Mechanical Properties of Topical Anti-Psoriatic Medicines: Implications for Patient Satisfaction with Treatment.

Different types of topical preparations are available as anti-psoriatic medicines, semisolid formulations being the preferred dosage forms for the treatment of body lesions. The mechanical characterization of these semisolid formulations is seldom reported, although mechanical features have been recognized to play an important role in treatment acceptability and adherence. The aim of this study was to characterize the mechanical properties of semisolid topical formulations commercially available for psoriasis treatment. One complementary aim was to evaluate patient satisfaction with topical treatment and discuss the results according to the mechanical features of the dosage form. Eight ointments (O 1-8), five creams (C 1-5), one oleogel (G1), and one excipient (E1-petrolatum) were characterized for textural properties (spreadability and penetration tests) and flow behavior. Power law model was fitted to the results. A questionnaire for the assessment of satisfaction with topical medicines used for psoriasis treatment over 6 months was developed and applied to 79 psoriasis patients. All the tested formulations presented a shear-thinning behavior with power law indexes (n) lower than 1. Ointments were distinct from the other dosage forms, since they presented higher consistency coefficients (K), firmness, and adhesiveness and this was evidenced by hierarchical cluster analysis, which identified two clusters based on the mechanical properties. Cluster 1 included the ointments and petrolatum and the cluster 2 enclosed the creams and the gel. The clusters were associated with several attributes classified by patients as analyzed with Fisher's exact test. In all cases, higher satisfaction was observed for cluster 2. The knowledge obtained regarding the influence of the dosage form on the degree of satisfaction with the treatment could be helpful in supporting the selection of the dosage form in clinical practice and thus improve treatment adherence and clinical outcomes. The differences observed between the mechanical properties of the formulations studied may be also relevant to the industry, as guidance to the development of new medicines.

Topical Therapy in Psoriasis.

Psoriasis is a chronic condition that progresses in remitting and relapsing phases. Most of these patients have mild-to-moderate illness, which can be managed with topical medications or could be thought of as continuing therapy after remission. Potential therapeutic efficacy is offered, and systemic treatment's negative side effects are constrained. Topical therapies have recently advanced in tandem with recent advancements in our understanding of psoriasis. To improve the quality of life of patients, appropriate knowledge and application of these topical agents are crucial.

Patient-Centric Design of Topical Dermatological Medicines.

Topical treatments are essential approaches to skin diseases but are associated with poor adherence. Topical vehicles have the primary purpose of ensuring drug effectiveness (by modulating drug stability and delivery, as well as skin properties) but have a marked impact on treatment outcomes as they influence patient satisfaction and, consequently, adherence to topical treatments. There is also a wide variety of vehicles available for topical formulations, which can complicate the decisions of clinicians regarding the most appropriate treatments for specific skin disorders. One of the possible strategies to improve topical-treatment adherence is the implementation of patient-centric drug-product design. In this process, the patient's needs (e.g., those related to motor impairment), the needs associated with the disease (according to the skin lesions' characteristics), and the patient's preferences are taken into consideration and translated into a target product profile (TPP). Herein, an overview of topical vehicles and their properties is presented, along with a discussion of the patient-centric design of topical dermatological medicines and the proposal of TPPs for some of the most common skin diseases.

Methodologies for medication adherence evaluation: Focus on psoriasis topical treatment.

Adherence to topical treatment has been less studied in comparison with systemic therapeutic regimens and is poorly understood. High-quality research on this area is essential to outline a strategy to increase medication adherence and clinical outcomes. For a more comprehensive understanding of this issue, a systematic review of the methodologies for topical treatment adherence evaluation in psoriasis was undertaken. Twenty one studies were selected from the literature which used six different adherence methodologies. Merely three studies used multiple adherence measurement methods. The most used method was questionnaire (44%) which was also associated with higher variability of the adherence results. One possible explanation is the lack of a validated questionnaire designed specifically for the evaluation of adherence to topical treatment. Only one method (medication weight) takes into consideration the applied dose. However, the estimation of the expected weight is complex, which renders this method, as used presently, less effective. The use of a dosing device could improve its accuracy and be helpful to clearly instruct the patients about the correct dose. As there is no single method that allows an accurate and complete assessment of adherence it is recommended to use a combination of methods, including self-report and medicines' weight measurements.