Mucus-Penetrating Alginate-Chitosan Nanoparticles Loaded with Berberine Hydrochloride for Oral Delivery to the Inflammation Site of Ulcerative Colitis.

The rectal enemas of berberine hydrochloride (BH) have emerged as one of the most effective strategies in the clinical treatment of ulcerative colitis (UC). However, oral dosages of BH exhibit a poor anti-inflammatory effect of UC, which may attribute to premature absorption of BH by the upper gastrointestinal tract. Moreover, the thick colonic mucus layer obstructs the penetration of the drug, resulting in low bioavailability to the inflammatory site of the colon. The aim of this study was to develop the mucus-penetrating sodium alginate-chitosan nanoparticles (SA-CS NPs) for oral delivery of BH to the site of colonic ulcer lesions. BH-loaded SA-CS NPs were developed through the ionic gelation method and analyzed for physicochemical characteristics, release performance, penetrability, site retention, and therapeutic efficacy. The results showed that the NPs have a particle size of 257 nm with a negative charge, presenting desired pH-dependent release behavior. The permeation studies elucidated that negatively charged SA-CS NPs had 2.9 times higher mucus penetration ability than positively charged CS NPs. An ex vivo retention study indicated the high retention of BH-SA-CS NPs at the colon site for more than 16 h. In vivo therapeutic effectiveness demonstrated that the prepared NPs could not only alleviate colonic injury by decreasing the disease activity index and colon mucosa damage index, but also improve the immunologic function by decreasing the spleen index. In conclusion, the BH-SA-CS NPs could enhance the mucus permeability and deliver drugs to the colonic inflammation site, providing new insights into improving the therapeutic effect of UC.

Development and Evaluation of Controlled and Simultaneous Release of Compound Danshen Based on a Novel Colon-Specific Osmotic Pump Capsule.

In the study, we developed a novel oral dosage form of Compound Danshen to resolve the problems of low bioavailability, disequilibrium in drug release, and stomach degradation of active components of Compound Danshen in conventional formulas. A colon-specific osmotic pump capsule (COPC) of Compound Danshen was prepared using a semipermeable shell with the core components. Using a single-factor method, we obtained the optimal formulation that consisted of Salvia miltiorrhiza extract, Panax notoginseng extract, Borneol, sodium chloride, polyethylene oxide wsr-N10, hydroxypropyl-ß-cyclodextrin, and ludipress. Moreover, in vitro dissolution test showed simultaneous releases of active ingredients from Compound Danshen COPC over 12 h at pH 7.8, displaying zero-order release characteristics. The impetus of drug release mainly depended on the difference in osmotic pressure across the capsule shell. Next, scanning electron microscopy showed morphological changes in the capsule shell during the dissolution test. More importantly, pharmacokinetic study in beagle dogs indicated that relative bioavailability was 330.58% and retention time was greatly prolonged in Compound Danshen COPC, compared with those in marketed Compound Danshen tablet products. Finally, in vivo imaging studies in beagle dogs showed that COPC was stable in gastrointestinal tract and the drug was specifically released in the colon region. A colon-specific osmotic pump capsule (COPC) of Compound Danshen was developed and optimized to achieve simultaneous zero-order release of multiple active components of Compound Danshen in the colon. More importantly, the COPC have proved to improve the bioavailability and prolong the retention time of Compound Danshen, compared with those in a marketed product.

A Nasal Temperature and pH Dual-Responsive In Situ Gel Delivery System Based on Microemulsion of Huperzine A: Formulation, Evaluation, and In Vivo Pharmacokinetic Study.

Huperzine A (hup A), extracted from the Chinese medicinal plant Huperzia serrata, is a reversible and highly selective second-generation acetylcholine esterase (AchE) inhibitor for treating Alzheimer's disease (AD), but it suffers from low bioavailability in the brain. This study aimed to develop a nasal temperature and pH dual-responsive in situ gel delivery system based on microemulsion of hup A (hup A-M-TPISG). The optimal formulation was obtained by central composite design and response surface methodology. The optimized mucoadhesive formulation, hup A-M-TPISG, was composed of pluronic F127 (20.80%), pluronic F68 (2.8%), and chitosan (0.88%) as the gel matrix, which could gelatinize under physiological conditions (29-34°C, pH 6.5) because of its temperature and pH responsiveness. The optimized hup A-M-TPISG formulation was further evaluated by in vitro release and in vivo pharmacokinetic studies via microdialysis. The in vitro release study showed continuous and steady drug release from hup A-M-TPISG, which was in accordance with the first-order model. Moreover, the pharmacokinetic results revealed that the optimized formulation for nasal administration, with convenient administration and improved patient compliance, could achieve similar brain-targeting properties as intravenous administration. In conclusion, the hup A-M-TPISG for intranasal administration, as an effective and safe vehicle, could enhance the absorption of hup A in vivo and would be a promising noninvasive alternative for partially improving brain-targeting therapy.

Preparation and Pharmacokinetics Evaluation of Solid Self-Microemulsifying Drug Delivery System (S-SMEDDS) of Osthole.

The study was performed aiming to enhance the solubility and oral bioavailability of poorly water-soluble drug osthole by formulating solid self-microemulsifying drug delivery system (S-SMEDDS) via spherical crystallization technique. Firstly, the liquid self-microemulsifying drug delivery system (L-SMEDDS) of osthole was formulated with castor oil, Cremophor RH40, and 1,2-propylene glycol after screening various lipids and emulsifiers. The type and amount of polymeric materials, good solvents, bridging agents, and poor solvents in S-SMEDDS formulations were further determined by single-factor study. The optimal formulation contained 1:2 of ethyl cellulose (EC) and Eudragit S100, which served as matrix forming and enteric coating polymers respectively. Anhydrous ethanol and dichloromethane with a ratio of 5:3 are required to perform as good solvent and bridging agent, respectively, with the addition of 0.08% SDS aqueous solution as poor solvent. The optimized osthole S-SMEDDS had a high yield (83.91 ± 3.31%) and encapsulation efficiency (78.39 ± 2.25%). Secondly, osthole L-SMEDDS was solidified to osthole S-SMEDDS with no significant changes in terms of morphology, particle size, and zeta potential. In vitro release study demonstrated a sustained release of the drug from osthole S-SMEDDS. Moreover, in vivo pharmacokinetic study showed that the Tmax and mean residence time (MRT(0-t)) of osthole were significantly prolonged and further confirmed that osthole S-SMEDDS exhibited sustained release effect in rabbits. Comparing with osthole aqueous suspension and L-SMEDDS, osthole S-SMEDDS increased bioavailability by 205 and 152%, respectively. The results suggested that S-SMEDDS was an effective oral solid dosage form, which can improve the solubility and oral bioavailability of poorly water-soluble drug osthole.

PEGylated niosomes-mediated drug delivery systems for Paeonol: preparation, pharmacokinetics studies and synergistic anti-tumor effects with 5-FU.

This work describes the preparation of a PEGylated niosomes-mediated drug delivery systems for Paeonol, thereby improving the bioavailability and chemical stability of Paeonol, prolonging its cellular uptake and enhancing its synergistic anti-cancer effects with 5-Fu. PEGylated niosomes, which are prepared from biocompatible nonionic surfactant of Spans 60 and cholesterol, and modified with PEG-SA. Pae-PEG-NISVs were evaluated in vitro and in vivo. The cytotoxicity of Pae-PEG-NISVs was investigated against HepG2 cells. Fluorescence microscope was used to detect the apoptotic morphological changes. Growth inhibition assays were carried out to investigate whether Pae-PEG-NISVs could enhance the antiproliferative effects of Pae co-treated with 5-FU on HepG2 cells. The optimized Pae-PEG-NISVs had mean diameters of approximately 166 nm and entrapment efficiency (EE) of 61.8%. Furthermore, the in vitro release study of Paeonol from PEGylated niosomes exhibited a relatively prolonged release profile for 12 h. Pharmacokinetic studies in rats after i.v. injection showed that Pae-PEG-NISVs had increased elimination half-lives (t1/2, 87.5 versus 17.0 min) and increased area under the concentration-time curve (AUC0-t, 38.0 versus 19.48 µg/ml*min) compared to Paeonol solution. Formulated Paeonol had superior cytotoxicity versus the free drug with IC50 values of 22.47 and 85.16 µg/mL at 24 h on HepG2 cells, respectively, and we found that low concentration of Pae-PEG-NISVs and 5-Fu in conjunction had obviously synergistic effect. Our results indicate that the PEG-NISVs system has the potential to serve as an efficient carrier for Paeonol by effectively solubilizing, stabilizing and delivering the drug to the cancer cells.