Background and importance Fast dissolving orodispersible films (ODF) provide an alternative formulation for patients with swallowing difficulties. Preparing these films is not yet part of the training in pharmacy school and is learned by self-training.

Aim and objectives ODFs were produced using a manual and a technical technique. These were then analysed.

Material and methods All solutions contained hydroxypropylmethylcellulose, glycerol 85%, water and, for quantitative analysis, propranolol hydrochloride (P-HCl). The films were manufactured using two different techniques: (1) dropping the solution with a syringe onto a foil: volume 0.1–1 mL; (2) solvent casting: pouring solution into a frame of 1000 µm height; fabricating stripes with the help of a film layering machine (Erichsen, Germany); after drying film stripes were cut in 1 cm² and 4 cm² pieces.

All ODFs were dried for 3 days at room temperature and analysed for:

1. height with a micrometer screw (Erichsen, model 497)

2. dissolving rates. The OFDs were exposed every 30 s to a drop of purified water put onto the film. Time was measured to when the film became permeable.

3. their content of P–HCl via UV/Vis.

Results Film strips were 50 µm in height. The smallest drops of 0.1 mL had 135 µm height; those of 1 mL had a gauge of 175 µm. Dissolving rates depended on the thickness and gauge of the film. Time ranged from 2 to 3.6 min. 98% of the expected amount of P-HCl content was in the 1 mL drops, with only 90% in the smaller 0.1 mL drops. The content of active ingredients was 0.34 mg P-HCl in the film pieces of 1 cm². It raised linearly to 1.38 mg P-HCl in 4 cm² pieces.

Conclusion and relevance Both methods led to suitable films. All films showed short dissolution rates and active ingredients had been inserted during the manufacturing process. The solvent casting method led to flatter films and therefore less active ingredient per cm². To receive a dose of 5 mg P-HCl, about 15 cm² of film should be taken orally. Further investigations are needed to improve this. Nevertheless, the dropping method is an elegant and easy method.

Conflict of interest No conflict of interest