Evaluation of the effect of polymer composition on the rheological, mechanical properties and drug released behavior of novel Eudragit L100-55/ gelatin gastro-resistance uncoated capsule

Abstract Capsules have been investigated as a popular oral dosage form among communities due to their simplicity and ease of production. Capsules that are considered in the gastro-resistance category can be very beneficial due to enhanced drug absorption, improved stability, targeted release, etc. This study investigated the effect of enteric polymers on uncoated hard capsule fabrication and dissolution properties. The polymers used in this study included HPMCPh and Eudragit L100-55. Eight different formulations based on HPMCPh, Eudragit, and gelatin were examined to identify the ideal formulation for the product of uncoated enteric hard capsules with preferred physicochemical and gastro-resistance properties. The results reveal that the capsules containing Eudragit (F1), HPMCPh (F2), Eudragit/HPMCPh/gelatin (F3), and Eudragit/gelatin (F4) are steady within the simulated stomach environment, and drug release does not occur for 120 minutes. The outcomes demonstrate that, among the proposed formulas, the F4 formula is suitable both in terms of capsulation form and delayed release properties and shows no microbial growth. The properties of the optimized sample were studied by FTIR, FESEM, tensile strength, humidity, and rheology. The results illustrated that gelatin-based hydrogels with Eudragit (F4) are potential candidates for manufacturing uncoated enteric hard capsules that inhibit drug release in a gastric pH medium and act as a pH-sensitive drug release system.