Determination of Encapsulation Efficiency of Novel Solid Lipid Nanoparticles Containing Oleic Acid-CAT3 Conjugates by Mini-Column Centrifugation Method / 中国药学杂志

OBJECTIVE: To establish a mini-column centrifugation method to determine the encapsulation efficiency (EE) of novel solid lipid nanoparticles containing oleic acid-CAT3 conjugates (OA-CAT3-SLN) and normal CAT3 SLN (CAT3-SLN). METHODS: Sephadex G-50 mini-columns were used to separate the encapsulated drug and free drug in the solid lipid nanoparticles (SLN) with the help of centrifugation. The boundary point of the elution between the encapsulated drug and free drug was established by the elution curve. The encapsulated drug in the SLN was eluted with 1 mL water for three times. Then 2 mL of ethanol was used to elute the separated free drug for three times. The eluted CAT3 was quantified by the verified HPLC-UV method and used to calculate the EE. The method was verified with the recovery and repeatability test. Finally, the EE of three batches of OA-CAT3-SLN and CAT3-SLN were determined. RESULTS: The mini-column centrifugation method could effectively separate the free drug from the encapsulated drug in SLN. The column recovery was (99.64±1.97)% (n=9), and the result of EE repeatability test of OA-CAT3-SLN was (83.71±0.70)% (n=5). The EE of OA-CAT3-SLN and CAT3-SLN were (86.26±2.65)% and (72.22±4.52)%, respectively (n=3). CONCLUSION: The established separation method is simple and reliable, with high recovery and good repeatability, and can distinguish different preparation processes.

Construction of Matrine Solid Lipid Nanoparticle and Determination of the Entrapment Efficiency / 中国药学杂志

OBJECTIVE: To prepare matrine solid lipoid nanoparticle,establish preparating method and determine the encapshlation efficiency. METHODS: Matrine solid lipoid nanoparticle was prepared by microemulsion-probe ultrasonic method and its quality was evaluated by particle size, Zeta potential, microscopic morphology and in vitro release. The encapsulation efficiency of the carrier was measured by different methods and their effect was compared. RESULTS: The diameter of matrine solid lipoid nanoparticle was (116.7±2.6) nm and its Zeta potential was (-45±1.7)mV. Transmission electron micrographs showed that the solid lipoid nanoparticle was uniform in size and spherical. The in vitro release result suggested the carrier exhibited control release character. Dextran gel microcolumn centrifugation can effectively separate free drugs and carriers, and the measured encapsulation efficiency data has little difference in stability. CONCLUSION: Matrine solid lipoid nanoparticle is successfully prepared and their particle size, Zeta potential and in vitro release quality are evaluated.Dextran gel microcolumn method is effective in the measurement of matrine solid lipoid nanoparticle, providing a reliable reference for the determination of water-soluble drug encapsulation efficiency.

Optimization of Formulation of Econazole Solid Lipid Nanoparticles Based on Pseudo-ternary Phase Diagrams and Central Composite Design-Response Surface Methodology / 中国药学杂志

OBJECTIVE: To optimize the formulation of econazole solid lipid nanoparticles(E-SLN) by combining pseudo-ternary phase diagrams and central composite design-response surface methodology (CCD-RSM). METHODS: Econazole solubility in different solid lipids and the capacity of lipid emulsion were tested. The microemulsion region was obtained by the pseudo-ternary phase diagrams. Then the E-SLN were prepared by microemulsion method. Drug/lipid (X1), lipid/surfactant (X2) and surfactant/cosurfactant (X3) were taken as individual factors, the encapsulation efficiency (Y1), particle size (Y2), Zeta potential (Y3) were taken as the dependent factors. The possible optimum formulation was predicted by CCD-RSM and validated. RESULTS: Econazole could be dissolved in tripalmitic acid glyceride (TAG), monostearic acid glyceride, stearic acid and lauric acid glyceride. TAG had a good capacity of emulsion. The optimized formulation was econazole 0.06 g, glyceryl palmitate 0.48 g, Tween-80 1.194 g, glycerol 0.274 g and added water to 30 mL by CCD-RSM. According to the optimized formulation, the encapsulation efficiency, particle size and Zeta potential were (94.06±1.54)%, (18.88±0.38)nm and (3.53±0.01)mV, respectively. The deviation was less than 5%. CONCLUSION: The stable and ultra-small size E-SLN with high encapsulation efficiency could be obtained by combining pseudo-ternary phase diagrams and CCD-RSM.

Absorption Mechanism of Baicalin and Its Solid Lipid Nanoparticles on Caco-2 Cells / 中国药学杂志

OBJECTIVE: To study the absorption mechanism of baicalin (BA) and baicalin solid lipid nanoparticles (BA SLN) by establishing an in vitro Caco-2 cell model. METHODS: A Caco-2 cell model was established. The appropriate concentration of BA and BA SLN in Caco-2 cell monolayer model was screened by CCK-8 method and LDH method. The content of BA was determined by high performance liquid chromatography, and the effects of time, concentration, temperature and endocytosis inhibitor on the uptake of BA and BA SLN were studied by this model. The transport of BA and BA SLN in the presence or absence of efflux inhibitors was also investigated. The expression of efflux protein was detected by Western blot. RESULTS: At 50-150 μg·mL-1, the uptake of BA and BA SLN was concentration-dependent; at 4 to 37 ℃, the uptake of BA and BA SLN increased with increasing temperature; endocytosis inhibitor influenced the cellular uptake of BA SLN; multidrug resistance-associated protein 2 (MRP2) inhibitors and breast cancer resistance protein (BCRP) inhibitors significantly reduced BA efflux, but did not affect BA SLN efflux; blank SLN and BA SLN can reduce the expression of MRP2 and BCRP in cells. CONCLUSION: BA is taken up and transported by small intestinal epithelial cells in a passive manner, and may be accompanied by energy dependence, which is related to MRP2 and BCRP efflux. BA SLN can significantly increase the uptake of drugs in the Caco-2 cell model, which may be related to the increase of endocytic pathway uptake and inhibition of extracellular repressor expression inhibition drug efflux.

Preparation and Characterization of Syringopicroside Solid Lipid Nanoparticles / 中国药房

OBJECTIVE： To prepare Syringopicroside solid lipid nanoparticles （SYR-SLN）， and optimize the formula and characterize SYR-SLN. METHODS： SYR-SLN were prepared by emulsion evaporation method. Using entrapment efficiency as index， based on single factor， orthogonal design was adopted to optimize the mass ratio of lecithin-monoglyceride， volume ratio of organ phase to water phase， poloxamer 188 （F68） concentration and drug dosage. The optimal formula technology was established to investigate entrapment efficiency， drug-loading amount， morphology， particle size， Zeta potential， stability， etc. RESULTS： The mass ratio of lecithin-monoglyceride was 3 ∶ 1； the volume ratio of organic phase to water phase was 1 ∶ 2； the concentration of F68 was 0.4％； drug dosage was 10 mg. The optimal formula included that monoglyceride 80 mg， lecithin 240 mg， 0.4％ F68， syringopicroside 10 mg， absolute ethyl alcohol 5 mL， distilled water 10 mL， emulsification temperature at 65℃ and stirring at 600 r/min. Encapsulation efficiency of SYR-SLN was （42.35±0.60）％ （n＝3）； drug-loading amount was （5.33±0.03）％ （n＝3）； SYR-SLN had a spherical morphology and was evenly distributed. The average particle size was （180.30±5.31） nm with Zeta potential of （－41.9±0.8） mV， and the SYR-SLN could maintain stable for 15 days at 4℃. CONCLUSIONS： SYR-SLN is prepared successfully， and the technology is simple with high encapsulation efficiency.

Preparation and characterization of non-viral gene delivery systems with pEGFP-C1 Plasmid DNA

ABSTRACT In recent years, non-viral delivery systems for plasmid DNA have become particularly important. They can overcome the disadvantages of viral systems such as insertional mutagenesis and unpredicted immunogenicity. Some additional advantages of non-viral gene delivery systems are; good stability, low cost, targetability, delivery of a high amount of genetic materials. The aim of the study was to develop novel non-viral nanosystems suitable for gene delivery. Two formulations were developed for this purpose: water-in-oil microemulsion (ME) and solid lipid nanoparticles (SLN). The microemulsion was composed of Peceol, Tween 80, Plurol oleique, ethanol and water. The SLN was consisting of Precirol, Esterquat-1 (EQ1), Tween 80, Lecithin, ethanol and water. Characterization studies were carried out by measuring particle size, zeta potential, viscosity and pH. TEM imaging was performed on SLN formulations. Protection against DNase I degradation was examined. Cytotoxicity and transfection efficacy of selected formulations were tested on L929 mouse fibroblast cells. Particle sizes of complexes were below 100 nm and with high positive zeta potential. TEM images revealed that SLNs are spherical. The SLN:DNA complexes have low toxicity and good transfection ability. All results showed that the developed SLN formulations can be considered as suitable non-viral gene delivery systems.

Pharmacokinetics and bioequivalence of evodiamine butyryl derivative-loaded lipid nanoparticles in rats / 中草药

Objective To study the pharmacokinetic characteristics and bioequivalence of evodiamine butyryl derivative (EAB) and evodiamine butyryl derivative-loaded lipid nanoparticles (EABLN) in rats. Methods EABLN were prepared by a film ultrasound method, 16 male SD rats were randomly divided into two groups, and their blood were extracted from eye socket after they were intragastric administrated EAB or EABLN (100 mg/kg) for a given time period. Plasma concentration of EAB was determined by HPLC, then pharmacokinetic data, bioequivalence between EAB and EABLN were analyzed by DAS software. Results The main pharmacokinetic parameters of EABLN were listed, AUC(0-72 h), Cmax, and tmax were (11 535.39 ± 261.08) μg∙h/L, (886.73 ± 15.40) μg/L, and (2.00 ± 0.17) h, respectively. Relative bioavailability of EABLN to EAB was 143%, the bioequivalence of AUC(0-72 h) and Cmax in EAB and EABLN were eligible, but bioequivalence of tmax was not eligible. Conclusion EABLN improved the pharmacokinetics of EAB in rats, meanwhile, oral bioavailability of EAB was significantly increased, and there was not bioequivalence between EABLN and EAB.

Surface modification of PGP for a neutrophil-nanoparticle co-vehicle to enhance the anti-depressant effect of baicalein

Exploiting cells as vehicles combined with nanoparticles combined with therapy has attracted increasing attention in the world recently. Red blood cells, leukocytes and stem cells have been used for tumor immunotherapy, tissue regeneration and inflammatory disorders, and it is known that neutrophils can accumulate in brain lesions in many brain diseases including depression. -Acetyl Pro-Gly-Pro (PGP) peptide shows high specific binding affinity to neutrophils through the CXCR2 receptor. In this study, PGP was used to modify baicalein-loaded solid lipid nanoparticles (PGP-SLNs) to facilitate binding to neutrophils . Brain-targeted delivery to the basolateral amygdala (BLA) was demonstrated by enhanced concentration of baicalein in the BLA. An enhanced anti-depressant effect was observed and The mechanism involved inhibition of apoptosis and a decrease in lactate dehydrogenase release. Behavioral evaluation carried out with rats demonstrated that anti-depression outcomes were achieved. The results indicate that PGP-SLNs decrease immobility time, increase swimming time and climbing time and attenuate locomotion in olfactory-bulbectomized (OB) rats. In conclusion, PGP modification is a strategy for targeting the brain with a cell-nanoparticle delivery system for depression therapy.

Excipient Formula Research of Nicotinate-Curcumin nanoparticles Prepared by Film Ultrasonic Method / 中国药学杂志

OBJECTIVE: To optimize the film-ultrasonic technique for preparing nicotinate-curcumin nanoparticles. METHODS: An HPLC method was established for determination of nicotinate-curcumin. Using the entrapment efficiency of nicotinate-curcumin as the evaluation indicator, the optimum excipient formula was selected through the Box-Bebnken reponse surface design of three factors (amounts of nicotinate-curcumin and lecithin and concentration of tween-80) at three levels. RESULTS: With the established optimal formula, ie 80 mg stearic acid, 150 mg lecithin and 20 mL tween-80 (0.6%), the entrapment efficiency of nicotinate-curcumin approached 65%. The mean particle size was 190 nm. CONCLUSION: The nicotinate-curcumin nanoparticles prepared by the film ultrasonic technique optimized by central composite design test have high entrapment efficiency, indicating that the technique is feasible.

Formulation and Evaluation of Solid Lipid Nanoparticle (SLN) Based Topical Gel of Etoricoxib.

The objective of present investigation was to prepare & evaluate solid lipid nanoparticle (SLN) based topical gel of non- steroidal anti-inflammatory drug (NSAID) etoricoxib for the treatment of arthritis which would attenuate the gastrointestinal related toxicities associated with oral administration. SLN were formulated by melt emulsification and solidification at low temperature method using stearic acid & tween 80. All the formulation were subjected to particle size, particle size distribution, zeta potential, scanning electron microscopy, crystallinity study by DSC and in-vitro release studies. It has been observed that, the high lipid concentration containing formulation have higher entrapment as compare to other two formulation. The SLN- dispersion shows 70.766% entrapment & zeta potential of the formulation were -25.6 which indicates the stability of formulation. The In Vitro drug release rate of gel was evaluated using Modified franz diffusion cell containing dialysis membrane with phosphate buffer pH 7.4 as the receptor medium. The in-vitro release was carried out in comparison with a carbopol gel & hydroxypropylmethylcellulose (HPMC) gel. The permeability parameters steady-state flux (Jss) was significantly increased in SLN-F3C (carbopol) formulation as compared with SLN-F3HPMC (hydroxypropyl methylcellulose) formulation. It was concluded that the Etoricoxib loaded SLN based gel formulation containing carbopol was suitable for topical application and shows much better result of anti-inflammatory activity.

Formulation Optimization of Indomethacin-loading Solid Lipid Nanoparticles by Box-Behnken Response Surface Methodology / 中国药房

OBJECTIVE:To optimize the formulation of indomethacin-loading solid lipid nanoparticle(SLN). METHODS:Us-ing indomethacin as model drug,glyceryl behenate as oil phase,poloxamer 188 and polyethylene glycol-12-hydroxystearic acid as emulsifier,with turbidity,entrapment efficiency and drug loading amount as index,Box-Behnken response surface methodology was used to optimize the amount of oil phase,emulsifier-oil phase ratio,drug-oil phase ratio. The physicochemical properties of SLNs were characterized by SEM and DSC. RESULTS:The optimal formulation was as follows as oil phase of 0.91%,emulsifier-oil ratio of 1∶1,drug-oil phase ratio of 1∶5. The turbidity,entrapment efficiency and drug loading amount of prepared nanoparticle were 1 025-1 030 NTU,98.94%-99.08%,2.43%-2.46%,respectively;particle size and polydispersity index(PDI)were 181.5-182.3 nm and 0.340-0.341(n=3). The results of DSC showed that indomethacin was not present in crystalline state dispersed into SLNs. CONCLUSIONS:The optimal formulation is screened successfully,and indomethacin-loaded SLNs have been prepared.

Quality Evaluation of Solid Lipid Nanoparticle of the Skin Extract of Bufobufo gargarizans / 中国药房

OBJECTIVE:To evaluate the quality of solid lipid nanoparticle of the skin extract of Bufobufo gargarzans. METH-ODS:The morphology of solid lipid nanoparticle of the skin extract of B. gargarzans was observed by TEM. The particle size was determined by laser scattering particle size analyzer. The contents of cinobufagin and resibufogenin, encapsulation efficiency, drug-loading amount and accumulative release rate of cinobufagin were determined by HPLC. The stability of nanoparticle was in-vestigated within 24 h at 60,25 and 4 ℃. RESULTS:The solid lipid nanoparticle of the skin extract of B. gargarzans were uni-form in particle size and showed round and spheroidicity shape;average particle size was(138.5±4.2)nm,The encapsulation effi-ciency of cinobufagin and resibufogenin were 90.60% and 91.51%,and drug-loading amount were 35.82% and 44.15%. The accu-mulative release rate of cinobufagin was 50%at 4 h and reached 88%at 48 h,which was in line with Weibull equation(r=0.9438). Under 3 kinds of temperature conditions,encapsulation efficiency decreased gradually as the holding time of nanoparticle pro-longed;the decrease degree was the smallest at 4 ℃.CONCLUSIONS:The quality evaluation results of solid lipid nanoparticle of the skin extract of B. gargarzans are in line with the standard,and prepared nanoparticles show sustained-release effects and should be kept under low temperature.

Preparation of paclitaxel-loaded PLGA solid lipid nanoparticles in microchannels / 中国药学杂志

OBJECTIVE: To prepare paclitaxel-loaded solid lipid nanoparticles (PTX-SLNs) and evaluate its physicochemical properties, release behavior and antitumor activity in vitro. METHODS: PTX-SLNs were prepared in a rectangular microchannels. The formulation of PTX-SLNs were optimized by the orthogonal design. The particle size distributions was determined by dynamic light scattering(DLS) techniques. The encapsulation efficiency and drug loading content were determined by HPLC. In vitro release behavior and in vitro antitumor activity of the PTX-SLNs were investigated by dialysis and MTT respectively. RESULTS: Transmission electron microscopy (TEM) image showed that the obtained nanoparticles shaped regularly round and dispersed uniformly. The particle size of PTX-SLNs was(129.73 ±2.41) nm, drug loading content and drug encapsulation efficiency were(3.11 ± 1.90)% and(43.67 ± 0.55)% respectively. The in vitro release behavior exhibited that the amount of cumulated paclitaxel released from PTX-SLNs was 87.3% with initial burst release and sustained release in 120 h. In vitro antitumor activity of the PTX-SLNs against human breast cancer MCF-7 indicated that in comparison with paclitaxel solution the minimal inhibitory concentration of paclitaxel-SLNs is remarkably lower. CONCLUSION: PTX-SLNs is easy to prepare in microchannels and its quality is stable. This preparation technique has a very good prospect in the field of pharmaceutics.

Preparation and in vitro release of lyophilized powder of sorafenib solid lipid nanoparticles / 中国药学杂志

OBJECTIVE: To prepare soraienib solid lipid nanoparticles and investigate its physicochemical properties and in vitro release profile. METHODS: Sorafenib solid lipid nanoparticles were prepared by emulsion evaporation-solidification at low temperature. The morphology was examined by transmission electron microscope. The particle size and Zeta potential were determined by laser granularity equipment. The encapsulation efficiency was detected by Sephadex gel chromatography and HPLC. The in vitro release pro-file of sorafenib solid lipid nanoparticles was studied using dialysis technology. The lyophilized powder of sorafenib solid lipid nanoparticles was prepared by refrigerated air dryer and its material phase was analyzed by DSC. RESULTS: The sorafenib solid lipid nanoparticles assumed spherical shape. The distribution of diameter was even with average particle size of (108.2±7.0) nm. The PDI and Zeta potential were (0.250±0.022) and (-16.4±0.7) mV, respectively. The average encapsulation efficiency was (73.49±1.87)%. The release in vitro accorded with Weibull order model. Equal volume of 15% mannitol was the best protective agent for lyophilized powder of sorafenib solid lipid nanoparticles. The formation of a new material phase was testified by analysis of DSC. CONCLUSION: The method of emulsion evaporation-solidification at low temperature was appropriate for preparation of sorafenib solid lipid nanoparticles. The nanoparticles had stable physical properties and significant sustained-release effect.

Preparation of sinomenine hydrochloride nanoparticle thermosensitive gel for intra-articular injection and its characteristic investigation / 中草药

Objective: To prepare the solid lipid nanoparticle (SLN) thermosensitive gel of sinomenine hydrochloride (SH) for intra-articular injection and to investigate its in vitro drug release behavior. Methods: Poloxamer 407 (P-407) and Poloxamer 188 (P-188) were used as gel matrix to prepare the gel, and the gelatinization temperature was applied as a target to optimize the prescription. The SH-SLN was prepared based on the microemulsion technique, and the gel system containing SH-SLN was obtained by cold-dissolving methods. The content of SH was determined by HPLC, in vitro release characteristics of SH-SLN thermosensitive gel were investigated by dialysis method. Results: The optimal gel prescription was finally confirmed as 18% P-407, 5% P-188, and 0.6% HPMC. The gelatination temperature for SH-SLN thermosensitive gel was (34.5 ± 0.2)°C, and the in vitro accumulated release rates of SH in the SLN thermosensitive gel system were (57.79 ± 0.36)% after 24 h and (75.16 ± 0.12)% after 48 h. Conclusion: The SH-SLN thermosensitive gel has the temperature sensitivity and obvious sustained-release effect. The combination of nanoparticle thermosensitive gel will be used as a new drug delivery for intra-articular injection.

Preformulations studies and preperation of dithranol loaded solid lipid nanoparticles.

Dithranol belongs to the keratolytic category, which is widely used drug in the treatment of psoriasis. The drug is practically insoluble in water. Many conventional dosage forms for psoriasis treatment have been have been formulated earlier, but they did not show good results. Hence in the present study, it was attempted to formulate dithranol in the form of solid lipid nanoparticle. Solid lipid nanoparticles of dithranol were obtained by adaption of lipid dispersion method. Preformulation studies were performed to check the compatibility of drug and excepient for the preparation of formulation by DSC and no interaction was found. Solubility study, partition coefficient determination, UV analysis, HPLC study, FTIR study were also performed. After the preformulation studies Dithranol loaded solid lipid nanoparticles was also prepared. Hence it was concluded that solid lipid nanoparticle of dithranol could be formulated.

Formulation and preparation of glycyrrhizic acid solid lipid nanoparticles / 第三军医大学学报

Objective To prepare the glycyrrhizic acid solid lipid nanoparticles(GL-SLN).Methods GL-SLN was prepared by conventional rotary-evaporated film-ultrasonication method.Based on the single-factor experiment,GL-SLN was prepared using orthogonal design for optimization of formulation and technology.The obtained GL-SLN was also evaluated.Results GL-SLN had even and regular appearance and the average diameter was 75.8 nm.Zeta potential was-19.7 mV.The drug loading was 8.27% and the entrapment ratio was 91.76%.Conclusion The entrapment ratio of GL-SLN and the stability of GL-SLN prepared by conventional rotary-evaporated film-ultrasonication method are high and good.

Experimental research on triptolide solid lipid nanoparticle for decreasing liver toxicity of triptolide / 中草药

Object To study the mechanism of triptolide solid lipid nanoparticle (TP-SLN) for decreasing liver toxicity of triptolide (TP). Methods With ig three doses of TP-SLN to mice for 60 d, the A LT, AST activities in serum and superoxide dismutase (SOD), glutathione peroxida se (GSH-Px) activites and malondialdehyde (MDA) contents in liver were determin ed. Results The activities of ALT, AST, SOD, GSH-Px and conten t of MDA between experimental group and blank group did not have remarkable diff e rence. However, the activites of ALT, AST, SOD, GSH-Px for the middle- (20 ?g /kg) and high-dose (30 ?g/kg) group were higher and the contents of MDA were lower than the experimental group. Conclusion TP-SLN can decrease the liver toxicity of TP.

Preparation of solid lipid nanoparticles containing volatile oil of Lignum dalbergia odoriferae / 中成药

AIM: To delevop new drug delivery system for volatile oil of lignum dalbergia odoriferae and to improve its effect. METHODS: Solid-lipid-nanopaticals were prepared by hot-dispersiom technique and treated further by sonication; the contents of dispersion and entrapment efficiency of nanoparticles were determined by HPLC. RESULTS: Solid lipid nanoparticles containing volatile oil of lignum dalbergia odoriferae was spherelike; The partical size was 40.0nm; the content of dispersion was 72.1%; entrapment efficiency of nanoparticles was 91.27%. CONCLUSION: Solid-lipid-nanopatical may be a suitable drug delivery system for volatile oil of lignum dalbergia odoriferae.