Developing a stable aqueous enteric coating formulation with hydroxypropyl methylcellulose acetate succinate (HPMCAS-MF) and colloidal silicon dioxide as anti-tacking agent

Enteric-coating film effect on the delayed drug release of pantoprazole gastro-resistant generic tablets

Background: Enteric coating films in acidic labile tablets protect the drug molecule from the acidic environment of the stomach. However, variations in the excipients used in the coating formulation may affect their ability to provide adequate protection. This study is the first to investigate the potential effects of coating materials on the protective functionality of enteric coating films for pantoprazole (PNZ) generic tablets after their recall from the market. Methods: A comparative analysis was conducted between generic and branded PNZ products, using pure drug powder for identification. The in vitro release of the drug was evaluated in different pH media. The study also utilized various analytical and thermal techniques, including differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), X-ray diffraction (XRD), scanning electron microscopy (SEM), Fourier-transform infrared (FTIR), and confocal Raman microscopy. Results: The in vitro assessment results revealed significant variations in the release profile for the generic product in acidic media at 120 min. DSC and TGA thermal profile analyses showed slight variation between the two products. XRD analysis exhibited a noticeable difference in peak intensity for the generic sample, while SEM revealed smaller particle sizes in the generic product. The obtained spectra profile for the generic product displayed significant variation in peaks and band intensity, possibly due to impurities. These findings suggest that the excipients used in the enteric coating film of the generic product may have affected its protective functionality, leading to premature drug release in acidic media. Additionally, the presence of polysorbate 80 (P-80) in the brand product might improve the properties of the enteric coating film due to its multi-functionality. Conclusions: In conclusion, the excipients used in the brand product demonstrated superior functionality in effectively protecting the drug molecule from acidic media through the enteric coating film, as compared to the generic version.

Viability of Lactobacillus acidophilus in Thin-Film Freeze-Dried Powders Filled in Delayed-Release Vegetarian Capsules in a Simulated Gastric Fluid

Previously, we have shown that thin-film freeze-drying can be applied to prepare dry powders of bacteria such as Lactobacillus acidophilus. Herein, we tested the viability of L. acidophilus in thin-film freeze-dried powders (TFF powders) filled in delayed-release vegetarian capsules in a simulated gastric fluid (SGF) consisting of 0.1N hydrochloric acid and sodium chloride. Initially, we determined the water removal rate from frozen thin films on relatively larger scales (i.e., 10-750 g). We then prepared and characterized two TFF powders of L. acidophilus with either sucrose and maltodextrin or sucrose and hydroxypropyl methylcellulose acetate succinate (HPMC-AS), a pH-sensitive polymer, as excipients and evaluated the viability of the bacteria after the TFF powders were filled in delayed-release vegetarian capsules and the capsules were incubated in the SGF for 30 min. On 10-750 g scales and at the settings specified, water removal from frozen thin films was faster than from slow shelf-frozen bulk solids. When the L. acidophilus in sucrose and HPMC-AS TFF powder was filled into a delayed-release capsule that was placed into another delayed-release capsule, the bacterial viability reduction after incubation in the SGF can be minimized to within 1 log in colony forming unit (CFU). However, for the L. acidophilus in sucrose and maltodextrin TFF powder, even in the capsule-in-capsule dosage form, bacterial CFU reduction was > 2 logs. TFF powders of live microorganisms containing an acid-resistant material in capsule-in-capsule delayed-release vegetarian capsules have the potential for oral delivery of those microorganisms.