Current Pharmaceutical Design - Volume 26, Issue 45, 2020

Background: Conventional practices of synthesis, manufacturing, and processing have led to severe adverse consequences for living beings and the environment.

Objectives: Although medications cannot be replaced, the methods of synthesizing, manufacturing, and processing them can be changed and/or replaced. This paper explains the significance of green chemistry practices in the pharmaceutical industry. It emphasizes that we must replace conventional drug synthesis, processing, and manufacturing techniques with greener ones that are cost-effective, sustainable, environment-friendly, and profitable.

Discussion: This paper comprises five sections. Section 1 is an introduction to green chemistry and its correlation with the pharmaceutical industry. Section 2 discusses the metrics necessary to measure the greenness of a process. Section 3 is about solvents used in the pharmaceutical industry, hazards, safety status, and environmental effects, including the ozone depletion potential. Section 4 explains catalytic amidation reactions because amides are one of the most commonly occurring functional groups with pharmacological activity. Section 5 discusses successful cases of converting conventional synthesis of active pharmaceutical ingredients and/or their intermediates to greener, sustainable alternatives.

Conclusion: A balance is necessary between profits, processes, consumers, and the environment to ensure the survival of all stakeholders and decrease the environmental burden of pharmaceuticals. Incentives such as green chemistry awards should be endorsed and encouraged, in addition to making green chemistry part of tertiary education. In addition, changes to rules and regulations for drug approval in the context of green chemistry principles are necessary in order to preserve our planet for future generations.

There is compelling evidence that drug molecules isolated from natural sources are hindered by low systemic bioavailability, poor absorption, and rapid elimination from the human body. Novel approaches are urgently needed that could enhance the retention time as well as the efficacy of natural products in the body. Among the various adopted approaches to meet this ever-increasing demand, nanoformulations show the most fascinating way of improving the bioavailability of dietary phytochemicals through modifying their pharmacokinetics and pharmacodynamics. Curcumin, a yellowish pigment isolated from dried ground rhizomes of turmeric, exhibits tremendous pharmacological effects, including anticancer activities. Several in vitro and in vivo studies have shown that curcumin mediates anticancer effects through the modulation (upregulation and/or downregulations) of several intracellular signaling pathways both at protein and mRNA levels. Scientists have introduced multiple modern techniques and novel dosage forms for enhancing the delivery, bioavailability, and efficacy of curcumin in the treatment of various malignancies. These novel dosage forms include nanoparticles, liposomes, micelles, phospholipids, and curcumin-encapsulated polymer nanoparticles. Nanocurcumin has shown improved anticancer effects compared to conventional curcumin formulations. This review discusses the underlying molecular mechanism of various nanoformulations of curcumin for the treatment of different cancers. We hope that this study will make a road map for preclinical and clinical investigations of cancer and recommend nano curcumin as a drug of choice for cancer therapy.

Biopolymers and their composites have been extensively investigated in recent years for multiple applications, especially in environmental, medical, and pharmaceutical fields. Bacterial cellulose (BC) has emerged as a novel biomaterial owing to its nontoxic, high-liquid absorbing and holding capacity, drug-carrying ability, and pollutant absorbing features. Additionally, its web-shaped three-dimensional (3D) structure and hydrogen bonding sites have incited a combination of various nanoparticles, polymers, and other materials with BC in the form of composites. Such BC-based composites have been developed through in-situ, ex-situ, and solution casting methods for targeted applications, such as air and water filters, controlled drug delivery systems, wound dressing materials, and tissue regeneration. This review details the production and development of BCbased composites with different materials and by various methods. It further describes various applications of BC-based composites in the environmental and pharmaceutical sectors, with specific examples from the recent literature. This review could potentially appeal a wide readership in these two emerging fields, where novel and advanced materials for different applications have been developed on a regular basis using BC as the base material.

Aerogels are a class of advanced materials having the lowest density with extraordinary characteristics of high surface area, extreme porosity, lowest thermal conductivity, and tunable surface chemistry. Aerogels of silica, alumina, carbon, metals, metal oxides, clay, cellulose, gelatin, chitosan, synthetic polymers and many others have attracted much interest for different potential applications. Several attempts have been made to improve the characteristics and performance efficiency of the aerogels. One of those is to fabricate composite aerogels to be used in several applications. In designing composite aerogels for biomedical and environmental purposes, the nature of the ingredient materials along with their net efficiency and cost are important to be considered. In this regard, various compositions of composite aerogels have been explored by researchers to make them suitable for use in these applications. In the present study, an attempt has been made to briefly summarize various studies of composite aerogels for biomedical and environmental applications.

Green synthesis, an emerging field in bionanotechnology, refers to the utilization of non-toxic, biologically safe, and eco-friendly substances for the synthesis of desired materials. It provides both economic and environmental benefits along with simple, cost-effective, and reproducible synthesis approaches that result in the development of stable materials. The green synthesis approaches use living biotemplates, including plants and different microorganisms such as viruses, bacteria, fungi, algae, and actinomycetes. The various metabolites present in different parts of the plants, such as leaves, fruits, seeds, flower, and others, serve as the reducing and stabilizing agents. At the same time, the diverse surface chemistry of microorganisms enables them to convert different substrates into a variety of nanomaterials. This review briefly describes the concept of ‘green synthesis’ and provides an overview of controlled and green synthesis of nanomaterials using the plants and microbial cells as biotemplates. It also discusses the effect of different reaction conditions such as temperature, pH, reaction time, precursor concentration, and the post-synthesis processing of nanoparticles (NPs) on the material properties. It further describes the applications of different NPs in pharmaceutical and environment sectors by considering their diverse antimicrobial, anticancer, antioxidant, antiviral, antimalarial, reduction, and catalytic properties. Finally, it describes various future perspectives of nanomaterials to broaden the understanding of their synthesis mechanism and expand their applications to other fields.

Equol (4',7-isoflavandiol), is a phytoestrogenic compound, which is synthesized from parent molecule diadzein by intestinal bacterial flora. It is among one of the most extensively researched molecule due to its high affinity towards estrogen receptors. Its enantiomeric form S-equol has been explored in the treatment of estrogen/androgen mediated diseases. Various therapeutic applications such as anti-cancer, cardioprotective, antidiabetic, antiosteoporosis, anti-ageing, and neuroprotective efficacy are attributed to it. This review explored major studies related to biochemistry and pharmacological applications of equol for human health.

Background: Due to the rapid growth in life threatening diseases such as cancer, diabetes, chronic wound and HIV/AIDS along with rise of side effects of the current treatments, world is now focusing to utilize new treatment options. Currently, the development of green nanotechnology field seems as a potential alternate for diseases diagnosis and treatment by preparation of various sizes and shapes of nanomaterials.

Objective: This review is to present the explored biological sources in synthesis of nanomaterials particularly metal and metal oxides nanoparticles and critical review of the applications of biosynthesized nanoparticles in pharmaceutical and biomedical fields.

Methods: In this review, the various biological sources including bacteria, fungi, algae and plants used in synthesis of nanomaterials and mechanism involved in preparation are elaborated. In addition, biosynthesized nanomaterials applied as drug delivery system for anticancer, antibiotic, antidiabetic agent and functioned as potential diagnostic, antimicrobial, anticancer and wound healing candidates are comprehensively reviewed.

Results: The synthesized metal and metal oxides from green protocol proved to have advantages such as being biocompatible, effective and cheap. Furthermore, the green synthesized metal and metal oxide nanoparticles showed to possess prominent physical, chemical and biological properties that can be efficiently utilized for pharmaceutical and biomedical applications.

Conclusion: The information gathered in this review will provide a baseline for exploring more potential usage of green synthesized metal and metal oxide nanomaterials for various other applications. However, a concrete understanding of the safety of these nanomaterials is still needed to minimize the potential side effects.

Background: Bacterial cellulose (BC) is a microbial biosynthesized polymer having exceptional physical and mechanical features as compared to plants derived cellulose. BC has a wide range of applications such as traditional dessert as well as gelling, stabilizing and thickening agent in many foods. The more unconventional applications of BC include but not limited to enzymes immobilization, tissue engineering, artificial blood vessels and heart valve prosthesis, bone and cartilage regeneration, corneal replacement, skin tissues repair and dental root canal treatment.

Objective: This review presents the applications of BC expanded by preparing its nanocomposites with drugs, fibres, metals and metallic oxides. These nanocomposites have been studied for applications in drug delivery and biosensors.

Methods: The current review focuses on the potential applications of BC-based green metallic and metal-based inorganic nanocomposites as wound dressing material, a tool for microbial control, cardiovascular stenting, and as bone tissue engineering material. In addition, the potential pharmaceutical applications of BC-based green metallic nanocomposites have also been discussed.

Results: The reported BC-based nanocomposites owe advantages in terms of stability, environment friendliness and cost-effectiveness, prolonged therapeutic effects and biocompatibility with body tissues, with faster wound healing and negligible cytotoxicity.

Conclusion: The current review provides a deep insight into the assessment of such nanocomposites in terms of useful applications and potential commercialization for pharmaceutical as well biomedical purposes.

Normally, antibiotics are used for the growth inhibition of a variety of pathogens. The ever- increasing resistance of the various disease-causing pathogens to the antibiotics has drawn tremendous attention of researchers to find efficient alternatives. The recent era of modern material science and nanotechnology has made it possible to replace the existing antibiotics up to some extent. Currently, a vast library of materials has been prepared, which shows excellent performance against pathogens. Such materials consist of certain metals. Through this review, we present some notable studies concerning the antimicrobial activities of various metal containing compounds and their mode of action.

Hydrogels are natural or synthetic polymeric networks, insoluble in water, or sometimes found as colloidal gel where the dispersion medium is water. Hydrogels can absorb approximately 90% water and are regarded as superabsorbent materials; hence these resemble the natural living tissues more than any other biological- based materials. Because of their ability to absorb water, they are used to investigate the properties of swollen polymer networks and have wide applications in different fields such as contact lenses, drug delivery systems for proteins, and many others. To make them biodegradable, labile chemical bonds are introduced in the main backbone through crosslinking. These unstable bonds can then be broken down by various agents chemically, physically, or enzymatically, generally by hydrolysis or through some controlled parameters. Hydrogels are frequently used in the medical field. For instance, pH and temperature-sensitive hydrogels may be used in the targeted drug delivery which have been explained in detail in the current review. The other applications of hydrogels are also explained with regard to personal health care products, biomedical, bio-separation, wound healing, tissue engineering, and drug delivery, etc., which make them promising materials in pharmaceutics. They are also used in agriculture and environmental remediation. The purpose of this review is to expose their salient features and biomedical applications.