Pharmacokinetics comparison of vardenafil as administered by an intranasal spray formulation vs a 10-mg oral tablet.

BACKGROUND: Oral vardenafil (VDF) tablet is an effective treatment for erectile dysfunction (ED), but intranasal administration with a suitable formulation can lead to a faster onset of action and offer more convenient planning for ED treatment. AIM: The primary purpose of the present pilot clinical study was to determine whether intranasal VDF with an alcohol-based formulation can result in more "user-friendly pharmacokinetics" as compared with oral tablet administration. METHODS: This single-dose randomized crossover study was conducted in 12 healthy young volunteers receiving VDF as a 10-mg oral tablet or 3.38-mg intranasal spray. Multiple blood concentrations were obtained, and VDF concentrations were determined with a liquid chromatography-tandem mass spectrometry assay. Pharmacokinetic parameters following each treatment were compared and adverse events assessed. OUTCOMES: Pharmacokinetic parameters were obtained: apparent elimination rate constant, elimination half-life, peak concentration, peak time, total area under the curve, and relative bioavailability. RESULTS: Although mean apparent elimination rate constant, elimination half-life, peak concentration, and total area under the curve were similar between intranasal and oral administration, the median peak time from intranasal was much shorter (10 vs 58 minutes, P < .001, Mann-Whitney U test). The variability of the pharmacokinetic parameters was also less with intranasal than oral administration. The relative bioavailability of intranasal to oral was 1.67. Intranasal VDF caused transient but tolerable local nasal reactions in 50% of subjects. Other adverse events (eg, headache) were similar between the treatments. The incidence of adverse events was, however, significantly less in the second treatment after initial exposure to VDF. No serious adverse events were noted. CLINICAL IMPLICATIONS: Intranasal VDF potentially offers a more timely and lower dose for the treatment of ED in patients who can tolerate the transient local adverse reactions. STRENGTHS AND LIMITATIONS: The strength of this study is its randomized crossover design. Because the study was conducted in 12 healthy young subjects, the results may not reflect those observed in elderly patients who may be likely taking VDF for ED. Nevertheless, the changes of pharmacokinetic parameters in the present study are likely a reflection of the differences between intranasal and oral administration of the formulations. CONCLUSION: Our study indicated that the present VDF formulation, when administered intranasally, can achieve a more rapid but similar plasma concentration with only about one-third dose when compared with the oral administration.

Use of conditional reprogramming cell, patient derived xenograft and organoid for drug screening for individualized prostate cancer therapy: Current and future perspectives (Review).

Prostate cancer mortality is ranked second among all cancer mortalities in men worldwide. There is a great need for a method of efficient drug screening for precision therapy, especially for patients with existing drug­resistant prostate cancer. Based on the concept of bacterial cell culture and drug sensitivity testing, the traditional approach of cancer drug screening is inadequate. The current and more innovative use of cancer cell culture and in vivo tumor models in drug screening for potential individualization of anti­cancer therapy is reviewed and discussed in the present review. An ideal screening model would have the ability to identify drug activity for the targeted cells resembling what would have occurred in the in vivo environment. Based on this principle, three available cell culture/tumor screening models for prostate cancer are reviewed and considered. The culture conditions, advantages and disadvantages for each model together with ideas to best utilize these models are discussed. The first screening model uses conditional reprogramed cells derived from patient cancer cells. Although these cells are convenient to grow and use, they are likely to have different markers and characteristics from original tumor cells and thus not likely to be informative. The second model employs patient derived xenograft (PDX) which resembles an in vivo approach, but its main disadvantages are that it cannot be easily genetically modified and it is not suitable for high­throughput drug screening. Finally, high­throughput screening is more feasible with tumor organoids grown from patient cancer cells. The last system still needs a large number of tumor cells. It lacks in situ blood vessels, immune cells and the extracellular matrix. Based on these current models, future establishment of an organoid data bank would allow the selection of a specific organoid resembling that of an individual's prostate cancer and used for screening of suitable anticancer drugs. This can be further confirmed using the PDX model. Thus, this combined organoid­PDX approach is expected to be able to provide the drug sensitivity testing approach for individualization of prostate cancer therapy in the near future.

Development of a simple and rapid HPLC-MS/MS method for quantification of streptomycin in mice and its application to plasma pharmacokinetic studies.

Streptomycin was the first discovered aminoglycoside antibiotic. It has been widely applied in veterinary medicine for the prevention and treatment of bacterial infection. However, the current detection methods are not satisfactory in terms of sensitivity and sample process, which makes them unsuitable for a pharmacokinetic study. A high-performance liquid chromatography-mass spectrometric method employing positive electrospray ionization was developed and validated for the determination of streptomycin concentration in mice plasma. A simple protein precipitation method was utilized to extract streptomycin as well as the internal standard (kanamycin) from mouse plasma. This assay method was validated in terms of specificity, sensitivity, precision, accuracy and recovery. This method was applied to a pharmacokinetic study in mice following intramuscular administration of 200 mg/kg streptomycin. The lower limit of quantification of the developed assay method for streptomycin was 10 ng/mL. The intra-day and inter-day precision was evaluated with the coefficient of variations <14.3%, whereas the mean accuracy ranged from 87.0 to 105.0%. The samples were stable under the experimental conditions. The present method provides a robust, fast and sensitive analytical approach for the quantification of streptomycin in mouse plasma and has been successfully applied to a pharmacokinetic study in mice.

Follow that botanical: Challenges and recommendations for assessing absorption, distribution, metabolism and excretion of botanical dietary supplements.

Botanical dietary supplements are complex mixtures containing one or more botanical ingredient(s), each containing numerous constituents potentially responsible for its purported biological activity. Absorption, distribution, metabolism, and excretion (ADME) data are critical to understand the safety of botanical dietary supplements, including their potential for pharmacokinetic botanical-drug or botanical-botanical interactions. However, ADME data for botanical dietary supplements are rarely available and frequently inadequate to characterize their fate in vivo. Based on an assessment of the current status of botanical dietary supplements ADME research, the following key areas are identified that require robust data for human safety assessment: 1) phytochemical characterization including contaminant analysis and botanical authentication; 2) in vitro and/or in vivo data for identifying potential botanical-botanical or botanical-drug interactions and active/marker constituents; 3) robust ADME study design to include systemic exposure data on active/marker constituents using traditional or novel analytical chemistry and statistical approaches such as poly-pharmacokinetics; and 4) investigation of human relevance. A case study with Ginkgo biloba extract is used to highlight the challenges and proposed approaches in using ADME data for human safety assessment of botanical dietary supplements.

Bioavailability of wilforlide A in mice and its concentration determination using an HPLC-APCI-MS/MS method.

Wilforlide A (WA), an active compound in Tripterygium wilfordii Hook F (TW) which is a traditional Chinese medicine for treatment of autoimmune diseases, is a quality control marker for TW product. At present, the bioavailability/pharmacokinetics of WA is not known. Such information is not only essential to evaluate the relevance of WA as a quality control maker, but also important for future clinical efficacy studies. Therefore, a high-performance liquid chromatography-atmospheric pressure chemical ionization tandem mass spectrometric method (HPLC-APCI-MS/MS) was developed and applied to a bioavailability/pharmacokinetic study of WA. WA and celastrol (the internal standard, IS) were extracted by a liquid-liquid extraction method using methyl tert-butyl ether. Multiple reaction monitoring (MRM) scanning in positive ionization mode was used to monitor the transition of m/z 455.1 to 191.3 for WA and 451.3 to 201.2 for IS. This method was validated and applied to a pharmacokinetic study of WA in mice following intravenous administration (IV, 1.2 mg/kg), intraperitoneal injection (IP, 6 mg/kg) and oral administration (PO, 30 mg/kg). The lower limit of quantification (LLOQ) for WA was 10 ng/ml. The intra- and inter-day precision was found to be within 15.4% while the accuracy within 94.1-115.7% for all the quality control and LLOQ samples. The samples were stable under all the usual storage and experimental conditions. The terminal elimination half-lives were 14.7, 9.1 and 22.7 min following IV, IP and PO dosing, while the absolute bioavailability for IP and PO WA were 9.39% and 0.58% respectively. These results indicated that the HPLC-APCI-MS/MS assay was suitable for the pharmacokinetic study of WA. WA was found poorly absorbed when given orally and therefore it may not be a relevant marker for the oral TW products in the market.

A simple and sensitive HPLC-MS/MS method for quantification of eggmanone in rat plasma and its application to pharmacokinetics.

Allosteric phosphodiesterase 4 (PDE4) inhibitors are highly sought after due to their important anti-inflammatory and anti-cancer therapeutic effects. We recently identified Eggmanone, an extraordinarily selective allosteric PDE4 inhibitor displaying favorable drug properties. However, a specific analytic method of Eggmanone in serum and its pharmacokinetics have not been reported yet. In this study, we developed a rapid and sensitive high performance liquid chromatography-mass spectrometric (HPLC-MS/MS) method to determine Eggmanone concentrations in rat plasma. This assay method was validated in terms of specificity, linearity, sensitivity, accuracy, precision, matrix effect, recovery and stability, and was applied to a pharmacokinetic study in rats following intravenous injection of Eggmanone at doses of 1 and 3 mg/kg. The lower limit of quantification (LLOQ) of this assay was 5 ng/mL and the linear calibration curve was acquired with R2 > 0.99 between 5 and 1000 ng/m. The intra-day and inter-day precision was evaluated with the coefficient of variations less than 11.09%, whereas the mean accuracy ranged from 98.38% to 105.13%. The assay method exhibited good recovery and negligible matrix effect. The samples were stable under all the experimental conditions. The plasma concentrations of Eggmanone were detected and quantified over 24 h with the terminal elimination half-live of 3.57 ±â€¯1.80 h and 5.92 ±â€¯3.34 h for the low dose (1 mg/kg) and high dose (3 mg/kg) respectively. In summary, the present method provides a robust, fast and sensitive analytical approach for quantification of Eggmanone in plasma and was successfully applied to a pharmacokinetic study in rats.

Enhanced anti-tumor efficacy and mechanisms associated with docetaxel-piperine combination- in vitro and in vivo investigation using a taxane-resistant prostate cancer model.

Docetaxel (DTX) is widely used for metastatic castrated resistant prostate cancer, but its efficacy is often compromised by drug resistance associated with low intracellular concentrations. Piperine (PIP) could enhance the bioavailability of other drugs via the inhibition of CYPs and P-gp activities. Thus, we hypothesize a positive effect with the DTX-PIP combination on the anti-tumor efficacy and intra-tumor DTX concentrations in taxane-resistant prostate cancer. ICR-NOD/SCID mice implanted with taxane-resistant human prostate cancer cells were administrated with saline as well as PIP and DTX separately or in combination. The tumor growth was monitored together with intra-tumor concentrations of DTX. The inhibitory effects on CYPs and P-gp were further assessed in mouse liver microsome and MDCK-MDR1 cells. Compared with DTX alone, DTX-PIP combination significantly inhibited the tumor growth (114% vs. 217%, p = 0.002) with corresponding significantly higher intra-tumor DTX concentrations (5.854 ± 5.510 ng/ml vs. 1.312 ± 0.754 ng/mg, p = 0.037). The percentage of DTX metabolism was significantly decreased from 28.94 ± 1.06% to 18.14 ± 2.22% in mouse liver microsome after administration of PIP for two weeks. DTX accumulation in MDCK-MDR1 cell was significantly enhanced in the presence of PIP. Further microarray analysis revealed that PIP inhibited P-gp as well as CYP1B1 gene expression and induced a significant gene expression change relating to inflammatory response, angiogenesis, cell proliferation, or cell migration. In conclusion, DTX-PIP combination significantly induces activity against taxane-resistant prostate tumor. Such effect appeared to be attributed to the inhibitory effect of PIP on CYPs and P-gp activity as well as gene expression changes relating to tumorigenesis and cellular responses.

Non-linear pharmacokinetics of piperine and its herb-drug interactions with docetaxel in Sprague-Dawley rats.

Piperine (PIP), the major alkaloid component from Piper longum L. and Piper nigrum L., could enhance the bioavailabilities of other drugs including rosuvastatin, peurarin and docetaxel (DOX) via inhibition of CYP3A and P-glycoprotein activity. Nevertheless, the effect of such drug combination usage on the in vivo exposure of PIP has not been investigated due to lack of assay for the simultaneous determination of PIP and other drugs such as DOX. Besides, the reported pharmacokinetics of PIP varied a lot without appropriate bioavailability determined from the same dose. In the current study, an LC/MS/MS method has been developed to simultaneously determine the plasma concentrations of PIP and DOX and further applied to investigate the pharmacokinetics properties of PIP after oral and intravenous administrations as well as the pharmacokinetics interactions between PIP and DOX after their co-administration. A simple protein precipitation method was employed for plasma sample treatment by adding a mixture of methanol and acetonitrile (1:1, v/v) with glibenclamide as internal standard (IS). The LC/MS/MS system consisted of Agilent 6430 series LC pumps and auto-sampler. The chromatographic separation was carried out in 15min on a Waters C18 column (150×3.9mm i.d., 4µm) with a mobile phase containing 0.2% formic acid and acetonitrile (1:1, v/v) at a flow rate of 0.4ml/min. The detection was performed using the positive ion electrospray ionization (ESI) in multiple reaction monitoring (MRM) mode with precursor-to-product ion transitions at m/z 286.1→201.1 for PIP, m/z 830.3→548.9 for DOX and m/z 494.2→369.0 for IS. The method demonstrated good linearity for both PIP and DOX over the concentration range of 2.5-1280ng/ml with LLOD at 2.5ng/ml. The intra-day and inter-day precisions were less than 13.34% and relative error (R.E.) representing accuracy was in the range of -11.38 to 3.15%. The recoveries of PIP, DOX and IS were above 75% and there was no matrix effect. PIP and DOX exhibited good stabilities under various conditions. PIP was administrated via intravenous bolus at 3.5mg/kg and via oral administration at 35mg/kg and 3.5mg/kg, while DOX was intravenously administrated at 7mg/kg to Sprague-Daley rats. The plasma concentrations of PIP and DOX were determined using the above developed and validated method. At the dose of 3.5mg/kg, the bioavailability of PIP was calculated to be 25.36%. Its AUC0→t was unproportionally increased with doses, indicating a potential non-linear pharmacokinetics profile of PIP. It was found that the AUC0→t and C0 of DOX and t1/2 of PIP were significantly increased after their combination use, suggesting potential enhanced bioavailability of not only DOX but also PIP, which may lead to the overall enhanced pharmacological effects.

Intralesional Injection of OK-432 in Cystic Hygroma.

BACKGROUND: Lymphangiomas are congenital malformations of the lymphatic system with characteristic dilated endothelium-lined spaces. It is vulnerability to infection or chemical irritants cause spontaneous reduction in size and in some cases complete resolution. Intralesional injection of OK-432 or Picibanil (lyophilized incubation mixture of Group A Streptococcus pyogenes of human origin) is slowly gaining recognition as its safety and efficacy standards have shown to avoid complications resulting from surgical interventions. The objective of this study was to evaluate the clinical outcomes of cystic hygroma patients who received OK-432 injections. METHODS: In between 2011 and 2013, six patients with cystic hygroma received intralesional injection of OK-432. All the patients were assessed clinically and radiologically either via ultrasound, computer tomography (CT) or magnetic resonant imaging (MRI) prior to and after receiving the injections. Patients' response towards treatment was classified as total shrinkage, marked shrinkage (greater than 50% reduction in size), slight shrinkage (less than 50% reduction in size) or non-responsive to treatment. RESULTS: Mean duration of follow-up was 12 months. Total shrinkage was achieved in one patient, marked shrinkage in three patients and one patient experienced mild shrinkage. Only one out of the six patients showed no response to treatment. None of the patients in this study experienced serious complications or adverse effects post intralesional injection of OK-432. CONCLUSIONS: Intralesional OK-432 injection is an effective and safe alternative in treating cystic hygroma.

Diagnosis of upper aerodigestive tract tumours using autofluorescence endoscopy in south east asian patients.

Diagnosis of upper aerodigestive tract tumours using autofluorescence endoscopy in south east asian patients. OBJECTIVES: Autofluorescence is a highly sensitive, and specific, complementary diagnostic tool for the photodiagnosis of head and neck squamous cell carcinomas. Together with ease of use, these properties suggest that autofluorescence, used alongside white light endoscopy, could be a promising tool for the screening of high-risk populations. The aim of this study was to evaluate its effectiveness in detecting tumours involving the upper aerodigestive tract, in comparison with histopathologic examination. METHODOLOGY: A cross-sectional prospective study was carried out from June 2011 till March 2012. Forty-five patients with clinical evidence of suspicious lesions involving the upper aerodigestive tract were enrolled and examined using conventional white light, and autofluorescence endoscopy. A biopsy of each lesion was subsequently submitted for histopathologic examination. RESULTS: Using histology as our gold standard, we compared the sensitivity, specificity, and predictive values of autofluorescence endoscopy in detecting upper aerodigestive tract tumours. In comparison to histopathologic examination, the sensitivity of autofluorescence endoscopy was 95%, with a specificity of 74% (P value<0.001). The positive and negative predictive values were 78%, and 94% respectively. These data confirm a statistically significant correlation between autofluorescence and histopathologic diagnoses. CONCLUSIONS: Autofluorescence endoscopy was effective in detecting upper aerodigestive tract tumours, with excellent discrimination between benign and malignant phenotypes; this methodology is an ideal adjunct to white light endoscopy.

Molecular signatures in the prevention of radiation damage by the synergistic effect of N-acetyl cysteine and qingre liyan decoction, a traditional chinese medicine, using a 3-dimensional cell culture model of oral mucositis.

Qingre Liyan decoction (QYD), a Traditional Chinese medicine, and N-acetyl cysteine (NAC) have been used to prevent radiation induced mucositis. This work evaluates the protective mechanisms of QYD, NAC, and their combination (NAC-QYD) at the cellular and transcriptional level. A validated organotypic model of oral mucosal consisting of a three-dimensional (3D) cell tissue-culture of primary human keratinocytes exposed to X-ray irradiation was used. Six hours after the irradiation, the tissues were evaluated by hematoxylin and eosin (H and E) and a TUNEL assay to assess histopathology and apoptosis, respectively. Total RNA was extracted and used for microarray gene expression profiling. The tissue-cultures treated with NAC-QYD preserved their integrity and showed no apoptosis. Microarray results revealed that the NAC-QYD caused the upregulation of genes encoding metallothioneins, HMOX1, and other components of the Nrf2 pathway, which protects against oxidative stress. DNA repair genes (XCP, GADD45G, RAD9, and XRCC1), protective genes (EGFR and PPARD), and genes of the NFκB pathway were upregulated. Finally, tissue-cultures treated prophylactically with NAC-QYD showed significant downregulation of apoptosis, cytokines and chemokines genes, and constrained damage-associated molecular patterns (DAMPs). NAC-QYD treatment involves the protective effect of Nrf2, NFκB, and DNA repair factors.

Bench to bed evidences for pharmacokinetic and pharmacodynamic interactions involving oseltamivir and chinese medicine.

Oseltamivir (OA), an ethyl ester prodrug of oseltamivir carboxylate (OC), is clinically used as a potent and selective inhibitor of neuraminidase. Chinese medicines have been advocated to combine with conventional drug for avian influenza. The current study aims to investigate the potential pharmacokinetic and pharmacodynamic interactions of a Chinese medicine formula, namely, Yin Qiao San and Sang Ju Yin (CMF1), commonly used for anti-influenza in combination with OA in both rat and human, and to reveal the underlined mechanisms. It was found that although C max, AUC and urinary recovery of OC, as well as metabolic ratio (AUCOC/AUCOA), were significantly decreased in a dose-dependent manner following combination use of CMF1 and OA in rat studies (P < 0.01), such coadministration in 14 healthy volunteers only resulted in a trend of minor decrease in the related parameters. Further mechanistic studies found that although CMF1 could reduce absorption and metabolism of OA, it appears to enhance viral inhibition of OA (P < 0.01). In summary, although there was potential interaction between OA and CMF1 found in rat studies, its clinical impact was expected to be minimal. The coadministration of OA and CMF1 at the clinical recommended dosages is, therefore, considered to be safe.

Nutraceuticals for prostate cancer chemoprevention: from molecular mechanisms to clinical application.

INTRODUCTION: Nutraceutical is a food, or part of a food, used for the prevention and/or treatment of diseases. A number of nutraceuticals serve as candidates for development of prostate cancer chemopreventive agents because of promising epidemiological, preclinical and pilot clinical findings. Their mechanisms of action may involve an ability to target multiple molecular pathways in carcinogenesis without eliciting toxic side effects. AREAS COVERED: This review provides an overview of several nutraceuticals, including green tea polyphenol, omega-3 fatty acids, vitamin D, lycopene, genistein, quercetin, resveratrol and sulforaphane, for the clinical relevance to chemoprevention of prostate cancer. Their mechanisms of action on regulating key processes of carcinogenesis are also discussed. For each of these agents, a brief summary of completed or currently ongoing clinical trials related to the chemopreventive efficacy on prostate cancer is given. EXPERT OPINION: Even though a few clinical trials have been conducted, review of these results indicate that further studies are required to confirm the clinical efficacy and safety, and to provide a guidance on how to use nutraceuticals for optimal effect. Future cancer prevention clinical trials for the nutraceuticals should recruit men with an increased risk of prostate cancer.

Bioavailability enhancement of glucosamine hydrochloride by chitosan.

Glucosamine, as a dietary supplement for management of osteoarthritis, has a low and erratic oral bioavailability due to its transport-mediated absorption and presystemic loss in liver and GI tract. The present study described an effective approach to improve glucosamine intestinal absorption and hence its bioavailability using chitosan. Effects of chitosan on intestinal permeability and pharmacokinetics of glucosamine were evaluated in Caco-2 cell monolayer and rats, respectively. In addition, randomized crossover pharmacokinetic studies in beagle dogs were performed to evaluate the oral bioavailabilities of the developed glucosamine oral formulations containing chitosan (QD-Glu solution and QD-Glu tablet) in comparison to its commercial products. Caco-2 permeability studies demonstrated that chitosan could enhance the absorptive transport of glucosamine by 1.9-4.0-fold via the reversible opening of the cell tight junction. After oral administration of glucosamine solutions containing chitosan in rats, it was found that 0.5% (w/v) chitosan exhibited the highest enhancement in Cmax (2.8-fold) and AUC0-∞ (2.5-fold) of glucosamine. Further pharmacokinetic studies in beagle dogs demonstrated that QD-Glu solution and QD-Glu tablet showed much higher relative bioavailabilities of 313% and 186%, when comparing with Wellesse™ solution and Voltaflex™ tablet, respectively. In conclusion, chitosan could serve as a promising oral absorption enhancer for glucosamine.

Utilization of gene expression signature for quality control of traditional Chinese medicine formula Si-Wu-Tang.

The current study utilized a combined pharmacokinetic and genomic approach to demonstrate the feasibility of a new quality control method by using a panel of special differentially expressed genes (DEGs) as unique fingerprint to serve as marker of in vivo bioactivity for a representative traditional Chinese medicine (TCM) formula, Si-Wu-Tang (SWT). The method involves firstly obtaining possible in vivo active components, i.e., the "absorbable" components from the permeate of the Caco-2 monolayer model to simulate oral administration of two specific SWT products (CU-SWT, J-SWT), their component single herbs (Angelicae, Chuanxiong, Paeoniae, and Rehmanniae), and a standard mixture of active compounds (ferulic acid, ligustilide, senkyunolide A). Then, these respective absorbable components were incubated with MCF-7 cells to determine the gene expression profile using microarray processing/analysis as well as real-time PCR. From the available DEGs identified following the incubation, the magnitude of change in DEGs by real-time PCR was found to be consistent with that by microarray. The designated DEGs from the CU-SWT permeate were found to be distinct from other 19 products. Furthermore, the changes in the DEGs resulting from MCF-7 cells treated by eight replicate extracts of CU-SWT on three separate days were consistent. These results demonstrated sufficient specificity and consistency of the DEG panel which could serve as a unique bioactive "fingerprint" for the designated SWT product. The present method for DEG determination may be applied to other TCM products and with further definitive study can potentially provide a unique method for quality control of TCM in the future.

Clinical pharmacokinetics of buffered propranolol sublingual tablet (Promptol™)-application of a new "physiologically based" model to assess absorption and disposition.

Sublingual administration of certain buffered propranolol may improve the rate and extent of absorption compared to oral administration. The main objectives of this study were to (1) compare the plasma propranolol concentrations (Cp-prop) following sublingual administration of a specially buffered formulation (Promptol™) to that following oral administration of Inderal(®) and (2) evaluate the utility of a special pharmacokinetic model in describing the Cp-prop following sublingual administration. Eighteen healthy volunteers received 10 mg sublingual Promptol™ or oral Inderal(®). Multiple Cp-prop were determined and their pharmacokinetics compared. Additional data following sublingual 40 mg Promptol™ or Inderal(®) were utilized for evaluation of a special advanced compartmental absorption and transit (ACAT) model. For model simulation, the physicochemical parameters were imported from AMET predictor, whereas the pharmacokinetic parameters were calculated and optimized by Gastroplus(®). Based on this model, the quantity of drug absorbed via buccal/sublingual mucosa was estimated. Cp-prop was higher at earlier times with 3-fold greater relative bioavailability following sublingual Promptol™ compared to that from oral Inderal(®). The special ACAT model provided excellent goodness of fit of Cp-prop-time curve and estimated a 56.6% increase in absorption rate from Promptol™ and higher initial Cp-prop compared to the regular formulation. The modified ACAT model provided a useful approach to describe sublingual absorption of propranolol and clearly demonstrated an improvement of absorption of Promptol™. The sublingual 10 mg Promptol™ achieved not only a similar systemic exposure as 30 mg oral Inderal(®) but an earlier effective Cp-prop which may be advantageous for certain clinical conditions.

Transcriptional profiling of Chinese medicinal formula Si-Wu-Tang on breast cancer cells reveals phytoestrogenic activity.

BACKGROUND: Si-Wu-Tang (SWT), comprising the combination of four herbs, Paeoniae, Angelicae, Chuanxiong and Rehmanniae, is one of the most popular traditional oriental medicines for women's diseases. In our previous study, the microarray gene expression profiles of SWT on breast cancer cell line MCF-7 were found similar to the effect of ß-estradiol (E2) on MCF-7 cells in the Connectivity Map database. METHODS: Further data analysis was conducted to find the main similarities and differences between the effects of SWT and E2 on MCF-7 gene expression. The cell proliferation assay on MCF-7 (ER-positive) and MDA-MB-231 (ER-negative) cells were used to examine such estrogenic activity. The estrogenic potency of SWT was further confirmed by estrogen-responsive element (ERE) luciferase reporter assay in MCF-7 cells. RESULTS: Many estrogen regulated genes strongly up-regulated by E2 were similarly up-regulated by SWT, e.g., GREB1, PGR and EGR3. Of interest with regard to safety of SWT, the oncogenes MYBL1 and RET were strongly induced by E2 but not by SWT. Quantitative RT-PCR analysis revealed a highly concordant expression change in selected genes with data obtained by microarrays. Further supporting SWT's estrogenic activity, in MCF-7 but not in MDA-MB-231 cells, SWT stimulated cell growth at lower concentrations (< 3.0 mg/ml), while at high concentrations, it inhibits the growth of both cell lines. The growth inhibitory potency of SWT was significantly higher in MDA-MB-231 than in MCF-7 cells. The SWT-induced cell growth of MCF-7 could be blocked by addition of the estrogen receptor antagonist tamoxifen. In addition, SWT was able to activate the ERE activity at lower concentrations. The herbal components Angelicae, Chuanxiong and Rehmanniae at lower concentrations (< 3.0 mg/ml) also showed growth-inducing and ERE-activating activity in MCF-7 cells. CONCLUSIONS: These results revealed a new mechanism to support the clinical use of SWT for estrogen related diseases and possibly for cancer prevention. This study also demonstrated the feasibility of using microarray transcriptional profiling to discover phytoestrogenic components that are present in natural products.

Meclizine metabolism and pharmacokinetics: formulation on its absorption.

Meclizine, an antihistamine, has been widely used for prophylactic treatment and management of motion sickness. However, the onset of action of meclizine was about 1 hour for the treatment of motion sickness and vertigo. A new suspension formulation of meclizine (MOS) was developed with the intention to achieve a rapid effect. To investigate the pharmacokinetics of the new MOS formulation versus the marketed meclizine oral tablet (MOT), a phase 1 pharmacokinetic study was performed in 20 healthy volunteers. In addition, an in vitro metabolic study using human hepatic microsome and recombinant CYP enzyme was also performed to determine the metabolic pathway in the human body. The plasma concentration of MOS appeared more rapidly in comparison to the MOT. The geometric mean ratios (90% confidence interval) of AUC(0-24) and AUC(0-∞) indicated no significant difference in bioavailability between the 2 formulations. CYP2D6 was found to be the dominant enzyme for metabolism of meclizine, and its genetic polymorphism could contribute to the large interindividual variability. In view of the similar bioavailability with a much shorter peak time of the plasma meclizine concentration from the MOS formulation, this new formulation is expected to produce a much quicker onset of action when used for the management of motion sickness.

An approach for rapid development of nasal delivery of analgesics--identification of relevant features, in vitro screening and in vivo verification.

Drug delivery via the nasal route is gaining increasing interest over the last two decades as an alternative to oral or parenteral drug administration. In the current study an approach for rapid identification of relevant features, screening and in vivo verification of potential therapeutic agents for nasal delivery was carried out using "analgesic agents" as an example. Four such drug candidates (rizatriptan, meloxicam, lornoxicam and nebivolol) were initially identified as potentially viable agents based on their therapeutic use and physicochemical characteristics. An in vitro screening was then carried out using the Calu-3 cell line model. Based on the in vitro screening results and the reported pharmacokinetic and the stability data, meloxicam was predicted to be the most promising drug candidate and was subsequently verified using an in vivo animal model. The in vivo results showed that nasal administration of meloxicam was comparable to its intravenous administration, with respect to plasma drug concentration and AUC(0-2h). In addition, nasal absorption of meloxicam was much more rapid with higher plasma drug concentration and AUC(0-2h) than that of oral administration. The current approach appears to be capable of developing "analgesic agents" suitable for nasal delivery. Further studies are needed to prove the clinical advantage of the specific selected agent, meloxicam, by nasal administration in patients.