Lipid carriers for mRNA delivery

Messenger RNA (mRNA) is the template for protein biosynthesis and is emerging as an essential active molecule to combat various diseases, including viral infection and cancer. Especially, mRNA-based vaccines, as a new type of vaccine, have played a leading role in fighting against the current global pandemic of COVID-19. However, the inherent drawbacks, including large size, negative charge, and instability, hinder its use as a therapeutic agent. Lipid carriers are distinguishable and promising vehicles for mRNA delivery, owning the capacity to encapsulate and deliver negatively charged drugs to the targeted tissues and release cargoes at the desired time. Here, we first summarized the structure and properties of different lipid carriers, such as liposomes, liposome-like nanoparticles, solid lipid nanoparticles, lipid-polymer hybrid nanoparticles, nanoemulsions, exosomes and lipoprotein particles, and their applications in delivering mRNA. Then, the development of lipid-based formulations as vaccine delivery systems was discussed and highlighted. Recent advancements in the mRNA vaccine of COVID-19 were emphasized. Finally, we described our future vision and perspectives in this field.

Formulation optimization of emodin nanostructured lipid carriers by Box-Behnken response surface method and in vitro quality evaluation / 中国中药杂志

Emodin nanostructured lipid carriers(ED-NLC) were prepared and their quality was evaluated in vitro. Based on the results of single-factor experiments, the ED-NLC formulation was optimized by Box-Behnken response surface method with the dosages of emodin, isopropyl myristate and poloxamer 188 as factors and the nanoparticle size, encapsulation efficiency and drug loading as evaluation indexes. Then the evaluation was performed on the morphology, size and in vitro release of the nanoparticles prepared by emulsification-ultrasonic dispersion method in line with the optimal formulation, i.e., 3.27 mg emodin, 148.68 mg isopropyl myristate and 173.48 mg poloxamer 188. Under a transmission electron microscope(TEM), ED-NLC were spherical and their particle size distribution was uniform. The particle size of ED-NLC was(97.02±1.55) nm, the polymer dispersion index 0.21±0.01, the zeta potential(-38.96±0.65) mV, the encapsulation efficiency 90.41%±0.56% and the drug loading 1.55%±0.01%. The results of differential scanning calorimeter(DSC) indicated that emodin may be encapsulated into the nanostructured lipid carriers in molecular or amorphous form. In vitro drug release had obvious characteristics of slow release, which accorded with the first-order drug release equation. The fitting model of Box-Behnken response surface methodology was proved accurate and reliable. The optimal formulation-based ED-NLC featured concentrated particle size distribution and high encapsulation efficiency, which laid a foundation for the follow-up study of ED-NLC in vivo.

Nanostructured lipid carriers as a novel tool to deliver sclareol: physicochemical characterisation and evaluation in human cancer cell lines

Sclareol (SC) is arousing great interest due to its cytostatic and cytotoxic activities in several cancer cell lines. However, its hydrophobicity is a limiting factor for its in vivo administration. One way to solve this problem is through nanoencapsulation. Therefore, solid lipid nanoparticles (SLN-SC) and nanostructured lipid carriers (NLC-SC) loaded with SC were produced and compared regarding their physicochemical properties. NLC-SC showed better SC encapsulation than SLN-SC and was chosen to be compared with free SC in human cancer cell lines (MDA-MB-231 and HCT-116). Free SC had slightly higher cytotoxicity than NLC-SC and produced subdiploid DNA content in both cell lines. On the other hand, NLC-SC led to subdiploid content in MDA-MB-231 cells and G2/M checkpoint arrest in HCT-116 cells. These findings suggest that SC encapsulation in NLC is a way to allow the in vivo administration of SC and might alter its biological properties

Effects of polyethylene glycol length on oral absorption of coumarin 6-loaded nanostructured lipid carrier / 中国药科大学学报

@#Polyethylene glycol (PEG) of different lengths were prepared to investigate their effects on oral absorption of nanostructured lipid carrier (NLCs).Three kinds of PEG-modified NLCs with different chain lengths, including polyethylene glycol (100) monostearate (S100), polyethylene glycol (55) monostearate (S55), polyethylene glycol (40) monostearate (S40), were prepared by film dispersion method.Coumarin 6 was chosen as a fluorescent probe to characterize the physicochemical properties of NLCs with different lengths.Meanwhile, the stability of NLCs in simulate buffer, the release behavior, cytotoxicity of NLCs, the uptake kinetics and cellular uptake mechanisms were evaluated. This work demonstrated that the thickness of the hydrated layer increased with the increase of PEG length. Of note, S100-modified NLCs (pNLC-EG100) exhibited higher cellular uptake efficiency compared with other formulations. Thus, S100 was optimized as the best molecular weight for PEG-modified NLCs on oral drug delivery system.

Intranasal delivery of nanostructured lipid carriers, solid lipid nanoparticles and nanoemulsions: A current overview of

The management of the central nervous system (CNS) disorders is challenging, due to the need of drugs to cross the blood‒brain barrier (BBB) and reach the brain. Among the various strategies that have been studied to circumvent this challenge, the use of the intranasal route to transport drugs from the nose directly to the brain has been showing promising results. In addition, the encapsulation of the drugs in lipid-based nanocarriers, such as solid lipid nanoparticles (SLNs), nanostructured lipid carriers (NLCs) or nanoemulsions (NEs), can improve nose-to-brain transport by increasing the bioavailability and site-specific delivery. This review provides the state-of-the-art of

Formulation, Optimization And Characterization Of Nanostructured Lipid Carrier Of Nitrofurantoin

Nitrofurantoin is effective against many urinary tract pathogens. It acts as bacteriostatic and/or bactericidal by inhibiting DNA-RNA protein& cell wall synthesis. Nanostructured Lipid Carriers (NLCs) of NFT was prepared by Hot Homogenization Process. Glyceryl Monostearate and Miglyol 812 were heated at 80ºC temperature on hot plate. In the melted lipid, drug was added with continuous stirring at high speed homogenization. Formulation NLC12B has % Entrapment efficiency 89.1 ± 0.5, PDI 0.11 ± 0.01 and mean particle size 237 ± 7nm represents narrow particle size distribution. Spherical feature of NLCs with better uniformity without aggregation of Nitrofurantoin loaded NLC was confirmed by TEM. Moreover, efficient miscibility of drug in lipids was confirmed by the absence of intense and characteristic peak of NFT in XRPD. After 6 month storage at 2-8°C there was no significant changes in the PDI as well as mean particle size.

Design, preparation and in vitro characterizations of fluconazole loaded nanostructured lipid carriers

Present study was aimed to prepare and characterize fluconazole loaded nanostructured lipid carriers (FLZ-NLCs) for the treatment of fungal infections. Fungal infections are tremendously widespread and are the often faced dermatological condition worldwide. FLZ-NLCs was prepared by ultrasonication emulsion technique using stearic acid (SA) as solid lipid, castor oil as liquid lipid and tween 20 as a surfactant. The mean diameter of optimized FLZ-NLCs were found to be 359.15 ± 9.83 nm. The drug content and entrapment efficiency of NLCs was found to be 102.97 ± 7.45% and 87 ± 0.59%, respectively. In vitro drug release studies of FLZ-NLCs showed 37.34 ± 2.08% drug release over a period of 72 h. The above studies confirmed the prepared FLZ-NLCs may be useful for the treatment of fungal infections.

Effect of nanostructured lipid carriers (NLCs) in improving stability of essential oils and its application / 中国中药杂志

Essential oils are easy to cause oxidative damage, chemical transformation or polymerization, and have some intrinsic problems, such as instability, low water solubility and low bioavailability, which restrict their application in the fields of product development. Nanostructured lipid carriers(NLCs) can overcome some of the restrictions of other colloidal carriers, such as emulsions, liposomes, polymer nanoparticles and solid lipid nanoparticles. NLC is an efficient and stable delivery system for bioactive substances. With unique lipid properties(mixture of solid and liquid lipid), it can overcome the disadvantages of essential oils and protect them from adverse environments, thus improving the stability, bioavailability and safety of essential oils, and achieve sustained release and controlled release. In EOs-NLCs system, essential oils, as special liquid lipid with biological activities and medicinal properties, can fully play the role of medicine-adjuvant integration by changing the structural characteristics of mixed lipid. Based on the development of nanocarriers system, this paper introduces the composition and structural characteristics of EOs-NLCs, and clarifies how to improve the stability of essential oils based on the effects of NLCs on physical and chemical properties, physical stability and release of active components of essential oils. In addition, it also introduces the application of the system in the fields of pharmaceutical, food, cosmetics and skin care products. This review aims to provide some references for improving the stability of essential oils and their applications by using NLCs.

Preparation，optimization and antibacterial activity of luteolin nanostructured lipid carriers / 中国药科大学学报

@#To prepare and optimize luteolin nanostructured lipid carriers (Lut-NLCs) and investigate their antibacterial activity in vitro. Lut-NLCs were prepared by hot melt emulsification-ultrasonic method. The solid lipid concentration (X1),liquid lipid concentration (X2) and surfactant concentration (X3) were used as independent variables,with the average particle size (Y1) and the encapsulation efficiency (Y2) as the dependent variables. The optimal formulation of Lut-NLCs was obtained through Box-Behnken experiment design. The microstructure of Lut-NLCs was observed by transmission electron microscopy(TEM). The in vitro release characteristics of Lut-NLCs were investigated. Furthermore, the in vitro antibacterial activities of luteolin and Lut-NLCs were compared. The formulation composition of Lut-NLCs was optimized as follows:the concentration of the solid lipid, liquid lipid and surfactant were 13.0 mg/mL,15.0 mg/mL,and 15.0 mg/mL,respectively. Three batches of Lut-NLCs were prepared with an average particle size of (210.4±17.3) nm,and an encapsulation efficiency of (88.4±1.2)%. Lut-NLCs were observed to be spheroidal,with a smooth surface and a uniform particle size distribution by TEM. The drug release profiles of Lut-NLCs showed a bursting release in the early stage and a slow and stable release in the later stage. Moreover, the cumulative release amount of drug reached 95% in 12 hours. The results of antibacterial circle experiment showed that the antibacterial effect of Lut-NLCs on Staphylococcus aureus and Escherichia coli was higher than that of luteolin raw materials. In this study,the formulation of Lut-NLCs prepared by simple preparation process is reasonable,and Lut-NLCs also exhibited the significant in vitro antibacterial activity. It is expected to be an effective way for external application of luteolin.

Design, Optimization And In Vitro Evaluation Of Antifungal Activity Of Nanostructured Lipid Carriers Of Tolnaftate

Objective: The main purpose of this work was to prepare tolnaftate (TOL) loaded nanostructured lipid carriers (NLCs), Evaluate its characteristics and in vitro release study. Methods: Tolnaftate loaded Nanostructured lipid carriers were prepared by the high shear homogenization method using different liquid lipids types (DERMAROL DCO® and DERMAROL CCT®) and concentrations, different concentration ratios of tween80® to span20® and different homogenization speeds. All the formulated nanoparticles were subjected to particle size (PS), zeta potential (ZP), polydispersity index (PI), drug entrapment efficiency (EE), Differential Scanning Calorimetry (DSC), Transmission Electron microscopy (TEM), release kinetics and in vitro release study was determined. Results: The results revealed that NLC dispersions had spherical shapes with an average size between 154.966±1.85 nm and 1078.4±103.02 nm. High entrapment efficiency was obtained with negatively charged zeta potential with PDI value ranging from 0.291±0.02 to 0.985±0.02. The release profiles of all formulations were characterized by a sustained release behavior over 24 h and the release rates increased as the amount of surfactant decreased. The release rate of TOL is expressed following the theoretical model by Higuchi. Conclusion: From this study, It can be concluded that NLCs are a good carrier for tolnaftate delivery

In vivo imaging in tumor-bearing animals and tissue distribution of nanostructured lipid carrier modified by hyaluronic acid loaded with three components in Panax ginseng / 中草药

Objective: Human hepatoma SMMC-7721 cells were transplanted into nude mice to study the tissue distribution of nanostructured lipid carrier modified by hyaluronic acid (HA-OUR-NLC) loaded with three components in Panax ginseng (oleanolic acid, ursolic acid, and ginsenosider Rg3, OUR). Methods: FITC and DiR were used as fluorescent probes to dynamically monitor the HA-OUR-NLC targeted behavior of various tissues and organs through fluorescence endoscopic confocal imaging and in vivo imaging studies. Results: RUE values of oleanolic acid, ursolic acid, and ginsenosider Rg3 in tumors were significantly increased in HA-OUR-NLC group, reaching 2.51 ± 1.23, 2.27 ± 1.43, and 2.77 ± 0.25, respectively, which indicated that nanoparticles modified by hyaluronic acid could enhance drug uptake in tumors. The DiR accumulation in tumors of DiR-HA-OUR-NLC was higher than that of DiR-OUR-NLC by the visualized fluorescence of in vivo imaging. Conclusion: It indicated that nanoparticles modified by hyaluronic acid loaded with three components in P. ginseng can be enriched in the tumor site of liver cancer, which is in line with the expectation and can significantly improve the tumor targeting of the drug delivery system.

Preparation, characterization and pharmacokinetics of dihydromyricetin phospholipids complex loaded by nanostructured lipid carriers / 中草药

Objective: To prepare dihydromyricetin (DMY) phospholipids complex (DMY-PC) and its nanostructured lipid carriers (DMY-PC-NLC), and carry out in vitro and in vivo evaluation. Methods: DMY-PC was prepared by solvent evaporation method. High pressure homogenization method was used to prepare DMY-PC-NLC. Orthogonal test was employed to optimize the ratio of solid/liquid lipid, dose of lipids materials, dose of DMY-PC and the concentration of emulsifier of poloxamer. The lyophilized powder of DMY-PC-NLC was prepared with 5% of mannitol as protective agent. The comparation of in vitro release and pharmacokinetics between DMY-PC and DMY-PC-NLC was also studied. Results: DMY was in an amorphous state in DMY-PC. The results of 1HNMR showed that the structure of DMY was not changed. The optimized prescription of DMY-PC-NLC determined by orthogonal test was as follow: The ratio of solid/liquid lipid was 5:1, dose of lipids materials was 325 mg, dose of DMY-PC was 45 mg and the concentration of emulsifier of poloxamer was 0.9%. The average size, Zeta potential, entrapment efficiency and drug loading of DMY- PC-NLC was (197.25 ± 4.42) nm, (-18.2 ± 2.1) mV, (71.68 ± 1.36)% and (3.94 ± 0.24)%, respectively. The in vitro release model was accord with Weibull model and the equation was lnln(1-Mt/M∞)=0.700 1 lnt-1.954 1 (r = 0.971 4). The relative bioavailability of DMY-PC and DMY-PC-NLC were enhanced to 1.63 and 3.22 times compared to DMY, respectively. Conclusion: Compared with DMY-PC, the absorption was promoted by DMY-PC-NLC in further, and the bioavailability of DMY was enhanced effectively.

Preparation of Small Peptide AEYLR Modified Paclitaxel Nanostructured Lipid Carriers and Evaluation of Its Anti-tumor Effects / 中国药房

OBJECTIVE： To prepare Paclitaxel（PTX）nanostructured lipid carriers （NLC） modified by small peptide alanine-glutamic acid-tyrosine-leucine-arginine （AEYLR）， and to evaluate its anti-tumor effect in vitro and in vivo. METHODS： NLC， PTX-NLC （P-NLC） and AEYLR modified P-NLC （A-P-NLC） were prepared by emulsion evaporation-low temperature solidification curing method. Its appearance， particle size， multi-dispersion index（PDI） and Zeta potential were characterized，encapsulation rate，drug loading and in vitro drug release were detected respectively. Using NCI-H1299 and S180 cells as objects， CCK-8 method was adopted to investigate inhibitory effects of free PTX， P-NLC and A-P-NLC （0.44-44.00 μg/mL， by PTX） to those cells. The half inhibition concentration （IC50） was calculated. Using S180 tumor-bearing mice as model animal， anti-tumor effects of free PTX， P-NLC and A-P-NLC （5 mg/kg， by PTX） were evaluated. RESULTS： P-NLC and A-P-NLC were round-like and dispersed evenly. The particle size， PDI and Zeta potential of A-P-NLC were （43.92±0.76） nm， 0.203±0.034 and （－19.77±1.16） mV， which were all increased to certain extent， compared with P-NLC. The encapsulation efficiency and drug loading of A-P-NLC were （95.71±0.68）％ and（1.97±0.25）％， which were both decreased to certain extent， compared with P-NLC. The cumulative release rate of A-P-NLC was（35.17±2.08）％ within 48 h， showing significant sustained-release effect compared with free PTX； the release of A-P-NLC was slower than P-NLC. Compared with free PTX and P-NLC， inhibitory rates of same concentration of A-P-NLC to NCI-H1299 cells and S180 cells were almost increased significantly， while IC50 values were all decreased significantly. There was no death in S180 tumor-bearing mice treated with A-P-NLC and the general condition was good； the volume of tumors was significantly reduced， the mass of tumors was significantly reduced， and the inhibition rate of tumors was significantly increased （P＜0.05 or P＜0.01）. CONCLUSIONS： A-P-NLC has significantly sustained-release effects； its inhibitory rate to NCI-H1299 cells and S180 cells in vitro， and its inhibitory effects on S180 solid tumor in mice are all better than free PTX and P-NLC， while the toxicity is decreased to certain extent.

Optimization of Preparation Technology of Celastrol Nanostructured Lipid Carrier and Its Characterization / 中国药房

OBJECTIVE： To optimize the preparation technology of Celastrol nanostructured lipid carriers （Cel-NLC）， and to characterize it. METHODS： Cel-NLC was prepared by melt-emulsification ultrasonic method. Based on single factor test， using encapsulation rate of Cel as index， the ratio of liquid lipid （the ratio of total mass）， the amount of compound emulsifier and the dose of main drug were optimized by central composite design-response surface methodology. Validation test was conducted. Zeta potential and particle size of Cel-NLC that prepared by optimal prescription were determined by using granularity and Zeta potential analyzer. The morphology of liposome was observed by TEM. RESULTS： The optimal prescription included that the ratio of liquid lipid was 39％；the amount of compound emulsifier was 196 mg；the dose of main drug was 8 mg. The average encapsulation efficiency of 3 batches of Cel-NLC was 87.22％； average particle size was （41.2±1.1） nm，and average Zeta potential was        （－18.4±0.2） mV （n＝3）. It was spherical under electron microscopy. CONCLUSIONS： The optimized technology is simple， stable and feasible， and it is suitable for the preparation of Cel-NLC.

Preparation of nanostructured lipid carriers for volatile oils from Artemisiae argyi Folium / 中成药

AIM To prepare nanostructured lipid carriers for volatile oils from Artemisiae argyi Folium.METHODS Heated melting-ultrasonic dispersion method was applied to preparing lipid carriers.Taking solid/liquid lipid ratio,amounts of lipid,emulsifier and volatile oils as influencing factors,and average paticle size as an evaluation index,the formulation was optimized by orthogonal test.With cineole,camphor and borneol as indices,GC-MS was adopted in the content determination of volatile oils.RESULTS The optimal formulation was determined to be 5 ∶ 5 for solid/liquid lipid ratio,1％,3％ and 0.5％ for amounts of lipid,emulsifier and volatile oils,respectively.The obtained clear and transparent lipid carriers demonstrated the average particle size of (72.33 ±1.93) nm,PDI of 0.273 ± 0.004 5,and Zeta potential of (-30.59 ± 1.42) mV,whose in vitro release rate was lower than that of raw medicine within 120 h,along with a higher stability under 4 ℃ than that under 25 ℃.The entrapment efficiencies of cineole,camphor and borneol were 87.49％,86.45％ and 92.12％ with the drug loadings of 8.25％,2.00％ and 3.38％,respectively.CONCLUSION It is suggested that nanostructured lipid carriers for volatile oils from Artemisiae argyi Folium should be stored under 4 ℃ with the features of sustainedrelease and stable physicochemical properties.

Preparation of Salinomycin Nanostructured Lipid Carriers and Formulation Optimization / 中国药房

OBJECTIVE: To prepare Salinomycin nanostructured lipid carriers (Sal-NLCs) and optimize its formulation. METHODS: Sal-NLCs was prepared by emulsion evaporation-low temperature solidification method. Using particle size, Zeta potential, encapsulation efficiency and drug loading as evaluation indexes, central composite design-response surface methodology was used to optimize the amount of Sal, the ratio of solid lipid glyceryl bisstearate to liquid lipid glyceryl octanoate in oil phase, ratio of surface active agent polyoxyethylene 35 castor oil (EL) to polyethylene glycol-15-hydroxy stearate (HS 15), the amount of polyoxyethylene (40) stearate (P40). The morphology, particle size, polydispersity index (PDI), Zeta potential, encapsulation efficiency, drug loading and in vitro release mechanism of Sal-NLCs were investigated. RESULTS: The optimal prescription was as follows as Sal 0. 86 mg, glyceryl bisstearate 40.70 mg, glyceryl octanoate 11.30 mg, EL 44.05 mg, HS15 7.95 mg, P40 3.8 mg. Prepared Sal-NLCs was round-like and dispersed evenly. The particle size, PDI, Zeta potential, encapsulation efficiency and drug loading of prepared Sal-NLCs were(81.81 ± 2.60) nm, 0.183 ± 0.042, (-24.9 ± 3.4) mV,(94.35 ± 1.50)％ and (1.47 ±0.04)％ (n=5), respectively.24 h accumulative release rate was (99.81 ± 3.90)％ (n=3).Drug release behavior was in line with Higuchi model, and relative error of particle size, Zeta-potential, encapsulation efficiency and drug loading to predicted value of model were all lower than 4％. CONCLUSIONS: Sal-NLCs with sustained-release effect is prepared successfully according to optimized formulation, and its quality meets the expected standard.

Optimization of prescription and preparation technology of brucine nanostructured lipid carriers / 中草药

Objective To optimize the prescription and preparation technology of brucine nanostructured lipid carriers (B-NLC). Methods The method of "the solvent emulsification ultrasound" was used to prepare B-NLC. The prescription and preparation was optimized using a single factor method combined with central composite design-response surface methodology (CCD-RSM). Results The resultant B-NLC was transparent liquid with light blue opalescence. The optimal conditions were that the dosage of drugs was 1.28 mg, the mass concentration of poloxamer 188 was 1.08%, and the ratio of solid lipid to liquid lipid was 1.45:1. The obtained NLC showed the average particle size of (136.89 ± 4.23) nm with a polydispersity index of 0.289 ± 0.005 and a zeta potential of (-34.46 ± 0.31) mV. The entrapment efficiency was calculated to be (68.98 ± 2.06)%, and the drug loading content was (1.90 ± 0.06)%. Conclusion B-NLC prepared by solvent emulsification ultrasound had a high entrapment efficiency and a narrow particle size distribution. The method was easy and simple and can be used to optimize the prescription and preparation of B-NLC, which provides a foundation for the further in vivo research of brucine.

Preparation and characterization of nanostructured lipid carrier modified by hyaluronic acid loaded with three components in Ginseng Radix / 中草药

Objective To prepare and characterize tri-components nanostructure lipid carrier of Ginseng Radix modified with hyaluronic acid (HA-OUR-NLC). Methods Nanostructured lipid carriers (NLC) was used to wrap mount three difficult soluble active ingredients in Ginseng Radix including oleanolic acid (OA), ursolic acid (UA), and ginsenoside Rg3. Then using hyaluronic acid (HA) as the target factor, NLC was modified by charge-adsorption. The dynamic dialysis method was used to test the release. The cellular uptake and cytotoxicity of HA-OUR-NLC on SMMC-7721 cells were investigated by flow cytometry instrument and MTT assay respectively. Results OUR-NLC was prepared by ultrasonic dispersion of solvent using NLC as carrier material and CTAB as emulsifier, and its appearance was light blue opalescence. Then HA-OUR-NLC was successfully prepared by charge-sorption method with round shape and uniform distribution. In vitro release showed that it had a sustained release effect. Cell uptake experiments showed that HA-OUR-NLC can be taken up by SMMC-7721 cells. MTT assay results showed that HA-OUR-NLC had inhibitory effect on SMMC-7721 cell proliferation. Conclusion HA-OUR-NLC prepared by solvent ultrasonic dispersion not only has good physical and chemical properties, but also has a certain sustained release effect.

Preparation and Quality Evaluation of Rifampicin Nano-structured Lipid Carriers / 中国药房

OBJECTIVE:To prepare rifampicin(RFP)nano-structured lipid carriers(RFP-NLCs)to improve its water-solubili-ty,and evaluate its quality. METHODS:Using liquid-solid lipid materials oleate and glyceryl monostearate as lipid materials,soy lecithin as emulsifier,poloxamer 188 as nonionic surfactant,melting-ultrasonic emulsification was used to prepare RFP-NLCs. Us-ing the comprehensive scores of particle size and encapsulation efficiency as indexes,the amount of lipid materials,proportion of liquid lipid materials,dosage,and mass ratio of soy lecithin-poloxamer 188 as factors,orthogonal test was adopted to optimize the formulation. The morphology,particle size,polydispersity index(PDI),Zeta potential,encapsulation efficiency,drug loading and in vitro release degree of prepared lipid carriers with optimal formulation were evaluated. RESULTS:In the optimal formulation, the amount of lipid materials was 150 mg,proportion of liquid lipid materials was 30%,amount of RFP was 10 mg,and mass ra-tio of soy lecithin-poloxamer 188 was 1:3. Prepared RFP-NLCs had rounded appearance,particle size was (124.07 ± 3.25) nm, PDI was 0.104±0.010,Zeta potential was(-31.07±2.94)mV,encapsulation efficiency was(80.90±2.59)%,and drug loading was(4.81±0.68)%(n=3). Compared with RFP raw materials,in vitro release degree of RFP-NLCs significantly slowed down, and the cumulative release degree within 12 h was 63.2%,which was in line with Weibull equation. CONCLUSIONS:Screened formulation can successfully prepare RFP-NLCs;the prepared RFP-NLCs have small particle size and high encapsulation efficien-cy,and the in vitro drug release shows certain sustained-release characteristics.

Formulation Optimization of Nanostructured Lipid Carriers Loaded with Lornoxicam by Central Compos-ite Design-response Surface Method / 中国药房

OBJECTIVE:To optimize the formulation of nanostructured lipid carriers loaded with lornoxicam (LN-NLC). METHODS:Emulsification-solvent evaporation method was used to prepare the LN-NLC. Using drug-lipid ratio,dosage of soy lec-ithin,liquid-lipid ratio (proportion of liquid lipid to total lipid) and dosage of emulsifier as factors,the overall normalized value was calculated by particle size,Zeta potential and entrapment efficiency as indexes was used as comprehensive index. Central com-posite design-response surface method was used to optimize the formulation and investigate the appearance and stability of prepared LN-NLC. RESULTS:The optimal formulation were as follows as drug-lipid ratio of 1:50,dosage of soy lecithin of 162.5 mg,liq-uid-lipid ratio of 25% and emulsifier dosage of 958.2 mg. The particle size of prepared LN-NLC was(96.9±3.3)nm,Zeta poten-tial was(-16.1±0.3)mV,entrapment efficiency was(60.1±0.9)%(n=3),which showed relative error of 2.47%,-4.55%,-0.17%with predicted value,respectively. The prepared LN-NLC was spherical. It had no obvious changes in particle size and Ze-ta potential in sealed storage for 30 d in 4 ℃,and the entrapment efficiency only declined 1.2%. CONCLUSIONS:The LN-NLC formulation is successfully optimized,and the LN-NLC has good stability.