OBJECTIVE: Development of oxybutynin chloride (OC) proniosomal gels and analyses of its efficacy for OAB treatment.

MATERIALS AND METHODS: Phase separation coacervation was used to prepare proniosomal gels using various non-ionic surfactants, lipids, soy lecithin and isopropyl alcohol. Gels were characterized with regard to entrapment efficiency (EE), vesicle size, surface morphology (using environmental scanning electron microscopy [E-SEM]), stability, attenuated total reflectance Fourier transform infrared (ATR-FTIR) spectroscopy, in vitro skin permeation, in vivo animal studies and histopathology.

RESULTS AND DISCUSSION: EE was 87-92%, vesicle size was 0.38-5.0 μm, and morphology showed some loosened pores in proniosomes after hydration. ATR-FTIR spectroscopy showed no significant shifts in peaks corresponding to OC and excipients. Most formulations exhibited >50% permeation but the cholesterol-containing formulations P3 (Span 20:Span 60 [1:1]) and P4 [Tween 20:Tween 80 (1:1)] had the highest percent cumulative permeation. P3 and P4 also showed faster recovery of cholinergic effects on salivary glands than oral formulations. P3 and P4 had pronounced therapeutic effects in reduction of urinary frequency and demonstrated improvements in bladder morphology (highly regenerative surface of the transitional epithelium).

METHOD: We enrolled 95 women (≥ 36 weeks gestation) on their attendance for planned ECV. All participants received terbutaline tocolysis. Regional anaesthesia was not used. ECV was performed in the standard fashion after the application of the allocated aid. If the first round (maximum of 2 attempts) of ECV failed, crossover to the opposing aid was permitted.

RESULTS: 48 women were randomised to powder and 47 to gel. Self-reported procedure related median [interquartile range] pain scores (using a 10-point visual numerical rating scale VNRS; low score more pain) were 6 [5-9] vs. 8 [7-9] P = 0.03 in favor of gel. ECV was successful in 21/48 (43.8%) vs. 26/47 (55.3%) RR 0.6 95% CI 0.3-1.4 P = 0.3 for powder and gel arms respectively. Crossover to the opposing aid and a second round of ECV was performed in 13/27 (48.1%) following initial failure with powder and 4/21 (19%) after failure with gel (RR 3.9 95% CI 1.0-15 P = 0.07). ECV success rate was 5/13 (38.5%) vs. 1/4 (25%) P = 0.99 after crossover use of gel or powder respectively. Operators reported higher satisfaction score with the use of gel (high score, greater satisfaction) VNRS scores 6 [4.25-8] vs 8 [7-9] P = 0.01.

CONCLUSION: Women find gel use to be associated with less pain. The ECV success rate is not significantly different.