Table 1. Literature data on medicated foams vs. other cutaneous pharmaceutical forms.

Drug	Set-up	Main Findings	Year	Refs.
In vitro
Clindamycin	Human skin; flow-through diffusion cells vs. gel	Greater accumulation after 24 h and earlier onset than clindamycin gel.	2005	[7]
Clobetasol propionate	Human skin; flow-through diffusion cells vs. cream, emollient cream, lotion, and solution	A faster initial permeation of clobetasol compared with the other vehicles. In the first 14 h, foam delivered a similar amount of drug (J and AUC) compared with the emollient cream and a greater amount of drug compared with the solution, cream, and lotion. The foam vehicle delivered more clobetasol than the other formulations.	2005	[7]
Clobetasol propionate	Different anatomic region of human skin vs. foam, cream, and emollient cream	Foam needs the least time to overcome anatomic region variations (= thickness), whereas cream and ointment take a longer time for the onset of delivery.	2005	[7]
Ketoconazole	Silastic membranes; static Franz cells	Penetration 11-fold higher vs. cream.	2005	[7]
Metronidazole	In vitro skin penetration study; excised human skin; a flow-through diffusion cell	The total cutaneous penetration of metronidazole was two- to three-fold higher than the reference cream.	2006	[8]
Vitamin E acetate	In vitro silicone membrane penetration study; in vitro skin tape stripping	The increase in Pluronic surfactant concentration after application modified the lipid nanoparticles to enable drug release and penetration into skin.	2009	[9]
Benzoyl peroxide	In vitro silicone membrane penetration study	Benzoyl peroxide loaded in nanoparticles was chemically stable over a 7 d period. Foams allowed to obtain a comparable flux to commercial gels and creams, but at much lower concentration.	2010	[10]
Minoxidil	In vitro silicone membrane penetration study	Foam delivered significantly more drugs across the membrane than the saturated aqueous solution. The cumulative permeant amount of drug depends on the surfactant concentration in the foam.	2010	[11]
Calcipotriene + betamethasone	Raman imaging	After propellant evaporation, a supersaturated environment was created, where drug crystals were absent for at least 26 h.	2016	[12]
Thiocolchicoside	Skin; Saarbruecken penetration model-based cells	At each incubation time, significant higher amounts of drug were detected for the foam formulation.	2008	[13]
Cholecalciferol + salicylic acid	Pig-ear test for irritancy potential evaluation	Incorporation of two incompatible drugs.	2017	[14]
In vivo
Minoxidil	Caucasian male volunteers aged between 22 and 29 years. Every 10 d, 0.007±0.002 g foam was applied to the chest and the occipital region of the scalp	Hair follicles contribute to the penetration of minoxidil into the blood circulation since faster absorption of minoxidil was detected when the hair follicle orifices were open.	2010	[15]
Betamethasone valerate	A Phase II, randomised, single-centre, blinded, right-left comparison within 30 patients with mild-to-moderate psoriasis	After 3 wk, statistical significant improvement from baseline in thickness, redness, scaling, itch and global score.	2006	[8]
Tarazotene	Phase I study	Reduced systemic levels of tazarotenic acid in comparison to the marketed gel.	2013	[16]
Azelaic acid	A Phase 3 randomized, double-blind, vehicle-controlled, parallel-group, multicenter study with participants with moderate to severe papulopustular rosacea	Azelaic acid foam at 15% resulted efficient and safe in patients with papulopustular rosacea.	2015	[17]
Azelaic acid	Eight dogs with nonseasonal mild/moderate canine atopic dermatitis were treated twice weekly with either a commercial foam or a foam/mousse containing components from plant extracts, for 14 d. After a wash-out period of 14 d received the other foam in a randomized blinded study	A significant improvement in both skin lesions and pruritus was noted for both treatment groups. This method of product delivery is easy to use for owners, improving compliance in practice.	2018	[18]
Econazole nitrate	Two randomized, double-blind, parallel-group, vehicle-controlled, multicenter studies enrolled males and females ≥12 y old with a clinical diagnosis of interdigital tinea pedis and baseline fungal culture positive for a dermatophyte. Subjects applied 1% econazole nitrate foam (n=246) or foam vehicle (n=249) once daily for 4 wk	The drug-loaded foam exhibited superiority over foam vehicle with a high mycologic cure rate for all pathogens evaluated. Econazole nitrate foam 1% was safe and well tolerated with a safety profile comparable with the foam vehicle.	2014	[19]
Tazarotene	Two randomized, double-blind, vehicle-controlled, parallel-group studies were randomly treated with either0.1% tazarotene foam or vehicle foam once daily for 12 wk	Tazarotene foam significantly reduced the number and severity of acne lesions after 12 wk and had a safe and acceptable tolerability profile.	2013	[20]