Can in vitro/in silico tools improve colonic concentration estimations for oral extended-release formulations? A case study with upadacitinib

Upadacitinib, classified as a highly soluble drug, is commercially marketed as RINVOQ®, an modified-release formulation incorporating hydroxypropyl methylcellulose as a matrix system to target extended release throughout the gastrointestinal (GI) tract. Our study aimed to explore how drug release will occur throughout the GI tract using a plethora of in vitro and in silico tools. We built a Physiologically-Based Pharmacokinetic (PBPK) model in GastroPlus™ to predict the systemic concentrations of the drug when administered using in vitro dissolution profiles as input to drive luminal dissolution. A series of in vitro dissolution experiments were gathered using the USP Apparatus I, III and IV in presence of biorelevant media, simulating both fasted and fed state conditions. A key outcome from the current study was to establish an in vitro-in vivo correlation (IVIVC) between (i) the dissolution profiles obtained from the USP I, III and IV methods and (ii) the fraction absorbed of drug as deconvoluted from the plasma concentration-time profile of the drug. When linking the fraction dissolved as measured in the USP IV model, a Level A IVIVC was established. Moreover, when using the different dissolution profiles as input for PBPK modeling, it was also observed that predictions for plasma Cmax and AUC were most accurate for USP IV compared to the other models (based on predicted versus observed ratios). Furthermore, the PBPK model has the utility to extract the predicted concentrations at the level of the colon which can be of utmost interest when working with specific in vitro assays.

Digitalizing the TIM-1 Model Using Computational Approaches─Part Two: Digital TIM-1 Model in GastroPlus

A TIM-1 model is an in vitro gastrointestinal (GI) simulator considering crucial physiological parameters that will affect the in vivo drug release process. The outcome of these experiments can indicate the critical bioavailability attributes (CBAs) that will impact the fraction absorbed in vivo. The model is widely used in the nonclinical stage of drug product development to assess the bioaccessible fraction of drugs for numerous candidate formulations. In this work, we developed a digital TIM-1 model in the GastroPlus platform. In a first step, we performed validation experiments to assess the luminal concentrations and bioaccessible fractions for two marker compounds. The digital TIM-1 was able to adequately reflect the luminal concentrations and bioaccessible fractions of these markers under different prandial conditions, confirming the appropriate integration of mass transfer in the TIM-1 model. In a second set of experiments, a case example with PF-07059013 was performed, where luminal concentrations and bioaccessible fractions were predicted for 200 and 1000 mg doses under fasted and achlorhydric conditions. Experimental and simulated data pointed out that the achlorhydric effect was more pronounced at the 1000 mg dose, showing a solubility-limited dissolution and, consequently, decreased bioaccessible fraction. Toward future applications, the digital TIM-1 model will be thoroughly applied to explore a link between in vitro and in vivo outcomes based on more case examples with model compounds with the access of TIM-1 and plasma data. Ideally, this digital TIM-1 can be directly used in GastroPlus to explore an in vitro-in vivo correlation (IVIVC) between the fraction dissolved (digital TIM-1 settings) and the fraction absorbed (human PBPK settings).

Digitalizing the TIM-1 Model using Computational Approaches-Part One: TIM-1 Data Explorer

The TIM-1 gastrointestinal model is one of the most advanced in vitro systems currently available for biorelevant dissolution testing. This technology, the initial version of which was developed nearly 30 years ago and has been subject to a number of significant updates over this period, simulates the dynamic environment of the human gastrointestinal tract, including pH, transfer times, secretion of bile, enzymes, and electrolytes. In the pharmaceutical industry, the TIM-1 system is used to support drug product design and provide a biopredictive assessment of drug product performance. Typically, the bioaccessibility data sets generated by TIM-1 experiments are used to qualitatively compare formulation performance, and the use of bioaccessibility data as inputs for physiologically based pharmacokinetic (PBPK) modeling for quantitative predictions is limited. To expand the utility of the TIM-1 model beyond standard bioaccessibility measurements (which define the fraction available for absorption), we have developed a computational tool, TIM-1 Data Explorer, to describe the fluid and mass balance within the TIM-1 system. The use of this tool allows a detailed inspection and in-depth interpretation of the experimental data. In addition to mass balance calculation, this model also can be used to describe the critical processes a drug substance would undergo during a TIM-1 experiment, such as dissolution, precipitation on transfer from the stomach to duodenum, and redissolution. The TIM-1 Data Explorer was validated in two case studies. In the first case study with paracetamol, we have shown the ability of the simulator to adequately describe mass transfer events within the TIM-1 system, and in the second study with a weakly basic in-house compound, PF-07059013, the TIM-1 Data Explorer was successfully used to describe dissolution and precipitation processes.

Effect of Food and a Proton-Pump Inhibitor on the Absorption of Encorafenib: An In Vivo-In Vitro-In Silico Approach

Encorafenib is a kinase inhibitor indicated for the treatment of patients with BRAF mutant melanoma and BRAF mutant metastatic colorectal cancer. To understand the effect of food and coadministration with a proton-pump inhibitor (PPI), in vitro, in vivo, and in silico data were generated to optimize the clinical dose, evaluate safety, and better understand the oral absorption process under these conditions. Study 1 evaluated the effect of food on the plasma pharmacokinetics, safety, and tolerability after a single oral dose of encorafenib 100 mg. Study 2 evaluated the same end points with coadministration of encorafenib and rabeprazole (PPI perpetrator). The in vitro gastrointestinal TIM-1 model was used to investigate the release of encorafenib and the amount available for absorption under different testing conditions (fasted, fed, and with the use of a PPI). The fasted, fed, and PPI states were predicted for the encorafenib commercial capsule in GastroPlus 9.8. In study 1, both AUC_inf and AUC_last decreased by 4% with the administration of a high-fat meal. The C_max was 36% lower than with fasted conditions. All 3 exposure parameters in study 2 (AUC_inf, AUC_last, and C_max) had mean changes of <10% when encorafenib was coadministered with a PPI. Using the in vitro gastrointestinal simulator TIM-1, the model demonstrated a similar release of drug, as the bioaccessible fraction, in the 3 conditions was equal (≥80%), predicting no PPI or food effect for this drug formulation. The modeling in GastroPlus 9.8 demonstrated complete absorption of encorafenib when formulated as an amorphous solid dispersion. To obtain these results, it was crucial to integrate the amorphous solubility of the drug that shows a 20-fold higher solubility at pH 6.8 compared with crystalline solubility. The increased amorphous solubility is likely the reason no PPI effect was observed compared with fasted state conditions. The prolongation in gastric emptying in the fed state resulted in delayed plasma T_max for encorafenib. No dose adjustment is necessary when encorafenib is administered in the fed state or when coadministered with a PPI. Both the TIM-1 and physiologically based pharmacokinetic model results were consistent with the observed clinical data, suggesting that these will be valuable tools for future work.

Investigating the Impact of Crohn's Disease on the Bioaccessibility of a Lipid-Based Formulation with an In Vitro Dynamic Gastrointestinal Model

The aim of the study was to investigate the impact of Crohn's disease (CD) on the performance of a lipid-based formulation of ciprofloxacin in a complex gastrointestinal simulator (TIM-1, TNO) and to compare the luminal environment in terms of bile salt and lipid composition in CD and healthy conditions. CD conditions were simulated in the TIM-1 system with a reduced concentration of porcine pancreatin and porcine bile. The bioaccessibility of ciprofloxacin was similar in simulated CD and healthy conditions considering its extent as well as its time course in the jejunum and ileum filtrate. Differences were observed in terms of the luminal concentration of triglycerides, monoglycerides, and fatty acids in the different TIM-1 compartments, indicating a reduction and delay in the lipolysis of formulation excipients in CD. The quantitative analysis of bile salts revealed higher concentrations for healthy conditions (standard TIM-1 fasted-state protocol) in the duodenum and jejunum TIM-1 compartments compared to published data in human intestinal fluids of healthy subjects. The reduced concentrations of bile salts in simulated CD conditions correspond to the levels observed in human intestinal fluids of healthy subjects in the fasted state.A lipidomics approach with ultra performance liquid chromatography (UPLC)/mass spectrometry (MS) has proven to be a time-efficient method to semiquantitatively analyze differences in fatty acid and bile salt levels between healthy and CD conditions. The dynamic luminal environment in CD and healthy conditions after administration of a lipid-based formulation can be simulated using the TIM-1 system. For ciprofloxacin, an altered luminal lipid composition had no impact on its performance indicating a low risk of altered performance in CD patients.

Cardiac tamponade - unusual clinical manifestation of undiagnosed malignant neoplasm

Cardiac tamponade may be the first or predominant symptom of some pathologies but its etiology is not uncommonly unknown on admission to hospital. The purpose of this study was to evaluate the predominant causes of cardiac tamponade in previously healthy patients treated emergently in a single cardiac surgical center. The study involved 81 patients with the mean age of 58.1±16.0 years who underwent emergent subxyphoid pericardiotomy due to cardiac tamponade. Pericardial effusion was analyzed macro- and microscopically. Examinations done in the cardiac surgical department revealed pericarditis secondary to infection (n=17) or autoimmunologic processes (n=2) and malignancy in 18 patients (predominantly of the lungs (n=11)). Pericardial effusion obtained from patients with viral and autoimmunologic-induced pericarditis was straw-color and odorless while with bacterial infections dark yellow, iridescent and usually malodorous. Additional workup in the regional hospitals enabled to reveal malignant tumors in 29 patients, leukemia or lymphoma in 5 subjects. In all but one of the neoplastic cases, pericardial fluid was turbid and dark red or plummy. In 10 patients etiology of tamponade remained unknown. In conclusion, cardiac tamponade in previously healthy patients may be occasionally the predominant symptom of cancer, especially of the lungs. Macroscopic intraoperative appearance of pericardial fluid may be helpful in identification of causative condition of cardiac tamponade.

Validation of Dissolution Testing with Biorelevant Media: An OrBiTo Study

Dissolution testing with biorelevant media has become widespread in the pharmaceutical industry as a means of better understanding how drugs and formulations behave in the gastrointestinal tract. Until now, however, there have been few attempts to gauge the reproducibility of results obtained with these methods. The aim of this study was to determine the interlaboratory reproducibility of biorelevant dissolution testing, using the paddle apparatus (USP 2). Thirteen industrial and three academic laboratories participated in this study. All laboratories were provided with standard protocols for running the tests: dissolution in FaSSGF to simulate release in the stomach, dissolution in a single intestinal medium, FaSSIF, to simulate release in the small intestine, and a "transfer" (two-stage) protocol to simulate the concentration profile when conditions are changed from the gastric to the intestinal environment. The test products chosen were commercially available ibuprofen tablets and zafirlukast tablets. The biorelevant dissolution tests showed a high degree of reproducibility among the participating laboratories, even though several different batches of the commercially available medium preparation powder were used. Likewise, results were almost identicalbetween the commercial biorelevant media and those produced in-house. Comparing results to previous ring studies, including those performed with USP calibrator tablets or commercially available pharmaceutical products in a single medium, the results for the biorelevant studies were highly reproducible on an interlaboratory basis. Interlaboratory reproducibility with the two-stage test was also acceptable, although the variability was somewhat greater than with the single medium tests. Biorelevant dissolution testing is highly reproducible among laboratories and can be relied upon for cross-laboratory comparisons.

Can dosage form-dependent food effects be predicted using biorelevant dissolution tests? Case example extended release nifedipine

AIMS

Food intake is known to have various effects on gastrointestinal luminal conditions in terms of transit times, hydrodynamic forces and/or luminal fluid composition and can therefore affect the dissolution behavior of solid oral dosage forms. The aim of this study was to investigate and detect the dosage form-dependent food effect that has been observed for two extended-release formulations of nifedipine using in vitro dissolution tests.

METHODS

Two monolithic extended release formulations, the osmotic pump Adalat® XL 60mg and matrix-type Adalat® Eins 30mg formulation, were investigated with biorelevant dissolution methods using the USP apparatus III and IV under both simulated prandial states, and their corresponding quality control dissolution method. In vitro data were compared to published and unpublished in vivo data using deconvolution-based in vitro - in vivo correlation (IVIVC) approaches.

RESULTS

Quality control dissolution methods tended to overestimate the dissolution rate due to the excessive solubilizing capabilities of the sodium dodecyl sulfate (SDS)-containing dissolution media. Using Level II biorelevant media the dosage form dependent food effect for nifedipine was described well when studied with the USP apparatus III, whereas the USP apparatus IV failed to detect the positive food effect for the matrix-type dosage form.

CONCLUSIONS

It was demonstrated that biorelevant methods can serve as a useful tool during formulation development as they were able to qualitatively reflect the in vivo data.

Heparin-induced thrombocytopenia in a patient with lung embolism and left-sided pneumonia: a case report

A case of a 73-year obese female with arterial hypertension, periodical metrorrhagia, polydipsia, and polyuria is presented. The patient was admitted to the hospital because of increasing dyspnea, cough, subfebrile body temperature, and decreasing exercise tolerance. Physical examination and laboratory tests were suggestive for massive lung embolism. Low molecular heparin was started and after 5 days' therapy, heparin-induced thrombocytopenia was diagnosed.

Pleuritis as the first symptom of pulmonary embolism: a case report

Pulmonary embolism (PE) is a common problem but its diagnosis is challenging since clinical signs and symptoms are not specific. Given the significant overlap between the presentation of PE and other not life threatening entities/diseases, it is important to be acquainted with diagnostic tests and treatment of PE. It is of vital importance to suspect PE in case of chest pain. We would like to present the patient complaining of acute left-sided chest pain, referred to the hospital after being unsuccessfully treated in outpatient clinic for chest infection.

Chemokine growth-regulated-alpha: a possible role in the pathogenesis of endometriosis

Endometriosis is a common disease in women at reproductive age. We investigated the concentration of neutrophil-activating factor (growth-regulated gene-alpha; GRO-alpha) (a member of the chemokine family), in peritoneal fluid of infertile women with or without endometriosis. Peritoneal fluid was obtained laparoscopically from 22 women with and 21 without visible endometriotic lesions. GRO-alpha concentration was measured by the use of an ELISA kit. Median concentration of GRO-alpha was 87.65 +/- 56.19 pg/ml in the study group and 60.72 +/- 11.98 pg/ml in the control group. The distribution of data differed from normal, therefore logarithmic transformation of data was performed. Concentration of GRO-alpha was significantly higher in the peritoneal fluid of women with endometriosis when compared with controls (p = 0.05). No correlation between concentration of GRO-alpha, stage of endometriosis, duration of infertility or sex steroid hormone levels was found. The study shows that GRO-alpha may play a role in the pathogenesis of endometriosis, possibly by chemoattraction and activation of neutrophils present in higher numbers in the peritoneal fluid of women with endometriosis. It is also feasible that the angiogenic properties of GRO-alpha might prompt the progression of endometriotic lesions.

13-cis retinoic acid and all-trans retinoic acid in the regulation of the proliferation and survival of human breast cancer cell line MCF-7

Retinoids are a group of compounds which inhibit cell proliferation and induce cellular differentiation. The aim of this study was to compare the antiproliferative activity of various concentrations of 13-cis retinoic acid (isotretinoin) and all-trans retinoic acid (tretinoin) in a culture of the estrogen-sensitive human breast cancer cell line MCF-7. Evaluation was based on [3H]thymidine incorporation into the cancer cells and through immunocytochemical analysis of cell cycle-associated PCNA and Ki-67 protein expression. Both retinoids inhibited [3H]thymidine incorporation into the cancer cells most effectively at a concentration of 3x10(-3) M. Two basic substances used for line MCF-7 culture experiments, one stimulating - estradiol - and the other inhibiting - tamoxifen - were applied. Estradiol added to a culture containing decreasing concentrations of isotretinoin (from 3x10(-3) to 3x10(-8) M) caused a statistically significant reduction in the percentage of [3H]thymidine incorporation into the cancer cell line MCF-7, compared to the 17 beta estradiol group (189.25%+/-62.64, control=100%, p<0.05). In the group of decreasing tretinoin concentrations, statistically significant differences were found only at 3x10(-3), 3x10(-4) and 3x10(-8) M. Following culture supplementation with tamoxifen (1 microM), statistically significant differences were observed only at the highest concentrations of both retinoids (3x10(-3) and 3x10(-4) M). The evaluation of breast carcinoma cells with a positive immunocytochemical reaction to PCNA and Ki-67 has revealed that isotretinoin reduces their percentage in the most determined and statistically significant way (38.00%+/-2.58 and 39.25%+/-3.09), compared to the control group (86.50%+/-9.20 and 100%+/-3.87, p<0.001 and p<0.0001) and to the estradiol group (87.00%+/-6.79 and 86.10%+/-7.0, p<0.001). Apart from their blocking effect on the cell cycle, retinoids also induce the apoptotic pathway.

Matrix metalloproteinase-9 and tissue inhibitor of matrix metalloproteinase-1: a possible role in the pathogenesis of endometriosis

BACKGROUND

Matrix metalloproteinases (MMPs) are a family of endopeptidases which play a role in the degradation and turnover of extracellular matrix proteins. Their action is regulated by specific tissue inhibitors called tissue inhibitors of metalloproteinases (TIMPs).

METHODS

We measured the concentrations of total and active MMP-9 in peritoneal fluid of infertile women with mild or moderate endometriosis (n = 22) and compared them with those in a control group of infertile patients (n = 21).

RESULTS

We found that the mean (+/-SD) total concentrations of MMP-9 in the peritoneal fluid of patients with endometriosis was 6.2 +/- 1.8 ng/ml, in comparison with 2.9 +/- 2.6 ng/ml in the control group (P = 0.001). Concentrations of active MMP-9 did not differ significantly between the groups. The concentrations of TIMP-1, after logarithmic transformation, were significantly lower (P = 0.017) in endometriotic peritoneal fluids than in peritoneal fluid of control women, 1.02 +/- 0.21 ng/ml and 1.16 +/- 0.18 ng/ml respectively. No correlation between stage of disease, steroid hormone concentration, MMP-9 (total and active) and TIMP-1 was found.

CONCLUSIONS

These results suggest that a disturbed equilibrium exists between MMP-9 and TIMP-1 in peritoneal fluid of women with endometriosis. This may play an important role in the pathogenesis of the disease.

[The effectiveness of hysteroscopic intrauterine septum resection in terms of reproductive outcome]

Uterine septum is the major intrauterine disorder associated with infertility and recurrent abortions. The aim of the study was to find out what is the effectiveness of hysteroscopic intrauterine septum resection in terms of reproductive outcome and in comparison with conventional procedure. The mean follow up period was 18 +/- 8.3 months. The pregnancy wastage before operation in study group was 79% and decreased to 45% after hysteroscopic treatment. Hysteroscopic resection of intrauterine septum is the treatment of choice for patients suffering from infertility or recurrent pregnancy wastage.

[Treatment of infertility by in vitro fertilization (IVF-ET)]

The authors survey available publications dealing with the indications for in vitro fertilization, ovary stimulation technique, control of the ovary stimulation, oocytes collection, and transfer of the embryo in human. The authors personal experience with in vitro fertilization is also discussed.