Engineering strategies and applications of cyanobacterial exopolysaccharides: A review on past achievements and recent perspectives.

Cyanobacteria are ideally suited for developing sustainable biological products but are underdeveloped due to a lack of genetic tools. Exopolysaccharide (EPS) is one of the essential bioproducts with widespread industrial applications. Despite their unique structural characteristics associated with distinct biological and physicochemical aspects, EPS from cyanobacteria has been underexplored. However, it is expected to accelerate in the near future due to the utilization of low-cost cyanobacterial platforms and readily available information on the structural data and specific features of these biopolymers. In recent years, cyanobacterial EPSs have attracted growing scientific attention due to their simple renewability, rheological characteristics, massive production, and potential uses in several biotechnology domains. This review focuses on the most recent research on potential new EPS producers and their distinct compositions responsible for novel biological activities. Additionally, nutritional and process parameters discovered recently for enhancing EPS production and engineering strategies applied currently to control the biosynthetic pathway for enhanced EPS production are critically highlighted. The process intensification of previously developed EPS extraction and purification processes from cyanobacterial biomass is also extensively explained. Furthermore, the newly reported biotechnological applications of cyanobacterial exopolysaccharides are also discussed.

Astaxanthin from microalgae: A review on structure, biosynthesis, production strategies and application.

Astaxanthin is a red-colored secondary metabolite with excellent antioxidant properties, typically finds application as foods, feed, cosmetics, nutraceuticals, and medications. Astaxanthin is usually produced synthetically using chemicals and costs less as compared to the natural astaxanthin obtained from fish, shrimps, and microorganisms. Over the decades, astaxanthin has been naturally synthesized from Haematococcus pluvialis in commercial scales and remains exceptional, attributed to its higher bioactive properties as compared to synthetic astaxanthin. However, the production cost of algal astaxanthin is still high due to several bottlenecks prevailing in the upstream and downstream processes. To that end, the present study intends to review the recent trends and advancements in astaxanthin production from microalgae. The structure of astaxanthin, sources, production strategies of microalgal astaxanthin, and factors influencing the synthesis of microalgal astaxanthin were discussed while detailing the pathway involved in astaxanthin biosynthesis. The study also discusses the relevant downstream process used in commercial scales and details the applications of astaxanthin in various health related issues.

3D Printing Technology in Pharmaceutical Dosage Forms: Advantages and Challenges.

Three Dimensional (3D) printing is a promising method for quick prototyping and manufacturing of any material. It is similar to photocopy or printing, where the new materials are formed on layers (3D) like their mother component. Following its growth and advancement in the 1980s, its application in pharmaceuticals is still limited. It has become one of the most innovative and influential tools serving as a technology for developing dosage forms from the last decade. The potential of 3D printing to produce drugs for precise measurement customized to specific patients' needs has shown the possibility of developing personalized medicines to novel dosage forms. The breakthrough allows the clear perception of the dosage structures on different shapes, sizes, surfaces and the associated challenges in delivering them by using such designed conditions. There are different difficulties related to the correct utilization of 3D imprinting in the pharmaceuticals, which have a strong impact on the scope of this technology. Recent advancements in the field of 3D printing technology used in the pharmaceutical industry mainly focused on different techniques for the fabrication of different dosage forms. The Food and Drug Administration's (FDA) recent approval of the first 3D prescription highlights possibilities for 3D printing innovation in the field of pharmaceutical drug supply. This analysis assesses 3D printing advancement possibilities, particularly in the area of custom prescriptions. This technology can be regarded as the future produced on demand, low-cost solid dosage forms and helps minimize side effects due to overdose.

Floating tablets of hydralazine hydrochloride: optimization and evaluation

Hydralazine hydrochloride has a half-life of 2 to 4 hours with an oral bioavailability of 26-50%. Since hydralazine has a demethylating effect on various suppressor genes, it can be used in various types of cancer to support chemotherapy. The purpose of this study was to optimize and evaluate floating tablets of hydralazine hydrochloride designed to prolong the gastric residence time and to provide controlled release of the drug for 14 h. The floating tablets of hydralazine hydrochloride were prepared by the wet granulation method. Semi-synthetic polymers of hydroxy propyl methyl cellulose (HPMC K100M) and ethyl cellulose were used as the release retarding agents. A 2² factorial design was applied to systematically optimize the drug release profile. The concentrations of HPMC K100M and ethyl cellulose were optimized to provide controlled release of hydralazine for 14h. Non-Fickian diffusion release transport was confirmed as the release mechanism for the optimized formulation and the predicted values agreed well with the experimental values. Drug excipient compatibility studies were investigated by FTIR, DSC and XRD. These data indicate that there were no chemical interactions between the drug and the polymer. In vivo X-ray imaging showed floating tablet performance in rabbits.

O cloridrato de hidralazina apresenta meia-vida de 2 a 4 horas, com biodisponibilidade oral de 26-50%. Uma vez que a hidralazina possui efeito desmetilante em vários genes supressores, ela pode ser utilizada para diversos tipos de câncer, em apoio à quimioterapia. O objetivo deste estudo foi o de avaliar e otimizar comprimidos flutuantes de cloridrato de hidralazina, planejados para prolongar o tempo de residência gástrica e proporcionar liberação controlada do fármaco por 14 h. Os comprimidos flutuantes de cloridrato de hidralazina foram preparados pelo método de granulação úmida. Polímeros semi-sintéticos de hidroxipropiletil celulose (HPMCK100M) e acetato de celulose foram utilizados como agente de retardamento de liberação. Aplicou-se planejamento fatorial 2² para otimizar sistematicamente o perfil de liberação do fármaco. As concentrações de HPMCK100M e de etilcelulose foram otimizadas para se obter liberação controlada de hidralazina durante 14 h. O transporte de liberação de difusão não-Fickiana foi confirmado como o mecanismo de liberação para a formulação otimizada e os valores previstos estiveram de acordo com os valores experimentais. Estudos de compatibilidade entre fármaco e excipiente foram realizados por FTIR, DSC e DRX. Estes dados indicaram que não havia interação química entre o fármaco e o polímero. Imagens de raios-X in vivo mostraram o desempenho dos comprimidos flutuantes em coelhos.