Relationship between intraperitoneal pressure and the development of hernias in peritoneal dialysis: confirmation for the first time of a widely accepted concept.

BACKGROUND: Intraperitoneal pressure (IPP) in peritoneal dialysis (PD) is an individual characteristic that can be modified by posture and intraperitoneal volume (IPV). It is considered one of the predisposing factors for complications in the abdominal wall, such as the appearance of hernias. No studies to date have confirmed this. The main aim of this study was to assess the relationship between the development of hernia in incident PD patients and IPP measured at PD onset. METHODS: A prospective observational study of incident patients in a PD programme between 2010 and 2020. IPP was measured using the Durand's method. RESULTS: One hundred and twenty-four incident patients on PD, 68% male, mean age 62.1 ± 15.23 years, body mass index (BMI) 27.7 ± 4.82 kg/m2, 44% were diabetic. IPP in supine was 16.6 ± 4.60 cm H2O for a mean IPV of 2047.1 ± 359.19 mL. Hernias were reported in 18.5% of patients during PD follow-up: 57% were inguinal hernias, 33% umbilical, and a further 10% presented in a combined form. PD hernias correlated positively with IPP in supine position (p = 0.037), patient age (p = 0.008), BMI (p = 0.043), a history of prior hernia (0.016), laparoscopic catheter placement (p = 0.026), and technique failure (p = 0.012). In the multivariate analysis, a higher IPP was independently related to the development of hernias (p = 0.028). CONCLUSIONS: The development of hernias in PD was related to a higher IPP at PD onset, older age, higher BMI, history of prior hernia, catheter placement by laparoscopy, and technique failure.

Tuning the Transdermal Delivery of Hydroquinone upon Formulation with Novel Permeation Enhancers.

Hydroquinone (HQ) is an anti-hyperpigmentation agent with poor physicochemical stability. HQ formulations are currently elaborated by compounding in local pharmacies. Variability in the characteristics of HQ topical formulations can lead to remarkable differences in terms of their stability, efficacy, and toxicity. Four different semisolid O/W formulations with 5% HQ were prepared using: i) Beeler´s base plus antioxidants (F1), ii) Beeler´s base and dimethyl isosorbide (DMI) as solubiliser (F2), iii) olive oil and DMI (F3), and iv) Nourivan®, a skin-moisturising and antioxidant base, along with DMI (F4). Amongst the four formulations, F3 showed the greatest physicochemical stability with less tendency to coalescence but with marked chromatic aberrations. An inverse correlation was established by multivariate analysis between the mean droplet size in volume and the steady-state flux, which explains why F3, with the smallest droplet size and the most hydrophobic excipients, exhibited the highest permeation across both types of membranes with enhancement ratios of 2.26 and 5.67-fold across Strat-M® and mouse skin, respectively, compared to F1. It is crucial to understand how the HQ is formulated, bearing in mind that the use of different excipients can tune the transdermal delivery of HQ significantly.