Water Soluble Active Components of Salvia miltiorrhiza and Related Plants

经化学研究，自９种鼠尾草属植物中获得各种多酚酸类化合物，其中１１个成分为缩酚酸类化合物，其化学结构是由Ｒ（＋）β（３，４二羟基苯基）乳酸和咖啡酸的衍生物或咖啡酸的二聚物酯化而成的。除了迷迭香酸和紫草酸以外，此类缩酚酸未曾从其它植物中分离得到，因此命名其为丹酚酸Ａ，Ｂ，Ｃ，Ｄ，Ｅ，Ｈ，Ｉ，Ｊ和异丹酚酸Ｃ。丹酚酸Ｆ，Ｇ和甘肃鼠尾草酸Ａ为新的多酚酸类化合物。药理实验结果说明这些多酚酸具有很强的抗氧化活性。对这些化合物的心、脑损伤保护作用亦进行了研究。     

Does the Intake of Ethanol Affect Oral Absorption of Poorly Soluble Drugs?

The presence of ethanol in gastrointestinal (GI) fluids may increase the solubility of poorly water-soluble drugs. This suggests that intake of ethanol with such compounds could result in increased drug absorption in the stomach and duodenum because of the greater concentration gradient present. To test this hypothesis, in vitro dissolution of 2 poorly soluble compounds (indomethacin and felodipine) was studied in simulated GI rat fluids in the presence or absence of ethanol. Results were used to predict plasma exposure of the compounds using the software PK-Sim. Finally, in vivo plasma exposure in rats was investigated after oral dosing followed by immediate administration of water or ethanol. Despite increased solubility in GI fluids in the presence of ethanol, simulations predicted a negligible effect on absorption. This was confirmed in the rat study where oral intake of indomethacin or felodipine with ethanol did not increase in vivo plasma exposure. A possible explanation for the lack of an effect may be that dilution, absorption, and transfer of ethanol upon arrival in the stomach resulted in intragastric and intraduodenal ethanol concentrations that did not reach the levels required to affect local solubility.     

Soluble Siglec-9 alleviates intestinal inflammation through inhibition of the NF-κB pathway

BackgroundSialic acid-binding immunoglobulin-like lectins (Siglecs) are a superfamily of immunoreceptors recognizing sialic acid. Siglec-9 has been shown to mediate inhibitory immune responses. The aim of this study was to evaluate the effect of a soluble form of Siglec-9 (sSiglec-9) on inflamed intestinal epithelial cells (IECs), murine macrophages, and experimental murine colitis models.MethodsCOLO 205 human IECs and RAW 264.7 murine macrophages were pretreated with sSiglec-9 and then stimulated with TNF-α or lipopolysaccharides, respectively. The expression of proinflammatory cytokines such as IL-8 and TNF-α was measured using real-time RT-PCR and ELISA. To demonstrate the inhibitory effects of sSiglec-9 on the NF-κB pathway, IκBα phosphorylation/degradation was determined using western blotting and the DNA binding activity of NF-κB was evaluated using an electrophoretic mobility shift assay. Further, mouse models with dextran sulfate sodium-induced acute colitis and piroxicam-induced IL-10^-/- chronic colitis were generated. Intraperitoneal injections of sSiglec-9 were performed, and body weight, colon length, and histopathologic findings were examined.ResultssSiglec-9 suppressed IL-8 and TNF-α gene expression in stimulated COLO 205 and RAW 264.7 cells. sSiglec-9 inhibited IκBα phosphorylation/degradation and the DNA binding activity of NF-κB. sSiglec-9 injections significantly ameliorated weight loss, colon shortening, and the severity of intestinal inflammation in acute and chronic colitis mouse models.ConclusionsSiglec-9 may inhibit NF-κB activation in IECs and macrophages and alleviate experimental colitis in mice, suggesting that sSiglec-9 is a potential therapeutic agent for the treatment of inflammatory bowel disease.     

Soluble T Cell Receptor Vβ Domains Engineered for High-Affinity Binding to Staphylococcal or Streptococcal Superantigens

Staphylococcus aureus and group A Streptococcus secrete a collection of toxins called superantigens (SAgs), so-called because they stimulate a large fraction of an individual’s T cells. One consequence of this hyperactivity is massive cytokine release leading to severe tissue inflammation and, in some cases, systemic organ failure and death. The molecular basis of action involves the binding of the SAg to both a T cell receptor (TCR) on a T cell and a class II product of the major histocompatibility complex (MHC) on an antigen presenting cell. This cross-linking leads to aggregation of the TCR complex and signaling. A common feature of SAgs is that they bind with relatively low affinity to the variable region (V) of the beta chain of the TCR. Despite this low affinity binding, SAgs are very potent, as each T cell requires only a small fraction of their receptors to be bound in order to trigger cytokine release. To develop high-affinity agents that could neutralize the activity of SAgs, and facilitate the development of detection assays, soluble forms of the Vβ regions have been engineered to affinities that are up to 3 million-fold higher for the SAg. Over the past decade, six different Vβ regions against SAgs from S. aureus (SEA, SEB, SEC3, TSST-1) or S. pyogenes (SpeA and SpeC) have been engineered for high-affinity using yeast display and directed evolution. Here we review the engineering of these high-affinity Vβ proteins, structural features of the six different SAgs and the Vβ proteins, and the specific properties of the engineered Vβ regions that confer high-affinity and specificity for their SAg ligands.     

Adaptive Focused Acoustics™ for Nanosuspensions to Enable Pharmacology Assessment of Poorly Soluble Molecules in Lead Optimization

In Drug Discovery, pharmacology studies often require benign formulation compositions for safe administration in animal models. Here, we applied Adaptive Focused Acoustics? (AFA) to a molecular scaffold with challenging physicochemical properties for intraperitoneal administration. Nanosuspensions can be prepared at small scales and provide broad applicability. Our results show that nanosuspension formulations prepared by AFA have improved PK performance relative to a DMSO solution formulation that is prone to precipitation in-vivo.     

The Solubility–Permeability Interplay and Its Implications in Formulation Design and Development for Poorly Soluble Drugs

While each of the two key parameters of oral drug absorption, the solubility and the permeability, has been comprehensively studied separately, the relationship and interplay between the two have been largely ignored. For instance, when formulating a low-solubility drug using various solubilization techniques: what are we doing to the apparent permeability when we increase the solubility? Permeability is equal to the drug’s diffusion coefficient through the membrane times the membrane/aqueous partition coefficient divided by the membrane thickness. The direct correlation between the intestinal permeability and the membrane/aqueous partitioning, which in turn is dependent on the drug’s apparent solubility in the GI milieu, suggests that the solubility and the permeability are closely associated, exhibiting a certain interplay between them, and the current view of treating the one irrespectively of the other may not be sufficient. In this paper, we describe the research that has been done thus far, and present new data, to shed light on this solubility–permeability interplay. It has been shown that decreased apparent permeability accompanies the solubility increase when using different solubilization methods. Overall, the weight of the evidence indicates that the solubility–permeability interplay cannot be ignored when using solubility-enabling formulations; looking solely at the solubility enhancement that the formulation enables may be misleading with regards to predicting the resulting absorption, and hence, the solubility–permeability interplay must be taken into account to strike the optimal solubility–permeability balance, in order to maximize the overall absorption.KEY WORDS: BCS class II compounds, drug solubility, intestinal permeability, oral absorption, poor aqueous solubility, solubility-enabling formulations, solubility–permeability tradeoff     

Incorporation With Dendrimer-Like Biopolymer Leads to Improved Soluble Amount and In Vitro Anticancer Efficacy of Paclitaxel

The aim of this study was to explore the solubilization efficacy of octenylsuccinate hydroxypropyl phytoglycogen (OHPP), an amphiphilic dendrimer-like biopolymer, in improving the soluble amount and efficacy of paclitaxel (PTX), a potent anticancer active pharmaceutical ingredient. PTX was incorporated with OHPP in the form of solid dispersion (PTX-OHPP SD), which was characterized for its PTX crystallinity, interactions between PTX and OHPP, PTX soluble amount and dissolution profile, and in vitro inhibitory efficacy against cancer cell lines. The incorporation with OHPP led to the amorphous state of PTX. FTIR spectra showed potential hydrogen bonding between PTX and OHPP, and hydrophobic interaction could play an important role in the association of PTX molecules with OHPP particulates. The soluble amount of PTX with PTX-OHPP SD was >14,000 times that of PTX alone. During dissolution, over 70% PTX dissolved in 5 min and this soluble amount was maintained for at least 180 min. With the 3 cancer cell lines tested, the PTX of PTX-OHPP SD showed a much lower IC₅₀ than the dimethyl sulfoxide–assisted PTX solutions. Based on the result, the mechanism of using OHPP as a highly potent solubilizer for PTX was discussed.     

Soluble βamyloid1-42: a critical player in producing behavioural and biochemical changes evoking depressive-related state?

Background and purpose:

Depression is common in early phases of Alzheimer''s disease (AD) and may represent prodromal symptoms of dementia. Recent reports suggest that early memory deficits and neuropsychiatric symptoms are caused by soluble rather than aggregated βamyloid (Aβ). Thus, we investigated the effects of soluble Aβ_1-42 on working memory and depressive/anxiety-related behaviour in rats and on 5-hydroxytryptaminergic neurotransmission and neurotrophin content in various brain regions.

Experimental approach:

Behavioural reactivity to novel object recognition, open field, elevated plus maze and forced swimming test were assessed 7 days after i.c.v. injection of Aβ_1-42 or its vehicle. BDNF (brain-derived neurotrophic factor) and NGF (nerve growth factor) mRNA and protein levels and 5-hydroxytriptamine (5-HT) content were measured in the prefrontal cortex (PFC), striatum (STR) and nucleus accumbens (NAc).

Key results:

Aβ_1-42 did not affect the ability to distinguish between familiar and novel objects, but Aβ-treated rats exhibited an increase in forced swimming immobility. No differences were revealed between experimental groups in the elevated plus maze test or in self-grooming (evaluated in the open field). In the PFC, but not STR or NAc, Aβ-injected rats exhibited a selective reduction in 5-HT content, BDNF and NGF expression.

Conclusions and implications:

Our data suggest that soluble Aβ-treated rats have a depressive, but not anxiogenic-like, profile, accompanied by brain region-dependent alterations in the expression of neurotrophins and 5-hydroxytryptaminergic neurotransmission. Hence, these alterations induced by soluble Aβ might be sensitive indicators of early phases of AD and possible risk factors for the expression of neuropsychiatric symptoms in AD.     

Lyophilized Silica Lipid Hybrid (SLH) Carriers for Poorly Water‐Soluble Drugs: Physicochemical and In Vitro Pharmaceutical Investigations

Lyophilization was investigated to produce a powdery silica–lipid hybrid (SLH) carrier for oral delivery of poorly water‐soluble drugs. The silica to lipid ratio, incorporation of cryoprotectant, and lipid loading level were investigated as performance indicators for lyophilized SLH carriers. Celecoxib, a nonsteroidal anti‐inflammatory drug, was used as the model poorly soluble moiety to attain desirable physicochemical and in vitro drug solubilization properties. Scanning electron microscopy and confocal fluorescence imaging verified a nanoporous, homogenous internal matrix structures of the lyophilized SLH particles, prepared from submicron triglyceride emulsions and stabilized by porous silica nanoparticles (Aerosil 380), similar to spray‐dried SLH. 20–50 wt % of silica in the formulation have shown to produce nonoily SLH agglomerates with complete lipid encapsulation. The incorporation of a cryoprotectant prevented irreversible aggregation of the silica‐stabilized droplets during lyophilization, thereby readily redispersing in water to form micrometre‐sized particles (<5 μm). The lyophilized SLH produced approximately 1.5‐fold and fivefold increased drug solubilization than the pure drug under nondigesting and digesting conditions, respectively. The feasibility of lyophilization for producing nanostructured SLH formulations with desirable lipid loading and drug solubilization properties for enhanced oral delivery of poorly water‐soluble therapeutics is confirmed. © 2014 Wiley Periodicals, Inc. and the American Pharmacists Association J Pharm Sci 103:2950–2959, 2014     

Theoretical Analysis of Interplay of Therapeutic Protein Drug and Circulating Soluble Target: Temporal Profiles of ‘Free’ and ‘Total’ Drug and Target

Purpose  

To systemically investigate, for a therapeutic protein with a circulating soluble target, how the interplay of target dynamics and drug pharmacokinetics defines the ‘total’ and ‘free’ drug and target temporal profiles.     

Application of an In Vitro Dissolution/Permeation System to Early Screening of Oral Formulations of Poorly Soluble,Weakly Basic Drugs Containing an Acidic pH-Modifier

This study aimed to evaluate the usefulness of the dissolution/permeation system (D/P system) as an in vitro tool for early screening of oral formulations of weakly basic drugs containing an acidic pH-modifier. Dipyridamole, having a prominent pH-dependent solubility, was used as a model drug, and various granules containing different amounts of fumaric acid were prepared. Prepared granules were administered orally to hypochlorhydria model rats. It was confirmed that fumaric acid improved the absorption of dipyridamole depending on its amount in the granules. Separately, dissolution and permeation of dipyridamole were observed in vitro in the D/P system. When using a medium with a low buffer capacity which mimicked the human intestinal fluid, rank order of the permeated amount of dipyridamole from various granules in the D/P system did not correlate with its absorption in hypochlorhydric rats. In contrast, when applying a medium with high buffer capacity, the permeated amount in the D/P system well reflected the effects of fumaric acid on the in vivo absorption of dipyridamole. In conclusion, by setting appropriate experimental protocols according to the properties of test compounds and formulations, D/P system can be a potent in vitro tool to predict in vivo performance of oral formulations.     

Design and Evaluation of an Osmotic Pump Tablet (OPT) for Prednisolone,a Poorly Water Soluble Drug,Using (SBE)7m-β-CD

Purpose. The purpose of this study was to develop a controlled-porosity osmotic pump tablet (OPT) for poorly water soluble drugs using a sulfobutyl ether--cyclodextrin, (SBE)_7m--CD or Captisol, which acted as both a solubilizer and as an osmotic agent. Methods. Prednisolone (PDL) was chosen as a model drug for this study. The release of PDL from osmotic pump devices and tablets was studied. In vivo absorption of PDL from OPT was evaluated in male beagle dogs. Results. PDL release from the osmotic pump tablet with (SBE)_7m--CD was complete. Another cyclodextrin, hydroxypropyl--cyclodextrin (HP--CD), and a sugar mixture of lactose and fructose resulted in incomplete release. Although PDL release from the OPT with (SBE)_7m--CD and the sugar formulation displayed mainly zero-order release characteristics, the tablet utilizing HP--CD showed apparent first-order release characteristics. An in vivo absorption study in dogs correlated very well with the in vitro release profiles using the Japanese Pharmacopoeia dissolution method. Conclusions. The present results confirm that (SBE)_7m--CD can serve as both the solubilizer and the osmotic agent for OPT of PDL, and modify the input rate of PDL without compromising oral bioavailability.     

Bioavailability Enhancement of Poorly Water Soluble and Weakly Acidic New Chemical Entity with 2-Hydroxy Propyl-β-Cyclodextrin: Selection of Meglumine,a Polyhydroxy Base,as a Novel Ternary Component

The purpose of the present study was to investigate the influence of a polyhydroxy base, N-acetyl glucamine (also know as Meglumine), as a ternary component on the complexation of DRF-4367, a poorly water-soluble and weakly acidic anti-inflammatory molecule, with 2-hydroxypropyl-β-cyclodextrin (HPβCD). The molecular inclusion of DRF-4367 with HPβCD alone and in combination with ternary component was aimed at improvement in solubility and, subsequently, dissolution rate-limited oral bioavailability. The solid complexes of DRF-4367 and HPβCD with or without meglumine (binary and ternary systems, respectively) were prepared as coevaporated product in different stoichiometric ratios and compared against physical mixture. The formation of inclusion complexes was confirmed by using classical instrumental techniques. Phase solubility studies suggested that meglumine was responsible for solubility improvement via multiple factors rather than just providing a favorable pH. Mechanisms and factors governing solubility enhancement were investigated by using phase solubility and thermodynamic parameters. The complexation of DRF-4367 with HPβCD is thermodynamically favored because the Gibbs free energies of transfer of the drug to the cyclodextrin cavity are negative. The solubilization efficiency and stability were further improved while retaining the favorable Gibbs free energies of transfer with the addition of meglumine. Inclusion ternary complex of DRF-4367 with HPβCD and meglumine showed significant improvement in dissolution compared with uncomplexed drug and binary system. Moreover, the phenomena of reprecipitation observed with binary system during dissolution could be avoided with meglumine as an enabling ternary component. This improved physicochemical behavior of ternary complex with the novel inclusion of a polyhydroxy base translated into an enhanced oral bioavailability of DRF-4367 compared with either uncomplexed drug or nanosuspension.     

<Emphasis Type="BoldItalic">In Vitro</Emphasis> and <Emphasis Type="BoldItalic">In Vivo</Emphasis> Characterization of Drug Nanoparticles Prepared Using PureNano™ Continuous Crystallizer to Improve the Bioavailability of Poorly Water Soluble Drugs

Purpose

The aim of this study was to enhance the dissolution and oral absorption of poorly water-soluble active pharmaceutical ingredients (APIs) using nanoparticle suspensions prepared with a PureNano? continuous crystallizer (PCC).

Method

Nanoparticle suspensions were prepared with a PCC, which is based on microfluidics reaction technology and solvent–antisolvent crystallization. Phenytoin, bezafibrate, flurbiprofen, and miconazole were used as model APIs. These APIs were dissolved in ethanol and precipitated by the addition of water and polyvinyl alcohol. Batch crystallization (BC) using a beaker was also performed to prepare the suspensions. Both PCC and BC formulations were freeze-dried before being characterized in vitro and in vivo.

Results

The particle sizes of the nanoparticle suspensions prepared with the PCC were smaller than those prepared by BC. The dissolution rate of each API in vitro significantly increased after crystallization. Reducing the particle size of either the BC or PCC formulation led to increased API flux across Caco-2 cell monolayers. PCC preparations showed higher plasma concentrations after oral administration, demonstrating the advantages of a fast dissolution rate and increased interaction with the gastrointestinal tract owing to the smaller particle size.

Conclusions

PCC can continuously produce nanoparticle APIs and is an efficient approach for improving their oral bioavailability.