Artemisinin Cocrystals for Bioavailability Enhancement: In vitro Formulation Design, In vivo and Physiologically Based Pharmacokinetic models

Artemisinin (ART) is the most promising antimalarial agent, which is both effective and well tolerated in patients, however, has therapeutic limitations due to its low solubility, bioavailability, short half-life and neurotoxicity. The objective of this work was to explore the possibility of formulating ART cocrystals, i.e., Artemisinin-Orcinol (ART-ORC) and Artemisinin-Resorcinol (ART2-RES) as oral dosage forms to deliver ART molecules for bioavailability enhancement. The aim of this research was to develop a simple and effective ART cocrystal formulation which can be used on an appropriate animal model to evaluate their preclinical pharmacokinetics for further development. The research reports the evaluation and prediction of pharmacokinetics (PK) performance of ART cocrystal formulations using in vivo murine animal and Physiologically Based Pharmacokinetic (PBPK) models. The study was divided into five tasks: (1) Formation and characterisation of Artemisinin cocrystals: Two pharmaceutical cocrystals of poorly water soluble active pharmaceutical ingredient (API) ART were synthesised, including 1:1 Artemisinin-Orcinol (ART-ORC) and 2:1 Artemisinin-Resorcinol (ART2-RES). The formation of pure cocrystals was confirmed by the characterisation techniques such as Infrared Spectroscopy (IR), Differential Scanning Calorimetry (DSC) and Powder X-Ray Diffraction (PXRD). (2) Formulation design of Artemisinin cocrystals The physiochemical properties of ART cocrystals were measured to provide valuable information for the strategy of formulation development. It was found that the ART solubility can be increased significantly by its cocrystals, i.e., 26-fold by ART-ORC and 21-fold by ART2-RES respectively. Copolymer Polyvinylpyrrolidone/vinyl Acetate (PVP-VA) was found to be the most effective crystallisation inhibitor through screening a set of polymers widely used in pharmaceutical products, including Polyvinylpyrrolidone (PVP), Hydroxypropyl Methylcellulose (HPMC) and Hydroxypropyl Methylcellulose Acetate Succinate (HPMC-AS) based on the powder dissolution performance parameter (DPP) analysis. The optimal concentration of PVP-VA at 0.05mg/mL within a formulation was then determined by a dissolution/permeability (D/P) method which represented a simplified permeation model to simultaneously evaluate the effects of a crystallization inhibitor on the dissolution and permeation performance of ART cocrystals. VII (3) Mechanistic understandings of effect of the polymeric excipient on Artemisinin cocrystal dissolution and permeation properties The surface dissolution of single ART cocrystals was monitored by Raman spectroscopy and Scanning Electron Microscope (SEM) and the diffusion properties of ART in solution were measured by 1H and diffusion-ordered spectroscopy (DOSY) nuclear magnetic resonance (NMR) spectroscopy. These experiments were conducted to gain an insight into how the excipient affects the ART cocrystal dissolution performance and bioavailability. (4) In vivo bioavailability of Artemisinin Cocrystals The efficacy of the ART cocrystal formulations along with the parent drug ART were tested in mice infected with Plasmodium berghei. Cocrystal formulations resulted in a five-fold reduction in parasitaemia in mice compared to ART alone at the same dose. The PK parameters including Cmax, Tmax, AUC were obtained by determining drug concentrations in the plasma using Liquid Chromatography-High Resolution Mass Spectrometry (LC-HRMS), showing enhanced ART levels after dosage with the cocrystal formulations. The dose-response tests revealed that a significantly lower dose of the ART cocrystals in the formulation was required to achieve a similar therapeutic effect as ART alone formulation. (5) Physiologically based pharmacokinetic (PBPK) modelling of Artemisinin Cocrystals A PBPK model was developed using a PBPK mouse simulator to accurately predict the in vivo behaviour of the cocrystal formulations by combining in vitro dissolution profiles with the properties of the parent drug ART. The study illustrated that information from classical in vitro and in vivo experimental investigations of the parent drug of ART formulation can be coupled with PBPK modelling to predict the PK parameters of an ART cocrystal formulation in an efficient manner. Therefore, the proposed modelling strategy could be used to establish structure−activity relationships for different cocrystals intended to improve dissolution properties and to support clinical candidate selection, contributing to assessment of cocrystal developability and formulation development.UK Engineering and Physical Sciences Research Council (EPSRC, EP/R021198/1

Evaluation of antihypertensive efficacy of Losartan + Hydrochlorthiazide versus Telmisartan + Hydrochlorthiazide in patients with stage 1 or stage 2 hypertension: a randomized controlled trial

Background: Cardiovascular disease (CVD) is the most common contributor of morbidity and mortality in underdeveloped and developing countries including the South Asian countries (including India and Pakistan). Amongst the cluster group of CVDs, Hypertension (HTN) represents the most common cardiovascular risk factor. The aim of this trial was to evaluate of antihypertensive efficacy and effect on biochemical parameters of Losartan + Hydrochlorthiazide versus Telmisartan + Hydrochlorthiazide in patients with stage 1 or stage 2 hypertension with a randomized controlled trial.Methods: This was a prospective, randomized controlled trial of Losartan + Hydrochlorthiazide versus Telmisartan + Hydrochlorthiazide in patients with stage 1 or stage 2 hypertension. The primary endpoint on treatment was analysis of antihypertensive efficacy of these drug combinations. The variables were compared at different time points- baseline, 3 and 6 months.Results: In the present study, 76 patients were enrolled with 38 patients each allocated to each treatment groups. The effect of Losartan 50mg + Hydrochlorthiazide 12.5mg OD was found to be significant on SBP and DBP in both supine as well as sitting position than Telmisartan 80mg + Hydrochlorthiazide 12.5mg OD group at 3 and 6 months.Conclusions: The results on anti- hypertensive efficacy was far better in Losartan 50mg + Hydrochlorthiazide 12.5mg OD group than Telmisartan 80mg + Hydrochlorthiazide 12.5mg OD group

Take Two: Immigrants

This exploration delves into the profound historical and contemporary significance of immigrants in shaping the United States. From the early settlers and Ellis Island arrivals to modern-day immigrants, their contributions have been pivotal to the country's development and cultural fabric. By debunking stereotypes, the study emphasizes the crucial role of immigrants in building American society. Their impact on technological progress, evident in inventions like iPhones and the telephone, further underscores their value. The article also addresses discrimination faced by newer immigrants and advocates for recognizing their immense worth, especially among those seeking asylum from perilous circumstances. With compelling historical and current evidence, the research highlights the indispensable role of immigrants in America's growth and diversity

Mammary tumour-induced dysregulation in hematopoiesis and DC development and the role of Lyn tyrosine kinase in DC activation

Previous studies have revealed that perturbations in myelopoiesis can lead to the emergence of immature cells, which can facilitate tumorigenesis and metastasis. Our studies showed that mammary tumours led to a myeloproliferative-like disease, characterized by anemia, leukocytosis, expansion of immature myeloid cells, and defects in the hematopoietic stem and progenitor cell (HSPC) compartment in tumour-bearing mice. Furthermore, mammary tumours impaired DC development resulting in the accumulation of DC progenitors and the emergence of immunosuppressive DCs with impaired ability to activate NK and T cells. Mammary tumour-bearing mice exhibited a shift in hematopoiesis from the bone marrow to the spleen, with large numbers of primitive and committed progenitors accumulating in the spleen. Mammary tumour development was also associated with epigenetic modifications that facilitated the expression of key hematopoiesis and leukemia regulatory genes, such as Hoxa9, a gene that critically controls HSPC differentiation. Using in vitro assays, we identified mammary tumour derived G-CSF as the factor mediating the dysregulation of the HSPC compartment and suppressing DC development. DCs are critical for the priming/activation of NK cells and cytotoxic T lymphocytes, which together are critical components of the anti-tumour immune response. Therefore, proper regulation of signaling thresholds is critical for DC activation and function. Lyn tyrosine kinase is important in regulating signaling thresholds in immune cells, including DCs, and Lyn gain-of-function (Lynup/up) mice show increased sensitivity to PAMPs (i.e. LPS) characterized by high levels of proinflammatory cytokines and increased susceptibility to endotoxin-mediated death. Our studies demonstrated that DCs were necessary for the enhanced LPS-induced inflammation in Lynup/up mice, by priming excessive IFN-γ production by NK cells. As such, we hypothesized that enhanced Lyn activity, and the associated changes in DC development and activation will evoke improved anti-tumour immune responses and preliminary data from our lab demonstrates that Lynup/up mice develop smaller mammary tumours than wild type mice. Taken together, our results suggest that targeting mammary tumour derived G-CSF may reverse mammary tumour-induced anemia, leukocytosis, and DC defects, conversely enhancing DC function by increasing Lyn activity may result in in a more robust anti-tumour immune response, leading to increased survival of breast cancer patients.Science, Faculty ofMicrobiology and Immunology, Department ofGraduat

Development of efficacious and less toxic endodontic irrigants from biosurfactants of bacterial origin – A confocal laser scanning microscope study

Aim: The study compared the penetration depth and area of Bacillus subtilis and Pseudomonas aeruginosa biosurfactants inside the dentinal tubules against sodium hypochlorite at three levels (coronal, middle, and apical) under a confocal laser scanning microscope. Materials and Methodology: Three experimental groups and one control were created using freshly extracted thirty-five maxillary central incisors; Group 1: B. subtilis biosurfactant; Group 2: P. aeruginosa biosurfactants; Group 3: sodium hypochlorite; and Group 4: distilled water. The experimental data were statistically analyzed by two-way analysis of variance, duly coupled with Tukey's post hoc test to draw concrete conclusions between paired comparisons, and P < 0.05 was considered statistically significant. Results: P. aeruginosa and B. subtilis biosurfactant showed the maximum mean penetration depth and area at all the level as compared to sodium hypochlorite. Conclusion: Biosurfactants showed better results than sodium hypochlorite in reaching to higher penetration depth and area at all the three levels