SciCombinator

Discover the most talked about and latest scientific content & concepts.

Journal: Drug design, development and therapy

225

The aim of the present work is to extensively evaluate the pharmaceutical attributes of currently available riluzole presentations. The article describes the limitations and risks associated with the administration of crushed tablets, including the potential for inaccurate dosing and reduced rate of absorption when riluzole is administered with high-fat foods, and the advantages that a recently approved innovative oral liquid form of riluzole confers on amyotrophic lateral sclerosis (ALS) patients. The article further evaluates the patented and innovative controlled flocculation technology used in the pseudoplastic suspension formulation to reduce the oral anesthesia seen with crushed tablets, resulting in optimized drug delivery for riluzole. Riluzole is the only drug licensed for treating ALS, which is the most common form of motor neurone disease and a highly devastating neurodegenerative condition. The licensed indication is to extend life or the time to mechanical ventilation. Until recently, riluzole was only available as an oral tablet dosage form in the UK; however, an innovative oral liquid form, Teglutik(®) 5 mg/mL oral suspension, is now available. An oral liquid formulation provides an important therapeutic option for patients with ALS, >80% of who may become unable to swallow solid oral dosage forms due to disease-related dysphagia. Prior to the launch of riluzole oral suspension, the only way for many patients to continue to take riluzole as their disease progressed was through crushed tablets. A novel suspension formulation enables more accurate dosing and consistent ongoing administration of riluzole. There are clear and important advantages such as enhanced patient compliance compared with crushed tablets administered with food or via an enteral feeding tube and the potential for an improved therapeutic outcome and enhanced quality of life for ALS patients.

Concepts: Pharmacology, Amyotrophic lateral sclerosis, Feeding tube, Electromyography, Frontotemporal dementia, Dosage forms, Riluzole, Dosage form

169

The taxanes (paclitaxel and docetaxel) represent an important class of antineoplastic agents that interfere with microtubule function leading to altered mitosis and cellular death. Paclitaxel (Taxol(®)) was originally extracted from a yew tree (Taxus spp., Taxaceae) a small slow-growing evergreen, coniferous tree. Due to the initial scarcity of paclitaxel, docetaxel (Taxotere(®)) a semisynthetic analog of paclitaxel produced from the needles of European yew tree, Taxus baccata was developed. Docetaxel differs from paclitaxel in two positions in its chemical structure and this small alteration makes it more water soluble. Today, paclitaxel and docetaxel are widely prescribed antineoplastic agents for a broad range of malignancies including lung cancer, breast cancer, prostate cancer, Kaposi’s sarcoma, squamous cell carcinoma of the head and neck, gastric cancer, esophageal cancer, bladder cancer, and other carcinomas. Although very active clinically, paclitaxel and docetaxel have several clinical problems including poor drug solubility, serious dose-limiting toxicities such as myelosuppression, peripheral sensory neuropathy, allergic reactions, and eventual development of drug resistance. A number of these side effects have been associated with the solvents used for dilution of these antineoplastic agents: Cremophor EL for paclitaxel and polysorbate 80 for docetaxel. In addition, reports have linked these solvents to the alterations in paclitaxel and docetaxel pharmacokinetic profiles. In this review, we provide preclinical and clinical data on several novel taxanes formulations and analogs which are currently US Food and Drug Administration (FDA)-approved or in clinical development in various solid tumor malignancies. Of the new taxanes nab-paclitaxel and cabazitaxel have enjoyed clinical success and are FDA-approved; while many of the other compounds described in this review are unlikely to be further developed for clinical use in daily practice. Furthermore, the successful clinical emergence of novel nontaxane microtubule-targeting chemotherapy agents such as epothilones and eribulin is liable to further restrict the development of novel taxanes.

Concepts: Cancer, Metastasis, Lung cancer, Chemotherapy, Squamous cell carcinoma, Paclitaxel, Taxus, Taxus baccata

166

The inherently toxic nature of chemotherapy drugs is essential for them to kill cancer cells but is also the source of the detrimental side effects experienced by patients. One strategy to reduce these side effects is to limit the healthy tissue exposure by encapsulating the drugs in a vehicle that demonstrates a very low leak rate in circulation while simultaneously having the potential for rapid release once inside the tumor. Designing a vehicle with these two opposing properties is the major challenge in the field of drug delivery. A triggering event is required to change the vehicle from its stable circulating state to its unstable release state. A unique mechanical actuation type trigger is possible by harnessing the size changes that occur when microbubbles interact with ultrasound. These mechanical actuations can burst liposomes and cell membranes alike allowing for rapid drug release and facilitating delivery into nearby cells. The tight focusing ability of the ultrasound to just a few cubic millimeters allows for precise control over the tissue location where the microbubbles destabilize the vehicles. This allows the ultrasound to highlight the tumor tissue and cause rapid drug release from any carrier present. Different vehicle designs have been demonstrated from carrying drug on just the surface of the microbubble itself to encapsulating the microbubble along with the drug within a liposome. In the future, nanoparticles may extend the circulation half-life of these ultrasound triggerable drug-delivery vehicles by acting as nucleation sites of ultrasound-induced mechanical actuation. In addition to the drug delivery capability, the microbubble size changes can also be used to create imaging contrast agents that could allow the internal chemical environment of a tumor to be studied to help improve the diagnosis and detection of cancer. The ability to attain truly tumor-specific release from circulating drug-delivery vehicles is an exciting future prospect to reduce chemotherapy side effects while increasing drug effectiveness.

Concepts: Immune system, Cancer, Oncology, Cell membrane, Chemotherapy, Neoplasm, Doxorubicin, Experimental cancer treatment

150

Obesity is a progressive metabolic disorder in the current world population, and is characterized by the excess deposition of fat in the adipose tissue. Pancreatic lipase is one of the key enzymes in the hydrolysis of triglycerides into monoglycerides and free fatty acids, and is thus considered a promising target for the treatment of obesity. The present drugs used for treating obesity do not give satisfactory results, and on prolonged usage result in severe side effects. In view of the drastic increase in the obese population day-to-day, there is a greater need to discover new drugs with lesser side effects.

Concepts: Metabolism, Nutrition, Fatty acid, Enzyme, Triglyceride, Fat, Fatty acid metabolism, Lipid

113

Chloroquine (CQ) and hydroxychloroquine (HCQ) are widely used in patients with rheumatic diseases, but their effects on the cardiovascular system remain unclear. We aimed to assess whether CQ/HCQ could reduce the risk of cardiovascular disease (CVD).

56

Metformin is the most commonly prescribed drug for type 2 diabetes mellitus. In recent years, in addition to glucose lowering, several studies have presented evidence suggesting some potential role for metformin, such as antitumor effect, antiaging effect, cardiovascular protective effect, neuroprotective effect or an optional treatment for polycystic ovary syndrome. This paper will critically review the role of metformin to provide reference for doctors and researchers.

Concepts: Insulin, Diabetes mellitus type 2, Diabetes mellitus, The Canon of Medicine, Obesity, Sulfonylurea, Metformin, Polycystic ovary syndrome

26

Mebendazole (MBZ) is an extremely insoluble and therefore poorly absorbed drug and the variable clinical results may correlate with blood concentrations. The necessity of a prolonged high dose treatment of this drug increases the risk of adverse effects.

Concepts: Pharmacology, Effectiveness, Adverse drug reaction, Anthelmintics, Mebendazole

25

The enzyme 3-hydroxy-3-methyl-glutaryl-coenzyme A (HMG-CoA) reductase is the key enzyme of the mevalonate pathway that produces cholesterol. Inhibition of HMG-CoA reductase reduces cholesterol biosynthesis in the liver. Synthetic drugs, statins, are commonly used for the treatment of hypercholesterolemia. Due to the side effects of statins, natural HMG-CoA reductase inhibitors of plant origin are needed. In this study, 25 medicinal plant methanol extracts were screened for anti-HMG-CoA reductase activity. Basella alba leaf extract showed the highest inhibitory effect at about 74%. Thus, B. alba was examined in order to investigate its phytochemical components. Gas chromatography with tandem mass spectrometry and reversed phase high-performance liquid chromatography analysis revealed the presence of phenol 2,6-bis(1,1-dimethylethyl), 1-heptatriacotanol, oleic acid, eicosyl ester, naringin, apigenin, luteolin, ascorbic acid, and α-tocopherol, which have been reported to possess antihypercholesterolemic effects. Further investigation of in vivo models should be performed in order to confirm its potential as an alternative treatment for hypercholesterolemia and related cardiovascular diseases.

Concepts: Cholesterol, Atherosclerosis, Low-density lipoprotein, Statin, Chromatography, High performance liquid chromatography, Alternative medicine, HMG-CoA reductase

25

24

A biosimilar is defined by the European Medicines Agency as a biological medicine that is similar to another biological medicine that has already been authorized for use. A science-based regulatory framework to ensure high-quality biosimilars has been established in Europe since 2005 and is monitored and updated on an ongoing basis. The guiding principle of a biosimilar development program is to establish similarity between the biosimilar and the reference medicine by the best possible means, ensuring that the previously proven safety and efficacy of the reference medicinal product also applies to the biosimilar. Development of a biosimilar is underpinned by state-of-the-art analytical techniques to characterize both reference medicines and biosimilars. The extent and nature of the nonclinical in vivo studies and clinical studies to be performed depend on the level of evidence obtained in the previous step(s), including the robustness of the physicochemical, biological, and nonclinical in vitro data. Extrapolation is an important element of the biosimilarity concept. When biosimilar comparability has been demonstrated in one indication, extrapolation of the data package to other indications of the reference medicine could be acceptable, but needs to be scientifically justified and considered in light of the demonstrated level of sameness by all analytical, nonclinical, and clinical data. The credibility of the scientific basis behind the biosimilar concept, and quality of regulatory decision-making, is demonstrated by the successful approval and clinical use of 20 biosimilar medicines since 2006 when Omnitrope(®) was the first biosimilar to be approved. The regulatory environment for biosimilars continues to evolve, both in recognition of advances in technology/analytical methods and the availability of new targets for biosimilar development.

Concepts: Pharmacology, Medicine, Evolution, In vivo, Avicenna, Clinical research, In vitro, Food and Drug Administration