Pharmaceutical Applications of Various Natural Gums

Microsponge-derived mini tablets loaded with immunosuppressive agents: Pharmacokinetic investigation in human volunteers, cell viability and IVIVC correlation

Sirolimus, a potent immunosuppressant, has been demonstrated to have remarkable activity in inhibiting allograft rejection in transplantation. The objective of the study was to fabricate microsponge mini tablets with enhanced solubility and bioavailability. β-Cyclodextrin and NEOCEL C91 were selected to prepare the microsponges (SLM-M) to improve the stability and solubility of sirolimus. The current study involved the quasi emulsion-solvent diffusion technique to design sirolimus-loaded microsponges that were further compressed into mini tablets 4 mm in diameter. Solid-state characterization, dissolution at different pH values, stability, and pharmacokinetic profiles with IVIVC data were analyzed in humans. Fourier transform infrared (FTIR) spectroscopy, differential scanning calorimetry (DSC), and X-ray diffraction (XRD) were used to characterize the formulations, and high-performance liquid chromatography (HPLC) was used to assess the drug stability of the compressed microsponge minitablets. The API changed from the crystalline state to an amorphous state, as shown by XRD and DSC. The compressed mini tablets showed a 4-fold enhancement in the drug dissolution profile. A toxicology investigation suggested that mini tablets were safe. In humans, the bioavailability of sirolimus compressed mini tablets from SLM-M was significantly improved. The results suggest that mini tablets prepared with β-cyclodextrin and NEOCEL C91 by a quasi emulsion-solvent diffusion process might be an alternative way to improve the bioavailability of sirolimus. In addition, the manufacturing process is easily scalable for the commercialization of drugs to market.

Satranidazole-loaded chitosan/locust bean gum/xanthan gum polysaccharide composite multiunit pellets for colon targeting: in vitro–in vivo investigation

Background

The colon has a significant site to deliver numerous active materials for colonic diseases. Highly biodegradable polymers hold significant promise among the several techniques available to deliver the drug to the colon. This research aimed to prepare chitosan, locust bean gum and xanthan gum polysaccharide composite satranidazole multiunit pellets for colonic release and assesses the bioavailability with pharmacokinetic parameters after administration of satranidazole raw drug compared to multiunit pellets. Satranidazole multiple unit pellets were prepared based on chitosan, locust bean gum and xanthan gum, which were inexpensive and harmless. The bioavailability study was done by crossover design in which satranidazole raw drug and test formulation was administered to six healthy white albino rats.

Results

The pharmacokinetic analyses were estimated using the deconvolution of the plasma profile. Compared to the satranidazole drug used as a reference, for the pellets, the maximum plasma concentration was lower (35.02 ± 3.91 ng/ml vs. 51.07 ± 1.21 ng/ml for the satranidazole drug), and the time to attain maximum concentration was 2.50 ± 0.55 h for both drugs and test formulation. Colonic drug content was significantly higher than that of free administered drug.

Conclusion

The results indicate the acquired pharmacokinetic studies and colonic analysis established the reliability of the pharmaceutical technique and the ability to release satranidazole at the colonic site.

Graphical Abstract

Pectin from Okra (Abelmoschus esculentus L.) Has Potential as a Drug Release Modifier in Matrix Tablets

Natural polymers have become attractive to pharmaceutical researchers and manufacturers as excipients because of the advantages they possess relative to their semisynthetic and synthetic counterparts. Although pectin from some natural sources has been investigated for use in the pharmaceutical industry as excipients, pectin from okra, which is readily available and used as food in many parts of the world, has not been extensively investigated as a potential control-releasing agent in tablets. This study thus seeks to determine the drug release modifying properties of okra pectin from 6 different genotypes of okra cultivated and available in Ghana. Pectin was extracted from different genotypes of okra, physicochemical properties were characterized, and control release matrix tablets of metformin (F1–F6) were formulated using the wet granulation method with the okra pectin as the drug release modifier, respectively. The drug content, in vitro drug release, and mathematical kinetic modeling of drug release from the matrix tablets were studied. Drug release profiles of formulated matrix tablets were compared to an existing (innovator) brand of metformin sustained-release tablet on the market using the similarity and difference factors, respectively. The extracted pectin had percentage yields ranging from 6 to 20% w/w with swelling indexes and water-holding capacities between 300–500% and 9-10 mL/g, respectively, and pH within 6.20–6.90. All the formulated batches passed the drug content test (90–105%) and produced the optimal release of metformin (>80%) after 24 hours. Different batches of formulated tablets exhibited different mechanisms of drug release with batches F1, F2, F5, and F6 being similar (ƒ₂ values being >50 and ƒ₁ values <15) to the innovator brand. Pectin from the 6 different genotypes of okra studied has the potential for use as drug release modifiers in pharmaceutical manufacturing of control release matrix tablets and production of more affordable medicines.

Biocompatible Hydrogels Based on Food Gums with Tunable Physicochemical Properties as Scaffolds for Cell Culture

Hydrogels composed of food gums have gained attention for future biomedical applications, such as targeted delivery and tissue engineering. For their translation to clinical utilization, reliable biocompatibility, sufficient mechanical performance, and tunable structure of polysaccharide hydrogels are required aspects. In this work, we report a unique hybrid polysaccharide hydrogel composed of salecan and curdlan, in which the former is a thickening agent and the latter serves as a network matrix. The physicochemical properties, such as mechanical strength, thermal stability, swelling, and morphology, of the developed composite hydrogel can be accurately modulated by varying the polysaccharide content. Importantly, cytotoxicity assays show the non-toxicity of this hybrid hydrogel. Furthermore, this hydrogel system can support cell proliferation, migration, and function. Altogether, our work proposes a new strategy to build a polysaccharide-constructed hydrogel scaffold, which holds much promise for tissue engineering in terms of cell engraftment, survival, proliferation, and function.