Xylan from Pineapple Stem Waste: a Potential Biopolymer for Colonic Targeting of Anti-inflammatory Agent Mesalamine

Self-Double-Emulsifying Drug Delivery System Enteric-Coated Capsules: A Novel Approach to Improve Oral Bioavailability and Anti-inflammatory Activity of Panax notoginseng Saponins

In this work, self-double-emulsifying drug delivery system enteric-coated capsules (PNS-SDE-ECC) were used to enhance the oral bioavailability and anti-inflammatory effects of Panax notoginseng saponins (PNS), which are rapidly biodegradable, poorly membrane permeable, and highly water-soluble compounds. The PNS-SDEDDS formulated by a modified two-step method spontaneously emulsified to W/O/W double emulsions in the outer aqueous solution, which significantly promoted the absorption of PNS in the intestinal tract. The release study revealed that PNS-SDE-ECC exhibited sustained release of PNS within 24 h and the stability study indicated that PNS-SDE-ECC were stable at room temperature for up to 3 months. Furthermore, compared to PNS gastric capsules, the relative bioavailability of NGR1, GRg1, GRe, GRb1, and GRd in PNS-SDE-ECC was increased by 4.83, 10.78, 9.25, 3.58, and 4.63 times, respectively. More importantly, PNS-SDE-ECC significantly reduced OXZ-induced inflammatory damage in the colon by regulating the expression of TNF-α, IL-4, IL-13, and MPO cytokines. Overall, the prepared PNS-SDE-ECC may serve as a viable vehicle for increasing the oral bioavailability of PNS and its anti-inflammatory action on ulcerative colitis.

Characteristics, Properties and Analytical/Bioanalytical Methods of 5-Aminosalicylic Acid: A Review

Five-aminosalicylic acid (5-ASA) is an anti-inflammatory drug indicated in the treatment of inflammatory bowel diseases such as ulcerative colitis and Crohn's disease. Among the analytical methods of quantification of 5-ASA described in the literature, the High Efficiency Liquid Chromatography stands out, a sensitive technique but with a high cost. In recent years, alternative methods have been developed, presenting efficiency and reduced cost, such as UV/visible spectrophotometric, spectrofluorescent, and electrochemical methods, techniques recommended for the application in quality control and quantification of 5-ASA in pharmaceutical forms and biological fluids. This article aims to review the physicochemical characteristics, pharmacokinetics, mechanisms of action, controlled release systems, and the different analytical and bioanalytical methods for the quantification of 5-ASA.

Recent advances in mesalamine colonic delivery systems

Background

Increased attention has been focused on the continuous development and improvement of mesalamine colonic specific delivery systems, for the effective treatment of inflammatory bowel diseases; thus enhancing therapeutic efficacy and reducing potential side effects. Mesalamine is a class IV drug, according to the Biopharmaceutics Classification System, used usually to treat inflammation associated with colon related diseases such as Crohn’s disease and ulcerative colitis.

Main text

An ideal colon targeting system aims to deliver a therapeutic agent, selectively and effectively, to the colon. This system should ideally retain the drug release in the upper GI tract (stomach and small intestine); while trigger the drug release in the colon. Several approaches have been used to fabricate formulations to achieve a colon specific delivery of mesalamine such as; time dependent, pH responsive, enzymatic/microbial responsive and ultrasound mediated approaches. This overview outlines the recent advances in mesalamine-colon delivery approaches for the potential treatment of ulcerative colitis and Crohn’ disease.

Conclusion

A combined pH-time dependent delivery system can improve mesalamine colonic drug delivery via employing carriers capable of retarding mesalamine release in the stomach and delivering it at predetermined time points after entering the intestine. The existence of specific enzymes, produced by various anaerobic bacteria present in the colon advocates the advantage of designing enzyme sensitive systems and combining it with pH-time dependent system to improve mesalamine colonic delivery. The use of ultrasound has shown promises to effectively treat inflammatory bowel diseases.

A novel view of the problem of Osteoarthritis in experimental rat model

Introduction: The article presents the results of the functional tests to improve the assessment of MIA-induced osteoarthritis development and the effectiveness of NSAID therapy.

Materials and methods: In the study, 26 male SD rats were used. MIA-induced osteoarthritis was simulated in the right knee joint. After an intra-articular injection of MIA, the animals were treated with ibuprofen and meloxicam. Pain assessment was studied in the following functional tests: incapacitance (hind limb weight bearing) test, von Frey test (mechanical allodynia), grip strength test, and knee diameter measurement. At the end of the study, a histological analysis of the knee joint was performed.

Results and discussion: An intra-articular MIA injection reduced 1.5 times the paw withdrawal threshold. In the rats that suffered MIA-induced osteoarthritis, the difference between the diameters of the intact and injected joints was 1.05 mm, compared to 0.03 mm difference in the control group. Hind limb weight bearing asymmetry was 89.5% when simulating MIA-induced osteoarthritis. The muscular hind limb grip strength in rats with MIA-induced osteoarthritis was significantly reduced on 3rd and 7th days after simulating osteoarthritis. Ibuprofen and meloxicam showed significant efficacy in all the above tests, although ibuprofen effectiveness was more pronounced than that of meloxicam.

Conclusion: The following functional tests were identified as the most significant and sufficient to assess the development of MIA-induced osteoarthritis and analgesic efficacy of NSAIDs: incapacitance test, allodynia test (von Frey filaments), measurement of hind limb grip strength and measurement of the diameter of the inflamed knee joint. The histological analysis made it possible to confirm the correspondence of the physiological response and pathological changes in the knee joint.