Topical formulation and delivery technologies for pharmaceutical application should simultaneously address efficacy, safety and convenience of therapy. This has historically proven to be challenging, since formulation features that drive efficacy often have undesirable consequences for safety and convenience and vice versa. Polyaphron dispersion (PAD) technology is a novel topical formulation and drug delivery system developed with the purpose of preserving these key attributes. PAD formulations are typically oil-in-water dispersions consisting of oil droplets encapsulated in a multi-molecular shell structure. This shell structure protects potentially unstable active molecules solubilized in the oil from hydrolytic degradation. Example data are presented of enhanced drug penetration from PAD formulations, including dermal delivery of calcipotriene, betamethasone dipropionate and tacrolimus as well as ocular delivery of ciclosporin A. Local tolerability is an important safety parameter for topical formulations, where high levels of surfactants can cause skin irritation. In this regard, a key benefit of PAD formulations is the inherent reduced requirement for surfactants to generate stable formulations compared to conventional emulsion systems. Patients with chronic diseases with topical manifestations such as psoriasis or atopic dermatitis have been reported to miss up to 70% of planned topical applications, mainly due to a lack of satisfaction with their therapy. Patients generally prefer light, moisturizing, non-greasy and quickly absorbed vehicles that are simple to use on all body parts. PAD formulations can generally be designed to meet these criteria. In conclusion, PAD technology provides high flexibility in topical drug design and can be applied to several body locations without compromising efficacy, safety or convenience of therapy. Clinical Trial Register : Clinicaltrials.gov: NCT03802344.

Background In psoriasis, poor treatment adherence is frequently related to low efficacy and limited cosmetic acceptability from the patients’ perspective. This study aimed to characterize the sensorial attributes of a calcipotriol (CAL) and betamethasone dipropionate (BDP)-cream vehicle based on polyaphron dispersion (PAD) Technology and to compare them with the conventional ointment and oleogel formulations for psoriasis. Methods A panel of 16 experts assessed sensory properties at four different stages: appearance, pick up, rub out and afterfeel. Descriptive sensory analysis was used to evaluate relevant attributes. Each attribute was rated on a line scale (range 0–100%). Active ingredients were not used because panellists were healthy volunteers, and vehicle formulations needed to be used instead. Results CAL/BDP PAD-cream vehicle was evaluated as having a low stickiness, low grease behaviour, good wetness, and good spreadability. Ointment showed the least desirable behaviour regarding these properties. Moreover, once CAL/BDP PAD-cream vehicle was absorbed, the gloss disappeared quickly, leaving low stickiness and a low amount of residue. This afterfeel behaviour was not observed with ointment. The oleogel formulation had good sensory properties, similar to CAL/BDP PAD-cream vehicle, but with lower integrity of shape, lower wetness and higher greasiness. Conclusion Overall, CAL/BDP PAD-cream vehicle has the desirable requirements for a topical product for the treatment of psoriasis, with better sensory properties than ointment and easier manipulation than oleogel, which may lead to greater acceptance and adherence.