Optimization of Polyarginine-Conjugated PEG Lipid Grafted Proliposome Formulation for Enhanced Cellular Association of a Protein Drug.

The purpose of this study was to develop an oral proliposomal powder of protein using poly-l-arginine-conjugated 1,2-distearoyl-sn-glycero-3-phosphoethanolamine-poly(ethylene glycol) (DSPE-PEG) (PLD) for enhancing cellular association upon reconstitution and to compare its effects with a non-grafted and PEGylated formulation. Cationic proliposome (CATL), PLD-grafted CATL (PLD-CATL), PEGylated CATL (PEG CATL), and PLD grafted-PEG CATL (PLD-PEG CATL) were prepared and compared. Successful conjugation between poly-l-arginine and DSPE-PEG was confirmed by 1H NMR and FT-IR. PLD was successfully grafted onto the proliposomal powder during the slurry process. Although reconstituted liposomal sizes of CATL and PLD-CATL were increased by agglomeration, PEGylation reduced the agglomeration and increased the encapsulation. The viabilities of cells treated with both CATL and PLD-CATL formulations were low but increased following PEGylation. With regard to cellular association, PLD-CATL enhanced cellular association/uptake more rapidly than did CATL. Upon PEGylation, PEG CATL showed a lower level of cellular association/uptake compared with CATL while PLD-PEG CATL did not exhibit the rapid cellular association/uptake as seen with PLD-CATL. However, PLD-PEG CATL still enhanced the higher cellular association/uptake than PEG CATL did without PLD. In conclusion, proliposomes with PLD could accelerate cellular association/uptake but also caused high cellular toxicity. PEGylation reduced cellular toxicity and also changed the cellular association pattern of the PLD formulation.

Enhancing the in vitro anticancer activity of albendazole incorporated into chitosan-coated PLGA nanoparticles.

To improve the solubility and anticancer activity of albendazole (ABZ), chitosan (CS)-coated poly-dl-lactic-co-glycolic acid (PLGA) nanoparticles were developed. CS was used to coat ABZ-loaded PLGA nanoparticles to enhance both mucoadhesiveness and colloidal stability. CS-coated PLGA nanoparticles were prepared by suspending the nanoparticles in CS solution after solvent diffusion. The CS-coated PLGA nanoparticles were characterized, and ABZ release was studied in vitro from various formulations. The mucoadhesive properties and in vitro anticancer activities of CS-coated PLGA nanoparticles were investigated by measurement of zeta potentials and the MTT assay, respectively. Spherical nanoparticles below 500nm in diameter were successfully prepared; the particle size distribution was narrow. Complete encapsulation of ABZ in CS-coated PLGA nanoparticles was confirmed by SEM, FTIR, DSC, and XRD. The particle sizes of CS-coated PLGA nanoparticles were in the range of 260-480nm; the encapsulation efficiency was 43.4-54.6%; and the yield 58.5-67.8%. The zeta potential of CS-coated nanoparticles was above +27mV and stability was maintained for 4 weeks. At pH 7.4, the in vitro release of ABZ from nanoparticles (P188-5) was 200-fold higher than that from untreated ABZ; this persisted for 12h. Moreover, ABZ release from CS-coated PLGA nanoparticles (P188-CS0.5) was 1.5-fold higher than that from untreated ABZ at pH 1.2. Additionally, the ABZ-loaded CS-coated nanoparticles exhibited superior mucoadhesion and improved cytotoxicity. The results show that CS coating of PLGA nanoparticles may improve the anticancer effect and the mucoadhesive properties of ABZ-loaded nanoparticles.

Determination of Morin in Maclura cochinchinensis Heartwood by HPLC.

The HPLC-DAD method was developed to determine morin content in Maclura cochinchinensis Corner heartwood extract. The chromatographic separation was performed using a Hypersil BDS C18 column, isocratic solvent system of 0.5% acetic acid in water:acetonitrile (80:20) with 1.0 mL/min flow rate and detected at 355 nm. The standard curve of morin was linear in the range of 7-905 µg/mL. The method was precise with intra-day relative standard deviation (RSD) of lower than 1% and 2.06% for inter-day RSD. The method accuracy represented by percent recover was 99.58%. The highly efficient HPLC system developed from this study could detect morin contents in M. cochinchinensis heartwood samples collected from various locations in Thailand in the range of 0.74-1.57% w/w. This developed method provided a useful standardization procedure of M. cochincihinesis materials for further application in pharmacy and other commercial developments.

Simultaneous determination of nine analytes in Clausena harmandiana Pierre. by new developed high-performance liquid chromatography method and the influence of locations in Thailand on level of nordentatin and dentatin.

BACKGROUND: Clausena harmandiana Pierre. (CH) contains various bioactive analytes with pharmacological benefits. Most researches were focused on carbazole analytes determined by isocratic high-performance liquid chromatography (HPLC), only few were focused on coumarin analytes and harvested location. OBJECTIVE: To develop and validate gradient HPLC method to analyze the variance of nine target analytes contained in roots of CH grown naturally in four different provinces of Thailand. MATERIALS AND METHODS: The analytical method was undertaken by gradient HPLC with 3% tetrahydrofuran in acetonitrile, and 0.05% phosphoric acid in water as mobile phases, on Hypersil ODS column (4.0 × 250 mm, 5 µm), at flow rate 1.0 mL/min and detected at wavelength 280 nm. The method was validated for system linearity, limit of detection, limit of quantitation, precision and accuracy. RESULTS: The new-developed method was able to detect the nine target analytes in CH root. The validation showed the reliability of the method. All system suitability parameters were within the satisfied limits. The linear responses of method were observed at r (2) ≥ 0.999 for all analytes. The obtained amount of nine analytes showed the biodiversity of contents in different provinces. Of the nine target analytes, the level of nordentatin and dentatin in coumarin groups were considerably high in plants collected from one specific province of Thailand. CONCLUSION: This study has shown that the new-developed method is reliable, precise, accurate and sensitive to determine and quantify the nine target analytes in CH. Nordentatin and dentatin obviously show the higher level in one specific province of Thailand.

Formation of protein nano-matrix particles with controlled surface architecture for respiratory drug delivery.

PURPOSE: To produce and examine the aerosol performance of protein nano-matrix particles with different surface roughness. METHODS: Aqueous lysozyme solutions were poured into isopropanol during high-shear mixing to produce nanoparticles by precipitation. The size of the nanoparticles was varied by adjusting the precipitation conditions. The resultant suspensions were spray-dried to obtain micron-sized aggregates (nano-matrices). Smooth particles were made by spray-drying a lysozyme solution. The aggregate size distribution, surface roughness, and cohesion were evaluated. The aerosol performance was assessed by dispersing 10 mg of powder from a Rotahaler(®) at 60 L/min or an Aerolizer® at 100 L/min into a Next Generation Impactor, followed by chemical assay (n=3). RESULTS: The median volume diameter and span of the nano-matrix particles were 1.0-1.2 µm and 1.5-1.6, respectively, which were comparable to those of the smooth particles. Surface roughness increased with the size of the primary nanoparticles. The nano-matrix particles were significantly less cohesive than the smooth particles. The fine particle fraction increased linearly with increasing surface roughness and decreasing cohesion. CONCLUSIONS: Nano-matrix particles with controlled surface architecture were successfully produced by spray-drying nanosuspensions. Aerosol performance was enhanced with increasing surface roughness due to the reduction in cohesion forces.