Optimization of preparation technology and in vitro release of baicalin-glycyrrhizic acid solid nanocrystals / 中国药房

OBJECTIVE To optimize the preparation technology of baicalin （BCN）-glycyrrhizic acid （GA） solid nanocrystals （BCN-GA-SN）， to characterize them and investigate their in vitro release characteristics. METHODS According to the compatibility ratio of classic couplet medicinals “Scutellaria baicalensis-Glycyrrhiza uralensis”， the compatibility ratio of BCN and GA was determined as 6∶1 （m/m）； BCN-GA nanosuspension was prepared by precipitation method combined with high-pressure homogenization method. The preparation technology of BCN-GA nanosuspension was optimized by using mean particle size and polydispersity index （PDI） as indexes and with types and dosage of stabilizers， stirring speed and time， high-pressure homogenization pressure and frequency as factors. The freeze-dried consolidation process of BCN-GA nanosuspension was optimized to prepare BCN-GA-SN using average particle size， PDI and redispersibility index （RDI） as indicators， with the type and dosage of freeze-dried protective agents as factors； then， the physicochemical properties and in vitro release of BCN-GA-SN were investigated. RESULTS The optimal preparation technology of BCN-GA-SN was as follows： BCN-GA nanosuspension was prepared by using 15% sodium dodecyl sulfate as a stabilizer， stirring at 1 000 r/min for 15 minutes， and homogenizing at 100 MPa for 20 times； then， BCN-GA nanosuspension was freeze-dried and solidified with 5% mannitol （corresponding to the dosage of BCN）. The average particle size of prepared BCN-GA-SN was （442.2±5.7） nm with PDI of 0.225±0.015 and RDI of 1.055± 0.013. The prepared BCN-GA-SN presented as the irregularly spherical shape with more uniform size； the drug-loading amount of BCN in the nanocrystal was （62.5±0.7）%， and that of GA was （9.4±0.2）%； the in vitro release results showed that the cumulative dissolution of BCN-GA-SN was higher than that of the physical mixture of BCN and GA. CONCLUSIONS BCN-GA-SN is prepared successfully in this study with uniform particle size and even distribution， which can effectively improve the dissolution of BCN.

Efavirenz dissolution enhancement V - A combined top down/bottom up approach on nanocrystals formulation

Abstract Efavirenz is one of the most commonly used drugs in HIV therapy. However the low water solubility tends to result in low bioavailability. Drug nanocrystals, should enhance the dissolution and consequently bioavailability. The aim of the present study was to obtain EFV nanocrystals prepared by an antisolvent technique and to further observe possible effect, on the resulting material, due to altering crystallization parameters. A solution containing EFV and a suitable solvent was added to an aqueous solution of particle stabilizers, under high shear agitation. Experimental conditions such as solvent/antisolvent ratio; drug load; solvent supersaturation; change of stabilizer; addition of milling step and solvents of different polarities were evaluated. Suspensions were characterized by particle size and zeta potential. After freeze- dried and the resulting powder was characterized by PXRD, infrared spectroscopy and SEM. Also dissolution profiles were obtained. Many alterations were not effective for enhancing EFV dissolution; some changes did not even produced nanosuspensions while other generated a different solid phase from the polymorph of raw material. Nevertheless reducing EFV load produced enhancement on dissolution profile. The most important modification was adding a milling step after precipitation. The resulting suspension was more uniform and the powder presented grater enhancement of dissolution efficacy.

Nanocristais de besifloxacino para o tratamento de conjuntivite bacteriana: preparação, caracterização físico-química e toxicidade / Besifloxacin nanocrystals for treating bacterial conjunctivitis: preparation, physicochemical characterization, and toxicity

A conjuntivite bacteriana tem significante impacto na Saúde Pública. Essa infecção representa mais de um terço das doenças oculares relatadas em âmbito global. É uma doença altamente contagiosa causada por variedade de bactérias aeróbias e anaeróbias. Diferentes antibióticos empregados no tratamento dessa doença têm apresentado elevada incidência de resistência bacteriana. Dentre os antibióticos de última geração, destaca-se o besifloxacino, antibiótico de quarta geração da classe das fluoroquinolonas, indicado exclusivamente para uso oftálmico tópico. Entretanto, esse fármaco possui baixa solubilidade em água, diminuindo sua biodisponibilidade. Tendo em vista superar esse desafio, foi proposta abordagem nanotecnológica para o desenvolvimento de nanocristais desse fármaco. A preparação de nanocristais de besifloxacino empregando moagem via úmida em escala reduzida foi promissora empregando tensoativo Povacoat®. O Diâmetro hidrodinâmico médio (DHM) da partícula foi de aproximadamente 550 nm, com índice de polidispersão (IP) menor que 0,2. Esse resultado permitiu aumentar a solubilidade de saturação em aproximadamente duas vezes em relação a matéria-prima, possibilitando aumentar a velocidade de dissolução desse fármaco e melhorar sua biodisponibilidade e segurança. Além disso, foi validado o método para quantificação do besifloxacino por CLAE, apresentando especificidade, linearidade no intervalo de 20 a 80µg/mL (r= 0,9996), precisão por repetibilidade (DPR= 1,20%, 0,84% e 0,39%), precisão intermediária (DPR= 0,94%) e exatidão 99,03%. Estudo de estabilidade acelerado (90 dias) na condição 40°C±2°C/75%UR±5%UR e estudo de estabilidade de acompanhamento (150 dias) na condição: 25°C ± 2°C / 60% UR ± 5% UR evidenciaram a estabilidade do teor no período avaliado. Ainda, a nanossuspensão de besifloxacino 0,6% m/m (nanocristais) na dose máxima (500 mg/kg) e o estabilizante Povacoat® (750 mg/kg) não apresentaram toxicidade em larvas de G. mellonella. A concentração inibitória mínima (CIM) para a formulação inovadora foi de 0,0960 µg/mL e 1,60 µg/mL frente a Staphylococcus aureus e Pseudomonas aeruginosa, respectivamente, confirmando eficácia in vitro

Bacterial conjunctivitis greatly impacts the population's health, presenting more than a third of eye diseases reported worldwide. It is an infection caused by various aerobic and anaerobic bacteria and is highly contagious. Therefore, it presents a high incidence of bacterial resistance to the antibiotics commonly used for treatment. Among the most recent antibiotics, besifloxacin is a fourth-generation fluoroquinolone antibiotic indicated exclusively for topical ophthalmic use. Due to its importance in treating bacterial conjunctivitis and its low solubility in the water, a nanotechnological approach was proposed to develop besifloxacin nanocrystals. The preparation of besifloxacin nanocrystals using small-scale wet milling was promising using Povacoat® surfactant. The particle's average hydrodynamic diameter (DHM) was approximately 550 nm, with a polydispersity index (IP) of less than 0.2. This result increased the saturation solubility approximately two times concerning the raw material, making it possible to increase the dissolution rate of this drug and improve its bioavailability and safety. In addition, the method for quantification of besifloxacin by HPLC was validated, presenting specificity, linearity in the range of 20 to 80µg/mL (r= 0.9996), precision by repeatability (DPR= 1.20%, 0.84% and 0.39%), intermediate precision (DPR= 0.94%) and accuracy 99.03%. Accelerated stability study (90 days) at 40°C±2°C/75%RH±5%RH condition and follow-up stability study (150 days) at 25°C ± 2°C / 60% RH ± condition 5% RH showed the stability of content in the evaluated period. Furthermore, the 0.6% besifloxacin nanosuspension (nanocrystals) at the maximum dose (500 mg/kg) and the Povacoat® stabilizer (750 mg/kg) did not show toxicity in G. mellonella larvae. The minimum inhibitory concentration (MIC) to innovative formulation was 0.0960 µg/mL and e 1.60 µg/mL against Staphylococcus aureus and Pseudomonas aeruginosa, respectively, confirming in vitro efficacy

Effect of particle size on the oral absorption of isoliquiritigenin nanocrystals

Abstract As one of the most promising formulations for poorly water-soluble drugs, nanocrystals have been attracting increasing attention in recent years. Isoliquiritigenin (ISL) is a flavonoid with a chalcone structure, and possesses many biological activities. However, its clinical application is significantly limited mainly due to its low oral bioavailability caused by poor hydrophilicity. To address this, ISL nanocrystals were developed in this study to improve its oral bioavailability. Three types of nanocrystals with differing particle size; R1, R2, and R3, were prepared by anti- solvent precipitation or anti-solvent precipitation combined with sonication, which was optimized by single-factor experiments. These nanocrystals were characterized based on their physical properties, in vitro release, and in vivo absorption performance. The mean particle size of R1, R2, and R3 was 555.7, 271.0, and 46.2, respectively. The dissolution ratio of ISL in the nanocrystals was significantly improved, with the quickest rate recorded in R2. Peak concentration and area under the concentration-time curve of R2 after oral administration in rats was 5.83- and 2.72-fold higher than that of the ISL solution, respectively. These findings indicate that the dissolution and absorption of ISL can be significantly enhanced by nanocrystals, and the dissolution behavior and pharmacokinetic properties of nanocrystals is significantly influenced by particle size.

Preparation and in vitro release of quercetin nanocrystals self-stabilized Pickering emulsion / 中国中药杂志

A new quercetin nanocrystals self-stabilized Pickering emulsion(QT-NSSPE) was prepared by high-pressure homogenization combined with probe ultrasonic method. The influences of oil fraction, quercetin(QT) concentration, and pH of water phase on the formation of QT-NSSPE were investigated. On this basis, the QT-NSSPE prepared under optimal conditions was evaluated in terms of microstructure, stability, and in vitro release and the droplet size and drug loading were 15.82 μm and 4.87 mg·mL~(-1), respectively. The shell structure formed by quercetin nanocrystals(QT-NC) on the emulsion droplet surface was observed under a scanning electron microscope(SEM). X-ray diffraction(XRD) showed that the crystallinity of adsorbed QT-NC decreased significantly as compared with the raw QT. There were not significant changes of QT-NSSPE properties after 30 days of storage at room temperature. The in vitro release experiment confirmed that QT-NSSPE has a higher accumulative release rate than the raw QT. All these results indicated that QT-NSSPE has a great stability and a satisfactory in vitro release behavior, which is a promising new oral delivery system for QT.

Study on oral absorption mechanisms of puerarin in nanocrystals self-stabilized pickering emulsion / 中国中药杂志

Nanocrystals self-stabilized Pickering emulsion(NSSPE) is a new kind of emulsion where only nanocrystals of poorly soluble drugs are used as stabilizers. Our previous study showed that NSSPE with Ligusticum chuanxiong oil as the main oil phase can significantly promote oral absorption of puerarin. The present study aimed to explore its absorption mechanism in oral administration. The in vitro dissolution test was carried out to study the effect of NSSPE on release of puerarin. The effects and mechanism of NSSPE on uptake and transport of puerarin across Caco-2 cell were investigated. The results showed that the drug release rate of NSSPE was similar to that of nanocrystals, with their cumulative dissolution of puerarin not affected by pH of releasing mediums, both significantly higher than that of crude material. The uptake of puerarin in NSSPE was concentration-dependent and significantly higher than that of solution or surfactant stabilized emulsion. Genistein and indomethacin, inhibitors of lipid rafts/caveolin, could significantly reduce the uptake of puerarin in NSSPE. Compared with solution, NSSPE and surfactants stabilized emulsion obviously increased transport rate K_a and apparent permeability coefficient P_(app) of puerarin in AP → BL direction, but there was no significant difference in BL → AP direction. It could be inferred that there were both passive and active transport mechanisms, as well as lipid raft/caveolin mediated endocytosis for absorption of NSSPE. The promoted oral absorption of puerarin in NSSPE was mainly related to the existing nanocrystal form which could promote dissolution, puerarin as well as Ligusticum chuanxiong oil which could promote drug transmembrane transport and inhibit drug efflux. It is the unique structure and composition of the compound NSSPE that promoted the oral absorption of puerarin.

The contribution of absorption of integral nanocrystals to enhancement of oral bioavailability of quercetin

In this study, self-discriminating hybrid nanocrystals was utilized to explore the biological fate of quercetin hybrid nanocrystals (QT-HNCs) with diameter around 280 nm (QT-HNCs-280) and 550 nm (QT-HNCs-550) following oral and intravenous administration and the contribution of integral nanocrystals to oral bioavailability enhancement of QT was estimated by comparing the absolute exposure of integral QT-HNCs and total QT in the liver. Results showed that QT-HNCs could reside

Advances in tumor targeted nanocrystals / 中国药科大学学报

@#Nanocrystals are nanoscale (1-1000 nm) dispersion systems in which small numbers of surfactants or polymers are used as stabilizers to disperse insoluble drug particles in water or oil. Nanocrystals enjoy not only high drug content, but also a simple and mature preparation process. At present, 24 nanocrystals products that have been marketed mainly focus on enhancing the solubility and bioavailability of poorly soluble drugs. And recent years have witnessed an increasing number of research reports on target drug delivery of nanocrystals through particle size control and surface modification. This paper mainly introduces three targeting strategies for prolonging the in vivo circulation time of nanocrystals, increasing the affinity for tumor cells and achieving the response to internal and external stimuli, and discusses the current challenges in the application of nanocrystal technology to targeted anti-tumor drugs.

Preparation and Quality Evaluation of Breviscapine Nanocrystals / 中国药房

OBJECTIVE：To prepare Brevisc apine（BRE） nanocrystals，and to evaluate its quality. METHODS ：BRE nanocrystal suspensions were prepared by media milling method. The diameter and amount of grinding beads ，grinding time ，type and ratio of stabilizer ，BRE ratio were investigated to screen the optimal technology and formulation with particle size and polydispersity index （PDI） as evaluation indexes. Using morphology ，color，particle size and PDI of BRE nanocrystals as evaluation index ，different lyoprotectants （50％ mannitol，5％ glucose，5％ lactose）and without lyoprotectant were investigated to screen the optimal lyoprotectant. Particle size analyzer ，scanning electron microscope （SEM），X-Ray diffraction （XRPD）， differential scanning calorimeter （DSC）were used to evaluate the quality of BRE nanocrystals which was prepared with the optimal technology and formulation. RESULTS ：The optimal technology and formulation of BRE nanocrystals included that particle size of 0.6 mm zirconia beads with the amount of 450 g，grinding time of 1 h，stabilizer of 15％ Tween-80，BRE ratio of 25％，without lyoprotectant. Prepared BRE nanocrystals were yellow powder with loose texture and uniform color. The average particle size of BRE nanocrystals was （283.10±3.08）nm，average PDI was （0.212±0.021）and average Zeta potential was （－38.48±0.39）mV. BRE nanocrystals were rod-like crystals ，uniform in distribution and had no change in crystalline state. Accumulative dissolution of BRE nanocrystals were （90.37±1.22）％ within 20 min. Under the condition of （40±2）℃ temperature and （75±5）％ relative humidity，BRE nanocrystals remained stable after being kept away from light for 3 months. CONCLUSIONS ：Established preparation method of BRE nanocrystals is simple and feasible. Prepared BRE nanocrystals show good stablility and dissolution.

Immunophenotyping, plasticity tests and nanotagging of stem cells derived from adipose tissue of wild rodent agouti (Dasyprocta prymnolopha) / Imunofenotipagem, testes de plasticidade e marcação com nanocristais de céluas-tronco derivadas de tecido adiposo em cutias

There is a growing interest in the study of unspecialized mesenchymal stem cells, for there are still some discussions about their in vitro behavior. Regenerative medicine is a science undergoing improvement which develops treatments as cell therapy using somatic stem cells. In several studies, adipose tissue is presented as a source of multipotent adult cells that has several advantages over other tissue sources. This study aimed to characterize and evaluate the tagging of mesenchymal stem cells from the agoutis adipose tissue (Dasyprocta prymonolopha), with fluorescent intracytoplasmic nanocrystals. Fibroblast cells were observed, plastic adherent, with extended self-renewal, ability to form colonies, multipotency by differentiation into three lineages, population CD90 + and CD45 - expression, which issued high red fluorescence after the tagging with fluorescent nanocrystals by different paths and cryopreserved for future use. It is possible to conclude that mesenchymal stem cells from agouti adipose tissue have biological characteristics and in vitro behavior that demonstrate its potential for use in clinical tests.(AU)

Há um interesse crescente no estudo das células estaminais mesenquimais, não especializadas, pois ainda existem algumas discussões sobre seu comportamento in vitro. A medicina regenerativa é uma ciência em fase de crescimento que desenvolve tratamentos como terapia celular utilizando células estaminais somáticas. Em vários estudos, o tecido adiposo é apresentado como uma fonte de células adultas multipotentes que tem várias vantagens em relação a outras fontes de tecido. Este estudo teve como objetivo caracterizar e avaliar a marcação de células estaminais mesenquimais do tecido adiposo de cutias (Dasyprocta prymnolopha) com nanocristais intracitoplasmáticos fluorescentes. Observaram-se células fibroblásticas, aderentes ao plástico, com autorrenovação prolongada, capacidade de formar colônias, diferenciação em três linhagens, população CD90 + e expressão CD45, que emitiram alta fluorescência vermelha após a marcação com nanocristais fluorescentes por diferentes vias, e criopreservadas para uso futuro. É possível concluir que as células estaminais mesenquimais do tecido adiposo de cutias têm características biológicas e comportamentos in vitro que demonstram seu potencial para uso em testes clínicos.(AU)

Formulation

Nitrofurantoin is a broad-spectrum bactericidal antibiotic that affects both Gramnegative and Gram-positive bacteria. Nitrofurantoin exhibits bacteriostatic or bactericidaleffects by inhibiting the synthesis of DNA, RNA, protein and cell wall synthesis. Nanocrystals ofNFT were prepared by Cold High Pressure Homogenization Technique. NFT was dispersed inaqueous surfactant solution containing Poloxamer 188, PVPK 30 and HPMC E3 undercontinuous stirring. Poloxamer 188 was used as a surfactant for the preparation of the NCsFormulation NC9B3 have mean particle size 231 ± 9nm with Polydispersity index 0.09 ± 0.02which indicates very narrow particle size distribution. % Entrapment efficiency was 98.3± 0.7Slow drug release profile indicates the homogeneous dispersion of NFT in lipid matrix. NCshave crystalline nature with rough surfaces which has been confirmed using SEM analysis.XRPD spectra show the reduction in crystalline behaviour of the drug and the lipid afterformation of the NCs. There was no significant change in the mean particle size andPolydispersity index after 6 month storage at 25°C/60% RH

Development of carrier-free nanocrystals of poorly water-soluble drugs by exploring metastable zone of nucleation

There has been increasing interest in research and development of nanocrystals for the delivery of poorly water-soluble drugs that can be directly produced from solution. Compared with traditional carrier-based or encapsulation designs, drug nanocrystals circumvent possible side-effects due to carrier polymers and poor stability issues associated with encapsulation. The production of carrier-free nanocrystals requires careful control of nucleation and thus a thorough understanding of the relevant solution's metastable zone. A solution may stay supersaturated without forming any nuclei and become metastable. The maximal degree of supersaturation is known as the metastable zone width. When nucleation is triggered directly from the metastable zone, it helps to produce homogeneous nuclei leading to uniform nanocrystals. Herein, we report a study in which the solubility and metastable limit of paclitaxel (PTX) in ethanol aqueous solution were measured at 40 °C. A wide range of metastable compositions were studied to prepare carrier-free PTX nanocrystals with particle size smaller than 250 nm and PDI less than 0.25. Compared with the raw material, dissolution rate of PTX nanocrystals was significantly increased. The study enables production of high-quality drug nanocrystals for treating patients.

Nanocristais de hidroximetilnitrofural: preparação, caracterização fí­sico-quí­mica, avaliação da atividade in vitro antileishmania / Hydroxymethylnitrofurazone nanocrystals: optimization, characterization, leishmanicidal activity evaluation

De acordo com a Organização Mundial de Saúde, existem atualmente 17 doenças tropicais negligenciadas prevalentes em 149 países, afetando aproximadamente um bilhão de pessoas, a nível global. A leishmaniose, problema de saúde prevalente nos países em desenvolvimento, é endêmica em aproximadamente 98 países e territórios, com 350 milhões de pessoas em risco e 12 milhões de casos de infecção no mundo. A transmissão da doença ocorre pela picada de flebotomíneos fêmeas infectadas. Essa doença apresenta três formas principais: leishmaniose cutânea (LC), leishmaniose mucocutânea (LMC) e leishmaniose visceral (LV). Enquanto a leishmaniose cutânea é a forma mais comum da doença, a leishmaniose visceral é a mais grave e pode ser fatal se não for tratada. Em 2016, o Brasil reportou 3.626 e 12.690 casos de LC e LV, respectivamente. O candidato a fármaco hidroximetilnitrofural (NFOH) mostrou atividade contra o parasita da doença de chagas e da leishmaniose. Embora o NFOH seja promissor para o tratamento da leishmaniose, esse possui baixa solubilidade em água. A nanotecnologia tem sido empregada como plataforma para o desenvolvimento de formas farmacêuticas inovadoras com maior eficácia e segurança. A redução do tamanho de partículas em escala nanométrica permite aumentar a biodisponibilidade oral de fármacos pouco solúveis em água. Os nanocristais apresentam vantagens, tais como, o aumento da solubilidade de saturação e da velocidade de dissolução, decorrentes do aumento da área superficial da partícula. Além disso, esses apresentam maior adesividade às membranas biológicas, membrana celular e superfície do trato gastrointestinal. No presente trabalho utilizou-se a moagem por via úmida em escala reduzida para a obtenção dos nanocristais de NFOH. Diferentes tensoativos foram avaliados empregando o método selecionado, os tensoativos poloxamer 188 e poloxamer 407 foram os que favoreceram a redução do tamanho das partículas. Tal característica foi observada na caracterização físico-química das nanosuspensões de NFOH. A utilização desse método permitiu a obtenção de nanocristais de NFOH, com diâmetro hidrodinâmico médio (DHM) de 184,8 ± 0,5 a 325,9 ± 2,2 nm, índice de polidispersão (IP) de 0,21 ± 0,01 a 0,57 ± 0,01 e DHM de 191,3 ± 2,1 a 326,8 ± 4,6 nm e IP de 0,21 ± 0,01 a 0,50 ± 0,01, respectivamente para o poloxamer 188 e 407. O uso de ambos os tensoativos resultaram em distribuição monomodal de tamanho das partículas. As formulações foram obtidas por meio de planejamento fatorial completo e experimentos por superfície de resposta tendo como variáreis independentes as concentrações de NFOH, dos tensoativos e o tempo de moagem. A resposta, DHM, foi determinada utilizando espalhamento de luz dinâmica (DLS). Adicionalmente, as avaliações empregando calorimetria exploratória diferencial (DSC) e difração de raio X (DRX) revelaram que não houve interação entre o fármaco e os excipientes, assim como, não foi observada alteração na estrutura cristalina do NFOH. A microscopia eletrônica de varredura demonstrou a morfologia característica do estado cristalino. Além disso, a preparação liofilizada apresentou instabilidade após armazenamento por três meses a temperatura de 25 e 4 °C

According to the World Health Organization, there are currently 17 neglected tropical diseases prevalent in 149 countries, affecting approximately one billion people globally. Leishmaniasis, a health problem prevalent in developing countries, is endemic in approximately 98 countries and territories, with 350 million people at risk and 12 million cases of infection worldwide. The transmission of the disease occurs by the bite of infected female sandflies. This disease has three main forms: cutaneous leishmaniasis (CL), mucocutaneous leishmaniasis (MCL) and visceral leishmaniasis (VL). While cutaneous leishmaniasis is the most usual form of the disease, visceral leishmaniasis is the most serious and can be fatal if left untreated. In 2016, Brazil reported 3.626 and 12.690 cases of LC and LV, respectively. The drug candidate for hydroxymethylnitrofurazone (NFOH) showed activity against the parasite of chagas disease and leishmaniasis. Although NFOH is promising for the treatment of leishmaniasis, it has low solubility in water. Nanotechnology has been used as a platform for the development of innovative pharmaceutical forms with greater effectiveness and safety. Particle size reduction on the nanoscale enables the oral bioavailability of poorly water-soluble drugs to be increased. Nanotechnology has been used as a platform for the development of innovative pharmaceutical forms, improving effectiveness and safety. Particle size reduction on the nanoscale enables the oral bioavailability of poorly water-soluble drugs to be increased. Nanocrystals have advantages such as increased saturation solubility and dissolution rate due to the increase in the surface area of the particle. In addition, this present greater adhesiveness to the biological membranes, cell membrane and surface of the gastrointestinal tract. In the present work, wet scale milling was used to obtain NFOH nanocrystals. Different surfactants were evaluated using the selected method, poloxamer 188 and poloxamer 407 surfactants favored the reduction of particle size. This characteristic was observed in the physical-chemical characterization of NFOH nanosuspensions. The use of NFOH nanocrystals with a mean hydrodynamic diameter (DHM) of 184.8 ± 0.5 to 325.9 ± 2.2 nm, polydispersity index (IP) of 0.21 ± 0, 01 to 0.57 ± 0.01 for poloxamer 188 and DHM of 191.3 ± 2.1 at 326.8 ± 4.6 nm and IP of 0.21 ± 0.01 at 0.50 ± 0.01 for poloxamer 407, both with monomodal size distribution. The formulations were obtained by means of complete factorial planning and surface response experiments having as independent variables the concentrations of NFOH, surfactants and milling time. The response, DHM, was determined using dynamic light scattering (DLS). In addition, evaluations using differential scanning calorimetry (DSC) and X-ray diffraction (DRX) revealed that there was no change in the crystal structure of NFOH and interaction between the drug and the excipients. Scanning electron microscopy demonstrated the characteristic morphology of the crystalline state. In addition, the lyophilized preparation was instable after storage for three months at 25 and 4 ° C

Preparation and pharmaceutical characteristics of naringenin nanocrystals / 中草药

Objective: To prepare and investigate the pharmaceutical characteristics of naringenin (NAR) nanocrystals. Methods: NAR nanocrystals were prepared by media milling combined with spray drying method. The mean particle size and polydispersity index (PDI) of NAR nanocrystals were analyzed by Malvern Zetasizer. The morphology of the nanoparticles was observed by scanning electron microscope (SEM). The crystalline state and the chemical structure of NAR before and after nanonization were characterized using X-ray powder diffraction (XRPD), differential scanning calorimetry (DSC), and fourier transform infrared spectrometry (FT-IR). Dissolution rate of NAR before and after nanonization were studied using rotary basket method. Results: The mean particle size of NAR nanocrystals was (400.7 ± 6.9) nm, and PDI value was 0.23. After nanonization, the crystalline state and chemical structure of NAR were not obviously altered, and the solubility was significantly increased (in pH 1.2 hydrochloric acid solution and pH 4.5 phosphate solution, P < 0.05; in pH 6.8 phosphate solution and water, P < 0.01). The dissolution was obviously improved, T50 and Td were visibly decreased (P < 0.01). Conclusion: The optimized process is stable and feasible for the preparation of NAR nanocrystals. NAR nanocrystals have a tiny and uniform particle size. After nanonization, NAR was still crystalline, the solubility and the dissolution were significantly increased, which can provide the basis for the further development of NAR.

Synthesis of tacrolimus nanocrystals and artificial tears surface modification / 国际生物医学工程杂志

Objective To synthesize a dual-function nanodrug with immunosuppression of tacrolimus (FK506) and lubrication of artificial tear carboxymethylcellulose sodium (CMC), and provide a basis for the clinical treatment of dry eye syndrome. Methods The FK506 nanocrystals were prepared by ultrasonic method, and polyallylamine hydrochloride (PAH) and CMC were deposited alternatively on the surface of FK506 nanocrystals using layer-by-layer (LbL) self-assembly technology to prepare the bifunctional nanodrug. The morphology, particle size, surface charge, and composition of the nanodrug were analyzed. Results The particle size of FK506 nanocrystals was uniform, and the FK506-(PAH/CMC)3 was approximately spherical with uneven surface. Zeta potential detection results showed that the charge changed alternatively with the increasing of layer number. The results of laser scanning confocal imaging and infrared spectroscopy showed that PAH and CMC were successfully modified on the surface of FK506 nanocrystals. Conclusion The prepared FK506-(PAH/CMC)3 nanodrug is expected to provide a scientific basis for the combined treatment of dry eye.

Injected nanocrystals for targeted drug delivery

Nanocrystals are pure drug crystals with sizes in the nanometer range. Due to the advantages of high drug loading, platform stability, and ease of scaling-up, nanocrystals have been widely used to deliver poorly water-soluble drugs. Nanocrystals in the blood stream can be recognized and sequestered as exogenous materials by mononuclear phagocytic system (MPS) cells, leading to passive accumulation in MPS-rich organs, such as liver, spleen and lung. Particle size, morphology and surface modification affect the biodistribution of nanocrystals. Ligand conjugation and stimuli-responsive polymers can also be used to target nanocrystals to specific pathogenic sites. In this review, the progress on injected nanocrystals for targeted drug delivery is discussed following a brief introduction to nanocrystal preparation methods, i.e., top-down and bottom-up technologies.

Nanocristais de furosemida: preparação, caracterização físico-química e avaliação in silico de absorção oral e pulmonar / Furosemide nanocrystals: preparation, physical-chemical characterization and in silico evaluation of oral and lung absorption

Segundo a Organização Mundial de Saúde, a hipertensão arterial é responsável por uma crise global de saúde pública, sendo as doenças cardiovasculares implicadas em aproximadamente 17 milhões de mortes/ano, das quais, 9,4 milhões ocasionadas por complicações provocadas pela hipertensão, como edema pulmonar. Quanto ao arsenal terapêutico disponível, a furosemida, potente diurético de alça, é amplamente utilizada em situações de controle e emergência relacionadas à hipertensão e ao edema pulmonar cardiogênico. Apesar do elevado índice de sua prescrição, esse fármaco pertence à classe IV do Sistema de Classificação Biofarmacêutica (SCB), apresentando absorções intestinais erráticas e variáveis. Tais características representam desafio para o desenvolvimento de formas farmacêuticas orais. Assim, adoção de tecnologias inovadoras associadas à via de administração pulmonar pode permitir abordagem terapêutica alternativa, com elevado potencial de aplicação. Entre as tecnologias inovadoras, a obtenção de nanocristais de fármacos classes II e IV tem sido promissora. Nanocristais podem exibir desempenho in vivo superior quando comparados aos seus homólogos, na forma micronizada. Portanto, estratégias que permitam o desenvolvimento de medicamentos contendo furosemida, com maior eficácia e segurança, são de fundamental importância. Nesse sentido, a aplicação de tecnologia in silico, com propriedade preditiva, contribui para a racionalização de ensaios na pesquisa e no desenvolvimento de novas formas farmacêuticas. Objetivou-se, desse modo, a preparação e a caracterização físico-química de nanocristais de furosemida e sua avaliação in silico na absorção oral e pulmonar empregando ferramenta computacional. Os nanocristais foram obtidos por moagem à alta energia, utilizando movimentos simultâneos de revolução/rotação. A determinação da distribuição do tamanho e a morfologia foram realizadas por difração de raios laser e microscopia eletrônica de varredura, respectivamente. As possíveis interações e/ou alterações do estado cristalino do fármaco foram investigadas por calorimetria exploratória diferencial, termogravimetria diferencial, difração de raio X e espectroscopia Raman de baixo deslocamento. Quanto à solubilidade do nanocristal, foram realizados ensaios para a determinação do aumento na solubilidade de equilíbrio e da velocidade dissolução, utilizando os métodos shake flask e velocidade de dissolução intrínseca (VDI), respectivamente. A moagem à alta energia permitiu a obtenção de nanocristais com tamanho médio trinta vezes menor (231nm) do que o tamanho inicial, na escala micrométrica (7,1 µm). Os nanocristais apresentaram estabilidade térmica. Não foram observadas interações entre os excipientes e os nanocristais, que, entretanto, exibiram estrutura cristalina menos definida, o que indica parcial amorfização do nanocristal. A solubilidade de saturação dos nanocristais aumentou aproximadamente três vezes; como consequência, houve aumento na VDI em 2,2 vezes, 1,8 vezes e 3,8 vezes, quando comparado à VDI da furosemida micronizada em meio SGF, tampão 4,5 e SIF, respectivamente. Quanto às avaliações in silico dos nanocristais, sua absorção oral revelou moderada alteração no perfil farmacocinético. Quando foi utilizada a via de administração pulmonar, os nanocristais apresentaram maior desempenho quando comparada a via de administração oral; destacando-se o aumento na Fa% e na Cmáx e a acentuada diminuição no Tmáx. Em conclusão, a plataforma tecnológica obtida tem potencial aplicação no desenvolvimento de formas farmacêuticas inovadoras para administração pulmonar de furosemida

According to the World Health Organization, hypertension is responsible for global public health crisis, being the cardiovascular diseases involved in approximately 17 million deaths a year, of these, 9.4 million occasioned by hypertension complications such as pulmonary edema. Regarding therapeutic arsenal available, Furosemide is a potent loop diuretic widely used in control and emergency situations related to hypertension and cardiogenic pulmonary edema. Despite the high level of prescribing, this drug belongs a class IV drug, according to Biopharmaceutics Classification System (BCS), exposing erratic and variable intestinal absorption. These characteristics represent a challenge for the development of oral dosage forms. Thus, adoption of innovative technologies associated with pulmonary route of administration may allow an alternative therapeutic approach, with high potential for application. Among the new technologies, those for obtaining nanocrystals of classes II and IV drugs have been a promising approach. Nanocrystals can exhibit in vivo higher performance when compared to their counterparts in micronized form. Therefore, strategies to develop medicines containing Furosemide, with greater efficacy and safety, are of critical importance. In this sense, the application of technology in silico, with predictive property, contributes to the rationalization of testing in research and development of new dosage forms. The objectives, as a result, were the preparation and the physicochemical characterization of Furosemide nanocrystals, and it's in silico evaluation on oral and pulmonary absorption using a computational tool. The nanocrystals were obtained using a high-energy milling technology under simultaneous revolution/rotation motion. The determination of the size distribution and morphology was performed using laser diffraction and scanning electron microscopy, respectively. Furthermore, differential scanning calorimetry, differential thermogravimetry, X-ray diffraction and Low Shift Raman spectroscopy were performed to investigate possible interactions and changes in the crystalline state of the nanocrystals. To measure the increase in the equilibrium solubility and dissolution rate, the shake flask and intrinsic dissolution rate (IDR) methods were used respectively. The nanocrystals size appeared thirty times lower (231 nm) compared to the initial size (7,1 µm). The nanocrystals were stable with concern to its thermal characteristic not showing interactions between the excipients and the nanocrystals; however, they exhibited less defined crystal structure, indicating partial amorphization. The nanocrystals saturation solubility increased approximately three times. Consequently, 2.2, 1.8 and 3.8 folds increase were observed in IDR when compared to the Furosemide raw material in SGF, buffer 4.5 and SIF, respectively. The in silico nanocrystal studies revealed moderate changes in its oral absorption and pharmacokinetic profile. When the pulmonary route of administration was used, the nanocrystals showed higher performance compared to oral route administration; highlighting the increase in Fa % and Cmax and a significant decrease in Tmax. In conclusion, the technology platform obtained has potential application in the development of innovative dosage forms for Furosemide pulmonary delivery

Cytotoxicity and pharmacokinetics study of paclitaxel nanocrystals / 国际药学研究杂志

Objective: To investigate the cytotoxicity of paclitaxel nanocrystals on breast cancer cells and the characteristics of pharmacokinetics and tissue distribution in mice. Methods: Precipitation method was used to prepare paclitaxel nanocrystals. Particle size, Zeta potential and particle morphology of nanocrystals were determined by dynamic light scattering and the transmission electron microscopy. MTT assay was performed to evaluate the cytotoxicity of nanocrystals on breast cancer cells. Paclitaxel concentration in vivo was detected by LC-MS/MS. Results: The average particle size of paclitaxel nanocrystals was 194.9 nm and the Zeta potential value was -29.6 mV. There was no significant difference (P >0.05) between paclitaxel nanocrystals and commercial Taxol on the cytotoxicity against MCF-7 cells. The plasma concentration-time profiles of paclitaxel nanocrystals and Taxol in mice were described by a two-compartment model. The t1/2,α were (2.91 ± 0.067) and (3.70 ± 0.063) min, t1/2, β were (69.41 ± 0.73) and (53.94 ± 0.62) min, AUC(0-∞) were (276 700 ± 960) and (464 160 ±710) μg · min/L, CL were (0. 036 ± 0. 011) and (0. 022 ± 0. 010) L/(min · kg), respectively. The drug concentration in liver and spleen was significantly increased for paclitaxel nanocrystals compared with Taxol(P<0.01), but lower in heart and kidneys(P < 0.01). Conclusion: Paclitaxel nanocrystals have the same cytoxicity as Taxol. Paclitaxel nanocrystals, mainly absorbed by the liver and spleen, could rapidly distribute into the surrounding tissue and reduce the toxicity in heart and kidneys, which have clinical significance to decrease the side effects.

Characterization and evaluation in vivo of baicalin-nanocrystals prepared by an ultrasonic-homogenization-fluid bed drying method / 中国天然药物

AIM@#To improve the absorption and bioavailability of baicalin using a nanocrystal (or nanosuspension) drug delivery system.@*METHODS@#A tandem, ultrasonic-homogenization-fluid bed drying technology was applied to prepare baicalin-nanocrystal dried powders, and the physicochemical properties of baicalin-nanocrystals were characterized by scanning electron microscopy, photon correlation spectroscopy, powder X-ray diffraction, physical stability, and solubility experiments. Furthermore, in situ intestine single-pass perfusion experiments and pharmacokinetics in rats were performed to make a comparison between the microcrystals of baicalin and pure baicalin in their absorption properties and bioavailability in vivo.@*RESULTS@#The mean particle size of baicalin-nanocrystals was 236 nm, with a polydispersity index of 0.173, and a zeta potential value of -34.8 mV, which provided a guarantee for the stability of the reconstituted nanosuspension. X-Ray diffraction results indicated that the crystallinity of baicalin was decreased through the ultrasonic-homogenization process. Physical stability experiments showed that the prepared baicalin-nanocrystals were sufficiently stable. It was shown that the solubility of baicalin in the form of nanocrystals, at 495 μg·mL(-1), was much higher than the baicalin-microcrystals and the physical mixture (135 and 86.4 μg·mL(-1), respectively). In situ intestine perfusion experiments demonstrated a clear advantage in the dissolution and absorption characteristics for baicalin-nanocrystals compared to the other formulations. In addition, after oral administration to rats, the particle size decrease from the micron to nanometer range exhibited much higher in vivo bioavailability (with the AUC(0-t) value of 206.96 ± 21.23 and 127.95 ± 14.41 mg·L(-1)·h(-1), respectively).@*CONCLUSION@#The nanocrystal drug delivery system using an ultrasonic-homogenization-fluid bed drying process is able to improve the absorption and in vivo bioavailability of baicalin, compared with pure baicalin coarse powder and micronized baicalin.

Solid State Characterization and Effect of PEG 20000 and Lecithin on Particle Size Reduction and Stability of Complexed Glibenclamide Nanocrystals.

Aims: To formulate and characterize GLB-PEG-LEC NCs (lecithin complexed Glibenclamide nanocrystals) and to analyze the effect of PEG 20000 and lecithin on drug properties, particle size reduction and stability of GLB NCs. Study Design: Precipitated (GLB-PEG) and complexed nanocrystals (GLB-PEG-LEC) of glibenclamide were characterized for particle size, size distribution, zeta potential and stability assessment using photon correlation spectroscopy. The crystallinity was analyzed by X-ray powder diffraction spectroscopy and differential scanning calorimetry. The chemical stability was assessed by means of infrared spectroscopy and surface morphology by scanning electron microscopy. Place and Duration of Study: Asian Institute of Medicine Science and Technology, Malaysia, between May 2102 and June 2013. Methodology: GLB-PEG NCs were prepared by precipitation technique using PEG 20000 and complexed by soybean lecithin. The effect of lecithin in particle size reduction, change in crystallinity, stability and surface properties of NCs were analyzed and compared with pure glibenclamide (GLB) and precipitated NCs. The formulations were optimized and its stability was assessed during a 3 month period. Results: Pure GLB exhibited an average particle size of 1551 nm. The average particle size of precipitated NCs was between 236 - 7000 nm, while that of complexed NCs was between 155 - 842 nm. The particle size of NC was found to decrease, whereas its zeta potential was found to increase after complexation. DSC studies showed no change in crystalline structure. PXRD studies proved that crystallinity was maintained in NCs. SEM analysis showed presence of spherical shape particles with a lipid coat on the surface after complexation. Stability studies revealed no change in particle size during 3 month period. FTIR studies showed the compatability of excipients with the drug. Conclusion: These results show that lecithin complexed GLB NCs could be utilized as promising carriers in development of various formulations due to its high stability and decreased particle size.