Impact of nanosizing on the formation and characteristics of polymethacrylate films: micro- versus nano-suspensions.

Aqueous-based film coating suspensions are associated with reliance on alkalinising reagents and poor film formation. The impact of particle size in this process and resultant film properties remains unclear. This study offers the first direct comparison of film formation properties between aqueous micro- and nano-suspensions of the enteric polymer Eudragit S100. High-pressure homogenisation was employed to produce nano-suspensions of the enteric polymer. Formed enteric suspensions (micro- and nano-) were evaluated in terms of size, morphology, and ability to form film; with resultant films analysed in terms of; film thickness, mechanical and thermoplastic properties, water uptake, weight loss, and drug permeability in acidic medium. High-pressure homogenisation yielded particles within a submicron range (150-200 nm). Produced nano-suspensions formed significantly thinner films (p < 0.01), at lower plasticiser concentrations, than films cast from micro-suspensions (differences in thickness up to 100 µm); however, exhibited comparative gastro-resistant properties (p > 0.05) in terms of water uptake (∼25% w/w), weight loss (<16% w/w) and drug permeability (<0.1%). Interestingly, nano-suspension-based films exhibited lower glass transition temperatures (Tg) (p < 0.01), when compared to films cast from micro-suspensions (∼7-20 °C difference), indicating enhanced plasticisation. This was reflected in film mechanical properties; where nano-suspension-based films demonstrated significantly lower tensile strength (p < 0.01) and higher percentage elongation (p < 0.05), suggesting high elasticity. Thinner, highly elastic films were formed from nano-suspensions, compared to films cast from micro-suspensions, exhibiting comparative properties; obviating the need for alkalinising agents and high concentrations of plasticiser.

Potential Cardio-Protective Agents: A Resveratrol Review (2000-2019).

With a 2030 projection of 23.6 million deaths per year, the prevalence and severity of cardiovascular disease are astoundingly high. Thus, there is a definitive need for the identification of novel compounds with the potential to prevent or treat the disease and associated states. Moreover, there is also an ever-increasing need for drug delivery systems (DDS) that cope with poor and ranging physiochemical properties of therapeutic compounds to achieve the clinical effect. The usage of resveratrol (RES) is a growing area of interest with innumerate pieces of research, evidencing the drug's efficacy. This drug is, however, marred; its notably poor physiochemical properties (namely poor water solubility) limit its use for oral drug delivery. RES analogues, however, potentially possess superior physiochemical characteristics offering a remedy for the aforementioned drawback. However, particulate based DDS are equally able to offer property amelioration and targeting. This review offers an extensive examination into the role of RES as a potential cardioprotective agent. The prevalence and suitability of associated analogues and the role of nanotechnology in overcoming physicochemical boundaries, particularly through the development of nanoparticulate formulations, will be discussed in detail.

Potential of Natural Biomaterials in Nano-scale Drug Delivery.

BACKGROUND: The usage of natural biomaterials or naturally derived materials intended for interface with biological systems has steadily increased in response to the high demand of amenable materials, which are suitable for purpose, biocompatible and biodegradable. There are many naturally derived polymers which overlap in terms of purpose as biomaterials but are equally diverse in their applications. METHODS: This review examines the applications of the following naturally derived polymers; hyaluronic acid, silk fibroin, chitosan, collagen and tamarind polysaccharide (TSP); further focusing on the biomedical applications of each as well as emphasising on individual novel applications. RESULTS: Each of the polymers was found to demonstrate a wide variety of successful biomedical applications fabricated as wound dressings, scaffolds, matrices, films, sponges, implants or hydrogels to suit the therapeutic need. Interestingly, blending and amelioration of polymer structures were the two selection strategies to modify the functionality of the polymers to suit the purpose. Further, these polymers have shown promise to deliver small molecule drugs, proteins and genes as nano-scale delivery systems. CONCLUSION: The review highlights the range of applications of the aforementioned polymers as biomaterials. Hyaluronic acid, silk fibroin, chitosan, collagen and TSP have been successfully utilised as biomaterials in the subfields of implant enhancement, wound management, drug delivery, tissue engineering and nanotechnology. Whilst there are a number of associated advantages (i.e. biodegradability, biocompatibility, non-toxic, nonantigenic as well as amenability) the selected disadvantages of each individual polymer provide significant scope for their further exploration and overcoming challenges like feasibility of mass production at a relatively low cost.