Enzyme-responsive mechanism based on multi-walled carbon nanotubes and pectin complex tablets for oral colon-specific drug delivery system

Mucoadhesive carriers for oral drug delivery

Among the various dosage forms, oral medicine has extensive benefits including ease of administration and patients' compliance, over injectable, suppositories, ocular and nasal. Despite of extensive demand and emerging advantages, over 50% of therapeutic molecules are not available in oral form due to their physicochemical properties. More importantly, most of the biologics, proteins, peptide, and large molecular drugs are mostly available in injectable form. Conventional oral drug delivery system has limitation such as degradation and lack of stability within stomach due to presence of highly acidic gastric fluid, hinders their therapeutic efficacy and demand more frequent and higher dosing. Hence, formulation for controlled, sustained, and targeted drug delivery, need to be designed with feasibility to target the specific region of gastrointestinal (GI) tract such as stomach, small intestine, intestine lymphatic, and colon is challenging. Among various oral delivery approaches, mucoadhesive vehicles are promising and has potential for improving oral drug retention and controlled absorption to treat local diseases within the GI tract, as well systemic diseases. This review provides the overview about the challenges and opportunities to design mucoadhesive formulation for oral delivery of therapeutics in a way to target the specific region of the GI tract. Finally, we have concluded with future perspective and potential of mucoadhesive formulations for oral local and systemic delivery.

Novel Developments on Stimuli-Responsive Probiotic Encapsulates: From Smart Hydrogels to Nanostructured Platforms

Biomaterials engineering and biotechnology have advanced significantly towards probiotic encapsulation with encouraging results in assuring sufficient bioactivity. However, some major challenges remain to be addressed, and these include maintaining stability in different compartments of the gastrointestinal tract (GIT), favoring adhesion only at the site of action, and increasing residence times. An alternative to addressing such challenges is to manufacture encapsulates with stimuli-responsive polymers, such that controlled release is achievable by incorporating moieties that respond to chemical and physical stimuli present along the GIT. This review highlights, therefore, such emerging delivery matrices going from a comprehensive description of addressable stimuli in each GIT compartment to novel synthesis and functionalization techniques to currently employed materials used for probiotic’s encapsulation and achieving multi-modal delivery and multi-stimuli responses. Next, we explored the routes for encapsulates design to enhance their performance in terms of degradation kinetics, adsorption, and mucus and gut microbiome interactions. Finally, we present the clinical perspectives of implementing novel probiotics and the challenges to assure scalability and cost-effectiveness, prerequisites for an eventual niche market penetration.

New insights in pectinase production development and industrial applications

Pectinase, a group of pectin degrading enzymes, is one of the most influential industrial enzymes, helpful in producing a wide variety of products with good qualities. These enzymes are biocatalysts and are highly specific, non-toxic, sustainable, and eco-friendly. Consequently, both pectin and pectinase are crucially essential biomolecules with extensive applicatory perception in the biotechnological sector. The market demand and application of pectinases in new sectors are continuously increasing. However, due to the high cost of the substrate used for the growth of microbes, the production of pectinase using microorganisms is limited. Therefore, low-cost or no-cost substrates, such as various agricultural biomasses, are emphasized in producing pectinases. The importance and implications of pectinases are rising in diverse areas, including bioethanol production, extraction of DNA, and protoplast isolation from a plant. Therefore, this review briefly describes the structure of pectin, types and source of pectinases, substrates and strategies used for pectinases production, and emphasizes diverse potential applications of pectinases. The review also has included a list of pectinases producing microbes and alternative substrates for commercial production of pectinase applicable in pectinase-based industrial technology.Key points• Pectinase applications are continuously expanding.• Organic wastes can be used as low-cost sources of pectin.• Utilization of wastes helps to reduce pollution.

Characterisation of pectin and optimization of pectinase enzyme from novel Streptomyces fumigatiscleroticus VIT-SP4 for drug delivery and concrete crack-healing applications: An eco-friendly approach

Pectinases are enzymes which are widely distributed in microbes that are present in pectin enriched sites. The agro-industrial residues can be utilized in the industrial scale for low-cost and efficient pectinase production in an eco-friendly approach. This study employs low-cost substrates (i.e. culinary fruit peels) for maximum pectinase production from novel Streptomyces fumigatiscleroticus VIT-SP4. The extraction and characterization of pectin from different fruit peels were investigated and pectinase activity was analyzed. The orange pectin gave maximum pectinase activity of about 45.93 (U/mL). Further, statistical optimization of process parameters was studied by using Taguchi method showed optimum values of pH-6, temperature −35 °C, orange pectin% − 2.5, incubation time- 48 h and RPM- 200 rpm and pectinase activity was found to be 98.65 (U/mL). The response surface methodology (RSM) was used for the optimization of media components which revealed that starch −1.17%, yeast extract-2%, and orange pectin% − 0.75% produces maximum pectinase of about 170.05 (U/mL). The drug-delivery study showed drug release was not observed at initial pH 3 after 4 h. The immediate drug release was noted at pH 6 caused due to disintegration of pectin by the pectinase activity. The self-healing of cracks by spray culture technique was investigated. The crack healing was observed up to 0.50 mm wide after 12 days. This confirms the ability of actinomycete spores to survive and they react to form calcite complex directly helps in crack healing process. This low-cost microbial pectinase can be used in drug delivery and concrete crack-healing applications sectors in future.

Interpolymer Complexes of Eudragit® Copolymers as Novel Carriers for Colon-Specific Drug Delivery

Interpolymer complexes (IPC) based on Eudragit^® EPO and Eudragit^® S100 were investigated as potential carriers for oral controlled drug delivery to the colon. IPC samples were prepared by mixing copolymer solutions in organic solvents (ethanol, isopropanol:acetone mixture (60:40, % v/v) and tetrahydrofuran). According to the data of elemental analysis, FTIR-spectroscopy, X-ray photoelectron spectroscopy and thermal analysis these IPCs have excess of anionic copolymer (Eudragit^® S100) in their structure; they are stabilized by hydrogen and ionic intermacromolecular bonds and do not include free copolymer domains. IPC have pH-independent swelling properties in the media mimicking gastrointestinal tract (GIT) conditions and provide colon-specific delivery of indomethacin in buffer solutions (pH 1.2; 5.8; 6.8; 7.4) and in biorelevant media (fasted state simulated gastric fluid, fasted state simulated intestinal fluid—version 2 and fasted stated simulated colonic fluid).

Design and application of oral colon administration system

Oral colon administration system has become a new method to treat intestinal diseases. The implementation of colon drug delivery system is restricted by many aspects, including physical and chemical properties, drug delivery mode, gastrointestinal physiological factors, and so on. Delivery methods to overcome these challenges revolve around the mechanisms of drug delivery, including the use of rational dosage forms to avoid the complex pH environment, and the prevention of drug release and absorption in the upper digestive tract.