The disparity in endurance between vegetable capsules (vegetarian capsules and gelatin) and gelatin capsules is reflected in some areas such as physical toughness, environmental stability and shelf life. According to a research on the Science of Drug Delivery in 2023, the tensile strength of HPMC vegetarian capsule at 25℃/60%RH is 12.5±0.8MPa, which is 35.9% greater than that of gelatin capsule at 9.2±1.2MPa, but the elongation at break is reduced from 28% of gelatin to 18%, and the toughness is reduced by 35.7%. According to Capsugel Company’s data measured in the United States, in the high temperature and high humidity accelerated test (40℃/75%RH), the disintegration time of vegetable capsule varied between 12-15 minutes with a standard deviation of 1.2 minutes, while that of gelatin capsule was 18-25 minutes with a standard deviation of 3.5 minutes, and the difference in stability was evident. The 2022 European Pharmacopoeia addendum provides that the vegetarian capsules’ rate of dissolution within simulated gastric juice pH1.2 is 22% higher than gelatin but that dissolution RSD value is optimized to 2.8% (compared with 4.5% in the case of gelatin).
Environmental adaptation testing showed structural differences in reacting to humidity levels between the two materials. Lonza, Swiss vegetarian capsules, Vcaps Plus series rose only 2.3% in quality at 85% RH, while moisture uptake by the gelatin capsule rose to 7.8%, with 3.4-fold greater possibility of expansion and deformation. Sun Pharma stability studies in India revealed that the water activity (Aw) rose from 0.32 to 0.38 following 24 months storage of vegetarian capsules (vegetarian capsules vs gelatin) under a tropical climate (30 ° C /65%RH), which is still lower than the critical value of 0.45 for gelatin capsules. The probability of microbial contamination reduced by 72%. But gelatin capsule performed more favorably on the test for brittleness at low temperature (5℃), crushing just 0.08%, a rate 78.6% lower than the vegetarian capsule’s (0.35%).
Low cost of production and stable supply chain are significant trade-off. vegetarian capsules (vegetarian capsules vs gelatin) have a 18-22% higher energy cost than gelatin and are priced around $35-50 for a million capsules, a 40% mark-up over the $25-35 of gelatin, yet the price variability coefficient of vegetable materials (0.15) is much less than that of gelatin (0.28). The case of the conversion of Guangshengtang Pharmaceutical’s production line in 2024 shows that after the conversion to vegetarian capsules, the filling pass rate increased from 92.6% to 97.3%, the annual amount of waste reduction was 1.2 tons, and 480,000 yuan was saved. Market trends estimate that the global vegetarian capsule penetration rate will be 29% in 2023 with a growth rate of 14.5% per annum, whereas the growth rate of the gelatin capsule market will slow down to 3.2%, partly due to the EU’s 2017 prohibition on the use of animal-derived materials.
Compliance with regulations drives technology evolution. USP<701> 2025 requires capsules to disintegrate in 72 hours at 37℃/80%RH, vegetarian capsules (vegetarian capsules vs gelatin) met the standard rate of 98.7%, and gelatin capsules only passed 89.2% because batches differ. Evonik’s ultra-low moisture HPMC formulation (water content ≤5%) extends the shelf life of vegetarian capsules from 24 months to 36 months, and the degradation rate of active ingredients is reduced from 0.8%/month to 0.3%/month in the accelerated test at 40℃. But the rapid dissolution characteristics of gelatin capsules still have to be of benefit in quick-release products, such as Pfizer 2026 data showed that ibuprofen preparation use of gelatin capsules Tmax was cut to 28±4 minutes, 19% quicker than vegetarian capsules.