Development and Characterization of Venetoclax Nanocrystals for Oral Bioavailability Enhancement.

Venetoclax (VX) used in the treatment of chronic lymphocytic leukemia possesses low oral bioavailability (5.4%) and undergoes first-pass metabolism. Development of a formulation to overcome its bioavailability problem can be done by using nanocrystals which has many scientific applications. Nanocrystals of VX were formulated using amalgamation of precipitation and high-pressure homogenization method, in which polyvinyl alcohol (PVA) was selected as stabilizer. Process parameters like concentration of stabilizer, homogenization pressure, number of homogenization cycle, and concentration of lyoprotectant were optimized to obtain the desired particle size for the preparation of nanocrystal formulation. HPLC methods were developed and validated in-house for determination of in vitro dissolution data and in vivo bioavailability data. Physicochemical characterization was done to determine the particle size (zeta sizer), crystalline nature (DSC and XRPD), solubility (shaker bath), and dissolution (USP type 2 apparatus). Lyophilized VX nanocrystals of size less than 350 nm showed substantial increase in saturation solubility (~20 folds) and dissolution in comparison with free VX. In vitro release study revealed that 100% dissolution was achieved in 120 min as compared to VX free base which is having less than 43.5% dissolution in 120 min. Formulations of VX remain stable for 6 months under accelerated stability conditions. In vivo pharmacokinetic data in male Sprague-Dawley rats showed (~2.02 folds) significant increase in oral bioavailability of VX formulation as compared to free drug because of rapid dissolution and absorption which makes the nanocrystal formulation a better approach for oral administration of poorly soluble drugs.

Study on Optimization of Formulation and Technology of Citronellol Submicroemulsion / 中国药房

OBJECTIVE：To optimize the p reparation technology of citronellol submicroemulsion. METHODS ：The content of citronellol in Citronellol submicroemulsion was determined by HPLC. Citronellol submicroemulsion by high-speed shearing dispersion-high pressure homogenization method ，with centrifugation stability constant （ke） and particle size were used as evaluation indexes. Its formulation and preparation technology were optimized and validated. Drug-loading amount and encapsulation rate of the preparation were detected. RESULTS ：The linear range of citronellol were 4-64 μg/mL（R 2＝0.999 9）. RSDs of precision ，stability（24 h）and reproducibility tests were all lower than 3％. The recoveries were 97.64％-101.97％（RSD＝ 2.28％，n＝3），97.71％-99.50％（RSD＝1.29％，n＝3），96.87％-101.48％（RSD＝2.86％，n＝3）. The optimal formulation included that total weight of soybean oil and medium chain triglycerides （1 ∶ 1，g/g）was 3.75 g，1.2％ soybean phospholipid was 0.6 g， cholesterol was 0.06 g，citronellol was 1.25 g，0.6 ％ sodium oleate was 0.3 g，15-hydroxystearic acid polyethylene glycol ester was 0.75 g，poloxamer 188 was 0.75 g，water added to 50 mL. After prepared by optimal technology at 4 ℃ which contained shearing speed of 13 000 r/min，lasting for 5 min， primary emulsion was adjusted to pH 7 with dilute hydro- chloric acid ，and homogenized with 600 Bar high pressure for 1434412440@qq.com 5 min. The parameters of Citronellol submicroemulsion accor- ding to optimal formulation and technology contained mean particle size of （91.05±0.26）nm，PDI of （0.20±0.01）， Zeta-potential of （－30.86±0.39）mV，average content of 649511230@qq.com citronellol（100.21±0.01）％，the drug-loading amount was （2.481 7 ± 0.000 7） mg/mL，the encapsulation rate was （99.27 ± 0.03）％ . CONCLUSIONS ：The optimal formulation and technology is stable and feasible.

Different preparations of magnolol: Preparation, characterization and pharmacokinetics comparative study in SD rats / 中草药

Objective: To prepare magnolol solid dispersions (Mag-SD), magnolol phospholipids complex (Mag-PC) and magnolol solid lipid nanoparticles (Mag-SLN), and compare their effects on the pharmacokinetics in vivo. Methods: Solvent evaporation method was used to prepare Mag-SD and Mag-PC. Their existential state of Mag in Mag-SD and Mag-PC were analyzed by X-ray power diffraction (XRPD). High pressure homogenization method was employed to prepare Mag-SLN, its particle size and Zeta potential were also studied. The dissolution in vitro of Mag-SD, Mag-PC and Mag-SLN were also studied compared to magnolol suspension. SD rats in each group were administered intragastrically with magnolol, Mag-SD, Mag-PC and Mag-SLN, respectively. The concentration of magnolol in blood was analyzed by HPLC, and the main pharmacokinetic parameters were obtained. The pharmacokinetic behavior and bioavailability of magnolol, Mag-SD, Mag-PC and Mag-SLN were also compared. Results: The results of XRPD indicated that magnolol showed an amorphous state in Mag-SD and Mag-PC. The average particle size and Zeta potential of Mag-SLN was (161.37 ± 3.77) nm and (-29.16 ± 1.83) mV, respectively. The results of dissolution in vitro indicated that the cumulative dissolution of magnolol was 30.6% within 12 h. Mag-SD, Mag-PC and Mag-SLN enhanced its cumulative dissolution to 96.3%, 76.4% and 45.9%, respectively. The results of pharmacokinetics in vivo showed that Cmax, AUC0-t and AUC0-∞ of Mag-SD, Mag-PC and Mag-SLN were enhanced greatly compared to magnolol suspension. Mag-PC, Mag-SD and Mag-SLN increased its Cmax from (429.67 ± 53.12) ng/mL to (533.62 ± 59.01), (721.73 ± 103.44) and (1 063.21 ± 108.22) ng/mL, respectively. The bioavailability of Mag-SD, Mag-PC and Mag-SLN were enhanced to 1.38, 2.12 and 3.45 times, respectively. Conclusion: Mag-SD, Mag-PC and Mag-SLN could promote the absorption of magnolol in SD rats notably. In addition, Mag-SLN could give a better effect on the bioavailability.

Rhynchophylline nanosuspensions sustained-release tablets: Preparation, optimization and release evaluation in vitro / 中草药

Objective: To prepare the rhynchophylline nanosuspensions and lyophilized powder, and study its sustained-release tablets. Methods: Rhynchophylline nanosuspensions were prepared by microprecipitation combined with high pressure homogenization method, and the particle size and zeta potential were determined. Scanning electron microscopy (SEM) was employed to observe the appearances of nanosuspensions. Nanosuspensions were prepared into lyophilized powder using lactose as freeze-dried protectors. HPMC (hydroxypropyl methyl cellulose) was used as hydrophilic matrix to prepare the sustained-release tablets. Single factor investigation and orthogonal experiments were employed to optimize the formulation of rhynchophylline nanosuspensions sustained-release tablets, and the model fitting was also been studied. Results: The particle size and zeta potential of rhynchophylline nanosuspensions were (153.7 ± 4.9) nm and (-18.54 ± 1.32) mV, respectively. The appearances of rhynchophylline nanosuspensions were spherical or nearly spherical. After orthogonal optimization, the cumulative release rate of rhynchophylline nanosuspensions sustained-release tablets was 92.53% in 12 h. The optimized formulation of hydrogel matrix sustained-release tablets was better accorded with Higuchi model: ln(1-Mt/M∞)=0.286 0 t1/2-0.069 0 (r=0.992 4). The drug release from hydrogel matrix sustained-release tablets were controlled by diffusion and degradation. Conclusion: The obtained rhynchophylline nanosuspensions has small particle size. The prepared hydrogel matrix sustained-release tablets can control the release of rhynchophylline nanosuspensions in a slow characteristic.

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 and Antitumor Activity of Etoposide-loaded Solid Lipid Nanoparticles / 中国药师

Objective:To prepare solid lipid nanoparticles of etoposide and evaluate the inhibitory rate against Lewis lung cancer cells in mice. Methods:Etoposide-loaded solid lipid nanoparticles were prepared by a hot melting emulsification and high pressure homogenization method. The physicochemical properties such as the appearance, microstructure, particle size distribution and zeta potential of the solid lipid nanoparticles were studied. The in vitro release behavior of the solid lipid nanoparticles were evaluated. The inhibitory effect of etoposide-loaded solid lipid nanoparticles and etoposide injection on Lewis lung cancer cells was compared. Results:Etoposide-loaded solid lipid nanoparticles showed a light blue transparent liquid,which was uniformly spherical under the transmission electron microscope. The average particle size was (153.2 ± 32.8) nm, PdI was (0.185 ± 0.031),and the zeta potential was(-17.4 ± 1.1) mV. The solid lipid nanoparticles could delay the drug release and 52.4% of the drug was released in 24 h. Etoposide-loaded solid lipid nanoparticles could significantly inhibit the growth of Lewis lung cancer cells in mice. And the inhibitory rate of the solid lipid nanoparticles was significantly higher than that of etoposide injection (P < 0.05). Conclusion:The solid lipid nanoparticles prepared by hot melting emulsification and high pressure homogenization method have good antitumor effect on Lewis lung cancer cells,which can be used as a new drug delivery system for etoposide with certain application prospect in lung cancer treatment.

Formulation and characterization of biocompatible and stable I.V. itraconazole nanosuspensions stabilized by a new stabilizer polyethylene glycol-poly(ß-Benzyl-l-aspartate) (PEG-PBLA).

Amphiphilic block copolymers, PEG-PBLA with different molecular weights, were synthesized and used as new stabilizers for Itraconazole nannosuspensions (ITZ-PBLA-Nanos). ITZ-PBLA-Nanos were prepared by the microprecipitation-high pressure homogenization method, and the particle size and zeta potential were measured using a ZetaSizer Nano-ZS90. Morphology and crystallinity were studied using TEM, DSC and powder X-ray. The effect of the PEG-to-PBLA ratio, and the drug-to-stabilizer ratio were investigated to obtain the optimal formulation. It was found that the optimal length of hydrophobic block was 25 BLA-NCA molecules and the optimal ratio of drug/stabilizer was 1:1, where the resulted average particle size of ITZ-PBLA-Nanos was 262.1±7.13nm with a PDI value of 0.163±0.011. The images of TEM suggest that ITZ-PBLA-Nanos were rectangular in shape. ITZ existed as crystals in the nanoparticles as suggested by the DSC and XRD results. Compared with the crude drug suspensions, the dissolution rate of ITZ nanocrystals, was significantly increased and was similar to Sporanox® injection. The ITZ-PBLA-Nanos also demonstrated better dilution stability and storage stability compared with ITZ-F68-Nanos. The particle size of ITZ-PBLA-Nanos did not change significantly after incubated in rat plasma for 24h which is a good attribute for I.V. administration. Acute toxicity tests showed that ITZ-PBLA-Nanos has the highest LD50 compared with ITZ-F68-Nanos and Sporanox® injection. ITZ-PBLA-Nanos also showed stronger inhibiting effect on the growth of Candida albicans compared with Sporanox® injection. Therefore, PEG-PBLA has a promising potential as a biocompatible stabilizer for ITZ nanosuspensions and potentially for other nanosuspensions as well.

Preparation of nanosuspensions of flavonoids from Glycyrrhizae Radix et Rhizoma and the in vitro dissolution rate / 中成药

AIM To prepare nanosuspensions of flavonoids from Glycyrrhizae Radix et Rhizoma and to determine the in vitro dissolution rate.METHODS Precipitation-high pressure homogenization method was adopted in the preparation of nanosuspensions.With mean particle size and polydispersity index (PDI) as evaluation indices,concentrations of flavonoids,povidone K30 (PVP K30) and polyethylene glycol 400 (PEG 400) as influencing factors,central composite design-response surface method was applied to optimizing the preparation.For the freedried powder prepared by freeze-drying method,the optimal kind and ratio of lyoprotectant were screened.Then the in vitro dissolution rates of freeze-dried powder and physical mixture were compared.RESULTS The optimal conditions were determined to be 10.00 mg/mL for flavonoids' concentration,and 2.30 mg/mL for both PVP K30 and PEG 400 concentrations,the mean particle size and PDI were (172.3 ± 1.2) nm and 0.175 ± 0.004,respectively.The optimal lyoprotectant was 5％ mannitol-lactose (3 ∶ 2),the mean particle size and PDI after redissolution were (239.7 ±2.1) nm and 0.193 ±0.032,respectively.The in vitro dissolution rate of lyoprotectant reached 87.7％ within 60 min,which was much higher than that of physical mixture (less than 30％).CONCLUSION Nanosuspension can effectively improve the in vitro dissolution rate of flavonoids from Glycyrrhizae Radix et Rhizoma.

Preparation and Pharmacokinetics in Rats of Celecoxib Nanosuspension / 中国药师

Objective:To prepare celecoxib nanosuspension ( CXB-NSs) and study the pharmacokinetics of CXB-NSs in rats. Methods:CXB-NSs were prepared by an anti-solvent precipitation and high pressure homogenization method. The particle size, polydispersion index ( PdI) and zeta potential of the nanosuspension were studied. Totally 12 Wistar rats were randomly divided into CXB-NSs group and CXB suspension group, and gastric drug dose was 100 mg·kg-1 . CXB concentration in plasma was determined by HPLC and the pharmacokinetic parameters were calculated by 3P97 software. Results: The particle size, polydispersion index, zeta potential of CXB-NSs was (442. 5 ± 61. 9) nm, 0. 312 ± 0. 057 and ( -31. 6 ± 3. 9) mV, respectively. AUC (0-t) of CXB suspension and CXB-NSs was (5.13 ±0.77) and (13.51 ±3.18) mg·L-1·h, half time (t1/2) was (12.31 ±1.91) and (12.73 ±1.83) h, Tmax was (2. 48 ± 0. 37) and (1. 41 ± 0. 27) h and Cmax was (0. 94 ± 0. 31) and (2. 38 ± 0. 25) mg·L-1 , respectively. Conclusion:CXB-NSs can remarkably increase bioavailability in rats.

Pharmacokinetic behavior of docetaxel lipid emulsion injection in rats / 中国药科大学学报

@#The aim of this study was to prepare and characterise docetaxel lipid emulsion injection and to conduct the characterization of its pharmacokinetics in rats after tail-vein injection. High pressure homogenization method was used to prepare docetaxel lipid emulsion. 12 Wistar rats were randomly divided into docetaxel lipid emulsion injection group and docetaxel injection group, and dosed at 6 mg/kg through tail-vein injection. Docetaxel concentration in plasma was determined by HPLC. The pharmacokinetic parameters of docetaxel in rats were obtained using the 3P97 program. Particle size, polydispersion index, Zeta potential of docetaxel lipid emulsion were found to be(221. 6±13. 4)nm, (0. 092±0. 003)and -30. 3 mV, respectively. t1/2(α) of docetaxel lipid emulsion injection and docetaxel injection were(0. 072±0. 014)and(0. 066±0. 015)h; t1/2(β) were(0. 573±0. 253)and(0. 432±0. 184)h; AUC0-12 h were(7. 98±1. 25)and(6. 26±1. 83)μg ·h/mL, respectively. Docetaxel lipid emulsion injection had similar pharmacokinetic characteristics to docetaxel injection. The pharmacokinetic data obtained for both preparations fitted a two-compartment model.

Preparation and Characterization of Resveratrol Microemulsions / 中国药师

Objective:To prepare resveratrol microemulsions by high pressure homogenization method and characterize the microe-mulsions. Methods:Using the particle size, polydispersion index and encapsulation efficiency as the indicators, the independent varia-bles of the preparation were inspected, and the microemulsions were characterized. The stability of resveratrol microemulsions was stud-ied by long term stability test preliminarily. Results:The mean particle size, polydispersion index and zeta potential of resveratrol mi-croemulsions was (231 ± 37. 8) nm, 0. 228 ± 0. 047 and ( -42. 5 ± 4. 3) mV, respectively. The microemulsions were found to be small and spherical with smooth surface under a transmission electron microscope. Long term stability studies showed that the microe-mulsions were stable in 3 months after stored at 25℃. Conclusion:The preparation process of high pressure homogenization method for resveratrol microemulsions is simple and feasible.

Preparation and Pharmacokinetics of Nevirapine Nanosuspensions in Rats / 中国药师

Objective:To prepare nevirapine nanosuspensions ( Nev-NS) and study the pharmacokinetics in rats. Methods:Nev-NS was prepared by a high pressure homogenization technology. The particle size, PDI and Zeta potential of the nanosuspensions were used as the indices to determine the influencing factors in the preparation process. Nevirapine plasma concentration was detected by HPLC and the pharmacokinetic parameters were calculated by 3P97 software. Results: The particle size, PDI and Zeta potential of Nev-NS was (456. 1 ± 72. 1) nm, 0. 441 ± 0. 072 and ( -24. 4 ± 4. 7) mV, respectively. AUC0-12 of Nev and Nev-NS was (7. 57 ± 0.52) and (11.72 ±1.83) mg·h·L-1, t1/2 was (2.45 ±0.31) and (3.16 ±0.39) h, Tmax was (1.43 ±0.38) and (1.61 ± 0. 32) h and Cmax was (1. 62 ± 0. 42) and (3. 15 ± 0. 52) mg·L-1 , respectively. Conclusion:Nev-NS can improve the pharmacoki-netic behavior of Nev in rats significantly, and obviously enhance the bioavailability when compared with nevirapine suspensions.

Preparation and solidification of redispersible nanosuspensions.

To test the feasibility of preparing redispersible powders from nanosuspensions without further addition of drying protectants, Lovastatin was processed into nanosuspensions and subsequently converted into a powder form using a spray-drying process. The effects of spray-drying process parameters and stabilizers on the properties of the spray-dried powders were evaluated. The inlet air temperature was found to have the most pronounced impact; a low-inlet air temperature consistently yielded dried powders with improved redispersibility. This was attributed to the low Peclet number associated with a low-inlet air temperature, making nanoparticles less prone to aggregation and coalescence during spray drying, as evidenced by the well-defined boundary shown between nanoparticles in the SEM photomicrographs of the spray-dried microparticles. The influence of atomization pressure is significant particularly at a low-inlet air temperature. The redispersibility index value of the powder is dependent on the type of stabilizers used in the nanosuspension formulation. Spray-dried powders with acceptable redispersibility were prepared with drug concentration as high as 3%. In conclusion, with optimized process parameters and selected stabilizers, spray drying is a feasible process in the solidification of nanosuspensions with high drug loading and acceptable redispersibility.

Preparation of nanoparticles of ZL-004 and preliminary study on its pharmacokinetics / 中国药学杂志

OBJECTIVE: To prepare ZL-004 loaded PLGA nanoparticles (ZL-004-NP) and evaluate its release characteristics in vitro and pharmacokinetics in rats. METHODS: In order to determine physico-chemical property of ZL-004, saturation-constant temperature method, potentiometric method and shake flask method were employed to obtain relative parameters, respectively. After investigating single factors, the orthogonal design was used to gain optimal formulation. Then characteristic of ZL-004-NP prepared under condition of best formulation was determined by scanning electronmicroscopy, laser particle size analyzer, dialysis method, respectively. Afterward, amounts of ZL-004 in plasma were determined under UPLC-MS/MS and relative bioavailability between ZL-004-NP and its raw material was calculated. RESULTS: The feature of ZL-004-NP met aim of experiment, which contained smooth spheres, 121.34 nm of diameter, 0.16 of PDI, 89.63% of encapsulation efficiency, 7.65% of loading drug content, sustained release about 216 h in vitro and less burst in initiate stage. In vivo, cmax of ZL-004-NP was increased robustly 1.7 times, which reached to 125 μg · L-1 and tmax was cut down rapidly from (6.47 ± 0.51) h to (4.13 ± 0.48) h, compared with crude ZL-004. Relative bioavailability between ZL-004-NP and crude ZL-004 was 200.99%, which greatly improved effect of oral absorption. CONCLUSION: ZL-004-NP might be developed to improve water-insolube nature of ZL-004, which could increase oral relative bioavailability.