Selection suitable solvents to prepare paclitaxel-loaded micelles by solvent evaporation method

Technology Transfer of a Validated RP-HPLC Method for the Simultaneous Estimation of Andrographolide and Paclitaxel in Application to Pharmaceutical Nanoformulation

Many analytical methods are reported for simultaneous estimation of pharmaceutical dosages form. However, only a few are reproducible at an industrial scale. The proposed research aims to establish a technology transfer (TT) protocol between two laboratories (Lab-X, originator) with binary and (Lab-Y, receiver) with quaternary high-performance liquid chromatography (HPLC) system. Thus, utilizing reverse-phase HPLC (RP-HPLC), a robust, sensitive and repeatable analytical method has been developed, validated and TT between two laboratories for simultaneous estimation of Andrographolide (AG) and Paclitaxel (PTX). The method has been developed on a Phenomenex Luna C18 column (150 x 4.6, 5) sustained at 40°C and validated under the International Conference on Harmonisation (ICH) Q2 (R1) regulatory guideline and TT USP chapter 1224. The mobile phase consisted of MilliQ (pH = 3) and a combination of acetonitrile and methanol (1:1) in the ratio 50:50 with a flow rate of 0.45 mL/min, linear gradient elution in both labs. The AG and PTX were detected on the PDA detector at 224 and 227 nm wavelength with retention time of 4.5 ± 0.34 and 8.2 ± 0.02 min and limit of detection was found 0.028 ± 0.004 μg/mL, and 0.028 ± 0.0007 μg/mL, whereas limit of quantification as 0.086 ± 0.011 μg/mL and 0.088 ± 0.0014 μg/mL respectively in both labs. Throughout, this approach we have proved that proposed method is repeatable in both labs, and it can be used to quantify AG and PTX in developed pharmaceutical nano-formulations.

Effects of processing parameters on the properties of amphiphilic block copolymer micelles prepared by supercritical carbon dioxide evaporation method

The operation parameters for the supercritical carbon dioxide (ScCO2) evaporation method greatly affect the properties of the prepared drug-loaded micelles. In this study, the effects of those key parameters on the drug-loading content (LC) and drug entrapment efficiency (EE) are discussed. It is observed that EE and LC of the micelles are slightly increased with the enhancing temperature and the copolymer molecular ratio of hydrophilic/hydrophobic segment, while decreased with the enhancing ScCO2 evaporation rate. The pressure and volume ratio of ScCO2 to H2O are observed the optimum condition. In addition, the verification experiment is carried out under the obtained optimizing parameters. The prepared micelles exhibit relatively regular spherical shape and narrow size distribution with the EE and LC value of 70.7% and 14.1%, respectively.

pH-responsive physical gels from poly(meth)acrylic acid-containing crosslinked particles: the relationship between structure and mechanical properties

Gels that feature high internal porosity and have both high elasticity and ductility have potential to provide immediate load support and enable subsequent tissue regeneration of damaged soft tissue if combined with cells. Herein, we report results from a recent investigation of novel poly(methyl methacrylate-co-methacrylic acid), (PMMA-MAA) and poly(ethyl acrylate-co-methacrylic acid), (PEA-MAA) biodegradable, pH-sensitive particle gels which are with high porosity, elasticity and ductility. These gels formed at physiological pH range and are potentially injectable. The particles were prepared using solvent evaporation. They were functionalized by crosslinking the MAA groups of the particles via bis-amide formation with either cystamine (CYS) or 3,3'-dithiodipropionic acid dihydrazide (DTP) which simultaneously incorporated reversibility due to the presence of disulphide bonds within the crosslinker. The crosslinked particles were observed by dynamic light scattering to swell appreciably in size upon increasing the pH. Concentrated dispersions formed elastic and ductile physical gels within the physiological pH range. A key finding of this study was that for crosslinked particles of similar composition the formation of considerably more elastic and ductile gels was observed from the most lightly crosslinked particles. Furthermore, compared to the PMMA-MAA/CYS and PEA-MAA/CYS gels, those formed from DTP-crosslinked particles had higher elasticity, thicker pore walls and improved interconnectivity. For the PMMA-MAA/DTP gels an elastic modulus value as high as 100 kPa and a yield strain greater than 100% were observed for a gel containing only 5 wt% of particles. The improved mechanical properties of these new gel-forming dispersions imply that they now have good potential for future application as injectable gels for regenerative medicine.