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Background: CDK7 inhibition is a promising therapeutic strategy in cancer; acting as a regulator of the cell cycle, transcription and endocrine receptor signalling [1]. Patients with HR+BC post CDK4/6 inhibitor treatment have a poor prognosis; median progression free survival (mPFS) of ~ 8 weeks for fulvestrant post CDK4/6i in HR+BC [2,3]. Pre-clinical HR+BC models indicate the potential for synergy when the CDK7 inhibitor samuraciclib is combined with the Selective Estrogen Receptor Degrader fulvestrant [4]Materials and Methods: This single arm cohort assessed the tolerability and efficacy of samuraciclib in combination with standard dose fulvestrant in patients with advanced HR+BC; all patients had previously received an aromatase inhibitor and a CDK4/6i for advanced disease.Results: 31 patients with HR+BC received the combination of standard dose with fulvestrant and samuraciclib. 6 patients received samuraciclib dose of 240mg once daily (QD) and 25 patients a dose of 360mg QD. The combination treatment was generally well tolerated, with adverse drug reactions (AE) of note being G1-2 nausea, vomiting and diarrhoea; the majority of patients staying on treatment until disease progression.RECIST evaluation indicates evidence of reduction in tumor disease burden, including a partial response in one patient who has been on treatment for ~ 1 year.Graphic illustrations of data, including ‘waterfall’ and ‘swimmer’ plots, will be presented along with stratification data based on demographic factors such as hepatic involvement and cfDNA analysis (ESR1m, PI3Km).Conclusions: Samuraciclib has demonstrated an acceptable safety profile with evidence of anti-tumour activity in combination with fulvestrant for patients with advanced HR+BC who have progressed on their prior CDK4/6i.References:1.Patel et al., Mol Cancer Therap. 20182.Juric et al., SABCS 20183.Lindeman et al., JCO 20214.Jeselsohn et al., SABCS 2019 Citation Format: Charles Coombes, Sasha J Howell, Matthew G Krebs, Simon Lord, Laura M Kenny, Ash Bahl, Glen Clack, Edward Ainscow, Paul A Dickinson, Raluca Fostea, Janine Mansi, Carlo Palmieri, Gianflippo Bertelli, Rinath Jeselsohn, Zahi Mitri, William J Gradishar, Sagar Sardesai, Joyce O'Shaughnessy, Patrick Ward, Pavani Chalasani, Manfred Lehnert, Simak Ali, Stuart McIntosh. Study of samuraciclib (CT7001), a first-in-class, oral, selective inhibitor of CDK7, in combination with fulvestrant in patients with advanced hormone receptor positive HER2 negative breast cancer (HR+BC) [abstract]. In: Proceedings of the 2021 San Antonio Breast Cancer Symposium; 2021 Dec 7-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2022;82(4 Suppl):Abstract nr GS3-10.

Background: CDK7 inhibition is a promising therapeutic strategy in cancer. CDK7 is a key kinase, regulating cell division, transcription and nuclear receptor function [1]. Although recent advances have been made in the treatment of TNBC this disease is still one of significant unmet need. Materials and Methods: Tolerability and efficacy of Samuraciclib were assessed in a TNBC expansion cohort of the first in human study of Samuraciclib. These patients had metastatic or locally advanced TNBC and had received prior taxane and anthracycline therapy including at least one line of chemotherapy for metastatic or locally advanced disease. Results: From 29th January 2019 to 12th April 2021, 23 women with advanced TNBC were recruited and dosed with Samuraciclib 360mg OD. Treatment has generally been well tolerated with all patients remaining on treatment until disease progression. The most common adverse drug reactions (AE) were: G1-2 Nausea (96%), Vomiting (52%) and Diarrhea (91%). There were 4 dose reductions to manage upper GI adverse events of nausea and/or vomiting. G3 events were as follows: 2 Grade 3 Diarrhea, 1 Grade 3 Vomiting, 1 Grade 3 Fatigue, 1 Grade 3 Stomatitis, 1 Grade 3 Anaemia and 1 Grade 4 Thrombocytopenia21 patients have had follow-up evaluations for assessment of efficacy. Stable disease was achieved in 14 patients, 1 with partial response (being on treatment for 72 weeks) and 7 patients with progressive disease; two additional patients remain on compassionate use treatment, following disease progression by RECIST. 5 patients have been on treatment for at least 24 weeks of whom 3 have exceeded 1 year. Conclusions: Samuraciclib demonstrated an acceptable safety and tolerability profile with evidence of antitumour activity in advanced TNBC. References1.Patel et al. ICEC0942, an Orally Bioavailable Selective Inhibitor of CDK7 for Cancer Treatment. Mol Cancer Ther. 2018. doi: 10.1158/1535-7163.MCT-16-0847. PMID:29545334. Citation Format: Sacha J Howell, Laura M Kenny, Simon Lord, Matthew G Krebs, Tobias Arkenau, Richard Baird, Iain R MacPherson, Ash Bahl, Glen Clack, Edward Ainscow, Anthony GM Barrett, Paul A Dickinson, Matthew J Fuchter, Manfred Lehnert, Simak Ali, Stuart McIntosh, Charles Coombes. A clinical study of samuraciclib (CT7001), a first-in-class, oral, selective inhibitor of CDK7, in patients with advanced triple negative breast cancer (TNBC) [abstract]. In: Proceedings of the 2021 San Antonio Breast Cancer Symposium; 2021 Dec 7-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2022;82(4 Suppl):Abstract nr P1-18-10.

Long acting injectables (LAI) products are a popular intervention for treating a number of chronic conditions,with their long drug release reducing the administration frequency and thus improving patient adherence.The extended release, however, can provide a major challenge to bioequivalence (BE) testing since the long absorption half-life results in a long washout period, meaning that a traditional BE study can be many months or years in length. The unique PK profile for LAI products also means that it is critical to haveappropriate metrics to summarise the plasma concentration profile. In this work, we use paliperidone as acase study to demonstrate how Population PK modelling can be utilised to explore sensitivity of summarymetrics to different products. We also determine a range of products that are bioequivalent after bothmultiple dosing and single dosing. Finally, we show how the modelling can be used in a (virtual) PKstudy as an alternative approach to determining bioequivalence. This work demonstrates the potentialfor Population PK modelling in bioequivalence assessment, opening doors to more streamlined productdevelopment.

This report summarizes the proceedings for Day 3 of the workshop titled "Current State and Future Expectations of Translational Modeling Strategies toSupportDrug Product Development, Manufacturing Changes and Controls". From a drug product quality perspective, patient-centric product development necessitates the development of clinically relevant drug product specifications (CRDPS). In this regard, Physiologically Based Biopharmaceutics modeling (PBBM) is a viable tool to establish links between in-vitro to in-vivo data, and support with establishing CRDPS. The theme of day 3 was practical applications of PBBM to support drug product quality. In this manuscript, case studies from US FDA, EMA and pharmaceutical industry on applications of PBBM in drug product quality are summarized which include 1) regulatory agency's perspectives on establishing the safe space and achieving study waivers, 2) model-informed risk assessment on the effects of acid reducing agents, bridging of dissolution methods, food effect, and formulation selection, and 3) understanding clinical formulation performance. Breakout session discussions focused on four topics - 1) terminologies related to physiologically based modeling in support of drug product quality, 2) regulatory harmonization on evidentiary standards, 3) CRDPS approaches and 4) bridging between biorelevant and quality control (QC) dissolution methods.

In order to meet the needs of employers and to make students more employable Laurea University, Finland has developed an “experiential” educational model through project-based learning in English based around real business projects linking theory studied. The programme is a bachelors degree conducted with international exchange students from many different countries (including Turkey, Germany, Romania, Spain, China, Holland, Mexico, Japan, and Italy) within project teams. English is a second language to these students, but it is not known as to how and if their language develops during the programme. The study considers the “experiential” nature of both the programme and the language from a literature perspective then focusing particularly on the learning of English by the students without any formal teaching classes. The students participated within projects for one semester (via an exchange programme) during an academic period from August 2018 to May 2020. There is a quantitative empirical approach (using a written questionnaire) which was qualitative in nature (including open questions) which related to the assessment of the English language learning experience of 29 international exchange students. Their feedback via answers to written questions forms the basis of the study. Findings reveal that such an approach to language learning can be successful and was positive in the sense of flexibility, relevance and enjoyability as well as the easy access and help of technology. The students generally felt their language level had improved through informal discussions and by use of a language app connected to the project work. Also, some students felt that the “learning by doing” (through the projects) improved their language authenticity and application. However, some students felt their language learning would have further increased by the use of a “weekly relevant noun/adjective list” during the project meetings. The research overall shows that some language improvement can be achieved informally within an “experiential” educational model through project-based learning. Additionally, that can be within one semester and by students from different countries with different educational systems. Article visualizations

Decision-making in drug development benefits from an integrated systems approach, where the stakeholders identify and address the critical questions for the system through carefully designed and performed studies. Biopharmaceutics Risk Assessment Roadmap (BioRAM) is such a systems approach for application of systems thinking to patient focused and timely decision-making, suitable for all stages of drug discovery and development. We described the BioRAM therapy-driven drug delivery framework, strategic roadmap, and integrated risk assessment instrument (BioRAM Scoring Grid) in previous publications (J Pharm Sci 103:3377–97, 2014; J Pharm Sci 105:3243–55, 2016). Integration of systems thinking with pharmaceutical development, manufacturing, and clinical sciences and health care is unique to BioRAM where the developed strategy identifies the system and enables risk characterization and balancing for the entire system. Successful decision-making process in BioRAM starts with the Blueprint (BP) meetings. Through shared understanding of the system, the program strategy is developed and captured in the program BP. Here, we provide three semi-hypothetical examples for illustrating risk-based decision-making in high and moderate risk settings. In the high-risk setting, which is a rare disease area, two completely alternate development approaches are considered (gene therapy and small molecule). The two moderate-risk examples represent varied knowledge levels and drivers for the programs. In one moderate-risk example, knowledge leveraging opportunities are drawn from the manufacturing knowledge and clinical performance of a similar drug substance. In the other example, knowledge on acute tolerance patterns for a similar mechanistic pathway is utilized for identifying markers to inform the drug release profile from the dosage form with the necessary “flexibility” for dosing. All examples illustrate implementation of the BioRAM strategy for leveraging knowledge and decision-making to optimize the clinical performance of drug products for patient benefit.

Aim We report on two Phase 1, open-label, single-arm studies assessing the effect of osimertinib on simvastatin (CYP3A substrate) and rosuvastatin (breast cancer resistance protein substrate [BCRP] substrate) exposure in patients with advanced epidermal growth factor receptor (EGFR)-mutated non-small cell lung cancer who have progressed after treatment with an EGFR tyrosine kinase inhibitor, to determine, upon coadministration, whether osimertinib could affect the exposure of these agents. Methods Fifty-two patients in the CYP3A study (pharmacokinetic [PK] analysis, n = 49), and 44 patients in the BCRP study were dosed (PK analysis, n = 44). In the CYP3A study, patients received single doses of simvastatin 40 mg on Days 1 and 31, and osimertinib 80 mg once daily on Days 3-32. In the BCRP study, single doses of rosuvastatin 20 mg were given on Days 1 and 32, and osimertinib 80 mg once daily on Days 4-34. Results Geometric least squares mean (GLSM) ratios (90% confidence intervals) of simvastatin plus osimertinib for area under the plasma concentration-time curves from zero to infinity (AUC) were 91% (77-108): entirely contained within the predefined no relevant effect limits, and Cmax of 77% (63, 94) which was not contained within the limits. GLSM ratios of rosuvastatin plus osimertinib for AUC were 135% (115-157) and Cmax were 172 (146, 203): outside the no relevant effect limits. Conclusions Osimertinib is unlikely to have any clinically relevant interaction with CYP3A substrates and has a weak inhibitory effect on BCRP. No new safety concerns were identified in either study.

Aims We investigated the effects of a strong CYP3A4 inhibitor (itraconazole) or inducer (rifampicin) on the pharmacokinetics of the epidermal growth factor receptor-tyrosine kinase inhibitor osimertinib, in patients with advanced non-small cell lung cancer in two Phase I, open-label, two-part clinical studies. Part one of both studies is reported. Methods In the itraconazole study (NCT02157883), patients received single-dose osimertinib 80 mg on Days 1 and 10 and itraconazole (200 mg twice daily) on Days 6-18 orally. In the rifampicin study (NCT02197247), patients received osimertinib 80 mg once daily on Days 1-77 and rifampicin 600 mg once daily on Days 29-49. Results In the itraconazole study (n = 36), the geometric least squares mean (GMLSM) ratios (osimertinib plus itraconazole/osimertinib alone) for Cmax and AUC were 80% (90% CI 73, 87) and 124% (90% CI 115, 135), respectively, below the predefined no-effect upper limit of 200%. In the rifampicin study (n = 40), the GMLSM ratios (osimertinib plus rifampicin/osimertinib alone) for Css,max and AUCτ were 27% (90% CI 24, 30) and 22% (90% CI 20, 24), respectively, below the predefined no-effect lower limit of 50%. The induction effect of rifampicin was apparent within 7 days of initiation; osimertinib Css,max and AUCτ values returned to pre-rifampicin levels within 3 weeks of rifampicin discontinuation. No new osimertinib safety findings were observed. Conclusions Osimertinib can be co-administered with CYP3A4 inhibitors, but strong CYP3A inducers should be avoided if possible.

BackgroundPreclinical Oncology drug development is heavily reliant on xenograft studies to assess the anti-tumour effect of new compounds. Patient derived xenograft (PDX) have become popular as they may better represent the clinical disease, however variability is greater than in cell-line derived xenografts. The typical approach of analysing these studies involves performing an un-paired t-test on the mean tumour volumes between the treated and control group at the end of the study. This approach ignores the time-series and may result in false conclusions, especially when considering the increased variability of PDX studies.AimTo test the hypothesis that a model-based analysis provides increased power than analysis of final day volumes and to provide insights into more efficient PDX study designs.MethodsData was extracted from tumour xenograft time-series data from a large publicly available PDX drug treatment database released by Novartis. For all 2-arm studies the percent tumour growth inhibition (TGI) at two time-points, day 10 and day 14 was calculated. For each study, the effect of treatment was calculated using an un-paired t-test and also a model-based analysis using the likelihood ratio-test. In addition a simulation study was also performed to assess the difference in power between the two data-analysis approaches for different levels of TGI for PDX or standard cell-line derived xenografts (CDX).ResultsThe model-based analysis had greater statistical power than the un-paired t-test approach within the PDX data-set. The model-based approach was able to detect TGI values as low as 25 percent whereas the un-paired t-test approach required at least 50 percent TGI. These findings were confirmed within the simulation study performed which also highlighted that CDX studies require less animals than PDX studies which show the equivalent level of TGI.ConclusionThe analysis of 59 2-arm PDX studies highlighted that taking a model-based approach gave increased statistical power over simply performing an un-paired t-test on the final study day. Importantly the model-based approach was able to detect smaller size of effect compared to the un-paired t-test approach is which maybe common of such studies. These findings were confirmed within simulated studies which also highlighted the same sample size used for CDX studies would lead to inadequately powered PDX studies. Application of a model-based analysis should allow studies to use less animals and run experiments for a shorter period thus providing effective insight into compound anti-tumour activity

Preclinical and clinical studies were conducted to determine the metabolism and pharmacokinetics of osimertinib and key metabolites AZ5104 and AZ7550. Osimertinib was designed to covalently bind to epidermal growth factor receptors, allowing it to achieve nanomolar cellular potency (Finlay et al., 2014). Covalent binding was observed in incubations of radiolabeled osimertinib with human and rat hepatocytes, human and rat plasma, and human serum albumin. Osimertinib, AZ5104, and AZ7550 were predominantly metabolized by CYP3A. Seven metabolites were detected in human hepatocytes, also observed in rat or dog hepatocytes at similar or higher levels. After oral administration of radiolabeled osimertinib to rats, drug-related material was widely distributed, with the highest radioactivity concentrations measured at 6 hours postdose in most tissues; radioactivity was detectable in 42% of tissues 60 days postdose. Concentrations of [(14)C]-radioactivity in blood were lower than in most tissues. After the administration of a single oral dose of 20 mg of radiolabeled osimertinib to healthy male volunteers, ∼19% of the dose was recovered by 3 days postdose. At 84 days postdose, mean total radioactivity recovery was 14.2% and 67.8% of the dose in urine and feces. The most abundant metabolite identified in feces was AZ5104 (∼6% of dose). Osimertinib accounted for ∼1% of total radioactivity in the plasma of non-small cell lung cancer patients after 22 days of 80-mg osimertinib once-daily treatment; the most abundant circulatory metabolites were AZ7550 and AZ5104 (

First-in-human (FIH) studies with AZD3514, a selective androgen receptor (AR) down-regulator, showed decreases of >30% in the prostate-specific antigen (PSA) in some patients. A modeling approach was adopted to understand these observations and define the optimum clinical use hypothesis for AZD3514 for clinical testing. Initial empirical modeling showed that only baseline PSA correlated significantly with this biological response, whereas drug concentration did not. To identify the mechanistic cause of this observation, a mechanism-based model was first developed, which described the effects of AZD3514 on AR protein and PSA mRNA levels in LNCaP cells with and without dihydrotestosterone (DHT). Second, the mechanism-based model was linked to a population pharmacokinetic (PK) model; PSA effects of clinical doses were subsequently simulated under different clinical conditions. This model was used to adjust the design of the ongoing clinical FIH study and direct the backup program.

Purpose To assess whether a model-based analysis increased statistical power over an analysis of final day volumes and provide insights into more efficient patient derived xenograft (PDX) study designs. Methods Tumour xenograft time-series data was extracted from a public PDX drug treatment database. For all 2-arm studies the percent tumour growth inhibition (TGI) at day 14, 21 and 28 was calculated. Treatment effect was analysed using an un-paired, two-tailed t-test (empirical) and a model-based analysis, likelihood ratio-test (LRT). In addition, a simulation study was performed to assess the difference in power between the two data-analysis approaches for PDX or standard cell-line derived xenografts (CDX). Results The model-based analysis had greater statistical power than the empirical approach within the PDX data-set. The model-based approach was able to detect TGI values as low as 25% whereas the empirical approach required at least 50% TGI. The simulation study confirmed the findings and highlighted that CDX studies require fewer animals than PDX studies which show the equivalent level of TGI. Conclusions The study conducted adds to the growing literature which has shown that a model-based analysis of xenograft data improves statistical power over the common empirical approach. The analysis conducted showed that a model-based approach, based on the first mathematical model of tumour growth, was able to detect smaller size of effect compared to the empirical approach which is common of such studies. A model-based analysis should allow studies to reduce animal use and experiment length providing effective insights into compound anti-tumour activity.

AIMS: We investigated the effects of a strong CYP3A4 inhibitor (itraconazole) or inducer (rifampicin) on the pharmacokinetics of the epidermal growth factor receptor‐tyrosine kinase inhibitor osimertinib, in patients with advanced non‐small cell lung cancer in two Phase I, open‐label, two‐part clinical studies. Part one of both studies is reported. METHODS: In the itraconazole study (NCT02157883), patients received single‐dose osimertinib 80 mg on Days 1 and 10 and itraconazole (200 mg twice daily) on Days 6–18 orally. In the rifampicin study (NCT02197247), patients received osimertinib 80 mg once daily on Days 1–77 and rifampicin 600 mg once daily on Days 29–49. RESULTS: In the itraconazole study (n = 36), the geometric least squares mean (GMLSM) ratios (osimertinib plus itraconazole/osimertinib alone) for C (max) and AUC were 80% (90% CI 73, 87) and 124% (90% CI 115, 135), respectively, below the predefined no‐effect upper limit of 200%. In the rifampicin study (n = 40), the GMLSM ratios (osimertinib plus rifampicin/osimertinib alone) for C (ss,max) and AUCτ were 27% (90% CI 24, 30) and 22% (90% CI 20, 24), respectively, below the predefined no‐effect lower limit of 50%. The induction effect of rifampicin was apparent within 7 days of initiation; osimertinib C (ss,max) and AUCτ values returned to pre‐rifampicin levels within 3 weeks of rifampicin discontinuation. No new osimertinib safety findings were observed. CONCLUSIONS: Osimertinib can be co‐administered with CYP3A4 inhibitors, but strong CYP3A inducers should be avoided if possible.

Two phase 1, open-label studies assessed the impact of food or gastric pH modification (omeprazole) on the exposure and safety/tolerability of osimertinib and its metabolites. The food effect study was an open-label, 2-period crossover study in patients with advanced non-small-cell lung cancer, randomized into 2 treatment sequences: single-dose osimertinib 80 mg in a fed then fasted state or fasted then fed. The gastric pH study was an open-label, 2-period fixed sequence study assessing the effect of omeprazole on osimertinib exposure in healthy male volunteers. In period 1, volunteers received omeprazole 40 mg (days 1-4), then omeprazole 40 mg plus osimertinib 80 mg (day 5). In period 2, volunteers received osimertinib 80 mg alone (single dose). Blood samples were collected at prespecified time points for pharmacokinetic analyses. Safety/tolerability was also assessed. In the food effect study 38 patients were randomized to fed/fasted (n = 18) or fasted/fed (n = 20) sequences with all patients completing treatment. Coadministration with food did not affect osimertinib exposure (geometric least-squares mean ratios [90% confidence intervals]: 106.05% [94.82%, 118.60%] [area under the plasma concentration time curve from zero to 72 hours] and 92.75% [81.40%, 105.68%] [maximum plasma concentration]). In the gastric pH study (n = 68 received treatment, n = 47 completed the study), coadministration with omeprazole did not affect osimertinib exposure (geometric least-squares mean ratios 106.66% [100.26%, 113.46%] [area under the concentration-time curve], 101.65% [94.65%, 109.16%] [peak concentration]). Osimertinib was well tolerated in both studies. Osimertinib may be administered without regard to food. Dose restriction is not required in patients whose gastric pH may be altered by concomitant agents or medical conditions. ClinicalTrials.gov: NCT02224053, NCT02163733.

PurposeThis article aims to examine academic literature and the taxation regulatory environment in Estonia in relation to small and medium enterprises (SMEs). The objective of the paper is to identify key areas of the taxation regulatory environment which affects SMEs and assess and link important academic literature in relation to those areas with the empirical research. In effect to explore that business reality including Estonia's Soviet historical background and compliance with her EU membership taxation obligations.Design/methodology/approachThis exploratory paper makes use of World Bank Surveys and primary tax law sources, together with qualitative empirical research from an SME manager and a taxation law firm, both from within the country assessed.FindingsIt confirms the correlation between economic growth and taxation and identifies the “key” aspects of the taxation regulatory environment for an SME through academic literature reviewed which is linked with the empirical research. This qualitative research provides in‐depth information and fills gaps from previous quantitative research. It emphasises a very positive progression including significant electronic development and compliance with EU directives and regulations has been made by Estonia encouraging SME activity.Practical implicationsThis research demonstrates the business reality of the Estonian taxation regulatory environment. Unofficial costs, a legacy from the Soviet period, are virtually non‐existent within the Estonian taxation system. Gaps within World Bank Surveys are filled by the interviews, which give a grass‐roots perspective on taxation regulation affecting an SME.Originality/valueThe research highlights the importance of the taxation regulatory environment and the reality of the regulation and compliance work for SMEs within a relatively new EU member state. Estonia is an important country within Europe's “Northern Dimension” and a former member of the Soviet Union. Consequently, any assessment of its taxation environment can be used as a guideline/model for others from similar backgrounds with similar aspirations.

The aim of Biopharmaceutics Risk Assessment Roadmap (BioRAM) and the BioRAM Scoring Grid is to facilitate optimization of clinical performance of drug products. BioRAM strategy relies on therapy-driven drug delivery and follows an integrated systems approach for formulating and addressing critical questions and decision-making (J Pharm Sci. 2014,103(11): 3777-97). In BioRAM, risk is defined as not achieving the intended in vivo drug product performance, and success is assessed by time to decision-making and action. Emphasis on time to decision-making and time to action highlights the value of well-formulated critical questions and well-designed and conducted integrated studies. This commentary describes and illustrates application of the BioRAM Scoring Grid, a companion to the BioRAM strategy, which guides implementation of such an integrated strategy encompassing 12 critical areas and 6 assessment stages. Application of the BioRAM Scoring Grid is illustrated using published literature. Organizational considerations for implementing BioRAM strategy, including the interactions, function, and skillsets of the BioRAM group members, are also reviewed. As a creative and innovative systems approach, we believe that BioRAM is going to have a broad-reaching impact, influencing drug development and leading to unique collaborations influencing how we learn, and leverage and share knowledge.

The aim of this study was to investigate the mechanisms that might explain the observed route-dependent stereoselective pharmacokinetics (PK) of R/S-verapamil (R/S-VER) following oral and intravenous (iv) administration, by using a novel pig-specific physiologically based pharmacokinetic (PBPK) model suitable for investigations of first-pass extraction in the gut (E(G)) and the liver (E(H)). The PBPK model consisted of eight tissue compartments and was designed to simultaneously model the plasma concentration-time (PCT) profiles from three sampling sites after intrajejunal (ij) or iv administration of VER. The PBPK model successfully described the observed PCT profiles and E(H) over time for R- and S-VER. Extensive tissue binding to gut mucosa, liver, and lungs was an important determinant of the observed PK data. The stereoselective PK of VER was explained by a combination of several processes, including enantioselective plasma protein binding, blood-to-plasma partition, and gut mucosa and liver tissue distribution. The absence of stereoselectivity after iv dosing indicates that the first-pass tissue binding effect is an important factor in determining the steroselective PK of R/S-VER after oral administration. Additionally a combination of extensive liver tissue binding and a metabolite inhibition mechanism explained the time-dependent E(H) for both R- and S-VER. An in vitro-in vivo correlation of absorption needs to consider these processes because tissue binding may confound analysis of a drug's biopharmaceutical properties when using classical deconvolution or convolution techniques. In conclusion, a combination of PK data from multiple plasma sampling sites and a PBPK modeling approach provided a mechanistic understanding of processes involved in the intestinal absorption and first-pass extraction of R- and S-VER.

In this study an advanced multisampling site pig model, with simultaneous venous blood sampling pre- and post liver, was applied to quantify the role of the intestine in relation to the liver in first-pass glucuronidation of raloxifene in vivo. The pharmacokinetic of raloxifene (a BCS/BDDCS class II compound) in humans is characterized by extensive metabolism (90%) and the major metabolite is the 4'-β-glucuronide (R-4-G). Following intra-jejunal (i.j.) single dose administration in pigs raloxifene was metabolized in the gut (E(G)) during first-pass to more than 70% and a high concentration (AUC(0-6 h) ratio R-4-G/raloxifene100) of R-4-G was reached in the portal vein. The hepatic extraction (E(H)) of raloxifene was ~50% and as in humans the bioavailability become low (~7%) in pigs. Interestingly the E(H) of raloxifene and R-4-G was time-dependent after i.j. administration. It is clear that the gut was the dominating organ in first-pass extraction of raloxifene in vivo in pigs. The quantification in this study support earlier human data and emphasize that intestinal glucuronidation should be considered early in the pharmaceutical development.

Pigs are becoming increasingly used as a test animal both in pharmacological and toxicological assessment of new drug compounds. For interspecies comparisons and predictions it is important to characterize the expression and function of membrane transport and enzymatic proteins in pigs, particularly at a mechanistic level which will make extrapolation of observation between pig and man to be made with more confidence. The major objective of this report was to increase the integrative knowledge of drug metabolism in pigs and to compare with corresponding data from human liver microsomes. This was done by using human substrates of CYP3A4 (verapamil and testosterone), CYP2C9 (diclofenac) and CYP2D6 (dextromethorphan). In addition, the mRNA expression of important drug metabolizing enzymes and carrier-mediated transporters were assessed in intestine and liver tissues from pigs. It was shown that CYP3A4 activity is quantitatively comparable between the two species but data suggest that qualitative differences may exist. Verapamil showed similar metabolism pattern as in humans and the CYP3A4 inhibitor ketoconazole was able to inhibit the depletion of both R- and S-verapamil. A correlation between individual pig CYP3A mRNA expression and in vivo hepatic extraction ratio was established which indicates that CYP3A is the major determinant factor in both pigs and humans. However, investigations of the metabolism of testosterone resulted in qualitative different metabolite pattern between pigs and humans. The metabolism of diclofenac was very low in pig liver microsomes and did not correlate to corresponding activity in human liver microsomes. In contrast dextromethorphan exhibited a very extensive and rapid metabolism in pig liver microsomes compared to human data. Together with previously determined gene expression data it confirms that CYP2D6 substrates will be very rapidly metabolized in pigs. The mRNA data increased the knowledge of the interindividual variability and the relative expression of different enzymes and transporters in pig intestine and liver. In conclusion, this study has increased the understanding of similarities and differences between pig and human biotransformation of drugs by providing new data for four different model compounds.

Purpose – This paper seeks to examine academic literature and business regulation for land acquisition in Estonia in relation to small and medium enterprises (SMEs). The objective of the paper is to give information beneficial for the enhancement of the business environment, for SMEs. Furthermore, to assist foreign SMEs decision making related to land acquisition within Estonia, an important country within the “Northern Dimension” of the expanded European Union (EU).Design/methodology/approach – This exploratory paper makes use of World Bank Surveys, primary business law sources together with an interview from a business within the country assessed giving a grass‐roots perspective.Findings – The investigation reaffirms the importance of SMEs within former economies from a Soviet background such as Estonia. It also emphasises the correlation between economic growth, land acquisition and business law and identifies the significance and “key” aspects of land acquisition for an SME. Furthermore, it assesses E...

This paper presents a neural network (NN) based air-to-fuel ratio (AFR) estimation scheme for spark ionization sensors in gasoline internal combustion (IC) engines. The proposed hardware and software estimation system results in a virtual wideband oxygen sensor for an individual cylinder. Principal component analysis (PCA) of the spark ionization signal is used with manifold absolute air pressure (MAP), fuel pulse width (FPW) and engine speed to train a NN offline to predict the AFR under transient engine load and speed settings. Experimental results from dynamometer tests on a port fuel-injected (PFI) four cylinder 1.6 l gasoline IC engine demonstrate that the NN based AFR prediction correlates well with AFR measured from a universal exhaust gas oxygen (UEGO) λ -sensor mounted in the exhaust manifold. The prediction is experimentally demonstrated to be robust to transients of load and engine speed. The experimental results significantly advance those of the previously published studies which have been largely restricted to simulation.

This paper proposes a system identification method to obtain a virtual in-cylinder air-to-fuel ratio (AFR) sensor using the measured engine variables of engine speed, manifold absolute pressure and fuel pulse width. An algebraic NARX model capable of estimating AFR, including transient behaviour, is identified from experimental data using ordinary least squares. A simple structure selection method is used to establish a low order algebraic model structure based on the correlation of the candidate terms with the output. The algebraic NARX structure should be more amenable to software implementation in current PCM architectures than those of alternative NN schemes. The ion current signal from the spark plug is introduced in a subsequent identification to improve the model quality. The information rich ion current signal is sampled every one degree of crank angle for 39 degrees during combustion and this window of data is then reduced to 6 inputs using principle component analysis. The two models are then critically compared with regards to the model fit.

Quality by design (QbD) has recently been introduced in pharmaceutical product development in a regulatory context and the process of implementing such concepts in the drug approval process is presently on-going. This has the potential to allow for a more flexible regulatory approach based on understanding and optimisation of how design of a product and its manufacturing process may affect product quality. Thus, adding restrictions to manufacturing beyond what can be motivated by clinical quality brings no benefits but only additional costs. This leads to a challenge for biopharmaceutical scientists to link clinical product performance to critical manufacturing attributes. In vitro dissolution testing is clearly a key tool for this purpose and the present bioequivalence guidelines and biopharmaceutical classification system (BCS) provides a platform for regulatory applications of in vitro dissolution as a marker for consistency in clinical outcomes. However, the application of these concepts might need to be further developed in the context of QbD to take advantage of the higher level of understanding that is implied and displayed in regulatory documentation utilising QbD concepts. Aspects that should be considered include identification of rate limiting steps in the absorption process that can be linked to pharmacokinetic variables and used for prediction of bioavailability variables, in vivo relevance of in vitro dissolution test conditions and performance/interpretation of specific bioavailability studies on critical formulation/process variables. This article will give some examples and suggestions how clinical relevance of dissolution testing can be achieved in the context of QbD derived from a specific case study for a BCS II compound.

PurposeThe purpose of this paper is to examine academic literature and business regulation for company formation in Estonia in relation to small to medium‐sized enterprises (SMEs). It is an example of a country which is a new member of the expanded European Union (EU) and its regulation.Design/methodology/approachThis exploratory paper makes use of World Bank Surveys, primary business law sources together with an interview from a business within the country assessed giving a grass‐roots perspective.FindingsThe investigation reaffirms the importance of SMEs within transitional economies from a Soviet background such as Estonia because of the Socialist black hole. It also emphasizes the correlation between SME development and business law and the significance and key aspects of company formation for an SME. Furthermore, transition economies like Estonia have complied with EU directives for company formation and advanced within the regulation process quickly. However, it is still more difficult for a person or entity from another EU Member State to form a company in Estonia.Practical implicationsThis research demonstrates that compliance on EU regulation for company formation by a new EU member has been provided for within the regulation of the wording. It also indicates that for an entity from another EU state (other than Estonia) it is slightly more difficult to form a company. Unofficial costs, a legacy from the Soviet period are almost non‐existent within the Estonian company registration system. Some of the gaps within the World Bank Surveys are filled by the interview, although further evaluation is needed from other academics.Originality/valueThe research highlights the importance of company formation for SMEs, the compliance of a new EU Member State with EU directives, and the reality of company formation regulation for an SME in Estonia.

Osimertinib (AZD9291) 80 mg once daily is approved by the US FDA for the treatment of patients with metastatic EGFR T790M-positive NSCLC whose disease has previously progressed on EGFR-TKI therapy. Osimertinib PK was evaluated to define the dose and dosing interval, whether a fixed-dosing approach can be used globally, and the impact of formulation and food on exposure.AURA (NCT01802632): single- and multiple-dose PK of osimertinib (20-240 mg daily) was determined in patients with advanced NSCLC. Bioavailability study (NCT01951599): single-dose PK of osimertinib (20 mg) was determined in healthy volunteers with administration of capsule, solution, or tablet formulations fasted, and as a tablet in the fed and fasted state.Osimertinib was slowly absorbed and displayed dose-proportional increases in exposure from 20 to 240 mg. Distribution was extensive and clearance low to moderate, resulting in a mean half-life of 48.3 h. Steady state was achieved by 15 days of dosing, consistent with single-dose PK, with a peak-to-trough ratio of 1.6. Two active metabolites circulated at ~10 % of osimertinib exposure. Ethnicity did not appear to affect exposure. Osimertinib PK profiles in healthy volunteers were similar to those in patients and were unaffected by formulation. Food caused a clinically insignificant increase in exposure.Osimertinib PK supports once-daily dosing; the same dose for Asian and non-Asian populations; a fixed-dosing approach; a minimal effect of food on exposure; and a switch to tablet formulation without alteration to dose or schedule. Osimertinib plasma concentrations are sustained throughout the dosing period, which is considered optimal for efficacy.

Background The EGFR T790M mutation is the most common mechanism of drug resistance to epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors in patients who have lung cancer with an EGFR mutation (EGFR-mutated lung cancer). In preclinical models, the EGFR inhibitor AZD9291 has been shown to be effective against both EGFR tyrosine kinase inhibitor-sensitizing and T790M resistance mutations. Methods We administered AZD9291 at doses of 20 to 240 mg once daily in patients with advanced lung cancer who had radiologically documented disease progression after previous treatment with EGFR tyrosine kinase inhibitors. The study included dose-escalation cohorts and dose-expansion cohorts. In the expansion cohorts, prestudy tumor biopsies were required for central determination of EGFR T790M status. Patients were assessed for safety, pharmacokinetics, and efficacy. Results A total of 253 patients were treated. Among 31 patients enrolled in the dose-escalation cohorts, no dose-limiting toxic effects occurred at the doses evaluated. An additional 222 patients were treated in five expansion cohorts. The most common all-cause adverse events were diarrhea, rash, nausea, and decreased appetite. The overall objective tumor response rate was 51% (95% confidence interval [CI], 45 to 58). Among 127 patients with centrally confirmed EGFR T790M who could be evaluated for response, the response rate was 61% (95% CI, 52 to 70). In contrast, among 61 patients without centrally detectable EGFR T790M who could be evaluated for response, the response rate was 21% (95% CI, 12 to 34). The median progression-free survival was 9.6 months (95% CI, 8.3 to not reached) in EGFR T790M-positive patients and 2.8 months (95% CI, 2.1 to 4.3) in EGFR T790M-negative patients. Conclusions AZD9291 was highly active in patients with lung cancer with the EGFR T790M mutation who had had disease progression during prior therapy with EGFR tyrosine kinase inhibitors. (Funded by AstraZeneca; ClinicalTrials.gov number, NCT01802632.).

Treatment of hexabromoosmic acid, H 2 OsBr 6 , with 4 equiv. of tetramethylcyclopentadiene (C 5 Me 4 H 2 ) in tert -butanol at reflux for 8 h affords the unusual salt [(C 5 Me 4 H) 2 OsBr] 2 [Os 2 Br 8 ], 1 , which is the bis(tetramethylcyclopentadienyl)bromoosmocinium(IV) salt of the octabromodiosmate(III) dianion. The brown color of the salt suggests that the anion adopts an eclipsed conformation ( D 4 h symmetry) and this conclusion has been confirmed by a single-crystal X-ray diffraction experiment. The X-ray crystal structure indicates that the osmium atoms in the [ Os 2 Br 8 2 - ] anion are disordered over two sites. The bromine atoms show no evidence of disorder and are disposed in a quasi-cubic arrangement; the two Os–Os vectors are almost exactly orthogonal to each other and each vector points toward a different pair of opposite square faces of the Br 8 cube. The Os–Os bond distances are 2.219(5) and 2.229(1) A; the average Os–Br distance in the anion is 2.417(2) A. Treatment of [(C 5 Me 4 H) 2 OsBr] 2 [Os 2 Br 8 ] with excess 1,5-cyclooctadiene in ethanol at gentle reflux for 3 h affords [(C 5 Me 4 H) 2 OsBr][Os 2 HBr 4 (cod) 2 ], 2 . An X-ray crystallographic study was carried out on a sample in which the cation was a mixture of [(C 5 Me 4 H) 2 OsBr + ] and [(C 5 Me 4 H) 2 OsH + ]. The results demonstrate that the anion adopts a confacial bioctahedral structure in which the hydride ligand and two bromides bridge between the two osmium centers. The C C bonds of the cod ligands are trans to the bridging bromide groups. The Os–Os bond distance in the anion is 2.874(1) A. The average Os–Br distance is 2.596(2) A for the bridging bromides and 2.565(2) A for the terminal bromides. Compound 2 is the first example of an anionic diosmium complex containing a bridging hydride. The reaction of 1 with cod also results in the formation of bis(tetramethylcyclopentadienyl)osmocene, (C 5 Me 4 H) 2 Os, 3 , which has been isolated and characterized. Treatment of (C 5 Me 4 H) 2 Os with 1.0 equiv. of HBF 4 · Et 2 O affords the osmocinium salt [(C 5 Me 4 H) 2 OsH][BF 4 ].

Treatment of H2OsBr6 with excess 1,5-cyclooctadiene (cod) in boiling tert-butyl alcohol affords the polymer [OsBr2(cod)]x (1), which reacts with acetonitrile to form the mononuclear adduct OsBr2(cod)(CH3CN)2 (2). Polymer 1 reacts with potassium trispyrazolylborate (KTp) in ethanol to afford the hydride TpOs(cod)H (3) and the bromide complex TpOs(cod)Br (4). Bromide complex 4 reacts with sodium methoxide in methanol to afford TpOs(cod)OMe (5), which has been structurally characterized. Treatment of hydride 3 with methyl trifluoromethanesulfonate (MeOTf) in diethyl ether results in loss of methane and formation of the triflate complex TpOs(cod)OTf (6), which reacts with MgMe2 to give the methyl complex TpOs(cod)Me (7). The addition of bis(dimethylphosphino)methane (dmpm) to the known compound TpOs(PPh3)2Cl yields a mixture of the substitution products TpOs(eta1-dmpm)(PPh3)Cl (8) and TpOs(eta2-dmpm)Cl (9); the latter reacts with methyllithium to generate the methyl compound TpOs(dmpm)Me (10). NMR and IR data for these new compounds are reported. Crystal data for 5.MeOH at -80 degrees C are as follows: monoclinic, P2(1)/n, a = 10.728(1) A, b = 14.004(2) A, c = 13.906(2) A, beta = 102.42(6) degrees , V = 2040.3(5) A3, Z = 4, R(F) = 0.0247 for Ior = 2sigma(I), and R(wF2) = 0.0539 for all data.

Purpose To describe a novel method for calculating intraocular lens (IOL) power after myopic laser in situ keratomileusis (LASIK) without using the inaccuracies of the post-LASIK corneal power. Setting Department of Ophthalmology, Wake Forest University Eye Center, Wake Forest University School of Medicine, Winston Salem, North Carolina, USA. Methods This retrospective chart review comprised 9 eyes of 9 patients who had phacoemulsification after LASIK using our method for IOL calculation. This new method assumes the patient never had myopic LASIK to calculate IOL power and then targets the IOL at the pre-LASIK amount of myopia. The pre-LASIK keratometry values, pre-LASIK manifest refraction, and the current axial length are placed in the Holladay formula, bypassing the post-LASIK corneal power. In theory, assuming that the patient had satisfactory LASIK results, the correct IOL can then be determined. Results The mean spherical equivalent postoperative refraction was +0.03 diopter (D) ± 0.42 (SD) (range −0.625 to +0.75 D). In all 9 eyes, our method consistently chose the most accurate and precise IOL compared with other methods. Conclusions The new method of calculating IOL power after LASIK provided excellent results and the most accurate and precise results to date.

The purpose of the study was to examine the disintegration of tablets in media designed to simulate conditions pertaining in the stomach. Although many studies have been performed to determine dissolution rates in these media, little work has been undertaken on the preliminary step in dissolution, namely disintegration. Two tablet formulations were prepared. One disintegrated rapidly (under 25 s in water) and the other more slowly (8 min in water). The disintegration times were measured by the BP 2000 test using discs. For the rapidly disintegrating tablets, disintegration times were similar in all media except for whole milk. This media is used to simulate the fed stomach and disintegration times were over five times longer than in the other media (P < 0.05). A similar effect was seen with the poorly disintegrating tablets in milk, and prolonged times were also observed in some of the other media. For these latter media, there was a good correlation between the penetration rate of the fluid into the tablet and the disintegration time. Penetration rates for milk were also slow which may be a reflection of its relatively high viscosity and low surface tension.

The biopharmaceutics risk assessment roadmap (BioRAM) optimizes drug product development and performance by using therapy-driven target drug delivery profiles as a framework to achieve the desired therapeutic outcome. Hence, clinical relevance is directly built into early formulation development. Biopharmaceutics tools are used to identify and address potential challenges to optimize the drug product for patient benefit. For illustration, BioRAM is applied to four relatively common therapy-driven drug delivery scenarios: rapid therapeutic onset, multiphasic delivery, delayed therapeutic onset, and maintenance of target exposure. BioRAM considers the therapeutic target with the drug substance characteristics and enables collection of critical knowledge for development of a dosage form that can perform consistently for meeting the patient's needs. Accordingly, the key factors are identified and in vitro, in vivo, and in silico modeling and simulation techniques are used to elucidate the optimal drug delivery rate and pattern. BioRAM enables (1) feasibility assessment for the dosage form, (2) development and conduct of appropriate "learning and confirming" studies, (3) transparency in decision-making, (4) assurance of drug product quality during lifecycle management, and (5) development of robust linkages between the desired clinical outcome and the necessary product quality attributes for inclusion in the quality target product profile.

Examines the role and effect of the small scale private sector on Eastern Europe’s economic development, i.e. small private companies, partnerships and entrepreneurs, indicating why it is important in the reform programmes. Discusses the need for an entrenchment of the small scale private sector’s contribution to economic development, through adequate legislation and the right regulatory framework including a competition policy, and a commercial code for business formation and insolvency. Focuses mainly on Poland, and takes into account the author’s own views, observations, discussions and interviews whilst working in Poznan from 1996 to 1997. In particular, finds evidence of an abundance of innate entrepreneurial skills in Poland including the propensity for risk taking, and the presence of one of the best laid regulated economic climates of the transforming economies, although there is still a need for government to encourage small business into manufacturing.

Current literature highlights the potential suitability of microcalorimetry for the investigation of cell-drug interactions. Previous work using bacteria or antigens derived from infectious organisms yielded conclusions that heat production is a quantitative means of measuring phagocytosis. In this study we evaluated the potential of flow-through microcalorimetry as a method of quantifying the phagocytosis of microsphere particulates. The technique avoids the need to incorporate radioactive or fluorescent markers into the particulate formulation, and would be widely applicable in biopharmaceutical research. Using the monocyte cell line Mono Mac 6 a power output of 9.00 microW per million cells was increased significantly on addition of zymosan, lipopolysaccaride (LPS) and phorbol myristate acetate but not following exposure to FITC labelled latex microspheres (LM). TNFalpha production increased on exposure to zymosan, LPS and LPS-phorbol myristate acetate, though not on exposure to LB. An assay was developed which allowed the quantification of internalised particulates in phagocytic cells using fluorescent activated cell sorting (FACS). In contrast to the microcalorimetric and TNFalpha data FACS revealed that 20% of the MM6 population phagocytosed a mean of 1.35 LM. Microcalorimetry and measurements of TNFalpha production are assays of cellular activation a phenomenon not necessarily associated with phagocytosis. FACS, however, serves as a specific and quantitative measure of phagocytosis. Microcalorimetry may not be a suitable technique for the quantitative assessment of the phagocytosis of drug delivery particulates.

A novel salbutamol prodrug was synthesised. Solubility in HFA-134a and susceptibility to rat lung homogenate, blood and plasma esterase enzymes were investigated. Whereas salbutamol had a very low solubility in HFA-134a, the prodrug was found to be miscible in all proportions. In lung homogenate, the prodrug hydrolysed with a half-life of 45 min, re-generating approximately 17% of expected salbutamol after 8 h incubation. The use of a solution pMDI for pulmonary delivery of the salbutamol prodrug is predicted to result in liberation of salbutamol in the lungs following in vivo hydrolysis by lung esterases.

The nasal bioavailability of fluorescein isothiocyanate-dextran (FITC-dextran) (Mw = 4300) encapsulated in non-mucoadhesive and mucoadhesive microspheres in New Zealand White rabbits was investigated. FITC-dextran was administered nasally encapsulated in carbopol 934P, chitosan and lactose microspheres and the bioavailability compared to intravenous administration of FITC-dextran solution. Administration of FITC-dextran as carbopol microspheres produced a significantly greater bioavailability (33%) than after administration as chitosan (13%) and non-mucoadhesive rapidly dissolving control lactose microspheres (9%). The FITC-dextran terminal plasma half-lives after carbopol 934P and chitosan microsphere administration were significantly longer than after intravenous administration of FITC-dextran. The FITC-dextran terminal plasma half-life after carbopol 934P microspheres administration was significantly longer than after lactose microsphere administration. This data suggested that the increase in FITC-dextran bioavailability after carbopol 934P microspheres administration was due to increased residence at the absorptive site via mucoadhesion and reduced mucociliary clearance. A change in mucosal permeability could not however be discounted especially for the chitosan microspheres.

Accurate prediction of the in vivo biopharmaceutical performance of oral drug formulations is critical to efficient drug development. Traditionally, in vitro evaluation of oral drug formulations has focused on disintegration and dissolution testing for quality control (QC) purposes. The connection with in vivo biopharmaceutical performance has often been ignored. More recently, the switch to assessing drug products in a more biorelevant and mechanistic manner has advanced the understanding of drug formulation behavior. Notwithstanding this evolution, predicting the in vivo biopharmaceutical performance of formulations that rely on complex intraluminal processes (e.g. solubilization, supersaturation, precipitation...) remains extremely challenging. Concomitantly, the increasing demand for complex formulations to overcome low drug solubility or to control drug release rates urges the development of new in vitro tools. Development and optimizing innovative, predictive Oral Biopharmaceutical Tools is the main target of the OrBiTo project within the Innovative Medicines Initiative (IMI) framework. A combination of physico-chemical measurements, in vitro tests, in vivo methods, and physiology-based pharmacokinetic modeling is expected to create a unique knowledge platform, enabling the bottlenecks in drug development to be removed and the whole process of drug development to become more efficient. As part of the basis for the OrBiTo project, this review summarizes the current status of predictive in vitro assessment tools for formulation behavior. Both pharmacopoeia-listed apparatus and more advanced tools are discussed. Special attention is paid to major issues limiting the predictive power of traditional tools, including the simulation of dynamic changes in gastrointestinal conditions, the adequate reproduction of gastrointestinal motility, the simulation of supersaturation and precipitation, and the implementation of the solubility-permeability interplay. It is anticipated that the innovative in vitro biopharmaceutical tools arising from the OrBiTo project will lead to improved predictions for in vivo behavior of drug formulations in the GI tract. © 2013 Elsevier B.V. All rights reserved. Chemicals/CAS: albendazole, 54965-21-8; amprenavir, 161814-49-9; celecoxib, 169590-42-5; cinnarizine, 298-57-7; cyclodextrin, 12619-70-4; danazol, 17230-88-5; diclofenac, 15307-79-6, 15307-86-5; dipyridamole, 58-32-2; ketoconazole, 65277-42-1; loviride, 147362-57-0; montelukast, 151767-02-1, 158966-92-8; octanol, 111-87-5, 29063-28-3; propranolol, 13013-17-7, 318-98-9, 3506-09-0, 4199-09-1, 525-66-6; saquinavir, 127779-20-8, 149845-06-7

In vitro 17β-estradiol release from controlled-release microspheres intended for intra-muscular administration was investigated using a rotating bottle apparatus. Prior to intra-muscular administration of 17β-estradiol loaded microspheres the in vivo pharmacokinetics of 17β-estradiol in NZW rabbits were determined: the clearance value was 50.0 ± 8.1 l/d/kg and the elimination half-life was 7.7 ± 2.2 min (n = 6 ± S.D.). The release of 17β-estradiol from the microspheres in vivo was determined and compared to the release profile obtained in vitro using two release protocols. There was a linear relationship from day 0 until day 30 irrespective of which in vitro test protocol was used. It is suggested that the rotating bottle apparatus is a good starting point for the development of an in vitro release test method for controlled-released intra-muscular dosage forms. Possible strategies for the improvement of an in vitro test to predict in vivo release are discussed.

Rat alveolar type II cells were isolated following elastase digestion and cultured on polycarbonate filters at various densities and in different media. Two days after seeding, the cells formed a monolayer on the filters which consisted predominantly of type II cells, these then de-differentiated to a alveolar type I-like cell monolayer by day 6. The seeding density and media utilized affected the transepithelial electrical resistance (TEER) generated by the monolayer. Only certain culture conditions allowed the production of a monolayer that mimics, putatively, the in vivo alveolar epithelium (TEER greater than 1000 omega cm2). Vmax and K(m) values for the uptake of putrescine by monolayers exhibiting low and high TEERs on day 6 were determined. The capacity of the putrescine uptake mechanisms was greater in cell monolayers exhibiting a high TEER than those exhibiting a low TEER, suggesting that the TEER does not only measure the "tightness" of the monolayer but contains an element representative of the viability of the cell monolayer. The selection of appropriate TEERs for cell culture investigations is discussed.