Formulation parameters determining the physicochemical characteristics of solid lipid nanoparticles loaded with all-trans retinoic acid

Solid lipid nanoparticles (SLNs) have gained attention as a colloidal drug carrier, particularly for drugs with limited solubility. The poor aqueous solubility of all-trans retinoic acid (ATRA) has been a limiting factor in its clinical use. This study was undertaken to overcome the solubility limitation of ATRA by loading in SLNs. The physicochemical characteristics of ATRA-loaded SLNs were investigated by particle size analysis, zeta potential measurement, thermal analysis and HPLC determination of ATRA content. The mean particle size of ATRA-loaded SLNs could be reduced (1) by mixing EggPC and Tween 80 as a surfactant and (2) by increasing the total surfactant amount. The smallest mean particle size of SLNs was obtained with 50 mg/g surfactant mixture composed of 54:46% (w/w) EggPC:Tween 80 (154.9 nm). The zeta potential of SLNs could be increased by mixing EggPC, Tween 80 and DSPE-PEG in the surfactant mixture. The zeta potential of SLNs prepared with 50 mg/g surfactant mixture composed of 48:6:46% (w/w) of EggPC:DSPE-PEG:Tween 80 was -38.18 mV. ATRA could be loaded at 2.4% (percentage of lipid matrix) on these SLNs without impairing their physical stability. After freeze-drying, the mean particle size and polydispersity index of ATRA-loaded SLNs were only slightly increased (181.8 vs. 265.2 nm, 0.173 vs. 0.200). Furthermore, no significant change was observed in the SLN-loaded concentration of ATRA and the zeta potential of SLNs after freeze-drying. Taken together, SLN formulation of ATRA with similar characteristics to those of parenteral emulsions could be obtained even after freeze-drying.     

Formulation,characterization and evaluation of cyclodextrin-complexed bendamustine-encapsulated PLGA nanospheres for sustained delivery in cancer treatment

PLGA nanospheres are considered to be promising drug carrier in the treatment of cancer. Inclusion complex of bendamustine (BM) with epichlorohydrin beta cyclodextrin polymer was prepared by freeze-drying method. Phase solubility study revealed formation of A_L type complex with stability constant (Ks?=?645?M^?1). This inclusion complex was encapsulated into PLGA nanospheres using solid-in-oil-in-water (S/O/W) technique. The particle size and zeta potential of PLGA nanospheres loaded with cyclodextrin-complexed BM were about 151.4?±?2.53?nm and???31.9?±?(?3.08)?mV. In-vitro release study represented biphasic release pattern with 20% burst effect and sustained slow release. DSC studies indicated that inclusion complex incorporated in PLGA nanospheres was not in a crystalline state but existed in an amorphous or molecular state. The cytotoxicity experiment was studied in Z-138 cells and IC₅₀ value was found to be 4.3?±?0.11?µM. Cell viability studies revealed that the PLGA nanospheres loaded with complex exerts a more pronounced effect on the cancer cells as compared to the free drug. In conclusion, PLGA nanospheres loaded with inclusion complex of BM led to sustained drug delivery. The nanospheres were stable after 3 months of storage conditions with slight change in their particle size, zeta potential and entrapment efficiency.     

Brain targeted solid lipid nanoparticles for brain ischemia: preparation and in vitro characterization

This study aims at formulating solid lipid nanoparticles (SLNs) of Vinpocetine (VIN) to be used as a brain targeted sustained drug-delivery system. VIN is a derivative of vincamine alkaloid, used for chronic cerebral vascular ischemia. However, it suffers from low bioavailability and short half-life. Its oral bioavailability is recorded to be between 7 and 55%. Its elimination half-life is 1–2?h so it would be a good candidate for a sustained drug-delivery system. VIN SLNs were prepared using modified high shear homogenization followed by ultrasonication technique. The effect of incorporating different lipids at different concentrations of various surfactants was investigated. The VIN SLNs were characterized by entrapment efficiency percent (EE%), particle size distribution, zeta-potential, and cumulative released percent after 96?h. The EE% ranged between 83.34% ± 0.95–94.56% ± 0.11 due to the lipophilic character of VIN. The mean particle size measured ranged from 123 nm–464?nm. The cumulative released percent after 96?h ranged from 23.55% to 75.67% showing a controlled release profile. Formula (F32) composed of 5% glyceryl monostearate (GMS) and stabilized by 2% surfactant mixture [Tween 80, Pluronic F 68 (1:1)] was the most appropriate formula for brain delivery having EE% of 89.09% ± 1.49, zero-order release kinetics with cumulative released percent of 72.12% after 96?h, zeta-potential of –11.3?±?0.97 mV. It showed a unimodal size distribution with particle size ≈90?nm and polydispersity index of 0.121. The formula of choice in this study exhibited a zero-order sustained release profile and met the requirement for a brain targeted SLN so it could be a promising formula to deliver VIN to the brain.     

Solid lipid nanoparticles loaded with insulin by sodium cholate-phosphatidylcholine-based mixed micelles: preparation and characterization

Solid lipid nanoparticles (SLNs) loaded with insulin-mixed micelles (Ins-MMs) were prepared by a novel reverse micelle-double emulsion method, in which sodium cholate (SC) and soybean phosphatidylcholine (SPC) were employed to improve the liposolubility of insulin, and the mixture of stearic acid and palmitic acid were employed to prepare insulin loaded solid lipid nanoparticles (Ins-MM-SLNs). Some of the formulation parameters were optimized to obtain high quality nanoparticles. The particle size and zeta potential measured by photon correlation spectroscopy (PCS) were 114.7 ± 4.68 nm and −51.36 ± 2.04 mV, respectively. Nanospheres observed by transmission electron microscopy (TEM) and scanning electron microscopy (SEM) showed extremely spherical shape. The entrapment efficiency (EE%) and drug loading capacity (DL%) determined with high performance liquid chromatogram (HPLC) by modified ultracentrifuge method were 97.78 ± 0.37% and 18.92 ± 0.07%, respectively. Differential scanning calorimetry (DSC) of Ins-MM-SLNs indicated no tendency of recrystallisation. The core-shell drug loading pattern of the SLNs was confirmed by fluorescence spectra and polyacrylamide gel electrophoresis (PAGE) which also proved the integrity of insulin after being incorporated into lipid carrier. The drug release behavior was studied by in situ and externally sink method and the release pattern of drug was found to follow Weibull and Higuchi equations. Results of stability evaluation showed a relatively long-term stability after storage at 4 °C for 6 months. In conclusion, SLNs with small particle size, excellent physical stability, high entrapment efficiency, good loading capacity for protein drug can be produced by this novel reverse micelle-double emulsion method in present study.     

Formulation and characterization of curcuminoids loaded solid lipid nanoparticles

Curcuminoids loaded solid lipid nanoparticles (SLNs) have been successfully developed using a microemulsion technique at approximately 75 degrees C. It was found that variation in the amount of ingredients had profound effects on the curcuminoid loading capacity, the mean particle size, and size distribution. At optimized process conditions, lyophilized curcuminoids loaded SLNs showed spherical particles with a mean particle size of approximately 450nm and a polydispersity index of 0.4. Up to 70% (w/w) curcuminoids incorporation efficacy was achieved. In vitro release studies showed a prolonged release of the curcuminoids from the solid lipid nanoparticles up to 12h following the Higuchi's square root model. After 6-month storage at room temperature in the absence of sunlight, the physical and chemical stabilities of the lyophilized curcuminoids loaded SLNs could be maintained, i.e. the mean particle size and the amount of curcuminoids showed no significant changes (P>0.05) compared to the freshly prepared SLNs. In addition, the chemical stability of curcuminoids incorporated into SLNs was further investigated by dispersing them into a model cream base. The results revealed that after storage in the absence of sunlight for 6 months, the percentages of the remaining curcumin, bisdemethoxycurcumin and demethoxycurcumin were 91, 96 and 88, respectively.     

Are nanostructured lipid carriers (NLCs) better than solid lipid nanoparticles (SLNs): development, characterizations and comparative evaluations of clotrimazole-loaded SLNs and NLCs?

In recent years, solid lipid nanoparticles (SLNs) and nanostructured lipid carriers (NLCs) are among the popular research topics for the delivery of lipophilic drugs. Although SLNs have demonstrated several beneficial properties as drug-carrier, limited drug-loading and expulsion of drug during storage led to the development of NLCs. However, the superiority of NLCs over SLNs has not been fully established yet due to the contradictory results. In this study, SLNs and NLCs were developed using clotrimazole as model drug. Size, polydispersity index (PI), zeta potential (ZP), drug-loading (L), drug encapsulation efficiency (EE), scanning electron microscopy (SEM), differential scanning calorimetry (DSC), X-ray diffractometry (XRD), drug release and stability of SLNs and NLCs were compared. Critical process parameters exhibited significant impact on the nanoparticles' properties. Size, PI, ZP and EE of the developed SLNs and NLCs were<100 nm, <0.17, <-22 mV and>82%, respectively. SEM images of SLNs and NLCs revealed spherical shaped particles (≈ 100 nm). DSC and XRD studies indicated slight difference between SLNs and NLCs as well as disappearance of the crystalline peak(s) of the encapsulated drug. NLCs demonstrated faster drug release than SLNs at low drug-loading, whereas there was no significant difference in drug release from SLNs and NLCs at high drug-loading. However, sustained/prolonged drug release was observed from both formulations. Furthermore, this study suggests that the drug release experiment should be designed considering the final application (topical/oral/parenteral) of the product. Regarding stability, NLCs showed better stability (in terms of size, PI, EE and L) than SLNs at 25°C. Moreover, there was no significant difference in drug release profile of NLCs after 3 months storage in compare to fresh NLCs, while significant change in drug release rate was observed in case of SLNs. Therefore, NLCs have an edge over SLNs.     

美洛昔康纳米脂质载体的制备及表征

目的制备美洛昔康纳米脂质载体(MX-NLC)胶体溶液及冻干粉,并对二者理化性质和体外释放行为进行考察。方法应用高压均质法制备MX-NLC胶体溶液,并对其冷冻干燥。以外观、含量、包封率、粒径、zeta电位、释放度为评价指标,考察MX-NLC胶体溶液及冻干粉的理化性质。结果冻干前后的平均含量质量分数为99.8%和98.5%,平均包封率为73.6%和72.5%;MX-NLC冻干前后的粒径分别为137 nm和154 nm,zeta电位分别为-28.4 mV和-25.2 mV。体外释放结果表明,MX-NLC具有明显的缓释效果。结论通过高压均质法和冷冻干燥技术可以得到美洛昔康纳米脂质载体。所制得MX-NLC粒径在100～200 nm内,具有明显的缓释特征,有可能实现静脉注射给药并具备被动靶向特征。     

单油酸甘油酯/TPGS/壳聚糖脂质纳米粒提高姜黄素稳定性的研究

目的制备载有姜黄素的单油酸甘油酯(GMO)/聚乙二醇1000维生素E琥珀酸酯(TPGS)/壳聚糖(CS)脂质纳米粒,考察该脂质纳米粒在提高药物稳定性方面的潜能。方法采用乳化-高压均质法制备载有姜黄素的GMO/TPGS/CS脂质纳米粒,对该纳米粒进行粒径及分布、zeta电位、微观形态、物理稳定性、UV-Vis光谱学及体外释放动力学等表征。并以姜黄素水溶液为对照,测定该脂质纳米粒在高温、光照、强碱等条件下的稳定性。结果该纳米粒为球形或类球形,平均粒径为(93.8±2.80)nm,多分散系数为(0.156±0.063),zeta电位为+(16.76±1.52)mV;有良好的物理稳定性;UV-Vis光谱显示,姜黄素可能通过疏水作用结合在纳米粒上,这使得药物产生缓释效果,符合Weibull方程。相比姜黄素水溶液,在高温、光照及强碱等强条件下,包封在纳米粒中的姜黄素降解程度显著减小。结论本试验证明了结合使用GMO/TPGS/CS制备姜黄素脂质纳米粒,可显著提高姜黄素的稳定性。     

Long circulating PEGylated PLGA nanoparticles of cytarabine for targeting leukemia

The present investigation was aimed at developing PEGylated PLGA nanoparticles of cytarabine. PLGA Nanoparticles were prepared by modified nanoprecipitation method, optimized for mean particle size (152?±?6?nm) and entrapment efficiency (41.1?±?0.8%) by a 32 factorial design. The PEGylated PLGA nanoparticles of cytarabine had a zeta potential of -7.5?±?1.3?mV and sustained the release of cytarabine for 48?h by Fickian diffusion. The IC?? values for L1210 cells were 6.5, 5.3, and 2.2 μM for cytarabine, cytarabine loaded PLGA nanoparticles and cytarabine loaded PLGA-mPEG nanoparticles respectively. Confocal microscopy and flow cytometry showed that the nanoparticles were internalized by the L1210 cells and not simply bound to their surface. Biodistribution studies showed that the PEGylated nanoparticles of cytarabine were present in significantly higher concentrations in blood circulation as well as in brain and bones and avoided RES uptake as compared to the free drug.     

Re-dispersible cationic solid lipid nanoparticles (SLNs) freeze-dried without cryoprotectors: characterization and ability to bind the pEGFP-plasmid.

Cationic solid lipid nanoparticles (SLNs) have recently been suggested for non-viral gene delivery as a promising alternative to the liposomes. The aim of this study was to investigate the possibility to obtain re-dispersible cationic SLNs after a freeze-drying process in the absence of lyo- and/or cryoprotectors. The physical-chemical characteristics of cationic SLNs and their ability to bind gene material were investigated before and after the freeze-drying. To perform this study three samples of cationic SLNs, based on stearic acid, Compritol or cetylpalmitate, were prepared and characterized by PCS (photon correlation spectroscopy) and AFM (atomic force microscopy). The results indicated that solely the re-dispersed sample of stearic acid (SLN-SA) became very similar in terms of size and morphology to the fresh prepared sample, although it displayed a sensible reduction of the zeta potential (from 39.2 to 23.3 mV). By both the DSC (differential scanning calorimetry) and the ESCA (electron spectroscopy for chemical analysis) determinations, the reduction of the zeta potential was ascribed to the loss of the cationic lipids from the particle surface due to the rearrangement of the stearic acid lattice after the freeze-drying. Finally, the gel electrophoresis analysis demonstrated that SLN-SA re-suspended in PBS are unable to complex the DNA, while the SLN-SA re-dispersed in water displayed the same ability to bind DNA as the fresh prepared sample. We can conclude that cationic SLNs, based on stearic acid, retain the ability to complex DNA even after the freeze-drying in the absence of lyo- or cryoprotectors; thus, the powder form of this sample represents an attractive candidate to be investigated as in vivo DNA vector formulation.     

柠檬苦素固体脂质纳米粒冻干粉的制备及质量评价

目的:制备柠檬苦素固体脂质纳米粒(LM-SLN)及冻干粉,并考察其体外释药性能。方法:采用薄膜超声法制备LM-SLN,以载药量及包封率为指标,借助均匀设计联合Box-Behnken法优化处方;采用Nano ZSE+MPT2粒度检测仪观测形态与粒径;透析法研究冻干粉体外释药行为。结果:处方工艺为柠檬苦素-硬脂酸-卵磷脂-4.5%泊洛沙姆188(10∶30∶35∶10),超声功率300 W,超声时间4 min;以5%甘露醇为冻干保护剂,于-20 ℃预冻12 h,转至-40 ℃以下冷冻干燥22 h。LM-SLN冻干粉呈类球形,结构均匀,包封率为79.38%、载药量为10.88%,平均粒径(182.4±0.2)nm,多分散系数(PDI)为0.290±0.013,Zeta电位为(-14.5±0.1)mV;原药12 h累积释放率为89.31%,LM-SLN冻干粉48 h为85.21%,48 h后释放趋于平缓。结论:LM-SLN处方工艺简单且重复性好,体外释放结果表明,LM-SLN冻干粉具有一定缓释作用。     

Chitosan nanoparticles for controlled delivery of brimonidine tartrate to the ocular membrane

Various efforts have been made to improve the bioavailability and to prolong the residence time of eye drops. Drug loaded polymeric nanoparticles offer several favorable biological properties. Thus, brimonidine tartrate (BT) loaded chitosan (CS) nanoparticles were prepared by inducing the ionic gelation upon addition of sodium tripolyphosphate (TPP). Nanoparticles were characterized by TEM, SEM, particle size, polydispersity index (PI), DSC, IR, entrapment efficiency which gave an insight of physicochemical interaction that influenced the CS nanoparticle formation and entrapment of BT. In vitro release of BT nanoparticle showed sustained release over the period of 4 h in saline phosphate buffer pH 7.4. Both placebo and BT loaded nanoparticles had a mean particle size range of about 270-370 nm with PI less than 0.5. DSC studies demonstrated structural interactions between BT, TPP and CS matrix. Entrapment efficiency of the CS nanoparticles ranged from 36-49% depending on the CS:TPP weight ratio. In vivo studies confirmed a significant sustained effect of BT nanoparticles compared to conventional eye drops. These results suggest that BT loaded CS nanoparticles could help to reduce dosage frequency by sustained drug release in the treatment of glaucoma.     

Effect of lipid on physicochemical properties of solid lipid nanoparticle of paclitaxel

The aim of this study was to compare physicochemical properties of solid lipid nanoparticles (SLN) made from different lipids. To make small, stable, uniform and highly encapsulated SLNs, many factors such as the components (lipid, stabilizer) and preparation condition (sonication time, power) can be considered. Out of those, we selected solid lipid as lipid matrix to investigate an effect on SLNs. The SLNs were characterized by particle size, zeta potential, solubility and in vitro release study. In this study, SLNs showed different physicochemical properties and release profiles according to used solid lipid. In case of particle size, M-SLN showed biggest particle size (412.5?±?29.4?nm) and highest encapsulation efficiency (61.2?±?4.8?%). And, B-SLN showed highest cumulative drug percentage (85.0?±?1.7?%, 24?h) in release study. These results suggest that lipids type affect physicochemical properties and release profile of SLN.     

Sterilization stability of vesicular phospholipid gels loaded with cytarabine for brain implant

The aim of this study was to investigate the sterilization stability of cytarabine (Ara-C) loaded vesicular phospholipid gels (VPGs). VPGs were prepared by high pressure homogenization method intended for the treatment of glioblastoma multiforme (GBM) in brain as injectable implant. The particle size of VPGs after redispersion was 119.6 ± 66.24 nm, and entrapment efficiency (EE) was 32.6 ± 2.1%. Drug release in vitro from VPGs sustained for 80 h with 48.1% initial release within 1h, and rheological studies demonstrated a gel-like behavior. Comparatively, after autoclaved sterilization, increased particle size and EE were obtained as 165.6 ± 71.89 nm and 62.6 ± 2.3%, respectively. Additionally, characteristics of drug release were significantly altered with obviously prolonged release time to 450 h and remarkable reduced initial release to 24.7%. Also, the viscoelasticity was reinforced with clearly decreased fluidity. This result could be explained by the fusion of small vesicles witnessed in TEM observation, which resulted in percentages change of vesicle groups with different size. However, reduced Ara-C and increased lysophosphatidylcholine (LPC) were observed. Among the stabilizers, addition of sodium sulfite showed best effects with high stability of Ara-C and phospholipids. This may be explained by the presence of SO(3)(-), free radicals produced by sodium sulfite. Being an hydroxyl radical scavenger, it can reduce the generation of HO free radicals. These results show that, with addition of appropriate stabilizers, VPGs can be autoclaved with high stability, and it is a promising dosage form for treatment of GBM after injection into resectable or nonresectable neoplasms with sustained release properties.     

Release characteristics of freeze-dried eugenol encapsulated with β-cyclodextrin by molecular inclusion method

The study investigated the thermo-physical properties of eugenol encapsulated with β-cyclodextrin (β-CD) by molecular inclusion and eugenol release characteristics at various relative humidities and storage temperatures. Particle size, Zeta-potential, thermal transition and morphology of β-CD-Eugenol complex after freeze-drying measured using Nanosizer®, differential scanning calorimeter (DSC) and transmission electron microscopy (TEM), respectively. The particle size, Zeta-potential and inclusion efficiency of encapsulated eugenol presented ～340 nm, ?34.5 mV and 91.7% after freeze-drying, respectively. The relationship between retention rate of eugenol and time during release was described by a mathematical model of Avrami equation. In these events, the parameter of release mechanism and the release rate constant were rapidly elevated with increasing relative humidity and storage temperature. Furthermore, the Arrhenius activation energy for the release of eugenol decreases with increasing relative humidity and storage temperature.     

Clinical comparative study of optimized metronidazole loaded lipid nanocarrier vaginal emulgel for management of bacterial vaginosis and its recurrence

The main focus of the current work was to design, evaluate and clinically compare the efficiency of novel metronidazole (MTD) loaded solid lipid nanoparticles (SLNs) vaginal emulgel with the marketed vaginal gel (Metron^®) against Bacterial vaginosis (BV). Eight formulations were fabricated using 2³ full factorial design and prepared by stearic acid and tween 80 as solid lipid and surfactant, respectively. Lipid and surfactant concentrations in addition to sonication amplitude were chosen as the independent variables (X₁–X₃). Then, the prepared MTD loaded SLNs were evaluated based on the dependent variables which were particle size, polydispersity index, zeta potential, entrapment efficiency, and cumulative % drug release for 24 h (Y₁–Y₅). The in vitro release study exhibited a sustained release of MTD from the SLNs up to 24 h. The optimal MTD loaded SLNs showed nanosized particles (256 nm) with EE% (52%), and an acceptable ZP value (−29.5 mV). Also, the optimized MTD-SLNs formulation was incorporated into Carbopol emulgel and investigated clinically for its effect against BV. Clinical studies recorded significant enhancement in therapeutic response of MTD from optimized SLNs vaginal emulgel formulation regarding the clinical treatment (p < .05) and low recurrence rate (p < .001) against the marketed product. In conclusion, our findings recommend that the fabricated MTD loaded SLNs vaginal emulgel have significant therapeutic effect in terms of BV management over commercially obtainable marketed vaginal gel (Metron^®).     

Preparation and characterization of galactosylated bovine serum albumin nanoparticles for liver-targeted delivery of oridonin

In this study, galactosylated bovine serum albumin (GB), which could be developed for a liver targeting carrier was synthetized and it was identified by Fourier transform infrared (FT-IR) spectrometer. Oridonin loaded bovine serum albumin nanoparticle (ORI-BSA-NP) and oridonin loaded GB nanoparticle (ORI-GB-NP) were prepared and optimized by the desolvation technique. During the preparation of ORI-GB-NP, galactosamine was introduced to end-cap the free aldehyde groups on nanoparticles. The characteristics of ORI-GB-NP such as particle size, zeta potential, particle morphologie, entrapment efficiency and drug loading were evaluated. The nearly spherical nanoparticles, with a narrow size distribution below 200 nm, were negatively charged with zeta potential of about −30 mV. Meanwhile, differential scanning calorimetry (DSC) and X-ray diffraction confirmed the amorphous state of ORI in ORI-GB-NP. The in vitro drug release of ORI from ORI-GB-NP presented a biphasic pattern with an initial burst effect and consequently sustained release. These results implied that the nanoparticles possessed fine physicochemical characteristics and seemed to be a stable delivery system for poorly soluble oridonin.     

硫酸阿米卡星多囊脂质体的制备及评价

目的 制备硫酸阿米卡星多囊脂质体(amikacin sulfate multivesicular liposomes, AMK-MVLs),对其进行质量评 价,并考察了其体外抗菌活性。方法 采用复乳法制备AMK-MVLs混悬液Ⅰ,Box-Behnken效应面法优化筛选最佳处方,采 用生理盐水洗涤后调整药物浓度得AMK-MVLs混悬液。采用光学显微镜、激光粒度仪、差示扫描量热(differential scanning calorimeter,DSC)考察制剂的理化性质,采用透析法考察其体外释放规律,通过微量稀释法初步考察其体外抗菌活性。结 果 优化得到AMK-MVLs混悬液Ⅰ的最佳处方为：大豆磷脂与胆固醇质量比为1.91:1,三油酸甘油酯用量为1.02%,PVA用量为 0.62%。AMK-MVLs呈堆叠有无数囊泡的非同心球状,AMK-MVLs混悬液包封率(87.12±1.55)%,平均粒径为11.93 μm。DSC 结果表明,AMK以无定型状态存在于脂质体内。体外释放结果显示AMK-MVLs混悬液在72 h时释药约80%。体外溶血实验表 明,AMK-MVLs脂质体粒子浓度低于400 μg/mL时无溶血风险。体外抗菌实验结果显示,相较于AMK溶液,AMK-MVLs混悬液对E. coli、 P. aeruginosa、S. aureus 3种细菌具有更好的抗菌效果。结论 成功制备了一种硫酸阿米卡星多囊脂质体,其粒径分布均匀、包 封率高,释药规律符合Higuchi动力学模型,具有增强的抗菌活性。     

Solid lipid nanoparticles and nanosuspension formulation of Saquinavir: preparation, characterization, pharmacokinetics and biodistribution studies

Solid lipid nanoparticles (SLNs) and nanosuspensions (NSs) have shown great promise for improving bioavailability of poorly water-soluble drugs. This study was aimed to develop SLNs and NS of Saquinavir (SQ) for improvement in bioavailability. These formulations were characterized and their pharmacokinetics and biodistribution in mice were evaluated. Saquinavir-loaded SLNs (SQSLNs) showed particle size 215?±?9?nm and entrapment efficiency 79.24?±?1.53%, while solid-state studies (differential scanning calorimetry and X-ray diffraction) indicated entrapment of the drug in SLNs. Saquinavir NS (SNS) showed particle size 344?±?16?nm with fourfold increase in saturation solubility and its solid-state studies showed reduction in crystallinity. Pharmacokinetics and biodistribution studies of orally administered SQSLN and SNS in mice exhibited higher plasma level concentration compared to saquinavir microsuspension (SMS). The relative bioavailabilities for SNS and SQSLN were 37.39% and 66.53%, respectively, compared to 18.87% bioavailability obtained after administration of SMS, indicating suitability of nanoparticulate formulations for improving bioavailability.     

Benzothieno[3,2-e][1,2,4]triazolo[4,3-c]pyrimidines: synthesis, characterization, antimicrobial activity, and incorporation into solid lipid nanoparticles

Fused triazolothienopyrimidines were prepared from the corresponding 2-amino-4,5,6,7-tetrahydrobenzo[b]thiophene-3-carbonitrile. These precursors were intern prepared by employing the Gewald's reaction. All the newly synthesized compounds were characterized by spectral and analytical data. Title compounds displayed promising antibacterial and antifungal activities. Compound 3h which exhibited good antimicrobial activity was incorporated into SLN and characterized for particle size, entrapment efficiency (EE%), scanning electron microscopy (SEM), differential scanning calorimetry (DSC) and in-vitro release studies. It showed narrow particle size distribution with high entrapment efficiency. In-vitro release study of compound loaded SLNs in phosphate buffer of pH 7.4, exhibited a biphasic pattern with an initial burst and prolonged release over 24 h.