Optimisation of HPMC ophthalmic inserts with sustained release properties as a carrier for thermolabile therapeutics.

A methodology was developed and optimised for the preparation of a new drug delivery system (DDS) with sustained release properties to allow ocular protein delivery and to limit destructive production steps during manufacturing. Elevated temperatures, shear forces and an oxidative environment should be avoided in order to prevent denaturation or oxidation of proteins. An aqueous HPMC solution was prepared using heat and casted into small semi-rod-shaped PVC blisters. The polymer solution was allowed to cool down and was partially dehydrated at room temperature. A drug solution containing glycerol, drug and water was subsequently added to rehydrate the partially dehydrated polymer matrix at a temperature of 2°C. Several parameters of the production process were varied to determine their influence on the release kinetics from HPMC inserts from three different molecules of different molecular weight. This production method was further optimised in order to shorten the rehydration time from weeks to days, while eliminating heat and shear forces on the selected drug molecules sodium fluorescein, lysozyme and albumin. Slow release kinetics were achieved for sodium fluorescein and lysozyme as model drug molecules. The higher molecular weight of albumin prevented a good penetration into the insert during the rehydration process resulting in predominantly burst release. The biocompatibility of a viscous HPMC solution was evaluated on SV40-human corneal epithelial cells with PrestoBlue® and no cytotoxic effects were observed.

A multicenter, prospective, clinical trial evaluating a novel adhesive baseplate (Provox StabiliBase) for peristomal attachment of postlaryngectomy pulmonary and voice rehabilitation devices.

OBJECTIVES/HYPOTHESIS: Assessment of a novel adhesive baseplate (Provox StabiliBase) for heat and moisture exchanger (HME) and/or automatic speaking valve (ASV) application. STUDY DESIGN: Prospective, clinical, multicenter trial. METHODS: This was a trial in laryngectomized patients comparing their usual adhesive with the trial adhesive. Primary outcome measure was overall patient preference; additional outcome parameters possibly explaining patients' preferences were 1) patient tolerance and preference with respect to daily handling of the adhesive; 2) adhesive lifespan, and 3) voice and speech with the adhesives. Study specific questionnaires, visual analog scales, patients' diaries, and stoma assessments were used for data collection. RESULTS: In total, 58 of the 65 laryngectomized individuals entered in the study completed the trial. Patients' overall preference for the new device was high (76%; P < .001). Significantly better performance was found for the trial adhesive with respect to ease of application (P = .034), fit (P < .001), and air leakage through the adhesive (P < .001). Comfort and stoma depth correlated weakly (r = 0.297; P = .024; deeper stoma-more comfort with StabiliBase). The adhesive lifespan with HME is significantly increased (1.7 times and 15.7 hours-plus airtight use; P < .001). This longer lifespan coincided with somewhat increased dirtying of the adhesive (P = .02). There were no serious adverse events. CONCLUSIONS: The StabiliBase adhesive for peristomal attachment of HMEs and/or ASVs was preferred by 76% of study participants and showed a promising prolonged lifespan. This new device further increases the options for stoma attachment in laryngectomized individuals, and subsequently the availability of optimal voice and pulmonary rehabilitation for a larger proportion of patients.