Formulation and characterization of hydroxyethyl cellulose-based gel containing metronidazole-loaded solid lipid nanoparticles for buccal mucosal drug delivery.

Local delivery of drug is a promising strategy to manage periodontitis characterized by chronic inflammation of the soft tissue surrounding the teeth. An optimized system should prolong the drug retention time and exhibit controlled drug permeation through the buccal mucosal layer. This study was aimed to develop hydroxyethyl cellulose (HEC)-based gel containing metronidazole (MTZ) loaded in solid lipid nanoparticles (SLNs), and to enhance the antimicrobial activity of MTZ. SLNs were prepared using a combination method of solvent evaporation and hot homogenization. The results showed that the fabricated SLNs, comprising of Precirol (2.93%, w/v), Tween 80 (1.8%, w/v), and the drug:lipid ratio of 19.3% (w/w), were approximately 200 nm in size, with a narrow distribution. The HEC (3%, w/w)-based gel formed a smooth, homogeneous structure and had preferable mechanical and rheological properties. Moreover, the MTZ-loaded SLNs-based HEC gel (equivalent to 1% of MTZ, w/w) exhibited a sustained in vitro drug release pattern, optimal ex vivo permeability, and enhanced in vitro antimicrobial activity after 24 h of treatment. These findings indicate the potential of the MTZ-loaded SLNs-based HEC formulation for local drug delivery at the buccal mucosa in managing periodontal disease.

PEGylated-Paclitaxel and Dihydroartemisinin Nanoparticles for Simultaneously Delivering Paclitaxel and Dihydroartemisinin to Colorectal Cancer.

PURPOSE: Development of a nanoplatform constructed by the PEG-dual drug conjugation for co-delivery of paclitaxel (PTX) and Dihydroartemisinin (DHA) to the tumor. METHODS: PEG was conjugated with PTX and DHA to form PTX-PEG-DHA complex as a nanocarrier. The PTX and DHA were co-encapsulated in PTX-PEG-DHA nanoparticles (PD@PPD NPs) by the emulsion evaporation method. The physicochemical properties of PD@PPD Nps were characterized, including size, zeta potential, and morphology. The drug loading capacity and entrapment efficiency, in vitro drug release at different pH conditions were also evaluated. For in vitro assessment, the effects of the NPs on HT-29 colorectal cancer cells, including intracellular uptake, cytotoxicity, and Bcl-2 protein expression were assessed. The in vivo distribution of the NPs was investigated by labelling the NPs with Cyanine 5.5 fluorophore. Finally, the antitumor efficacy of the NPs was evaluated in HT-29 tumor-bearing mice. RESULTS: The nanoparticles were formed at small size (~114 nm) and narrow distribution. The combination of PTX and DHA in the DHA-PEG-PTX nanosystems (PD@PPD) showed remarkably increased apoptosis in colorectal adenocarcinoma HT-29 cells, as compared to free drug treatment. More importantly, the PD@PPD nanoparticles exhibited significantly higher accumulation in the tumor site owing to the enhanced permeability and retention (EPR) effect, effectively restrained the tumor growth in vivo at low-dose of PTX while reducing the systemic toxicity. CONCLUSIONS: The combination of PTX and DHA in a PEG-conjugated dual-drug co-delivery system can minimize the severe side effect associated with the high-dose of PTX while enhancing the antitumor efficacy.

Immediate-released pelletized solid dispersion containing fenofibrate: Formulation, in vitro characterization, and bioequivalence studies in experimental beagle dogs.

There have been many strategies to increase solubility, dissolution rates, and oral bioavailability of fenofibrate such as micronization, nanonization, solid dispersion, and emulsion so far. To our knowledge, only first three technologies have been applied in producing marketed products, and no combination of solid dispersion and pellet has been found even in laboratory-based reports. Therefore, the aim of this study was to develop novel solid dispersion-based pellets via an one-step process directly from fenofibrate powder using layering method. Developed fenofibrate pellets were in vitro characterized on size distribution, dissolution rates, sensory evaluation and stability. In addition, the transformation from crystalline fenofibrate to amorphous fenofibrate, and intermolecular interactions of fenofibrate in solid dispersion were confirmed using physico-chemical methods. The dissolution rate of pellets containing fenofibrate was significantly higher than that of the reference, Lipanthyl® 160 mg tablets at early stage, satisfying the criteria in USP 38. The pellets, then, were packed in hard capsules for bioequivalence studies in experimental beagle dogs using a validated HPLC assay. Final findings of the present study should be beneficial for further development of new fenofibrate formulations containing solid dispersion-based pellets which were bioequivalent to Lipanthyl® 160 mg tablets.