogels processed by freeze-drying were prepared from βCD modified toCNF suspensions and compared with reference samples of unmodified toCNF. The impact of modification on water sorption and mechanical properties was assessed. It was shown that the water sorption behaviour for films is driven by adsorption, with a clear impact of the chemical makeup of the fibres (charge content, pH, and adsorption of cyclodextrin). Modified toCNF cryogels (acidic pH and addition of cyclodextrins) displayed lower mechanical properties linked to the modification of the cell wall porosity structure. Esterification between βCD and toCNF under acidic conditions was performed by freeze-drying, and such cryogels exhibited a lower decrease in mechanical properties in the swollen state. These results are promising for the development of scaffold and films with controlled mechanical properties and added value due to the ability of cyclodextrin to form an inclusion complex with active principle ingredient (API) or growth factor (GF) for biomedical applications.

An assay to determine rivaroxaban in pharmaceutical formulations by micellar liquid chromatography

Rivaroxaban is one of the most prescribed anticoagulants. The ingestion of the correct dosage is a key to the success of the therapy. A procedure to evaluate the content of active principle ingredient in rivaroxaban pharmaceutical formulations, based on micellar liquid chromatography, has been developed. Tablets were solved in the mobile phase and directly injected, thus avoiding the use of large volumes of organic solvents. Analysis was performed using a C18 column and a mobile phase containing 0.05 M sodium dodecyl sulfate—12.5% 1-propanol, buffered at pH 7 with phosphate salt, running under isocratic mode at 1 mL/min. The analyte was resolved in less than 6.0 min. Detection was by UV absorption at 250 nm. The method was successfully validated by the guidelines of the International Conference of Harmonization in terms of specificity, calibration range (0.01–1.00 mg/L), linearity, limit of detection (0.002 mg/L), limit of quantification (0.006 mg/L), trueness (99.6–99.7%), precision (< 2%), robustness, system suitability, carry-over effect and stability, thus proven the adequate quality of the analytical results. A set of incurred and quality control samples was analyzed in the same run; and adequate results were obtained. The procedure was found practical, easy-to-conduct, rapid, safe, eco-friendly, inexpensive and with a high sample throughput; and then useful for routine analysis for pharmaceutical quality control purposes.

Bacterial nanocellulose membranes loaded with vitamin B-based ionic liquids for dermal care applications

The development of innovative bio-based skin care products has received an increased attention in the latter years. In the present work, the synthesis of original active principle ingredients based on ionic liquids (ILs) with cholinium cation and vitamins B anions, followed by their incorporation in bacterial nanocellulose (BC) membranes for topical applications, is reported. Three ILs, namely cholinium nicotinate [Ch][B3], cholinium pantothenate [Ch][B5] and cholinium pyridoxylate [Ch][B6], were synthesized through a metathesis reaction and their structure characterized in detail. Thermal analysis confirmed their denomination as ILs and their high thermal resistance. The solubility of these ILs was higher than their vitamin precursors, especially in the case of [Ch][B3] whose solubility increased 30.6-fold enhancing the bioavailability of this vitamin. The incorporation of ILs in BC led to translucent and homogeneous membranes stable up to 190 °C. ILs acted as plasticizers reducing BC brittleness that facilitated their application on irregular skin regions. Moreover, the re-hydration ability of BC-ILs membranes was improved 2.9 to 4.8-fold in comparison to BC, ensuring adequate hydration for ILs release, while the release of ILs in buffer solutions was more complete and faster than the release of vitamins. Finally, BC-ILs were proven not cytotoxic to skin epithelial cells and thus are suitable materials for skin care applications.

Biodistribution of polycyanoacrylate nanoparticles encapsulating doxorubicin by Matrix-Assisted Laser Desorption Ionization (MALDI) Mass Spectrometry Imaging (MSI)

Nanoparticles are widely used as carrier for the delivery of Active Principle Ingredients (API). From safety point of view, the fate of nanoparticles and API after administration becomes a key question. Today qualitative and quantitative biodistribution of such carriers or encapsulated API can be performed by chemical modification with a fluorescent probe or a radiolabeling and require a first acquisition step for visualization and a second step for quantification by tissues extraction. LC-MS/MS can be considered but the information about the localization of the API is lost.After a long period focused on the sample preparation method development, Matrix-Assisted Laser Desorption/Ionization Mass Spectrometry Imaging (MALDI-MSI) is nowadays recognized as the most promising technique for the study of biodistribution of small molecular weight API without additional labeling, combining a visual and quantitative approach.In this study, we extended the scope of use of MALDI-MSI to polycyanoacrylate nanoparticles loaded with doxorubicin. MALDI-MSI allowed the detection and quantification of doxorubicin and polycyanoacrylate, the polymer used as carrier, forming the nanoparticles in mouse liver section. Additionally, MALDI-MSI was able to detect doxorubicinol, the metabolite of doxorubicin.This Proof Of Concept was successful emphasizing the benefits of this technique (label free and quantitative approach) and offers the possibility to use a unique technique for the detection of encapsulated API and the carrier opening a wide field of application in drug delivery of formulated API.

Validación de un método para el análisis de cocaína en muestras de orina empleando extracción en fase sólida (SPE) y cromatografía líquida de alta resolución (HPLC)

Los altos costos que implica el consumo de cocaína pura, llevó a la producción de base de cocaína o bazuco (crack), un producto de menor valor económico, gran demanda y generalmente más usado por consumidores de bajo nivel socioeconómico. El bazuco es una sustancia blanca, o pardusca, semisólida o sólida, cuyo principio activo es la cocaína. La cocaína es un alcaloide con una larga historia de uso y abuso. Su determinación, tanto en muestras no biológicas como en fluidos biológicos continúa siendo una tarea de primer orden. En el presente trabajo se reporta la validación de un método de extracción de la cocaína en muestras de orina, usando la técnica de extracción en fase sólida (SPE). Porcentajes de recuperación entre el 99.4 y el 99.8% fueron obtenidos para cocaína empleando SPE. La técnica cromatográfica fue estandarizada, empleando una columna C18, un detector ultravioleta (254 nm), una fase móvil de agua-acetonitrilo-ácido acético (58-40-2) a un flujo de 0.4 mL/min. El rango de linealidad estuvo entre 0.01 µg/mL y 1.0 µg/mL. Se crearon tres curvas de cuantificación: 10 – 20 ppb, 20 – 100 ppb y 100 – 1000 ppb con coeficientes de determinación r 2 de 0.9965, 0.9947 y 0.9973 respectivamente. El método fue aplicado en muestras de orina de un grupo de personas voluntarias que consumen bazuco en la ciudad de Popayán, Cauca, Colombia.

Norbixin Protects Retinal Pigmented Epithelium Cells and Photoreceptors against A2E-Mediated Phototoxicity In Vitro and In Vivo.

The accumulation of N-retinylidene-N-retinylethanolamine (A2E, a toxic by-product of the visual pigment cycle) in the retinal pigment epithelium (RPE) is a major cause of visual impairment in the elderly. Photooxidation of A2E results in retinal pigment epithelium degeneration followed by that of associated photoreceptors. Present treatments rely on nutrient supplementation with antioxidants. 9’-cis-Norbixin (a natural diapocarotenoid, 97% purity) was prepared from Bixa orellana seeds. It was first evaluated in primary cultures of porcine retinal pigment epithelium cells challenged with A2E and illuminated with blue light, and it provided an improved photo-protection as compared with lutein or zeaxanthin. In Abca4-/- Rdh8-/- mice (a model of dry AMD), intravitreally-injected norbixin maintained the electroretinogram and protected photoreceptors against light damage. In a standard rat blue-light model of photodamage, norbixin was at least equally as active as phenyl-N-tert-butylnitrone, a free radical spin-trap. Chronic experiments performed with Abca4-/- Rdh8-/- mice treated orally for 3 months with norbixin showed a reduced A2E accumulation in the retina. Norbixin appears promising for developing an oral treatment of macular degeneration. A drug candidate (BIO201) with 9’-cis-norbixin as the active principle ingredient is under development, and its potential will be assessed in a forthcoming clinical trial.

Quantitative 13C Solid-State NMR Spectra by Multiple-Contact Cross-polarization for Drug Delivery: From Active Principles to Excipients and Drug Carriers

In this contribution, we present an analysis of the main parameters influencing the efficiency of the 1H → 13C multiple-contact cross-polarization nuclear magnetic resonance (NMR) experiment in the context of solid pharmaceutical materials. Using the optimum experimental conditions, quantitative 13C NMR spectra are then obtained for porous metal–organic frameworks (potential drug carriers) and for components present in drug formulations (active principle ingredient and excipients, amorphous or crystalline). Finally, we show that mixtures of components can also be quantified with this method and, hence, that it represents an ideal tool for quantification of pharmaceutical formulations by 13C cross-polarization under magic-angle spinning NMR in the industry as it is robust and easy to set up, much faster than direct 13C polarization and is efficient for samples at natural abundance.

COX-1 Inhibitors: Beyond Structure Toward Therapy.

Biosynthesis of prostaglandins from arachidonic acid (AA) is catalyzed by cyclooxygenase (COX), which exists as COX-1 and COX-2. AA is in turn released from the cell membrane upon neopathological stimuli. COX inhibitors interfere in this catalytic and disease onset process. The recent prominent discovery involvements of COX-1 are mainly in cancer and inflammation. Five classes of COX-1 inhibitors are known up to now and this classification is based on chemical features of both synthetic compounds and substances from natural sources. Physicochemical interactions identification between such molecules and COX-1 active site was achieved through X-ray, mutagenesis experiments, specific assays and docking investigations, as well as through a pharmacometric predictive model building. All these insights allowed the design of new highly selective COX-1 inhibitors to be tested into those disease models in which COX-1 is involved. Particularly, COX-1 is expressed at high levels in the early to advanced stages of human epithelial ovarian cancer, and it also seems to play a pivotal role in cancer progression. The refinement of COX-1 selective inhibitor structure has progressed to the stage that some of the inhibitors described in this review could be considered as promising active principle ingredients of drugs and hence part of specific therapeutic protocols. This review aims to outline achievements, in the last 5 years, dealing with the identification of highly selective synthetic and from plant extracts COX-1 inhibitors and their theranostic use in neuroinflammation and ovarian cancer. Their gastrotoxic effect is also discussed.

Calibration transfer from powder mixtures to intact tablets: A new use in pharmaceutical analysis for a known tool

Calibration transfer is commonly used for spectra obtained in different spectrometers or other conditions. This paper proposed the use of calibration transfer between spectra recorded for the same samples in different physical forms. A new method was developed for the direct determination of nevirapine in solid pharmaceutical formulations based on diffuse reflectance near infrared spectroscopy (NIRS) and partial least squares (PLS). This method was developed with 50 powder mixtures and then, successfully extended to the quantification in intact tablets by using calibration transfer with double window piecewise direct standardization (DWPDS). This chemometric strategy provided good results with a small number of tablet transfer samples, only seven, prepared out of the narrow range of active principle ingredients (API) content around the nominal value of the formulation (100%). The method was fully validated in the working range of 83.0–113.9% of nevirapine and the use of DWPDS allowed to significantly decreasing the root mean square error of prediction (RMSEP) from 4.8% (tablets predicted by a model built with only powder samples) to 2.6%. The range of relative errors decreased from −5.1/8.7% to −4.6/3.3%. Considering that the amount of raw materials demanded for preparing tablets is up to ten times higher than for powder mixtures, this type of application is of particular interest in pharmaceutical analysis. In the context of process analytical technology (PAT), the use of the same multivariate model in different steps of the production is very advantageous, saving time and labor.

Modelling solubility of solid active principle ingredients in sc-CO2 with and without cosolvents: A comparative assessment of semiempirical models based on Chrastil's equation and its modifications

Predicting solubility of solids in supercritical solvents with and without cosolvents is a key step supporting the application of supercritical fluids to processes as the extraction of natural compounds and particle engineering. The aim of this work is modelling the solubility of solid therapeutic compounds in supercritical carbon dioxide with and without cosolvents using semiempirical models. A comparative assessment of eight models is presented based on deviations, number of parameters, range of applicability (concentration of cosolvents and proximity to the mixture critical point) and cosolvent–solute interactions.All equations provide an average deviation on solubility around 10%. The use of the González (with four parameters) and Reddy and Madras equation (with five parameters) is judged the most convenient as they have the smaller number of parameters and are applicable over a suitable range of cosolvent concentrations. In all cases it has been possible to relate the solubility behaviour to the cosolvent–solute interaction and the concentration of cosolvent. However, deviations increase when conditions are slightly close to the mixture critical point.A modification is proposed through the introduction of a “q exponential function”. The modified q-models can be regarded as generalized models based on the Tsallis's statistical non-extensive entropy theory. In fact, the original Chrastil and González equation can be seen as a particular case of the q-Chrastil and q-González models. They have deviations similar to the other model and show potential for further studies.

Deep Eutectic Solvent-Assisted Synthesis of Biodegradable Polyesters with Antibacterial Properties

Bacterial infection related to the implantation of medical devices represents a serious clinical complication, with dramatic consequences for many patients. In past decades, numerous attempts have been made to develop materials with antibacterial and/or antifouling properties by the incorporation of antibiotic and/or antiseptic compounds. In this context, deep eutectic solvents (DESs) are acquiring increasing interest not only as efficient carriers of active principle ingredients (APIs) but also as assistant platforms for the synthesis of a wide repertoire of polymer-related materials. Herein, we have successfully prepared biodegradable poly(octanediol-co-citrate) polyesters with acquired antibacterial properties by the DES-assisted incorporation of quaternary ammonium or phosphonium salts into the polymer network. In the resulting polymers, the presence of these salts (i.e., choline chloride, tetraethylammonium bromide, hexadecyltrimethylammonium bromide, and methyltriphenylphosphonium bromide) inhibits bacterial growth in the early postimplantation steps, as tested in cultures of Escherichia coli on solid agar plates. Later, positive polymer cytocompatibility is expected to support cell colonization, as anticipated from in vitro preliminary studies with L929 fibroblasts. Finally, the attractive elastic properties of these polyesters permit matching those of soft tissues such as skin. For all of these reasons, we envisage the utility of some of these antibacterial, biocompatible, and biodegradable polyesters as potential candidates for the preparation of antimicrobial wound dressings. These results further emphasize the enormous versatility of DES-assisted synthesis for the incorporation, in the synthesis step, of a wide palette of APIs into polymeric networks suitable for biomedical applications.

Thermal and spectral characterization of a binary mixture (acyclovir and fluocinolone acetonide): Eutectic reaction and inclusion complexes with β-cyclodextrin

The thermal and structural properties of acyclovir (ACV) and fluocinolone acetonide (FA) have been studied alone and in the corresponding binary mixture, using differential scanning calorimetry (DSC), hot stage microscopy (HSM) and Fourier Transform Infrared spectroscopy (FT-IR).The temperatures and enthalpies of solid–solid transitions and melting for the pure compounds were obtained from the DSC data. The predominant crystalline or amorphous character of pure compounds was noticed by HSM experiments and the characteristics absorption bands were obtained using FT-IR spectroscopy.For the binary mixtures, a eutectic reaction was observed in all DSC curves at 526K, followed by decomposition, a phenomenon that was confirmed by FT-IR measurements. The phase diagram and Tamman's plot suggest a eutectic composition at xACV=0.80. From the DSC curves and FT-IR spectra obtained for the mixtures of active principle ingredients (APIs) with β-CD we concluded that the inclusion complexes formation takes place for 1:1 mole ratio.