Selection and justification of drying in ocular insert development

Relevance. This study describes aspects of drying in the development of ocular inserts, parameters affecting the kinetics of moisture loss by film-forming polymers of various nature, as well as features of the equipment used in the technological process.

Objective. The aim of the study is to develop methods for drying the basis of an innovative ocular medicinal insert intended for the treatment of bacterial infections.

Materials and methods. A film-forming agent of natural origin - hydroxyethylcellulose (Natrosol™ HHX 250, Ashland, USA) was used to prepare the polymer base. Glycerin (Tula Pharmaceutical Factory LLC, Russia) was added as a substance that gives the insert elasticity and plasticity, as well as an excipient that increases bioadhesion, poloxamer (Kolliphor® P 188, BASF, Germany). Purified water was used to dissolve the substances.

Placebo inserts were dried outdoors, in a dehydrator (Kitfort KT-1908, China), a thermostat (BINDER BD 56 Avantgarde.Line, Germany), freeze dryer (Harvest right, USA) and vacuum dryer (HETO CT/DW 60 E, Jouan, Gydevang, Denmark). The finished polymer base was evaluated according to the parameters humidity (gravimetric), bioadhesion (separation force), biodegradation time, thickness (micrometer) and elasticity.

Results and discussion. Drying of the bases turned out to be less prolonged in a dehydrator, in contrast to the technology carried out in a thermostat, freeze dryer and in an open space. Despite the increased drying time in a freeze dryer with a single mode, the parameters of the polymer base did not have significant differences, while ensuring the sterility of the process and the possibility of using an active pharmaceutical ingredient of different nature.

Conclusion. The selection of equipment for drying technology is carried out in accordance with the main parameters - ventilation, temperature constancy, humidity, vacuum, the possibility of carrying out the process in sterile conditions, and also the physico-thermal features of reducing the moisture of the dosage form are taken into account. The optimal ratio of drying parameters provides a polymer base at the output, which has certain physical properties that characterize the quality indicators of the future drug in the form of an ocular insert.