Formulation and Evaluation of Orodispersible Tablet Containing Combination of Phosphodiesterase-5 Inhibitor and Herbal Aphrodisiac

Purpose: Sildenafil citrate is widely used drug for the treatment of Erectile Dysfunction (ED) and Ginseng is a natural aphrodisiac reported to benefit this condition. The objective of the present study was to develop orodispersible tablets (ODTs) containing combination of Sildenafil citrate and Ginseng extract to improve the bioavailability, reduce the dosing frequency and thereby maintaining the therapeutic efficacy of the drug. Methods: The ODTs were prepared using superdisintegrants such as Croscarmellose sodium (CCS), povidone, and sodium starch glycolate (SSG) at varying concentrations (2%, 4% and 6%) by direct compression. The bitter taste of Sildenafil citrate was masked by Doshion resin. The optimized formulation based on least disintegration time (DT) was chosen to reformulate using sublimating agents such as camphor, menthol or thymol at varying concentrations (1%, 2%, 3%) to further reduce the DT. The compatibility of drug with excipients was investigated and the prepared formulations were evaluated for pre and post-compression parameters. Results: The post-compression parameters such as weight variation, hardness, friability, DT and in-vitro drug release was found within specified limit. The formulation with camphor (2%) had DT of 12 sec and drug release >90% within 5 min hence was considered as optimized formulation. The accelerated stability study and kinetics modelling was performed for optimized formulation. Conclusion: The formulated Sildenafil citrate and Ginseng ODT’s were found to be promising formulation with quicker DT and drug release which will eventually have higher bioavailability and better efficacy along with averting the issues of swallowing and improving patient compliance.

Preparation and antifungal activity of water-soluble graphene-based itraconazole antifungal eye drops / 中华实验眼科杂志

Objective:To prepare water-soluble graphene-based itraconazole antifungal eye drops and evaluate its antifungal activity against Fusarium solani. Methods:By oxidative modification of graphene and modification of polymer materials, water-soluble graphene oxide-modified polyethylene glycol (GO-PEG) composites were prepared.The composites were characterized by scanning electron microscopy, zeta potential, and Raman spectroscopy.The antifungal drug itraconazole was loaded onto the GO-PEG vector by solvent evaporation method, and itraconazole eye drops were obtained.The drug loading of itraconazole eye drops was measured using a UV and visible spectrophotometer.The antifungal effect in vitro was assessed by the microdilution method and light microscopy. Results:Scanning electron microscopy showed that GO-PEG had a two-dimensional nanosheet structure and many wrinkles.The zeta potential of GO-PEG was -42.40 mV.Raman spectroscopy showed that the ID/ IG of GO-PEG was 1.003.Using the water-soluble GO-PEG vector, a maximum itraconazole concentration of 10 mg/ml was achieved with a 10 000-fold increase in apparent solubility (10 mg/ml vs 0.001 mg/ml). The antifungal results showed that the minimum inhibitory concentration of itraconazole eye drops against Fusarium solani was approximately 1.88 μg/ml, but the GO-PEG vector has no significant antifungal activity against Fusarium solani. Conclusions:GO-PEG achieves effective loading and solubilization of itraconazole, demonstrating an in vitro inhibitory effect on Fusarium solani.

Preliminary pre-prescription study of tetrodotoxin / 药学实践杂志

Objective To investigate the solubility and stability of Tetrodotoxin (TTX) in different solvents, and the effect of temperature and pH on its stability. Methods Solutions of TTX in different matrices were prepared. Their concentrations at different temperatures and pH buffers were determined by high performance liquid chromatography and their solubility and stability were analyzed and calculated. Results TTX was most soluble at pH 3.5 and its solubility decreased as the pH increased. TTX degraded most rapidly under strong alkali conditions, with complete degradation after 20 min of reaction at 0.1 mol/L sodium hydroxide and 70 ℃. The stability test results similarly demonstrated that TTX was least stable under alkaline conditions. In a PBS buffered solution at 37 ℃, pH 7.4, TTX concentration began to decrease consistently at 1~10h, with a degradation rate of 88.07±0.27% after 28 days. Conclusion TTX is readily soluble in acidic aqueous solutions at pH 3.5 and almost insoluble in alkaline aqueous solutions. Its stability is closely related to the temperature and pH of the medium. It is more stable in acidic aqueous solutions and easily degrades under alkaline conditions, and its degradation process could be accelerated by increasing temperature.

Effect of Microemulsion on Content of Index Components in Different Phases of Zexietang Extract / 中国实验方剂学杂志

ObjectiveTo investigate the effect of microemulsion on the distribution of index components in different phases of Zexietang extract based on high performance liquid chromatography（HPLC） and phase separation process. MethodParticle size meter and transmission electron microscope were used to characterize the colloidal particles in blank microemulsion， aqueous extract of Zexietang and microemulsion extract of Zexietang. The phase separation process was established by high-speed centrifugation and dialysis， and based on this process， the aqueous extract and microemulsion extract of Zexietang were separated into the true solution phase， the colloidal phase and the precipitation phase， respectively. The contents of six components， including atractylenolide Ⅲ， atractylenolide Ⅱ， 23-acetyl alisol C， alisol A， alisol B and alisol B 23-acetate， were determined by HPLC with the mobile phase of water（A）-acetonitrile（B） for gradient elution（0-5 min， 40%-43%B； 5-20 min， 43%-45%B； 20-45 min. 45%-60%B； 45-75 min， 60%-80%B）. The solubility of the index components in water and microemulsion was determined by saturation solubility method. ResultThe colloidal particles in the aqueous extract， microemulsion extract and blank microemulsion were all spherical， and the particle size， polydispersity index（PDI） and Zeta potential of the colloidal particles were in the order of aqueous extract >microemulsion extract >blank microemulsion. The results of phase separation showed that the colloidal phase and the true solution phase could be completely separated by dialysis for 2.5 h， and the phase separation process was tested to be stable and feasible. Compared with the aqueous extract of Zexietang， the use of microemulsion as an extraction solvent could increase the contents of atractylenolide Ⅲ， 23-acetyl alisol C， atractylenolide Ⅱ ， alisol A， alisol B and alisol B 23-acetate by 3.75， 6.82， 35.47， 10.66， 35.41， 27.75-fold， and could increase the extraction efficiencies of the latter five constituents by 2.03， 1.15， 1.70， 6.43， 5.53 times. The solubility test showed that the microemulsion could significantly improve the solubility of atractylenolide Ⅱ， alisol A， alisol B and alisol B 23-acetate， but it had less effect on the solubility of atractylenolide Ⅲ and 23-acetyl alisol C. ConclusionMicroemulsion can improve the extraction efficiency and increase the distribution of the index components in the colloidal phase state of Zexietang to different degrees， providing a reference for the feasibility of microemulsion as an extraction solvent for traditional Chinese medicine.

Cause Analysis and Solution Strategy of Poor Solubility of Dioscoreae Rhizoma Formula Granules / 中国实验方剂学杂志

Dioscoreae Rhizoma formula granules are made from decoction pieces by decocting， extracting， separating， concentrating， drying and granulating， which have the advantages of simple dispensing， convenient use and easy to take without decoction. However， because Dioscoreae Rhizoma is rich in starch and mucus components， its extract powder and formula granules are poorly soluble and difficult to dissolve or disperse completely within 5 min， and the insoluble material is difficult to dissolve completely even after 24 h in water， which affects the quality evaluation of the formula granules and medication psychology of patients. Therefore， by studying the dissolution process and mechanism of Dioscoreae Rhizoma extract and its formula granules， it was found that the special chemical composition of Dioscoreae Rhizoma， the denaturation of starch and its compounding with protein and other substances during the high temperature extraction process， and the contraction of coating membrane during the spray drying process were combined to form the special microstructure of coating membrane covering starch granules， and it is the root cause of poor solubility of Dioscoreae Rhizoma formula granules. Based on the research on the structure， property and function of the powder， this paper proposed a technical strategy to improve the solubility of Dioscoreae Rhizoma formula granules by powder modification process， and experimentally demonstrated that the modified Dioscoreae Rhizoma formula granules could completely dissolve within 2 min， which solved the technical problem and could provide reference for the improvement of solubility of other similar varieties， and promote the high-quality development of traditional Chinese medicine formula granule industry.

Technology and principle of improving solubility of Dioscoreae Rhizoma formula granules based on powder modification / 中国中药杂志

The powder modification technology was used to improve the powder properties and microstructure of Dioscoreae Rhizoma extract powder, thereby solving the problem of poor solubility of Dioscoreae Rhizoma formula granules. The influence of modifier dosage and grinding time on the solubility of Dioscoreae Rhizoma extract powder was investigated with the solubility as the evaluation index, and the optimal modification process was selected. The particle size, fluidity, specific surface area, and other powder properties of Dioscoreae Rhizoma extract powder before and after modification were compared. At the same time, the changes in the microstructure before and after modification was observed by scanning electron microscope, and the modification principle was explored by combining with multi-light scatterer. The results showed that after adding lactose for powder modification, the solubility of Dioscoreae Rhizoma extract powder was significantly improved. The volume of insoluble substance in the liquid of modified Dioscoreae Rhizoma extract powder obtained by the optimal modification process was reduced from 3.8 mL to 0 mL, and the particles obtained by dry granulation of the modified powder could be completely dissolved within 2 min after being exposed to water, without affecting the content of its indicator components adenosine and allantoin. After modification, the particle size of Dioscoreae Rhizoma extract powder decreased significantly, d_(0.9) decreased from(77.55±4.57) μm to(37.91±0.42) μm, the specific surface area and porosity increased, and the hydrophilicity improved. The main mechanism of improving the solubility of Dioscoreae Rhizoma formula granules was the destruction of the "coating membrane" structure on the surface of starch granules and the dispersion of water-soluble excipients. This study introduced powder modification technology to solve the solubility problem of Dioscoreae Rhizoma formula granules, which provided data support for the improvement of product quality and technical references for the improvement of solubility of other similar varieties.

Preparation and in vitro property evaluation of β-cyclodextrin-daidzein/PEG_(20000)/Carbomer_(940) nanocrystals / 中国中药杂志

This study aims to improve the solubility and bioavailability of daidzein by preparing the β-cyclodextrin-daidzein/PEG_(20000)/Carbomer_(940) nanocrystals. Specifically, the nanocrystals were prepared with daidzein as a model drug, PEG_(20000), Carbomer_(940), and NaOH as a plasticizer, a gelling agent, and a crosslinking agent, respectively. A two-step method was employed to prepare the β-cyclodextrin-daidzein/PEG_(20000)/Carbomer_(940) nanocystals. First, the insoluble drug daidzein was embedded in β-cyclodextrin to form inclusion complexes, which were then encapsulated in the PEG_(20000)/Carbomer_(940) nanocrystals. The optimal mass fraction of NaOH was determined as 0.8% by the drug release rate, redispersability, SEM morphology, encapsulation rate, and drug loading. The inclusion status of daidzein nanocrystals was determined by Fourier transform infrared spectroscopy(FTIR), thermogravimetric analysis(TGA), and X-ray diffraction(XRD) analysis to verify the feasibility of the preparation. The prepared nanocrystals showed the average Zeta potential of(-30.77±0.15)mV and(-37.47±0.64)mV and the particle sizes of(333.60±3.81)nm and(544.60±7.66)nm before and after daidzein loading, respectively. The irregular distribution of nanocrystals before and after daidzein loading was observed under SEM. The redispersability experiment showed high dispersion efficiency of the nanocrystals. The in vitro dissolution rate of nanocrystals in intestinal fluid was significantly faster than that of daidzein, and followed the first-order drug release kinetic model. XRD, FTIR, and TGA were employed to determine the polycrystalline properties, drug loading, and thermal stability of the nanocrystals before and after drug loading. The nanocrystals loaded with daidzein demonstrated obvious antibacterial effect. The nanocrystals had more significant inhibitory effects on Staphylococcus aureus, Escherichia coli, and Pseudomonas aeruginosa than daidzein because of the improved solubility of daidzein. The prepared nanocrystals can significantly increase the dissolution rate and oral bioavailability of the insoluble drug daidzein.

Application and problems analysis of traditional Chinese medicine volatile oil preparation technology based on ionic liquids / 中国中药杂志

Ionic liquids(ILs) are salts composed entirely of anions and cations in a liquid state at or near room temperature, which have a variety of good physicochemical properties such as low volatility and high stability. This paper mainly reviewed the research overview of ILs in the application of traditional Chinese medicine(TCM) volatile oil preparation technology. Firstly, it briefly introduced the application of TCM volatile oil preparation technology and composition classification and physicochemical properties of ILs, and then summarized the application of ILs in the extraction, separation, analysis, and preparation of TCM volatile oil. Finally, the problems and challenges of ILs in the application of TCM volatile oil were explained, and the application of ILs in TCM volatile oil in the future was prospected.

Preformulation screening of lipids using solubility parameter concept in conjunction with experimental research to develop ceftriaxone loaded nanostructured lipid carriers

Abstract Development of ceftriaxone loaded nanostructured lipid carriers to increase permeability of ceftriaxone across uninflamed meninges after parenteral administration. Lipids were selected by theoretical and experimental techniques and optimization of NLCs done by response surface methodology using Box-Behnken design. The Δδt for glyceryl monostearate and Capryol90 were 4.39 and 2.92 respectively. The drug had maximum solubility of 0.175% (w/w) in glycerol monostearate and 2.56g of Capryol90 dissolved 10mg of drug. The binary mixture consisted of glyceryl monostearate and Capryol90 in a ratio of 70:30. The optimized NLCs particle size was 130.54nm, polydispersity index 0.28, % entrapment efficiency 44.32%, zeta potential -29.05mV, and % drug loading 8.10%. In vitro permeability of ceftriaxone loaded NLCs was 5.06x10-6 cm/s; evidently, the NLCs pervaded through uninflamed meninges, which, was further confirmed from in vivo biodistribution studies. The ratio of drug concentration between brain and plasma for ceftriaxone loaded NLCs was 0.29 and that for ceftriaxone solution was 0.02. With 44.32% entrapment of the drug in NLCs the biodistribution of ceftriaxone was enhanced 7.9 times compared with that of ceftriaxone solution. DSC and XRD studies revealed formation of imperfect crystalline NLCs. NLCs improved permeability of ceftriaxone through uninflamed meninges resulting in better management of CNS infections.

PVP solid dispersions containing Poloxamer 407 or TPGS for the improvement of ursolic acid release

Abstract Solid dispersions (SDs) of ursolic acid (UA) were developed using polyvinylpyrrolidone K30 (PVP K30) in combination with non-ionic surfactants, such as D-α-tocopherol polyethylene glycol 1000 succinate (TPGS) or poloxamer 407 (P407) with the aim of enhancing solubility and in vitro release of the UA. SDs were investigated using a 24 full factorial design, subsequently the selected formulations were characterized for water solubility, X-ray diffractometry (XRD), differential scanning calorimetry (DSC), particle diameter, scanning electron microscopy, drug content, physical-chemical stability and in vitro release profile. SDs showed higher UA water-solubility than physical mixtures (PMs), which was attributed by transition of the drug from crystalline to amorphous or molecular state in the SDs, as indicated by XRD and DSC analyses. SD1 (with P407) and SD2 (with TPGS) were chosen for further investigation because they had higher drug load. SD1 proved to be more stable than SD2, revealing that P407 contributed to ensure the stability of the UA. Furthermore, SD1 and SD2 increased UA release by diffusion and swelling-controlled transport, following the Weibull model. Thus, solid dispersions obtained with PVP k-30 and P407 proved to be advantageous to enhance aqueous solubility and stability of UA.

Influence of solvent choice and operating conditions on Chlorzoxazone crystal shape and size

Abstract Solubility of pharmaceutical drugs in organic solvents is one of the important parameters to understand the equilibrium concentration of solute-solvent, which helps optimize and design crystallization conditions to obtain the desired product crystals. In the present study, Chlorzoxazone (CHZ) is used as a model pharmaceutical compound to investigate the equilibrium solubility, the influence of solvent and the operating conditions on the shape, and the size distribution. The solubility of CHZ is determined in organic solvents like Isopropanol, Ethanol, and 2-Ethoxyethylacetate, Ethylacetate and Ethyllactate using shake flask method from -5ºC to 60ºC. The solubility of CHZ in these solvents shows an increasing trend as the temperature increases in the following order: ethyllactate + water (0.5+0.5) < ethylacetate < isopropanol < ethanol < 2-ethoxyethylacetate < ethyllactate + water (0.75+0.25). The solvents, isopropanol, ethanol, and ethyl lactate, produce needle-shaped crystals, while 2-ethoxyethylacetate and ethyl acetate tend to produce plate shaped crystals. CHZ crystals obtained from 2-ethoxyethylacetate tend to have plate shaped crystals with a lower aspect ratio and are selected for batch cooling crystallization experiments performed at different cooling rates, and agitation. It is found that the agitation at 300 rpm and the cooling rate 0.2ºC/min produce more uniform crystal size distribution

Análise de metodologias para avaliação da solubilidade do cimento à base de silicato de cálcio Bio-C Sealer / Analysis of methodologies for evaluating the solubility of calcium silicate-based sealer Bio-C Sealer

Introdução: Cimentos endodônticos à base de silicato de cálcio demonstram maior solubilidade em água destilada. Emprego de metodologias alternativas pode auxiliar em melhor compreensão sobre a solubilidade desses materiais. Objetivo: Avaliar o efeito da solução de imersão e do tipo de modelo experimental na solubilidade de cimento pronto para uso Bio-C Sealer. Material e método: Modelos circulares de polietileno ou dentina bovina (n = 16) foram confeccionados. Após inserção do cimento, os espécimes foram mantidos em estufa a 37 °C por 48 horas. Posteriormente, as amostras foram pesadas em balança de precisão para determinação da massa inicial. Na sequência, os espécimes foram imersos em 7,5 mL de água destilada (pH 6,5) ou PBS (pH 7,0) (n = 8) por 28 dias. Após isso, as amostras foram removidas das soluções e pesadas a cada 24 horas até a estabilização da massa final (0,001g). Corpos de prova confeccionados com Bio-C Sealer foram empregados como controle. A solubilidade foi avaliada de acordo com a diferença entre a massa inicial e final em porcentagem. Teste ANOVA Two-Way e teste post-hoc de Tukey foram realizados (α = 0,05). Resultado: Imersão em água destilada proporcionou maior solubilidade em comparação com PBS, independentemente do modelo experimental (p < 0,05). Corpos de prova apresentaram maior solubilidade, seguidos dos modelos de polietileno e dentina imersos em água destilada (p < 0,05). Não houve diferença entre os modelos experimentais imersos em PBS (p > 0,05). Conclusão: Bio-C Sealer apresenta solubilidade significativamente maior em água destilada do que em PBS em todas condições. Modelo experimental empregando dentina bovina e PBS como solução de imersão demonstra diminuir a perda de massa de Bio-C Sealer e pode ser uma alternativa valiosa para avaliar a solubilidade de cimentos biocerâmicos

Introduction: Calcium silicate-based sealers demonstrate greater solubility in distilled water. The use of alternative methodologies can help at better understanding the solubility of these materials. Objective: To evaluate the effect of the immersion solution and the type of experimental model on the solubility of readyto-use Bio-C Sealer. Material and method: Circular models of polyethylene or bovine dentin (n = 16) were made. After insertion of the sealer, the specimens were kept in an oven at 37°C and 95% humidity for 48h. Subsequently, the samples were weighed on a precision balance to determine the initial mass. Next, the specimens were immersed in 7.5 mL of distilled water (pH 6.5) or PBS (pH 7.0) (n = 8) for 28 days. After that, the samples were removed from the solutions and weighed every 24 hours until the final mass stabilized (0.001g). Test specimens made with Bio-C Sealer were used as a control. Solubility was evaluated according to the difference between the initial and final mass in percentage. Two-Way ANOVA test and Tukey post-hoc tests were performed (α=0.05). Result: Immersion in distilled water provided greater solubility compared to PBS regardless of the experimental model (p<0.05). The test specimens showed greater solubility, followed by polyethylene and dentin models immersed in distilled water (p<0.05). There was no difference between the experimental models immersed in PBS (p>0.05). Conclusion: Bio-C Sealer presents significantly greater solubility in distilled water than in PBS under all conditions. Experimental model using bovine dentin and PBS as an immersion solution demonstrates reduction in the mass loss of Bio-C Sealer and can be a valuable alternative for evaluating the solubility of bioceramic sealers

Development and evaluation of wafer loaded with sertaconazole solid dispersion for the treatment of oral candidiasis

Abstract Candidiasis is one of the most common fungal infections of oral cavity in humans, causing great oral discomfort, pain and aversion to food. To develop more effective antifungal systems for the treatment of oral candidiasis, an oral mucoadhesive wafer containing sertaconazole solid dispersion (STZ-SD) was developed in this study. Dispersion of STZ in Soluplus® as a solubility enhancement excipient was done by melting, solvent evaporation and freeze drying method at various STZ to Soluplus® ratios. The optimized STZ-SD was then incorporated in the sodium carboxymethyl cellulose (SCMC) gel, xanthan gum gel, or their combination to prepare the lyophilized wafers. The swelling capacity, porosity, and mechanical, release and mucoadhesive properties of the wafers, together with their antifungal activity, were then evaluated. The melting method sample with the ratio of 8:1 showed the best results in terms of saturation solubility and dissolution rate. The STZ-SD-composite wafer exhibited higher hardness and mucoadhesion, as compared to those made of the SCMC polymer. The STZ-SD-wafer also exhibited a greater antifungal effect when compared to the STZ-wafer. The present study, thus, suggested that the STZ-SD-wafer could serve as a novel effective delivery system for oral candidiasis treatment.

Development of inclusion complex based on cyclodextrin and oxazolidine derivative

Abstract Oxazolidine derivatives (OxD) have been described as third-line antibiotics and antitumoral agents. The inclusion complexes based on cyclodextrin could improve the solubility and bioavailability of these compounds. A novel synthetic OxD was used, and its inclusion complexes were based on 2-hydroxy-beta-cyclodextrin (2-HPßCD). We conducted an in silico study to evaluate the interaction capacity between OxD and 2-HPßCD. Characterization studies were performed through scanning electron microscopy (SEM), Fourier-transformed infrared (FTIR), nuclear magnetic resonance spectroscopy (1H-NMR), X-ray diffraction (XRD), and thermal analyses. A kinetic study of the OxD was performed, including a cytotoxicity assay using peripheral blood mononuclear cells (PBMCs). The maximum increment of solubility was obtained at 70 mM OxD using 400 mM 2-HPßCD. SEM analyses and FTIR spectra indicated the formation of inclusion complexes. 1H-NMR presented chemical shifts that indicated 1:1 stoichiometry. Different thermal behaviors were obtained. The pharmacokinetic profile showed a short release time. Pure OxD and its inclusion complex did not exhibit cytotoxicity in PBMCs. In silico studies provided a foremost insight into the interactions between OxD and 2-HPßCD, including a higher solubility in water and an average releasing profile without toxicity in normal cells

Optimization of the preparation process of Soft-shelled turtle blood lyophilized powder using Box-Behnken response surface methodology / 中国药房

OBJECTIVE To optimize the preparation process of Soft-shelled turtle blood lyophilized powder （STBLP）， and to provide a reference for improving the availability and quality stability of soft-shelled turtle blood （STB）. METHODS STBLP was prepared with vacuum freeze-drying. Taking the solubility as the index， the preparation process parameters of STBLP were optimized by single factor experiment and Box-Behnken response surface method. RESULTS The optimal freeze-drying process for STBLP was obtained： pre-freezing time of 4 h， total drying time of 13 h （before at 0 ℃）， and resolution drying temperature of 25 ℃. The average solubility of 3 batches of STBLP prepared according to the optimal process was 95.72% （RSD＝0.68%， n＝3）， the relative error of which was －0.97% to the theoretical solubility （96.66%）. CONCLUSIONS Optimized lyophilization process in this study are stable and feasible， the solubility of the prepared sample is high.

The relationships among Flory-Huggins specific interaction parameters, maximum amorphous capacity, and solid-state interactions of spray dried amorphous drug dispersions with conventional and novel pharmaceutical polymers / Las relaciones entre los parámetros de interacción específicos de Flry-Huggins, la capacidad amorfa máxima y las interacciones en estado sólido de las dispersiones de fármacos amorfos secados por aspersión con polímeros farmacéuticos convencionales y nuevos

This study evaluated the specific interactions between drug and polymers in amorphous spray dried dispersions (SDDs). Four Biopharmaceutics Classification System (BCS) II class drugs were evaluated. Binary and ternary SDDs were manufactured with conventional polymers and arabinogalactan. Specific interaction parameters between drug and polymer were determined using theoretical calculations and DSC data. Analytical methods were used to evaluate solid and solution state interactions. Maximum amorphous content for each formulation was calculated using DSC. Flory-Huggins Specific Interaction Parameters were calculated. Negative specific parameters were associated with solid-state interactions and improved capacity of drug in the amorphous state. Ternary SDDs containing drug, polymer, and arabinogalactan displayed similar hydrogen bonding as was observed with binary SDDs. Solution-state interactions observed in binary systems may be used in tertiary systems to improve the amorphous drug capacity and improved dissolution compared to the binary. The resultant tertiary systems are an improvement over binary drug polymer systems.

Este estudio evaluó las interacciones específicas entre el fármaco y los polímeros en dispersiones amorfas secadas por pulverización (SDD). Se evaluaron cuatro fármacos de clase II del Sistema de Clasificación Biofarmacéutica (BCS). Los SDD binarios y ternarios se fabricaron con polímeros convencionales y arabinogalactano. Los parámetros de interacción específicos entre el fármaco y el polímero se determinaron utilizando cálculos teóricos y datos de DSC. Se utilizaron métodos analíticos para evaluar las interacciones del estado sólido y de la solución. El contenido amorfo máximo para cada formulación se calculó usando DSC. Se calcularon los parámetros de interacción específicos de Flory-Huggins. Los parámetros específicos negativos se asociaron con interacciones en estado sólido y una capacidad mejorada del fármaco en el estado amorfo. Los SDD ternarios que contienen fármaco, polímero y arabinogalactano mostraron enlaces de hidrógeno similares a los observados con los SDD binarios. Las interacciones de estado de solución observadas en sistemas binarios pueden usarse en sistemas terciarios para mejorar la capacidad del fármaco amorfo y mejorar la disolución en comparación con el binario. Los sistemas terciarios resultantes son una mejora con respecto a los sistemas de polímeros de fármacos binarios.

Caracterización fisicoquímica y evaluación in vitro de sistemas autoemulsionables de liberación de indometacina

Objetivo: incorporar la indometacina en sistemas autoemulsionables de liberación con la finalidad de aumentar su solubilidad en medio acuoso, la velocidad de disolución y permeación in vitro. Metodología: se llevaron a cabo ensayos de solubilidad al equilibrio para preparar formulaciones con los excipientes, en los cuales la indome-tacina presentó mayor incremento de solubilidad; los sistemas fueron caracterizados por medio del tiempo de autoemulsificación, estabilidad física, tamaño de partícula, potencial zeta, perfiles de disolución y permeación a través de membrana sintética. Resultados: el diseño experimental de los sistemas autoemulsionables de liberación permitió crear formulaciones que aumentaron la solubilidad de la indometacina en un orden de 105 veces con respecto a la solubilidad acuosa. Las formulaciones que resultaron viables presentaron tiempos de autoemulsificación menores que 60 segundos, además, las distribuciones de tamaño de partícula de las dispersiones fueron inferiores a los 300 nm, presentó índices de polidispersión inferiores a 0,3 y valores de potencial zeta menores de -25 mV. Los perfiles de disolución mostraron que las formulaciones cumplen con un valor de factor de similitud mayor que 50, además, la permeabilidad a través de membrana sintética es mayor para las formulaciones autoemulsionables que el producto de referencia. Conclusiones: la formulación de indometacina en sistemas autoemulsionables de liberación incrementa la solubilidad en medio acuoso, aumenta la disolución y liberación. Estos resultados sugieren que la administración oral de indometacina incorporada en sistemas autoe-mulsionables puede acelerar el inicio del efecto farmacológico.

SUMMARY Aim: To load indomethacin into self-emulsifying delivery systems in order to increase, water-solubility, rate dissolution and in vitro permeation. Methodology: Equilibrium solubility tests were carried out to prepare formulations with the excipients, in which indomethacin presented a greater increase in solubility; the systems were characterized by self-emulsification time, physical stability, particle size, zeta potential, dissolution profiles and permeation through synthetic membrane. Results: The experimental design of self-emulsifying delivery systems allowed to create formulations that increase the solubility of indomethacin in an order of 105 times with respect to the aqueous solubility. The feasible formulations presented autoemulsification times less than 60 seconds, in addition, the particle size distributions of the dispersions were less than 300 nm, with polydispersity index smaller than 0.3, and zeta potential values lower than -25 mV. The dissolution profiles showed that the formulations comply with a similarity factor value greater than 50, in addition, the permeability through a synthetic membrane is higher for the self-emulsifying formulations than the reference product. Conclusion: The formulation of indomethacin into self-emulsifying delivery systems enhances the solubility in aqueous medium, increases dissolution and accelerate release. These results suggest that the oral administration of indomethacin incorporated into self-emulsifying delivery systems can accelerate the onset of the pharmacological effect.

Objetivo: incorporar a indometacina em sistemas de liberação autoemulsificantes a fim de aumentar sua solubilidade em meio aquoso, a taxa de dissolução e permeação in vitro. Metodologia: foram realizados testes de solubilidade de equilíbrio para preparar formulações com os excipientes, nas quais a indometacina apresentou maior aumento na solubilidade; os sistemas foram caracterizados quanto ao tempo de autoemulsificação, estabilidade física, tamanho de partícula, potencial zeta, perfis de dissolução e permeação através de membrana sintética. Resultados: o desenho experimental dos sistemas de liberação autoemulsificantes permitiu a criação de formulações que aumentaram a solubilidade da indometacina na ordem de 105 vezes em relação à solubilidade aquosa. As formulações que se mostraram viáveis apresentaram tempos de autoemulsificação inferiores a 60 segundos, além disso, as distribuições granulométricas das dispersões foram inferiores a 300 nm, apresentaram índices de polidispersidade inferiores a 0,3 e valores de potencial zeta inferiores a -25 mV. Os perfis de dissolução mostraram que as formulações atendem a um valor de fator de similaridade maior que 50, além disso, a permeabilidade através da membrana sintética é maior para as formulações autoemulsionantes do que para o produto de referência. Conclusões: a formulação de indometacina em sistemas de liberação autoemulsificantes aumenta a solubilidade em meio aquoso, aumenta a dissolução e a liberação. Esses resultados sugerem que a administração oral de indometacina incorporada em sistemas autoemulsificantes pode acelerar o início do efeito farmacológico.

Diseño y caracterización de un sistema de entrega de fármacos autoemulsificable (SEDDS) de estradiol por diagramas de fases pseudoternarios y pruebas fisicoquímicas

Introducción: el estradiol es una hormona esteroide sexual femenina usada ampliamente como terapia hormonal que presenta una baja biodisponibilidad, debido a su baja solubilidad acuosa y a su alta hidrofobicidad, perteneciendo a la clase II del sistema de clasificación de biofarmacéutica. Objetivos: diseñar y caracterizar un sistema de entrega de fármacos autoemulsificable (SEDDS) para el fármaco estradiol por pruebas fisicoquímicas con el fin de obtener la relación óptima que permitiera mejorar su solubilidad acuosa, velocidad de disolución y potencialmente su biodisponibilidad. Método: estudios de solubilidad en diferentes solventes, diagramas de fases pseudoternarios constituidos por aceites, tensioactivos, cotensioactivos y agua permitieron reconocer las diferentes regiones de formación de SEDDS e identificar los porcentajes de excipientes que conducen a la formación de soluciones isotrópicas; las formulaciones resultantes fueron caracterizadas en tiempo de autoemulsificación, robustez a la dilución, punto de nube y perfil de disolución en capsula dura. Resultados: las formulaciones que contenían Capmul MCM®, Kolliphor® RH40 y Transcutol®, tuvieron un tiempo de autoemulsificación de aproximadamente 1 min; fueron estables en tres distintos pH (1,2; 4,5 y 7,2), en diferentes volúmenes de dilución, exhibiendo una apariencia transparente, ligeramente azulada, sin precipitados, o separación de fases, puntos de nube mayores en comparación de las formulaciones que contenían Gelucire® 44/14. Conclusiones: las estrategias de caracterización empleadas en el desarrollo de esta investigación demostraron ser eficientes para la selección adecuada de excipientes y su proporción óptima para el diseño eficaz de un sistema de entrega de fármaco autoemulsificable (SEDDS).

SUMMARY Introduction: Estradiol is a female sex steroid hormone widely used as hormonal therapy that has low bioavailability, due to its low aqueous solubility and high hydro-phobicity, belonging to class II of the Biopharmaceutical Classification System. Aim: To design and characterize a self-emulsifying drug delivery system (SEDDS) for the drug estradiol by physicochemical tests to obtain the most optimal ratio that would improve its aqueous solubility, dissolution rate, and potentially its bioavailability. Method: Solubility studies in different solvents; pseudo ternary phase diagrams made up of oils, surfactants, co-surfactants, and water, allowed to recognize the different regions of SEDDS formation and identify the percentages of excipients that lead to the formation of isotropic solutions; The resulting formulations were characterized in autoemulsification time, robustness to dilution, cloud point and dissolution profile in a hard capsule. Results: The formulations containing Capmul MCM®, Kolliphor® RH40, and Transcutol®, had an autoemulsification time of approximately 1 minute; were stable at three different pHs (1.2, 4.5 and 7.2), at different dilution volumes, exhibiting a transparent, slightly bluish appearance, without precipitates, or phase separation, higher cloud points compared to the formulations containing Gelucire® 44/14. Conclusions: The characterization strategies used in the development of this research proved to be efficient for the adequate selection of excipients and their optimal ratio for the effective design of a self-emulsifying drug delivery system (SEDDS).

Introdução: o estradiol é um hormônio esteroide sexual feminino amplamente utilizado como terapia hormonal que apresenta baixa biodisponibilidade devido à sua baixa solubilidade aquosa e alta hidrofobicidade, pertencente à classe II do sistema de classificação biofarmacêutica. Objetivos: projetar e caracterizar um sistema de liberação de drogas autoemulsificante (SEDDS) para o fármaco estradiol por meio de testes físico-químicos a fim de obter a proporção ideal que melhore sua solubilidade aquosa, taxa de dissolução e potencialmente sua biodisponibilidade. Método: estudos de solubilidade em diferentes solventes, diagramas de fases pseudoternários compostos por óleos, tensoativos, cotensoativos e água permitiram reconhecer as diferentes regiões de formação de SEDDS e identificar as porcentagens de excipientes que levam à formação de soluções isotrópicas; as formulações resultantes foram caracterizadas quanto ao tempo de autoemulsificação, robustez à diluição, ponto de turvação e perfil de dissolução da cápsula dura. Resultados: as formulações contendo Capmul MCM®, Kolliphor® RH40 e Transcutol®, tiveram um tempo de autoemulsificação de aproximadamente 1 min; foram estáveis em três diferentes pH's (1,2; 4,5 e 7,2), em diferentes volumes de diluição, apresentando aspecto transparente, levemente azulado, sem precipitados ou separação de fases, pontos de turvação mais elevados em relação às formulações contendo Gelucire® 44/14. Conclusões: as estratégias de caracterização utilizadas no desenvolvimento desta pesquisa mostraram-se eficientes para a seleção adequada de excipientes e sua proporção ideal para o desenho eficaz de um sistema de liberação de fármacos autoemulsificante (SEDDS).

Does Anzer Propolis Have a Protective Effect on Rabbit Spinal Cord Ischemia/Reperfusion Injury?*

Abstract Introduction: In this study, Anzer propolis, which can only be obtained from the Eastern Black Sea region in Turkey, is studied for its effect on spinal cord ischemia/reperfusion injury. Methods: A total of 12 healthy male New Zealand White rabbits with an average weight of 3.0 to 3.5 kg were separated into two blind and randomized groups: the ischemia/reperfusion group (n=6) and the treatment group (n=6). Each rabbit in the treatment group was given a dose of 100 mg/kg of ethanol-dissolved Anzer propolis orally 1 hour before surgery. Blood samples were examined at the 0th hour and postoperatively at the 24th and 48th hours. Tissue samples were taken at the 48th hour during the sacrification. Results: There was a statistically significant difference between the two groups in terms of postoperative Tarlov scoring (P=0.012). There was a difference between the two groups in terms of the blood levels of interleukin-6 (IL-6) and tumor necrosis factor-alpha (TNF-α) at the 48th hour, myeloperoxidase (MPO) at the 24th and 48th hours, ischemia-modified albumin (IMA) at the 24th hour, and intercellular adhesion molecule-1 (ICAM-1) and total oxidant status (TOS) at the 48th hour (P<0.005). There was also a difference between the two groups in terms of apoptotic index data obtained with the terminal deoxynucleotidyl transferase (TdT)‐mediated dUTP nick‐end labelling (TUNEL) method in the histopathological examination (P=0.001). In the transmission electron microscopic (TEM) analysis, while ischemia/reperfusion group generally had axon-myelin separation, axoplasmic dissolution and myelin separation, the propolis treatment group had normal myelin sequencing. Discussion: In our study, after biochemical, histopathological, ultrastructural and neurological functional examination, it was demonstrated that Anzer propolis has sufficient neuroprotective effect on spinal cord ischemia/reperfusion injury in rabbits.

A comparison of the physicochemical properties of AH Plus Jet with samples taken from the beginning, middle and final portions of the automix syringe system

Aim To evaluate physicochemical properties and semi-quantitative elemental analysis of AH Plus Jet with samples from the beginning, middle and final portions of the automix syringe system. Methodology Three experimental groups based on the source of the material used (beginning, middle and final portion) were established for each of the evaluated properties. Setting time, flow and radiopacity were evaluate following ANSI/ADA n. 57 specification. Set specimens was used in the semi-quantitative elemental analysis in an energy-dispersive X ray spectroscopy and scanning-electron microscopy (EDS/SEM). Statistical analysis was performed using one-way ANOVA followed by Tukey test (P<0.05). Results Flow, setting time, solubility and EDS/SEM tests showed no significant differences among the three portions of the automix syringe (P>0.05). Radiopacity test showed significant differences in the beginning of the syringe comparing to the middle and final portions (P<0.05). EDS/SEM analysis identified the presence of C, O, Al, Ca, Zr and W. The element Al, however, was found only in the final portion of the syringe. Conclusions The results of AH Plus Jet suggested an adequate ratio of the components, without segregation between organic and inorganic components, since the results of setting time, flow, solubility and EDS/SEM analysis presented similar values regardless of the portion of the syringe from where the sealer was taken.