The Influence of Anti‐irritants on Captopril Hydrophilic Gel

Evaluation of the effects of 10% and 30% gluconolactone chemical peel on sebum, pH, and TEWL

BACKGROUND

Gluconolactone (GLA) exhibits antioxidant and moisturizing effects. It also presents soothing effects, protects elastin fibers from UV-induced degradation, and improves the function of the skin barrier.

AIMS

Evaluation of skin parameters such as pH, transepidermal water loss (TEWL), sebum levels before, during, and after a series of applications of 10% and 30% GLA chemical peel in a split-face model.

MATERIALS AND METHODS

The study involved 16 female subjects. Three split-face procedures were performed using two concentrations of GLA solution applied on two sides of the face. The skin parameters were measured before treatments and 7 days after the last procedure at four measurement sites on either side of the face, that is, on the forehead, around the eye, on the cheek, and on the nose wing.

RESULTS

Measurement of sebum demonstrated some statistically significant changes between sebum levels in the cheeks after a series of treatments. The pH measurement showed that the pH value was reduced after each treatment at all measurement points. The level of TEWL after treatments was significantly lower around the eyes, on the left forehead, and on the right cheek. There were no significant differences between the use of different concentrations of the GLA solution.

CONCLUSIONS

The results of the study show that GLA has a significant influence on lowering skin pH and TEWL. GLA also has seboregulatory properties.

Transdermal delivery of Angiotensin Converting Enzyme inhibitors

The Angiotensin Converting Enzyme (ACE) inhibitor class of drugs has been in clinical use since the 1970s for the management of all grades of heart failure, hypertension, diabetic nephropathy and prophylaxis of cardiovascular events. Because of the advantages associated with transdermal delivery compared with oral delivery many researchers have investigated the skin as a portal for administration of ACE inhibitors. This review summarises the various studies reported in the literature describing the development and evaluation of transdermal formulations of ACE inhibitors. Captopril, enalapril maleate, lisinopril dihydrate, perindopril erbumine and trandolapril are the most studied in connection with transdermal preparations. The methodologies reported are considered critically and the limitations of the various skin models used are also highlighted. Finally, opportunities for novel transdermal preparations of ACE inhibitor drugs are discussed with an emphasis on rational formulation design.

The effect of component of cream for topical delivery of hesperetin

The aim of this study was to optimize hesperetin cream formulations by in vitro permeation study and evaluate topical whitening active effect and skin irritation by in vivo study. The results showed that the solubility of lipophilic compound of hesperetin was increased by short-chain alcohol including ethanol, glycerin, propylene glycol and polyethylene glycols 400 (PEG 400). PEG 400 showed strongest solubilized effect by increased 3400-fold. With the addition of 5% enhancers, it was found that menthol showed the most potent enhancing effect, followed by azone and depigmentation agents (linoleic acid and lecithin). Moreover, enhancers could shorten the lag time from 3.7 to 1 h. Combination of menthol, linoleic acid and lecithin of 2.5% had a higher permeation rate of 9.8 microg/cm(2)/h and lower lag time 1 h, therefore the formulation was selected to process the skin whitening and irritation test. The results showed that a significantly topical photoprotective effect with acceptable skin irritation was obtained after hesperetin cream topical application when compared with that of the non-treatment group, indicating that the hesperetin cream may be used as an effective whitening agent.

Effect of intraurethral captopril gel on the recurrence of urethral stricture after direct vision internal urethrotomy: Phase II clinical trial

OBJECTIVE

The purpose of this study is to evaluate the effect of intraurethral captopril gel as an antifibrotic agent on patients with urethral stricture.

MATERIALS AND METHODS

In the first phase of clinical trial, 13 rabbits were included and local side-effects of captopril gel were evaluated. In the second phase, 56 patients were enrolled from April 2004 to January 2006. After internal urethrotomy the patients were classified into three patient groups: (i) received placebo gel (group I); (ii) received 0.1% captopril gel (group II); and (iii) instilled 0.5% captopril gel intraurethrally (group III).

RESULTS

In phase I, no significant local side-effects were seen in the urethra of rabbits. In phase II, the mean age of the patients was 39.5 and the mean follow-up duration was 16 months. The most common etiology of the urethral stricture in the patients was iatrogenic (35.7%), most of their strictures had a depth of 0.5 cm or less (67.8%), and the length of most strictures was between 1 and 2 cm (41.1%). The patients' maximum urine flow increased more in groups II and III, than in group I (P < 0.04, P < 0.05, respectively). The recurrence rate was less in groups II and III than in group I (P < 0.05). In terms of the maximal urine flow and recurrence rate, no significant difference was seen between group II and group III (P = 0.13, P = 0.21, respectively).

CONCLUSION

Captopril gel is a safe, effective and non-toxic agent for decreasing the recurrence rate of the urethral stricture after internal urethrotomy. However, more studies, including more cases and a longer follow up, are needed to prove the effect of captopril gel on patients' urethra.

Anti-irritants I: dose–response in acute irritation

The term 'anti-irritant' (AI) was coined in 1965 by Goldemberg to describe a diverse group of topical product ingredients, which were able to reduce the irritation potential of other more irritating ingredients in the same product. 'AIs' are being added to cosmetic formulations in order, allegedly, to benefit tolerability of the products and allow claims such as 'soothing' and 'healing' ingredients. Limited documentation in favour of the efficacy of AIs is published. We studied the dose-related effect of 4 alleged AIs (nifedipine, (-)-alpha-bisabolol, canola oil and glycerol) on experimentally induced acute irritation in healthy volunteers. Each AI was used in 3 concentrations. Acute irritation was induced by occlusive tests with 1% sodium lauryl sulfate and 20% nonanoic acid in N-propanol. The irritant reactions were treated twice daily with AI-containing formulations from the time of removal of the patches. Evaluation of skin irritation and efficacy of treatments were performed daily for 4 days using clinical scoring, evaporimetry (transepidermal water loss), hydration measurement and colourimetry. Only glycerol showed dose-response and effects potentially better than no treatment. There was no significant effect and no difference between the three other AIs.