Study on formulation and preparation technology of the composite cellulose-based enteric capsule shells

To study the new formulation and technology of composite cellulose-based enteric capsule shell with one-time dipping molding without organic solvent.

Hydroxypropyl methylcellulose phthalate-55S (Hp55S) was used as the main film-forming material, agar as gelling agent, and hydroxypropyl methylcellulose (HPMC) as disintegrating regulator. The preparation technology was as follows: ① Hp55S was dissolved in dilute ammonia solution with pH of 10 ∼ 11 at room temperature to obtain transparent Hp55S solution. ② The mixture of HPMC, KCl, and Tween-80 was fully dispersed in the agar solution at 90 ∼ 100 °C and cooled to 50 ∼ 55 °C under continuous stirring to obtain a transparent agar/HPMC solution. ③The Hp55S solution was heated to 50 ∼ 55 °C and poured into the agar/HPMC solution and stirred evenly to obtain the composite cellulose solution, which was kept at 50 ∼ 55 °C for standby. ④The composite cellulose-based enteric capsule shells were prepared by dipping, spinning, drying, stripping and trimming, and joining.

The composite cellulose-based enteric capsule shell prepared according to this formula and process met the quality requirements of 'enterosoluble vacant capsules' in Chinese Pharmacopeia.

Compared with the traditional formula and preparation technology of enteric capsule shell, the product is a plant type enteric capsule shell, no organic solvent is used in the formula, and the forming steps of multiple dipping solution is not used in the process. The advantages of this study are that the production steps are simplified, the production process is environmentally friendly, and the production cost is reduced.