Novel taste-masked orally disintegrating tablets for a highly soluble drug with an extremely bitter taste: design rationale and evaluation.

The purpose of this study was to evaluate the taste masking potential of novel solid dispersions (SDs) using Eudragit® EPO as the excipient when incorporated into the orally disintegrating tablets (ODTs) for delivering a highly soluble drug with an extremely bitter taste. The pyridostigmine bromides (PB) SDs (PBSDs) were prepared by solvent evaporation-deposition method. The physicochemical properties of PBSDs were investigated by means of differential scanning calorimetry and Fourier transformed infrared spectroscopy. The dissolution test showed that only about 8% of PB was released from PBSDs in the simulated salivary fluid in 30 s. Therefore, PBSDs were considered taste-masked and selected for formulation of PBODTs. A central composite design was employed for process optimization. Multiple linear regression analysis for process optimization revealed that the optimal PBODTs were obtained, when the microcrystalline cellulose and crospovidone were 17.16 and 5.55 (%, w/w), respectively, and the average in vivo disintegration time was 25 s. The bitterness threshold of PB was examined by a sensory test, and the threshold value was set as 3 mg in each tablet. Taste evaluation of PBODTs in 18 volunteers revealed considerable taste masking with bitterness below the threshold value. PBODTs also revealed rapid drug release (around 99%, 2 min) in the simulated gastric fluid. The mean PB plasma concentration-time profiles of PBODTs and that of the commercial tablets were comparable, with closely similar pattern. Bioequivalence assessment results demonstrated that PBODTs and the commercial tablets were bioequivalent. In conclusion, PBODTs are prepared successfully, with taste masking and rapid disintegration in the oral cavity.

Design and evaluation of a novel evodiamine-phospholipid complex for improved oral bioavailability.

A novel evodiamine (EVO)-phospholipid complex (EPLC) was designed to improve the bioavailability of EVO. A central composite design approach was employed for process optimization. EPLC were characterized by differential scanning calorimetry, ultraviolet spectroscopy, Fourier transformed infrared spectroscopy, (1)H-NMR spectroscopy, matrix-assisted laser desorption/ionization time-of-flight spectroscopy, apparent solubility, and dissolution rate. After oral administration of EPLC, the concentrations of EVO at different time points were determined by high-performance liquid chromatography. The optimal formulation for EPLC was obtained where the values of X (1), X (2), and X (3) were 2, 0.5, and 2.5 mg/mL, respectively. The average particle size and zeta potential of EPLC with the optimized formulation were 246.1 nm and -26.94 mV, respectively. The EVO and phospholipids in the EPLC were associated with non-covalent interactions. The solubility of EPLC in water and the dissolution rate of EPLC in phosphate-buffered solution (pH 6.8) were substantially enhanced. The plasma EVO concentration-time curves of EPLC and free EVO were both in accordance with the two-compartment model. The peak concentration and AUC(0-∞) of EPLC were increased, and the relative bioavailability was significantly increased to 218.82 % compared with that of EVO.

[Pharmacokinetics of mestinon-phospholipid complex in rats].

OBJECTIVE: To determine the pharmacokinetics characteristics of mestinon-phospholipid complex (PBPLC) in rats. METHODS: This study adopted a single-dose, randomized, open-label, two-period crossover trial design. Twelve healthy rats were randomly divided into two groups. One group was orally administered with mestinon-phospholipid complex, and the other group was orally administered with reference mestinon solution (1.5 mg/kg of mestinon). The plasma concentrations of the drugs in ophthalmic vein bloods were determined using HPLC. The pharmacokinetic parameters were calculated with the aid of DAS2.1.1 software. RESULTS: Pharmacokinetic parameters of mestinon-phospholipid complex were Tmax 2 h, Cmax 22.79 microg x min/mL and AUC(0-infinity) 7128.21 microg x min/mL, which were different from those of free mestinon--Tmax, 2 h, Cmax 6.00 microg/mL and AUC(0-infinity) 1772.36 microg x min/mL. The relative bioavailability of mestinon-phospholipid complex was 410.98% of free mestinon. CONCLUSION: The oral bioavailability of mestinon increases remarkably when administered as mestinon-phospholipid complex.

Tissue regeneration effect of betulin via inhibition of ROS/MAPKs/NF-ĸB axis using zebrafish model.

Betulin is the primary anti-inflammatory component of Betula platyphylla suk. cortex (birch bark), a time-honored Traditional Chinese Medicine (TCM) for healing trauma and tissue regeneration. However, the tissue regeneration effects and underlying molecular mechanism of betulin remain unknown. Therefore, it is necessary to investigate the wound repair effects and validate the mechanism of betulin in an appropriate model. In the present study, we evaluated the effects of tissue regeneration, melanin scavenging, and reactive oxygen species (ROS) inhibition of betulin using a zebrafish model. The mechanism of target genes and pathways were confirmed using quantitative polymerase chain reaction and western blotting in vivo, while molecular docking, absorption, distribution, metabolism, excretion, and toxicity investigations in-silico were conducted. Betulin significantly promoted the regeneration of zebrafish caudal fin length and area and alleviated melanin aggregation, as well as ROS generation. The relative mRNA expression of IL-1ß, TNF-α, p38α, ERK1/2, and Caspase3, and the relative protein expression of p38α, ERK1/2, Caspase3, phosphorylated proteins of p-p38α, p-ERK1/2, and p-p65 were down-regulated following betulin administration. Meanwhile, the protein ratios of p-p38α/p38α, p-ERK/ERK, and p-p65/p65 were significantly decreased. In an in-silico study, binding affinities between betulin and P38α, ERK1, ERK2, and Caspase3, and the pharmacokinetic profile of betulin were predicted. The findings suggest that the tissue regeneration mechanism of betulin is based on the inhibition of excessive inflammatory responses, melanin aggregation, and the pro-apoptotic factor, Caspase3, during the proliferation phase via the ROS/MAPKs/NF-ĸB signaling axis. Our results suggest betulin as a potential candidate for tissue regeneration.

[Study on effect of berberine on modulating lipid and CPT I A gene expression].

OBJECTIVE: To investigate the modulating effect on lipid and gene expressions of CPT I A caused by berberine (Ber) in experimental hyperlipidemia rats. METHOD: Male SD rats were randomly divided into 5 groups according to the blood lipid values: normal group, hyperlipidemia group, 300 mg x kg(-1) x d(-1) Ber-treated group, 60 mg x kg(-1) x d(-1) Ber-treated group, and 7.2 mg x kg(-1) x d(-1) lovastatin-treated group. Normal group were fed with base diet and other groups were fed with high fat and cholesterol diet. 12 weeks after drugs were given the TC, TG, LDL-C, and HDL-C from rat blood samples were tested by automatic biochemistry analyzer. Gene expressions of CPT I A and PPARalpha were evaluated by RT-PCR and Western blot, respectively. RESULT: It was shown that Ber significantly decreased TC and LDL-C, but increased HDL-C in dose-dependent manner, elevated expressions of CPT I A mRNA and protein without influence on PPARalpha expression. Similar effects from lovastatin on lipidemia were observed except the Ber effect on CPT I A gene expression. CONCLUSION: Ber has modulating effect on the lipid metabolism, the mechanism of which may be by promoting the CPT I A gene expression.

Self-Nanoemulsifying Drug Delivery System of Genkwanin: A Novel Approach for Anti-Colitis-Associated Colorectal Cancer.

PURPOSE: The aim of the present study was to develop an optimized Genkwanin (GKA)-loaded self-nanoemulsifying drug delivery system (SNEDDS) formulation to enhance the solubility, intestinal permeability, oral bioavailability and anti-colitis-associated colorectal cancer (CAC) activity of GKA. METHODS: We designed a SNEDDS comprised oil phase, surfactants and co-surfactants for oral administration of GKA, the best of which were selected by investigating the saturation solubility, constructing pseudo-ternary phase diagrams, followed by optimizing thermodynamic stability, emulsification efficacy, self-nanoemulsification time, droplet size, transmission electron microscopy (TEM), drug release and intestinal permeability. In addition, the physicochemical properties and pharmacokinetics of GKA-SNEDDS were characterized, and its anti-colitis-associated colorectal cancer (CAC) activity and potential mechanisms were evaluated in AOM/DSS-induced C57BL/6J mice model. RESULTS: The optimized nanoemulsion formula (OF) consists of Maisine CC, Labrasol ALF and Transcutol HP in a weight ratio of 20:60:20 (w/w/w), in which ratio the OF shows multiple improvements, specifically small mean droplet size, excellent stability, fast release properties as well as enhanced solubility and permeability. Pharmacokinetic studies demonstrated that compared with GKA suspension, the relative bioavailability of GKA-SNEDDS was increased by 353.28%. Moreover, GKA-SNEDDS not only significantly prevents weight loss and improves disease activity index (DAI) but also reduces the histological scores of inflammatory cytokine levels as well as inhibiting the formation of colon tumors via inducing tumor cell apoptosis in the AOM/DSS-induced CAC mice model. CONCLUSION: Our results show that the developed GKA-SNEDDS exhibited enhanced oral bioavailability and excellent anti-CAC efficacy. In summary, GKA-SNEDDS, using lipid nanoparticles as the drug delivery carrier, can be applied as a potential drug delivery system for improving the clinical application of GKA.

Baicalein improves liver inflammation in diabetic db/db mice by regulating HMGB1/TLR4/NF-κB signaling pathway.

The current study was designed to investigate the hepatoprotective effects and possible mechanisms of Baicalein (BA) on the diabetic liver injury in vivo and in vitro. The results exhibited that BA significantly restored the blood glucose in oral glucose tolerance test (OGTT) and inhibited the levels of insulin, alanine aminotransferase (ALT), aspartate aminotransaminase (AST), total cholesterol (TC) and triglyceride (TG) in C57BL/KsJ-db/db mice. Moreover, BA strikingly attenuated the extent of steatosis in the liver tissues of diabetic mice. These results confirmed the hepatoprotective effects of BA on diabetic liver injury. Further in vivo investigations revealed that the hepatoprotective activities of BA was due to the effects on remarkably suppressing the inflammatory cascade, including attenuating the expressions of HMGB1, TLR4, Myd88, NF-κB and IκB proteins and inhibiting the production of interleukin (IL)-1ß, IL-6 and tumor necrosis factor (TNF)-α in diabetic mice. Finally, the hepatoprotective effects of BA were characterized in human hepatic HepG2 cells. With response to palmitic acid-challenge, increased amount of insulin, ALT, AST, TG, TC were observed, whereas BA pretreatment significantly restored these changes in HepG2 cells. Inflammation condition was also recovered with BA treatment as shown by the changes of HMGB1, TLR4, Myd88, NF-κB and IκB expressions and the levels of IL-1ß, IL-6 and TNF-α. These findings elucidated that BA exhibited prominent hepatoprotective activities in diabetic live injury.

Neuroprotective effect of ginkgolide K against acute ischemic stroke on middle cerebral ischemia occlusion in rats.

Ginkgolide K, a natural platelet-activating factor receptor antagonist, was isolated from the leaves of Ginkgo biloba. However, little is known about its neuroprotective effect in ischemia-reperfusion (I/R)-induced cerebral injury. Hence, the present study was carried out to investigate the effect of ginkgolide K on neuroprotection and the potential mechanisms in the rat I/R model induced by middle cerebral artery occlusion (MCAO). The rats were pretreated with ginkgolide K 2, 4 and 8 mg/kg (i.v.) once a day for 5 days before MCAO. Neurological deficit score (NDS), brain water content, 2,3,5-triphenyltetrazolium chloride (TTC) staining and pathology of brain tissue, as well as indexes of oxidative stress [superoxide dismutase (SOD), malondialdehyde (MDA), nitric oxide (NO) and nitric oxide synthase (NOS)] were measured at 24 h after ischemia. The results indicated that pretreatment with ginkgolide K significantly diminished the volume of infarction and brain water content, and improved NDS. Moreover, ginkgolide K markedly reversed the level of MDA, NO, NOS and SOD to their normal state in serum or cerebral ischemic section. In addition, hematoxylin and eosin staining showed the neuronal injury was significantly improved after being pretreated with ginkgolide K. These findings demonstrate that ginkgolide K exhibits neuroprotective properties through its antioxidative action in MCAO rats.

Uricase from Bacillus fastidious loaded in alkaline enzymosomes: enhanced biochemical and pharmacological characteristics in hypouricemic rats.

The aim of this study was to assess the potential of a novel alkaline enzymosome to deliver uricase from Bacillus fastidious (UBF) and enhance its biochemical and pharmacological characteristics. The in vitro catalytic activity of the UBF loaded in the novel alkaline enzymosomes (ESUBFs) was almost 3.8 times that of free UBF at the optimum pH or 1.5 times that of free UBF at the physiological pH. Following intravenous (i.v.) administration (2000 mU/kg) in rats, ESUBFs provided significantly higher (22.5-fold) area under the plasma concentration (AUC) and longer (8.2-fold) circulation half-life (t(1/2)) compared with free UBF, respectively. Further, it took only 4.5h (or 1.1h) for ESUBFs to lower the plasma uric acid concentration from a high level to the normal level of rat (or human beings), compared with 7.6h (or 5.4h) for free UBF. Our results showed that ESUBFs could efficiently deliver UBF and favorably modify its biochemical and pharmacological characteristics by increasing the AUC, t(1/2), and catalytic activity. Therefore, ESUBFs might be a preferred alternative to cure hyperuricemia and gout.

Role of a novel pyridostigmine bromide-phospholipid nanocomplex in improving oral bioavailability.

A novel pyridostigmine bromide (PB)-phospholipid nanocomplex (PBPLC) was prepared to increase the bioavailability of PB. A central composite design approach was employed for process optimization. The physicochemical properties of PBPLC were investigated by means of differential scanning calorimetry, ultraviolet spectroscopy, Fourier transformed infrared spectroscopy and the n-octano/water partition coefficient. The intestinal permeability of PBPLC was observed via a single pass intestinal perfusion in rats. After oral administration of PBPLC, the concentrations of PB at predetermined time points were determined by HPLC, and the pharmacokinetic parameters were computed by DAS 2.1.1 software. Multiple linear regression analysis for process optimization revealed that the optimal PBPLC was obtained when the values of X(1), X(2), and X(3) were 8, 40°C, and 4 mg/mL, respectively. The average particle size and zeta potential of PBPLC with the optimized formulation were 204.60 nm and -25.12 mV, respectively. Non-covalent interactions between PB and phospholipids were found in the PBPLC. The n-octanol/water partition coefficient of PBPLC was substantially increased. PBPLC had better intestinal permeability in comparison with free PB. Mean plasma drug concentration-time curves of PBPLC and free PB after oral administration were both in accordance with the two-compartment open model. The values of pharmacokinetic parameters of PBPLC and free PB were the peak time (T(max)) 2 h vs 2 h, the maximum concentration (C(max)) 22.79 µg/mL vs 6.00 µg/mL, and the value of the area under the concentration vs time curve (AUC(0-∞)) 7128.21 µg·min/mL vs 1772.36 µg·min/mL, respectively. In conclusion, compared with free PB, PBPLC remarkably improves the oral bioavailability of PB, which is likely due to its higher lipophilicity and permeability.

Improved biological properties and hypouricemic effects of uricase from Candida utilis loaded in novel alkaline enzymosomes.

OBJECTIVE: Previous studies on various enzymosomes (functional lipid vesicles encapsulating an enzyme) have been mostly carried out in vitro and have focused on preserving catalytic activity and improving the stability of the enzyme. Until now, few studies have focused on their in vivo fate. Similarly, although we have previously reported the increased in vitro uricolytic activity (about 2.2 times higher than that of free uricase, or three times higher than that of PEGylated uricase, Puricase(®), under physiological pH and temperature) and improved stability of the novel alkaline enzymosomes (functional lipid vesicles encapsulating uricase from Candida utilis: uricase-containing lipid vesicles, UOXLVs), it is still necessary to study the biological properties and hypouricemic effects of UOXLVs in vivo. METHODS: The enzyme kinetics, pharmacokinetics, pharmacodynamics, immunogenicity, and preliminary safety of UOXLVs were evaluated. RESULTS: The Michaelis constant (K(m)) value of the UOXLVs was slightly lower than that of the free enzyme. The enzyme release from the UOXLVs lasted over 12 hours and their circulation half-life was about sevenfold longer than that of the free uricase. Meanwhile, the UOXLVs had a 22-fold increase in the area under the curve compared with the free uricase. Furthermore, it took less than 3 hours for the UOXLVs to lower the plasma uric acid concentration from a high to a normal level, compared with 6 hours for the free uricase. In addition, the UOXLVs had much less immunogenicity than free uricase and were well tolerated by all animals throughout the observation period. CONCLUSION: The UOXLVs markedly improved the biological properties and enhanced the hypouricemic effects of uricase in vivo.

Anti-hyperuricemic and nephroprotective effects of Smilax china L.

ETHNOPHARMACOLOGICAL RELEVANCE: Smilax china L., popularly known as "Jin Gang Ten", has been widely used as a traditional herbal medicine for the treatment of gout, rheumatoid arthritis and other diseases for a long time in China. AIM OF STUDY: The present study was carried out to investigate the effect of Smilax china L. on hyperuricemia and renal dysfunction in induced hyperuricemic animals. MATERIALS AND METHODS: Five fractions (petroleum ether, chloroform, ethyl acetate, n-butanol and residual ethanol fraction) of Smilax china L. were orally administered to potassium oxonate-induced hyperuricemic mice for three days. The xanthine oxidase inhibitory activities and modes of action of nine compounds isolated from ethyl acetate fraction (EAF) were then examined in vitro. Finally, different dosages of EAF were administered to 10% fructose-induced hyperuricemic rats. RESULTS: EAF (250 mg/kg) exhibited stronger anti-hyperuricemic activity in hyperuricemic mice compared with the other four fractions. Caffeic acid, resveratrol, rutin and oxyresveratrol isolated from EAF showed different inhibitory activities on xanthine oxidase in vitro, with the IC(50) values of 42.60, 37.53, 42.20 and 40.69 µM, respectively, and exhibited competitive or mixed inhibitory actions. Moreover, EAF (125, 250 and 500 mg/kg) markedly reversed the serum uric acid level (p<0.05, p<0.01 and p<0.001, respectively), fractional excretion of urate (p<0.05, p<0.01 and p<0.01, respectively) and blood urea nitrogen (p<0.05, p<0.01 and p<0.01, respectively) to their normal states, and prevented the renal damage against tubulointerstitial pathologies in hyperuricemic rats. CONCLUSION: These findings show that Smilax china L. exhibits anti-hyperuricemic and nephroprotective activity in hyperuricemic animals.