Potentiometric sensing of ibuprofen over ferric oxide doped chitosan grafted polypyrrole-based electrode.

The present work demonstrates the correlation between structure, properties, and self-sensing protocols of in situ prepared ferric oxide doped grafted copolymer composite, comprised of ferric oxide, chitosan, and polypyrrole (α-Fe2O3-en-CHIT-g-PPy) for residual ibuprofen present in natural and artificial samples. The chemical structure, morphology, functionality, and physio-mechanical properties of the composite were determined by Fourier transform infrared spectrometer (FT-IR), Raman spectra, X-ray diffraction (XRD), Scanning electron microscope (SEM), X-ray photoelectron spectroscopy (XPS), Two probe method, and standard ASTM techniques to explore sensing nature. The results confirm the evolution of axially aligned structure against 110 planes of α-Fe2O3 and chemically functionalized expanded polymer matrix during in-situ chemical polymerization of pyrrole, with better porosity, interactivity, and improved electrical conductivity i.e. 7.32 × 10-3 S cm-1. Further, a thin film of prepared composite coated on an ITO glass plate was explored for potentiometric sensing of ibuprofen (IBU) present in artificial and natural samples without the use of any additional energy sources. The observed sensing parameters are the sensing ranging 0.5 µM to 100.0 µM, sensitivity 2.5081 mV µM-1 cm-2, response time 50 s, recovery time 10 s, and stability for 60 days. The sensing mechanism of the IBU sensor and effective charge transfer in the electrode was also discussed based on changes in IR spectra of the electrode recorded before and after sensing due to surface oxidation of IBU due to the presence of iron and doping effect of iron oxide in the composite.

Interchangeability of medications and biopharmaceutical implication of taking drugs with fluids other than water: ibuprofen case study

Abstract The aim of this study was to compare the dissolution properties of ibuprofen solid oral dosage forms commercially available in Bosnia and Herzegovina and to estimate the influence of dissolution medium composition on the drug release. Eight products (A-H) were subjected to in vitro dissolution test using experimental conditions described in USP42-NF37. Dissolution properties of one selected product were examined in the presence of alcohol (22.2% v/v) and fruit juice (22.2% v/v). Products marked B-H complied with the pharmacopeial criteria. Dissolution profile of product B was similar with dissolution profiles of products D, E, F and G and similarity was also found between products A-D, C-G, D-G and E-F. Drug release from most of the examined preparations fitted best to the Weibull kinetic model. In the presence of alcohol in the medium, higher amount of ibuprofen was dissolved. Contrary, ibuprofen dissolved in the presence of fruit juice was significantly lower. Differences in the dissolution profiles of investigated preparations suggest that their interchangeability should be additionally considered and demonstrated with in vivo bioequivalence studies. Presence of different substances in the medium can affect dissolution properties of ibuprofen, emphasizing the importance of the patient's compliance.

Pharmaceuticals, natural and synthetic hormones and phenols in sediments from an eutrophic estuary, Jurujuba Sound, Guanabara Bay, Brazil.

A screening for microcontaminants performed by gas chromatography detected several microcontaminants in 12 sediment samples from the eutrophic estuary Guanabara Bay (GB) in southeastern Brazil. Bisphenol A (BPA) ranged from 1.4 to 20.3 ng g-1, 4-octylphenol, from

Evaluation of copaiba oil as enhancer of ibuprofen skin permeation

Abstract The administration of medications on the skin through transcutaneous routes is a practice that has been used by mankind for millennia. Some studies have been reporting the use of terpenes and natural oils rich in terpenes as an enhancer of cutaneous penetration. Copaiba oil, due to its rich content of terpenes, presents itself as a great choice of penetration enhancer for drugs administered on the skin. In this study, we developed two cream formulations containing 5% of ibuprofen (IBU) and copaiba oil: IBCO5 and IBCO10 with 5% and 10% of copaiba oil respectively. Ex vivo cutaneous penetration/permeation studies of IBU were performed using pig ear skin as biological membrane in the Franz-type diffusion cells. The steady-state flux of IBU samples, IBCO5 (35.72 ± 6.35) and IBCO10 (29.78 ± 2.41) were significantly higher when compared with control without copaiba oil (10.32 ±1.52) and with a commercial product (14.44 ± 2.39). In the penetration analysis, the amount of IBU found in the samples IBCO5 and IBCO10 was markedly higher in the dermis than epidermis. Our results showed that copaiba oil possesses attracting properties in promoting skin penetration and permeation of IBU when added into cream formulations.

Direct distinction of ibuprofen and flurbiprofen enantiomers by ion mobility mass spectrometry of their ternary complexes with metal cations and cyclodextrins in the gas phase.

Enantiomeric drugs are widely used and play important roles in pharmaceuticals. Ion mobility spectrometry coupled with mass spectrometry technology provides a unique method for distinguishing the enantiomeric drugs, enantiomeric identification, and quantitation in the gas phase. In this study, enantiomeric molecules of ibuprofen and flurbiprofen were clearly recognized by forming host-guest complex ions using trapped ion mobility time-of-flight mass spectrometry. Ternary complex ions can be produced easily by electrospray ionization of the mixed solutions of ibuprofen, cyclodextrins, and CaCl2 , LiCl, or NaCl, as well as flurbiprofen, cyclodextrins, and CaCl2 . The relative contents of different chiral ibuprofens in a mixed solution were also quantitatively measured. This new method is a simple, effective, and a convenient enantioselective analysis method.

Quantitation of active pharmaceutical ingredient through the packaging using Raman handheld spectrophotometers: A comparison study.

Handheld Raman spectroscopy is actually booming. Recent devices improvements aim at addressing the usual Raman spectroscopy issues: fluorescence with shifted-excitation Raman difference spectroscopy (SERDS), poor sensitivity with surface enhanced Raman scattering (SERS) and information only about the sample surface with spatially offset Raman spectroscopy (SORS). While qualitative performances of handheld devices are generally well established, the quantitative analysis of pharmaceutical samples remains challenging. The aim of this study was to compare the quantitative performances of three commercially available handheld Raman spectroscopy devices. Two of them (TruScan and IDRaman mini) are equipped with a 785 nm laser wavelength and operate in a conventional backscattering mode. The IDRaman has the Orbital Raster Scanning (ORS) option to increase the analyzed surface. The third device (Resolve) operates with an 830 nm laser wavelength both in backscattering and in SORS modes. The comparative study was carried out on ibuprofen-mannitol-microcrystalline cellulose ternary mixtures. The concentration of ibuprofen ranged from 24 to 52% (w/w) while the proportions of the two excipients were varied to avoid cross-correlation as much as possible. Analyses were performed either directly through a glass vial or with the glass vial in an opaque polypropylene flask, using a validated FT-NIR spectroscopy method as a reference method. Chemometric analyses were carried out with the Partial Least Squares Regression (PLS-R) algorithm. The quantitative models were validated using the total error approach and the ICH Q2 (R1) guidelines with ±â€¯15% as acceptance limits.

Nickel-iron layered double hydroxide nanostructures for micro solid phase extraction of nonsteroidal anti-inflammatory drugs, followed by quantitation by HPLC-UV.

Layered double hydroxides (LDHs) of nickel and iron were hydrothermally prepared by co-precipitation using urea hydrolysis. The Ni-Fe LDH nanostructures were characterized by X-ray diffraction, FT-IR spectroscopy, scanning electron microscopy, thermogravimetric and energy dispersive X-ray analysis. The LDHs are shown to be a viable sorbent for micro solid phase extraction by packed sorbent of the nonsteroidal anti-inflammatory drugs (NSAIDs) diclofenac, ibuprofen, mefenamic acid and naproxen from human urine. Adsorption and desorption parameters were optimized using a central composite design. Following desorption with a methanol/water mixture (95:5 v:v) containing 0.1% formic acid, the NSAIDs were quantified by HPLC with UV detection. Under the optimal conditions, response is linear in the 10-1000 ng.mL-1 NSAID concentration range. Limits of detection and intra-day and inter-day RSDs are <10 ng.mL-1 and 10.2%, respectively. The method was successfully applied to the determination of NSAIDs in some positive human urine samples. Relative recoveries from spiked samples range from 94.8 to 113%. Graphical abstract Layered double hydroxides of nickel and iron were synthesized and packed in a spinal syringe for micro solid phase extraction of non-steroidal anti-inflammatory drugs.

Mesoporous silica from batik sludge impregnated with aluminum hydroxide for the removal of bisphenol A and ibuprofen.

The present study reports the removal of Bisphenol A (BPA) and Ibuprofen (IBP) using adsorbents prepared from batik sludge. The calcite sludge-aluminum hydroxide (CAl) adsorbent was prepared by calcination and followed by aluminum hydroxide impregnation. The batik sludge and prepared adsorbents were characterized by FESEM, TGA, XRD, FTIR and BET techniques. The maximum adsorption capacity, adsorption time, different initial solution pH, ionic strength and regeneration study of the adsorbents were also investigated. Furthermore, the sorption behavior of the pollutants were studied by the Langmuir and Freundlich isotherms. The deposition of Al(OH)3 enhanced the BPA and IBP adsorption capacity on the CAl surface. The maximum removal capacity of BPA and Ibuprofen were 83.53 mg g-1 and 34.96 mg g-1 for the CAl adsorbent. In addition, the kinetic data for BPA and IBP were fitted to the pseudo first order, pseudo second order, Elovich, parabolic diffusion and power function equations to understand the sorption behavior. The adsorption behavior of BPA and IBP was mainly chemisorption. This study shows that CAl is a promising adsorbent for the removal of BPA and IBP.

An evaluation of crude palm oil (CPO) and tocotrienol rich fraction (TRF) of palm oil as percutaneous permeation enhancers using full-thickness human skin.

The drawbacks associated with chemical skin permeation enhancers such as skin irritation and toxicity necessitated the research to focus on potential permeation enhancers with a perceived lower toxicity. Crude palm oil (CPO) is obtained by direct compression of the mesocarp of the fruit of the oil palm belonging to the genus Elaeis. In this research, CPO and tocotrienol-rich fraction (TRF) of palm oil were evaluated for the first time as skin permeation enhancers using full-thickness human skin. The in vitro permeation experiments were conducted using excised human skin mounted in static upright 'Franz-type' diffusion cells. The drugs selected to evaluate the enhancing effects of these palm oil derivatives were 5-fluorouracil, lidocaine and ibuprofen: compounds covering a wide range of Log p values. It was demonstrated that CPO and TRF were capable of enhancing the percutaneous permeation of drugs across full-thickness human skin in vitro. Both TRF and CPO were shown to significantly enhance the permeation of ibuprofen with flux values of 30.6 µg/cm2 h and 23.0 µg/cm2 h respectively, compared to the control with a flux of 16.2 µg/cm2 h. The outcome of this research opens further scope for investigation on the transdermal penetration enhancement activity of pure compounds derived from palm oil.

Decomposition of ibuprofen in water via an electrochemical process with nano-sized carbon black-coated carbon cloth as oxygen-permeable cathode integrated with ultrasound.

The main aim of the present investigation was the treatment of ibuprofen (IBP)-polluted aquatic phase using a novel oxygen-permeable cathode (OPC)-equipped electrochemical process (ECP) integrated with ultrasound (US). According to kinetic modeling, the decomposition rate of IBP by the integrated process was 3.2 × 10-2 min-1 which was significant in comparison with the OPC-equipped ECP (1.4 × 10-2 min-1) and US alone (2.4 × 10-3 min-1). Increasing the current resulted in the enhanced generation of H2O2 and consequently, improved the degradation of IBP in the solution. Excessive concentrations of Na2SO4 as supporting electrolyte led to no significant enhancement in the reactor efficiency. At initial IBP concentration of 1 mg L-1, complete removal of IBP with reaction rate of 1.7 × 10-1 min-1 was happened within a short reaction time of 30 min. The pulse mode of US led to more than 10% increase in the removal efficiency compared with the normal mode. The presence of scavenging compound of methanol caused the highest drop in the efficiency of the integrated treatment process, indicating the substantial role of free hydroxyl radicals in the degradation of IBP. Intermediate byproducts generated in the solution during the decomposition were also identified and interpreted.

Determination of ibuprofen enantiomers in breast milk using vortex-assisted matrix solid-phase dispersion and direct chiral liquid chromatography.

A mixture of ß-cyclodextrin (ß-CD) and primary and secondary amine (PSA) sorbents was employed for the extraction and quantification of ibuprofen enantiomers from human breast milk, combining a vortex-assisted matrix solid-phase dispersion method (MSPD) and direct chiral liquid chromatography (CLC) with ultraviolet detection (UV). The MSPD sample preparation procedure was optimized focusing on both the type and amount of dispersion/sorption sorbents and the nature of the elution solvent, in order to obtain acceptable recoveries and avoiding enantiomer conversion. These MSPD parameters were optimized with the aid of an experimental design approach. Hence, a factorial design was used for identification of the main variables affecting the extraction process of ibuprofen enantiomers. Under optimum selected conditions, MSPD combined with direct CLC-UV was successfully applied for ibuprofen enantiomeric determination in breast milk at enantiomer levels between 0.15 and 6.0µgg-1. The proposed analytical method also provided good repeatability, with relative standard deviations of 6.4% and 8.3% for the intra-day and inter-day precision, respectively.

In vitro evaluation of sustained released matrix tablets containing ibuprofen: a model poorly water-soluble drug

ABSTRACT A matrix system was developed that releases ibuprofen (IB) over a 12-hour period and the influence of the polymer type and concentration on the release rate of the drug was evaluated. Tablets containing different concentrations of Carbopol (CP), hydroxypropyl methylcellulose (HPMC), or ethyl cellulose (EC) were prepared using direct compression and the drug content, content uniformity, hardness, friability, dissolution performance, and in vitro release kinetics were examined. Formulated tablets were found to be within acceptable limits for physical and chemical parameters. The release kinetics of the Carbopol(r)971P 8% formulation showed the best linearity (r 2 =0.977) in fitting zero-order kinetics, suggesting the release rate was time independent. The drug release from tablets containing 8% CP was extended over approximately 18 hours and the release kinetics were nearly linear, suggesting that this system has the potential to maintain constant plasma drug concentrations over 12 hours, which could reduce the frequency of administration and the occurrence of adverse effects associated with repeated administration of conventional IB tablets.

Enantioselective simultaneous analysis of selected pharmaceuticals in environmental samples by ultrahigh performance supercritical fluid based chromatography tandem mass spectrometry.

In order to assess the true impact of each single enantiomer of pharmacologically active compounds (PACs) in the environment, highly efficient, fast and sensitive analytical methods are needed. For the first time this paper focuses on the use of ultrahigh performance supercritical fluid based chromatography coupled to a triple quadrupole mass spectrometer to develop multi-residue enantioselective methods for chiral PACs in environmental matrices. This technique exploits the advantages of supercritical fluid chromatography, ultrahigh performance liquid chromatography and mass spectrometry. Two coated modified 2.5 µm-polysaccharide-based chiral stationary phases were investigated: an amylose tris-3,5-dimethylphenylcarbamate column and a cellulose tris-3-chloro-4-methylphenylcarbamate column. The effect of different chromatographic variables on chiral recognition is highlighted. This novel approach resulted in the baseline resolution of 13 enantiomers PACs (aminorex, carprofen, chloramphenicol, 3-N-dechloroethylifosfamide, flurbiprofen, 2-hydroxyibuprofen, ifosfamide, imazalil, naproxen, ofloxacin, omeprazole, praziquantel and tetramisole) and partial resolution of 2 enantiomers PACs (ibuprofen and indoprofen) under fast-gradient conditions (<10 min analysis time). The overall performance of the methods was satisfactory. The applicability of the methods was tested on influent and effluent wastewater samples. To the best of our knowledge, this is the first feasibility study on the simultaneous separation of chemically diverse chiral PACs in environmental matrices using ultrahigh performance supercritical fluid based chromatography coupled with tandem mass spectrometry.

Graphene oxide-based dispersive solid-phase extraction combined with in situ derivatization and gas chromatography-mass spectrometry for the determination of acidic pharmaceuticals in water.

A fast and low-cost sample preparation method of graphene based dispersive solid-phase extraction combined with gas chromatography-mass spectrometric (GC-MS) analysis, was developed. The procedure involves an initial extraction with water-immiscible organic solvent, followed by a rapid clean-up using amine functionalized reduced graphene oxide as sorbent. Simple and fast one-step in situ derivatization using trimethylphenylammonium hydroxide was subsequently applied on acidic pharmaceuticals serving as model analytes, ibuprofen, gemfibrozil, naproxen, ketoprofen and diclofenac, before GC-MS analysis. Extraction parameters affecting the derivatization and extraction efficiency such as volume of derivatization agent, effect of desorption solvent, effect of pH and effect of ionic strength were investigated. Under the optimum conditions, the method demonstrated good limits of detection ranging from 1 to 16ngL(-1), linearity (from 0.01 to 50 and 0.05 to 50µgL(-1), depending on the analytes) and satisfactory repeatability of extractions (relative standard deviations, below 13%, n=3).

Sorption, desorption and displacement of ibuprofen, estrone, and 17ß estradiol in wastewater irrigated and rainfed agricultural soils.

Sorption and leaching potential of ibuprofen, estrone and 17ß estradiol were tested in two agricultural soils: one irrigated using municipal wastewater and the other used in rainfed agriculture. Batch sorption-desorption experiments and undisturbed soil column assays were carried out using both soils to which were added a mixture of the target compounds. The three compounds were sorbed to a different extent by both soils: estrone>17ß estradiol>ibuprofen. Higher sorption was observed in the irrigated soil, which was attributed to the accumulation of organic matter caused by wastewater irrigation. Desorption of hormones was hysteretic in the irrigated soil, while ibuprofen showed low hysteresis in both soils. Retardation of the compounds' displacement was consistent with the sorption pattern observed in the batch tests. Retardation factor (RF) was similar for the three compounds in the two tested soils, indicating that the target compounds are much more mobile in the soil columns than would be predicted based on their equilibrium sorption parameters. The results obtained in the experiments clarify the role of wastewater irrigated soils as a filter and degradation media for the target micropollutants.

Sensing chiral drugs by using CdSe/ZnS nanoparticles capped with N-acetyl-L-cysteine methyl ester.

Chiral quantum dots (QDs), differing in their core or shell size and, consequently, in their optical properties, were synthesized by the treatment of commercially available amine-capped quantum dots with methyl ester N-acetyl-L-cysteine (CysP). Interestingly, their colloidal methanol solutions remain stable for several months. Their NMR and IR spectra were in accordance with CysP binding to the QD surface through two anchoring groups; its thiolate (strongly bound) and the carbonyl group of its ester (weaker bound) group, whereas their circular dichroism (CD) spectra showed a new broad redshifted band, suggesting that the attachment to the QD surface modified the conformational equilibrium towards conformer(s) with optical activity in this region. These QDs were sufficiently fluorescent to perform studies of the chiral recognition of drugs, in particular the aryl propionic acids (APAs) ketoprofen (KP), naproxen (NP), flurbiprofen (FP), and ibuprofen (IP). We used different drug concentration ranges, depending on the QD solubility. All the assayed drugs quenched the QD emission in a concentration-dependent mode. Quenching fluorescence assays with the chiral QDs (CS@CysP) showed their extraordinary capacity for the chiral recognition of KP, NP, and FP, and particularly in the case of KP and FP, a remarkable positive allosteric effect was detected for the R enantiomer. By using a drug/CS@CysP molar ratio of 5000:1 and 2500:1, the changes of intensity and the sign of the CD spectrum of the drug evidenced the dissociation of the drug carboxylic group in the presence of the QD.

Evaluation of Cedrela gum as a binder and bioadhesive component in ibuprofen tablet formulations

The compressional, mechanical and bioadhesive properties of tablet formulations incorporating a new gum obtained from the incised trunk of the Cedrela odorata tree were evaluated and compared with those containing hydroxypropylmethylcellulose (HPMC). Compressional properties were evaluated using Hausner's ratio, Carr's Index, the angle of repose, and Heckel, Kawakita and Gurnham plots. Ibuprofen tablets were prepared using the wet granulation method. Bioadhesive studies were carried out using the rotating cylinder method in either phosphate buffer pH 6.8 or 0.1 M hydrochloric acid media. The gum is a low viscosity polymer (48 cPs), and Fourier transform infrared spectroscopy revealed the presence of a hydroxyl group. Py and Pk values, which are measures of plasticity, showed the gum to be significantly (p<0.05) more plastic than HPMC, and plasticity increased with polymer concentration. All tablet formulations were non-friable (<1.0%), and the formulations containing the gum had a higher crushing strength (130.95 N) than those containing HPMC (117.85 N) at 2.0% w/w binder. Formulations incorporating the gum were non-disintegrating and had a significantly longer drug release time than those containing HPMC. At the highest binder concentration, Cedrela gum formulations adhered to incised pig ileum longer than those containing HPMC. Cedrela gum exhibited better compressive, flow and binding properties than HPMC and is suitable as a bioadhesive and for sustained release of drugs.

Propriedades de compressão, mecânicas e de formulações de comprimidos bioadesivos, que incorporam nova goma de mascar obtidas a partir de incisão de tronco da árvore de Cedrela odorata, foram avaliadas e comparadas com aquelas contendo hidroxipropilmetilcelulose (HPMC). Propriedades de compressão foram avaliadas usando a razão de Hausner, índice de Carr, ângulo de repouso e os gráficos de Heckel, Kawakita e Gurnham. Prepararam-se comprimidos de ibuprofeno utilizando o método de granulação a úmido. Realizaram-se estudos de bioadesividade utilizando o método de cilindro rotativo em tampão fosfato pH 6,8, ou meio ácido com 0,1 M de ácido clorídrico. A goma é um polímero de baixa viscosidade (48 cPs) e a espectroscopia no infravermelho por Transformada de Fourier (FTIR) revelou a presença de um grupo hidroxila. Valores de Py e Pk, que são medidas de plasticidade, mostraram que a goma é significativamente (p <0,05) mais plástica do que HPMC e que a plasticidade aumenta com a concentração de polímero. Todas as formulações de comprimidos mostraram-se não-friáveis (<1,0%) e aquelas contendo a goma apresentaram maior resistência ao esmagamento (130.95N) do que aquelas contendo HPMC (117.85N) em 2,0% (p/p) do ligante. As formulações que incorporaram a goma eram não-desintegrantes e apesentaram tempo de liberação significativamente maior do que aquelas contendo HPMC. As formulações de goma de Cedrela aderiram à incisão de íleo de porco por tempo maior do que aquelas contendo HPMC com a maior concentração de ligante. A goma Cedrela apresentou melhor fluxo, compressão e propriedades de ligação do que HPMC e é adequada como bioadesivo e para a liberação sustentada de fármacos.

Determination of non-steroidal anti-inflammatory drugs in water samples by solid-phase microextraction based sol-gel technique using poly(ethylene glycol) grafted multi-walled carbon nanotubes coated fiber.

In this study, poly(ethylene glycol) (PEG) grafted multi-walled carbon nanotubes (PEG-g-MWCNTs) were synthesized by the covalent functionalization of MWCNTs with hydroxyl-terminated PEG chains. PEG-g-MWCNTs was used as a novel stationary phase to prepare the sol-gel solid-phase microextraction (SPME) fiber in combination with gas chromatography-flame ionization detector (GC-FID) for the determination of ibuprofen, naproxen and diclofenac in real water samples. Some parameters which influencing the extraction efficiency were such as desorption temperature and time, extraction temperature and time, pH, salt effect and stirring speed that were investigated and optimized. Under the optimal conditions, the method detection limits (S/N=3) were in the range of 0.007-0.03 ng mL(-1) and the limits of quantification (S/N=10) between 0.05 and 0.07 ng mL(-1). The relative standard deviations (RSDs) for one fiber (repeatability) (n=5) were obtained from 5.9 up to 8.1% and between fibers or batch to batch (n=3) (reproducibility) in the range of 7.2-9.1%. The developed method was successfully applied to real water samples while the relative recovery percentages obtained for the spiked water samples at 0.2 ng mL(-1) were from 84 to 107%.

Comparative study of sustained-release lipid microparticles and solid dispersions containing ibuprofen

Ibuprofen is one of the most important non-steroidal anti-inflammatory drugs used in the treatment of inflammatory diseases. In its pure state, ibuprofen presents poor physical and mechanical characteristics and its use in solid dosage forms needs the addition of excipients that improve these properties. The selection of the best excipients and the most suitable pharmaceutical dosage form to carry ibuprofen is very important for the industrial success of this drug. Given these factors, lipid microparticles and solid dispersions of ibuprofen with cetyl alcohol, stearic acid, and hydrogenated castor oil were prepared. These formulations were intended to improve the physical and mechanical characteristics and to sustain the release of this drug. Physical mixtures were also prepared with the same ingredients in similar proportions. The solid dispersions of ibuprofen/stearic acid and ibuprofen/hydrogenated castor oil showed the best flow characteristics compared with pure ibuprofen. Further, gelatin capsules filled with lipid microparticles and solid dispersions were submitted to dissolution tests in order to study the influence of the prepared systems in the release profiles of ibuprofen. Prolonged release of ibuprofen was achieved with the lipid microparticles and solid dispersions prepared with the different types of excipients.

O ibuprofeno é um dos antiinflamatórios não esteróides mais utilizados no tratamento de patologias associadas a processos inflamatórios. Este fármaco, quando no seu estado puro, apresenta características físicas e mecânicas pouco satisfatórias e a sua utilização em formas sólidas só é possível se forem adicionados excipientes que permitam melhorar estas propriedades. A seleção dos excipientes ideais e da forma farmacêutica mais adequada para veicular o ibuprofeno é fundamental para o sucesso industrial deste fármaco. Tendo em conta estes fatores, prepararam-se micropartículas lipídicas e dispersões sólidas de ibuprofeno com cada um dos seguintes excipientes: álcool cetílico, ácido esteárico e óleo de rícino hidrogenado. Estas formulações tinham por finalidade melhorar as características físicas e mecânicas e prolongar a liberação deste fármaco. Foram, também, preparadas misturas físicas do ibuprofeno com os mesmos excipientes e nas mesmas proporções. As dispersões sólidas de ibuprofeno/ácido esteárico e as dispersões sólidas de ibuprofeno/óleo de rícino hidrogenado foram aquelas que apresentaram melhores características de escoamento comparativamente com o ibuprofeno puro. Por outro lado, foram preparadas cápsulas de gelatina com as diferentes micropartículas lipídicas e dispersões sólidas e submetidas a ensaios de dissolução com o objetivo de estudar a influência dos sistemas preparados nos perfis de liberação do ibuprofeno. A liberação prolongada do ibuprofeno foi conseguida nas diferentes micropartículas lipídicas e dispersões sólidas preparadas com os diferentes excipientes.

Microspheres prepared with biodegradable PHBV and PLA polymers as prolonged-release system for ibuprofen: in vitro drug release and in vivo evaluation

In this study, poly(hydroxybutyrate-co-hydroxyvalerate) (PHBV) and poly(l-lactide) (PLA) microspheres containing ibuprofen were prepared with the aim of prolonging the drug release. The oil-in-water (O/W) emulsion solvent evaporation technique was used, varying the polymer ratio. All formulations provided spherical particles with drug crystals on the surface and a porous and rough polymeric matrix when PHBV was used and smooth external surface when prepared with PLA. The in vitro dissolution profiles show that the formulation containing PHBV/PLA at the proportion of 30/70 presented the best results in terms of prolonging the ibuprofen release. The analysis of the concentration of ibuprofen in the blood of rats showed that maximum levels were achieved at between one and two hours after administration of the immediate-release form (pure drug), while the prolonged microspheres led to a small amount of the drug being released within the first two hours and reached the maximum level after six hours of administration. It was concluded that it is possible to prolong the release of ibuprofen through its incorporation into PHBV/PLA microspheres.

No presente estudo foram preparadas microesferas de poli(hidroxibutirato-co-hidroxivalerato) (PHBV) e poli(ácido láctico) (PLA) com o objetivo de prolongar a liberação do ibuprofeno, utilizado como fármaco modelo. Empregou-se o método de emulsificação e evaporação do solvente óleo em água (O/A), variando-se a proporção entre os polímeros. Todas as formulações originaram partículas esféricas com cristais de fármaco aderidos à superfície externa. As microesferas apresentaram superfície rugosa e porosa, quando o PHBV foi utilizado, e superfície externa lisa, quando preparadas com o PLA. Os perfis de dissolução in vitro evidenciaram que a formulação que continha PHBV/PLA na proporção de 30/70 apresentou melhores resultados para prolongar a liberação do ibuprofeno. Através da análise da concentração de ibuprofeno no plasma de ratos, após administração oral, verificou-se que os níveis máximos ocorreram entre 1 e 2 horas após a administração de ibuprofeno não encapsulado, enquanto o fármaco presente nas microesferas atingiu um pico máximo após 6 horas da administração. Conclui-se, portanto, que é possível prolongar a liberação do ibuprofeno após a sua incorporação às microesferas preparadas com os polímeros PHBV e PLA, especialmente na proporção de 30/70.