A Non-Lipolysis Nanoemulsion Improved Oral Bioavailability by Reducing the First-Pass Metabolism of Raloxifene, and Related Absorption Mechanisms Being Studied.

OBJECTIVE: A non-lipolysis nanoemulsion (NNE) was designed to reduce the first-pass metabolism of raloxifene (RAL) by intestinal UDP-glucuronosyltransferases (UGTs) for increasing the oral absorption of RAL, coupled with in vitro and in vivo studies. METHODS: In vitro stability of NNE was evaluated by lipolysis and the UGT metabolism system. The oral bioavailability of NNE was studied in rats and pigs. Finally, the absorption mechanisms of NNE were investigated by in situ single-pass intestinal perfusion (SPIP) in rats, Madin-Darby canine kidney (MDCK) cells model, and lymphatic blocking model. RESULTS: The pre-NNE consisted of isopropyl palmitate, linoleic acid, Cremophor RH40, and ethanol in a weight ratio of 3.33:1.67:3:2. Compared to lipolysis nanoemulsion of RAL (RAL-LNE), the RAL-NNE was more stable in in vitro gastrointestinal buffers, lipolysis, and UGT metabolism system (p < 0.05). The oral bioavailability was significantly improved by the NNE (203.30%) and the LNE (205.89%) relative to the suspension group in rats. However, 541.28% relative bioavailability was achieved in pigs after oral NNE intake compared to the suspension and had two-fold greater bioavailability than the LNE (p < 0.05). The RAL-NNE was mainly absorbed in the jejunum and had high permeability at the intestine of rats. The results of both SPIP and MDCK cell models demonstrated that the RAL-NNE was absorbed via endocytosis mediated by caveolin and clathrin. The other absorption route, the lymphatic transport (cycloheximide as blocking agent), was significantly improved by the NNE compared with the LNE (p < 0.05). CONCLUSION: A NNE was successfully developed to reduce the first-pass metabolism of RAL in the intestine and enhance its lymphatic transport, thereby improving the oral bioavailability. Altogether, NNE is a promising carrier for the oral delivery of drugs with significant first-pass metabolism.

Nanoemulsion improves hypoglycemic efficacy of berberine by overcoming its gastrointestinal challenge.

Berberine (BBR) is an important natural product with poor gastrointestinal behavior includes low permeability, P-glycoprotein efflux, and mass elimination in the intestine. The aim of this study was to develop a novel nanoemulsion (NE) to improve the hypoglycemic efficacy of BBR. NE was prepared and characterized by morphology and droplet size detection, stored stability, in vitro intestinal lipolysis and metabolism, Caco-2 cells transport, in situ single-pass intestinal perfusion, oral bioavailability in rats, and hypoglycemic efficacy in high-fat diet and streptozocin-induced mice. BBR-loaded NE exhibits small droplet size (30.56 ±â€¯0.35 nm) and good stability. NE could remain intact after lipolysis and protect BBR against the intestinal metabolism mediated by CYP2D6 and CYP3A4. Cells transport and intestinal perfusion studies revealed that NE decreases the P-glycoprotein efflux of BBR by 2-fold and enhances its permeability by 5.5-fold. Consequently, NE increased the oral bioavailability of BBR in rats by 212.02%. Compared to BBR control, blood glucose level of diabetic mice by NE was decreased by 3-fold. This novel NE provides a promising carrier to improve the hypoglycemic efficacy of BBR by overcoming its gastrointestinal deficiency, which may offer a product for the therapy of diabetes.

Research progress on berberine with a special focus on its oral bioavailability.

The natural product berberine (BBR) has become a potential drug in the treatment of diabetes, hyperlipidemia, and cancer. However, the oral delivery of BBR is challenged by its poor bioavailability. It is necessary to improve the oral bioavailability of BBR before it can be used in many clinical applications. Understanding the pharmacokinetic characteristics of BBR will enable the development of suitable formulas that have improved oral bioavailability. The key considerations for BBR are how to enhance the drug absorption and to avoid the intestinal first-pass effect. This review summarizes the pharmacological activities of BBR and analyzes the factors that lead to its poor oral bioavailability. In particular, the therapeutic potential of BBR in new indications from the aspect of oral bioavailability is discussed. In conclusion, BBR is a promising drug candidate for metabolic disorders and cancer but faces considerable challenges due to its poor oral bioavailability.

[Preparation and Dissolution Evaluation of Breviscapine Self-microemulsion].

OBJECTIVE: To study the prescription and preparation technology of breviscapine self-microemulsion for oral administration, and to evaluate the quality, stability and in vitro dissolution. METHODS: The prescription and preparation technology were selected and optimized through the solubility experiment, compatibility test, and pseudo-ternary phase diagram method, using the self-emulsifying time, appearance, particle diameter and stability as indexes. The droplet morphous, drug content, stability and dissolution were evaluated. Results:The prescription composition of breviscapine self-microemulsion was caprylic/capric triglyceride(GTCC,40%), Cremophor RH-40(50%), and PEG-400 (10%), with the drug loading of 7. 0 mg/g. The breviscapine self-microemulsion exhibited uniform and transparent,with the particle size of 38. 57 nm,Zeta potential of - 8. 80 mV. The results of dissolution indicated that the accumulative dissolution in 0. 1 mol/L hydrochloric acid was able to reach 90. 30% after 90 min, being 5. 9 times to that of the raw material medicine. The stability result showed that the content of breviscapine self-microemulsion was affected by high temperature, indicating it should be stored at low temperature. CONCLUSION: The preparation of breviscapine self-microemulsion is simple, which can increase the solubility of breviscapine in water and the absorption of breviscapine in the stomach and intestine, and conform to the main indexes of oral drug delivery system. It offers the basis for further research of breviscapine.

Lobelia chinensis: chemical constituents and anticancer activity perspective.

Research has demonstrated that many chemical constituents dominated by piperidine alkaloids and flavonoids, such as lobelanidine, lobeline, and lobelanine, have been obtained from Lobelia chinensis Lour. Experimental studies and clinical applications have also indicated that L. chinensis possesses a number of pharmacological activities (e.g., diuretic, choleretic, breathing excitement, anti-venom, anti-bacterial, and anticancer). This paper focuses on the properties, chemical constituents, and anticancer activity of L. chinensis to clarify the connection among them, and identify the active anticancer compounds. This work serves as the foundation for further research and development of L. chinensis.

[Preparation and quality evaluation of tanshinone IIA microemulsion for parenteral injection].

OBJECTIVE: To study the prescription and preparation technology of tanshinone IIA microemulsion for parenteral injection, and to evaluate its quality. METHODS: The prescription was selected and optimized through single-factor test, compatibility experiment and the pseudo-ternary phase diagram method. The preparation technology was investigated, and the droplet morphous, particle diameter, zeta potential, stability and haemolyticus were evaluated. RESULTS: The prescription composition of tanshinone IIA microemulsion was MCT:Solutol HS-15: fabaceous lecithin: absolute alcohol = 9:10:5:6(m/m), oil phase: aqueous phase = 1:10, with the drug-loaded of 1. 0 mg/g. The acquired microemulsion exhibited salmon pink,uniform and transparent, with the average particle diameter of 16. 04 nm, Zeta potential of -11. 57 mV, and the encapsulation efficiency of 98. 53%. The stability result showed that tanshinone IIA content in microemulsion was influenced by high temperature and illumination, indicating tanshinone IIA microemulsion should to be stored at low temperature and protected from light. The preparation was without hemolytic crisis. CONCLUSION: The preparation of tanshinone IIA micro- emulsion is simple,corresponding to the main index of parenteral injection and offering the basis for new dosage form development of tanshinone IIA.

[Drug delivery systems of baicalin, baicalin-phospholipid complex and self-microemulsifying drug across Caco-2 cell model].

OBJECTIVE: To study the absorption of baicalin (BA), baicalin-phospholipid complex (BA-PC), and two kinds of self-microemulsifying drug delivery system (SMEDDS) of BA-PC (BA-PC-NE-SMEDDS with natural emulsifier and BA-PC-NS-SMEDDS with nonionic surfactants) and predict the ability of improving bioavailability through changing the formulation of BA. METHODS: Transmembrane transports of each formulation were studied by Caco-2 cell model and the concentration of BA was determined by HPLC. RESULTS: With the increasing concentration of BA, the transport rate and apparent permeability coefficient (Papp) of BA was increased,indicating the passive absorption mechanism of BA. While with the increase of transport time, the transport rate and Papp of BA was decreased slowly, most likely due to the biological transformation of BA during the permeation process as reported in other people's paper. When coupled with P-gp inhibitor (Verapamil), the efflux rate (ER) of BA decreased from 2.07 to 0.48, indicating it was the substrate of P-gp. Compared with BA,the cumulative permeate quantity of BA-PC and BA-PC-SMEDDS were with no significant increase before 90 min (P > 0.05), but increased obviously after 90 min (P < 0.05). Three hours later, the cumulative permeate quantity and Papp showed significant differences (P < 0.05) among each formulation and were arranged in the following order: BA-PC-NS-SMEDDS > BA-PC-NE-SMEDDS > BA-PC > BA. Furthermore, the Papp of BA-PC and BA-PC-SMEDDS was significantly greater than that of BA coupled with Verapamil (P < 0.05). CONCLUSION: PC promotes the permeation of BA; PC-SMEDDS further accelerates its permeation bases on BA-PC; And BA-PC-NS-SMEDDS shows the better effect than BA-PC-NE-SMEDDS to promote the permeation of BA.

The pharmacokinetics of recombinant human interferon-alpha-2b poly(lactic-co-glycolic acid) microspheres in rats.

Interferon-alpha2b (IFN α-2b) microspheres were prepared at various concentrations (5%, 10%, 15%, 20% and 25%) and viscosities (0.39, 0.6, 0.89 and 1.13 dL/g) of poly(lactic-co-glycolic acid) (PLGA) using double emulsion solvent evaporation. The optimal formulation of IFN α-2b microspheres was determined to be 0.89 dL/g PLGA, as assessed by the in vitro release test. The pharmacokinetics of IFN α-2b microspheres was investigated. Nine groups of rats were injected intramuscularly with three doses (0.5, 1 and 2 MIU) of commercial lyophilized IFNα-2b injection or IFN α-2b microspheres. At a dose of 0.5 MIU, the IFN α-2b microsphere released significantly longer than that of the IFN α-2b injection. At a dose of 2 MIU, each pharmacokinetics parameter of microspheres prepared with the IFNa-2b stock solution was manifestly greater than those of the injection. Our study indicated that the IFN α-2b microspheres prepared in 15% of 0.89 dL/g PLGA provided a sustained drug effect for up to 21 days in rats.

[Preparation and in vitro evaluations of topically applied capsaicin transfersomes].

OBJECTIVE: Capsaicin transfersomes were prepared and its quality specifications were evaluated. METHOD: Capsaicin transfersomes were prepared by high shear dispersing machine and evaluated on the entrapment efficiency, drugs release rate and in vitro skin permeation. RESULT: Capsaicin transfersomes is composed of single unilamellar vesicles, with average size of 150.6 nm. Capsaicin entrapment efficiency achieved 96.7% while concentration of lecithin used was 8%. cumulative release amount of capsaicin was in direct proportion to the ethanol concentration in the medium. The in vitro rate cumulative penetration rate of capsaicin was higher in transfersomes than in cream and suspension in rats. Adomen skin cumulative penetration rate in vitro of capsaicin transfersomes in mouse was significantly higher than that from rat and men. In the same way,cumulative penetration rate in vitro of capsaicin transfersomes through abdomen skin epidermal membrance was significantly higher than that with derma and full skin in men. CONCLUSION: Entrapment efficiency of capsaicin transfersomes reached 96.7%, meeting the criterion of China pharmacopia( > 80%), skin penetration of capsaicin was enhanced by a capsaicin transfersomes preparation and was affected by diverse characters and levels of skin.

[Determination of capsaicin in Pheretima aspergillum from different habitats by RP-HPLC].

OBJECTIVE: To determine the content of hypoxanthine in Pheretima aspergillum from different habitats. METHOD: A RP-HPLC method was established. The chromatographic column was Inertsil ODS-EP. The mobile phase was H2O-CH3OH-C4H8O(93:: 7: 0.05). The flow rate was 1.0 ml/min, and the detection wavelength was 254 nm. RESULTS: The average recoveries for hypoxanthine was 98.6% , precision of the method was 0. 50% (RSD, n = 6). CONCLUSION: The method can be used to determine the content of hypoxanthine in Pheretima aspergillum from diffrent habitats.

Preparation and in vitro and in vivo evaluations of topically applied capsaicin transfersomes / 药学学报

<p><b>AIM</b>To prepare capsaicin transfersomes and evaluate them in vitro and in vivo.</p><p><b>METHODS</b>Capsaicin transfersomes were prepared by high shear dispersing machine and evaluated by entrapment efficiency, release rate, in vitro skin permeation and distribution in different tissues in vivo.</p><p><b>RESULTS</b>Capsaicin transfersomes were composed of single unilamellar vesicles with an average diameter of 150.6 nm. Capsaicin entrapment efficiency increased distinctly with increasing of concentration of lecithin and entrapment efficiency is 96.7% while concentration of lecithin to 8%. Cumulative release amount of capsaicin is in direct proportion to the ethanol concentration in the receptor medium. In vitro capsaicin cumulative penetration amount showed higher levels in transfersomes than cream and suspension in rat abdominal skin. Abdominal skin cumulative penetration amount in vitro of capsaicin transfersomes in mouse was significantly higher than that from rat and men. In the same way, abdominal skin epidermal membrane cumulative penetration amount in vitro of capsaicin transfersomes was significantly higher than that from derma and full skin in human abdominal skin. The capsaicin tissue distribution of capsaicin injection by multiple celiac injections in rats is different: bone > plasma > skin > muscle. There is a similar result by multiple thigh topical application of capsaicin transfersomes: bone > skin > plasma > muscle.</p><p><b>CONCLUSION</b>Entrapment efficiency of capsaicin transfersomes reached the criterion of China Pharmacopoeia (> 80%) and capsaicin skin penetration can be increased by capsaicin transfersomes. It should be noted that the diverse characters and levels of skin may probably affect the permeating capability of capsaicin. Capsaicin tissue distribution in bone and muscle is similar and is different in plasma and skin by multiple injections and topical skin apply.</p>

[The preparation and the in vitro release of OANO-1 microspheres].

OBJECTIVE: To prepare OANO-1 microspheres and test their release in vitro. METHOD: OANO-1 microspheres were made by W/O/W-liquid drying process. The surface morphology of the microspheres was observed by SEM. The mean diameter and the size distribution of microspheres, the drug loading and the incorporation efficiency were examined. The release of OANO-1 microspheres in vitro was examined by small cup method. The accumulated release percent of OANO-1 microspheres was examined. RESULT: The OANO-1 microspheres were regular in their morphology. The average particle size was 8.59 microm with over 90% of the microspheres being in the range of 1-12 microm. The drug loading and the incorporation efficiency were 48.39% and 19.32% respectively. The accumulated release percent of OANO-1 microspheres was 78.4% after 108 h. The release half-life t1/2 was 40.8 h and Higuchi equation was Y = 0.1326 X - 0.4782, r = 0.9951. CONCLUSION: The preparation of OANO-1 microspheres was well. The release in vitro of OANO-1 microspheres showed significant sustained release.