Emulsion dermatological

Safety to skin is very important and protective action and cosmetic properties are also essential. These systems require the use of high concentrations of disperse phase. The vehicle may be oil-in-water (O/W) or water-in-oil (W/O) emulsion, dermatological paste and clay suspensions. Parenteral suspensions are examples with low solid content (usually 0.5-5%), except penicillin (antibiotic content > 35%). 

Stabilizer, emulsions depilatories Beeswax, synthetic Crodacol CSSO stabilizer, emulsions dermatologi-cals... 

The anhydrous petrolatum base may be made more miscible with water through the use of an anhydrous liquid lanolin derivative. Drugs can be incorporated into such a base in aqueous solution if desired. Poly-oxyl 40 stearate and polyethylene glycol 300 are used in an anti-infective ointment to solubilize the active principle in the base so that the ointment can be sterilized by aseptic filtration. The cosmetic-type bases, such as the oil-in-water (o/w) emulsion bases popular in dermatology, should not be used in the eye, nor should liquid emulsions, owing to the ocular irritation produced by the soaps and surfactants used to form the emulsion. 

Multiple emulsions have been used to deliver active agents with prolonged release in dermatological treatments. For example, O/W/O emulsions have been used to deliver pilocarpine hydrochloride as a myopic agent in eye infections [440]. Here the active agents was placed in the internal oil phase of the O/W/O emulsion to provide an appropriate rate of release. Similar approaches have been used in other treatments, using W/O/W emulsions [440]. 

Emulsions have been used for centuries for the oral administration of medical oils and vitamins and as dermatological vehicles. Recently, their application has been extended as drug carriers in the delivery and targeting of ophthalmic drags. An indomethacin emulsion has been reported to increase ocular bioavailability and efficacy compared to commercially available formulation in rabbits. 0.4% indomethacin emulsion showed 2.2 fold increase in the area under the anterior aqueous drag concentration/time curve compared to a 1% indomethacin suspension. The emulsion formulation also reduced ocular surface irritation caused by indomethacin Similar advantages have been shown for a pilocarpine emulsion which produced a prolonged therapeutic effect in comparison with pilocarpine hydrochloride eyedrops in man. It can be administered only twice a day, rather than four times daily for conventional formulation. 

Emulsions are formulated for virtually all the major routes of administration, and there are a number of dermatological, oral and, parenteral preparations available commercially. The internal phase may contain water-soluble drugs, preservatives, and flavoring agents whilst the oil phase may itself be therapeutically active or may act as a carrier for an oil-soluble drug. Such preparations provide an effective approach to... 

The better understanding of the mechanisms of stability incomplex dermatological emulsions stabilized by surfactants and amphiphiles has enabled the development of a rapid microscopic method for evaluation of potential emulsifiers. The method is based on the observation that good emulsifier blends that stabilize emulsions by the formation of multilayers of stable gel phase also swell spontaneously in water at ambient temperature and this process can be observed microscopically. Mixtures that do not form gel phase or form metastable gels only after a heating and cooling cycle cannot be observed to swell spontaneously at ambient temperature. ... 

In general, the preparation of such formulations as poultices and pastes is extemporaneous, and it is unlikely that the industrial pharmaceutical formulator will be required to develop stable, safe and efficacious products of this type. Solutions and powders lack staying power (retention time) on the skin and can only afford transient relief. In modern-day pharmaceutical practice, semi-solid formulations are preferred vehicles for dermatological therapy because they remain in situ and deliver their drug payload over extended periods. In the majority of cases, therefore, the developed formulation will be an ointment, emulsion or a gel. Typical constituents for these types of formulations are shown in Table 14.5. 

The most common emulsions used in dermatological therapy are creams. These are two-phase preparations in which one phase (the dispersed or internal phase) is finely dispersed in the other (the continuous or external phase). The dispersed phase can be either hydrophobic based (oil-in-water creams, O/W) or aqueous based (water-in-oil creams, W/O). Whether a cream is O/W or W/O is dependent on the properties of the system used to stabilize the interface between the phases. Given the fact that there are two incompatible phases in close conjunction, the physical stability of creams is always tenuous, but may be maximised by the judicious selection of an appropriate emulsion stabilizing system. In most pharmaceutical emulsions, stabilizing systems are comprised of either surfactants (ionic and/or non-ionic), polymers (non-ionic polymers, polyelectrolytes or biopolymers) or mixtures of these. The most commonly used surfactant systems are sodium alkyl sulphates (anionic), alkylammonium halides... 

Nielsen J, Raschke T, Riedel H (2005) Cosmetic and dermatological preparations in the form of o/co-emulsions containing sterols and/or C12-C40 fatty acids. US Patent 0037036 Al... 

Multiple emulsions have been used to deliver active agents with prolonged release in dermatological treatments. For example, O/W/O emulsions have been used to deliver pilocarpine hydrochloride as a myopic agent in eye infections... 

Uses Emulsifier, bodying agent, emollient, lubricant, vise, modifier for pharmaceuticals (clinical nutrition, coating, delivery/absorption enhancement, dermatological emulsion, infant formulas, nutritional/sports supplements, suppositories, tablets) emollient, emulsifier, lubricant, vise, modifier for cosmetics (creams/lotions, mascara, foundation, sun care preps.) Properties Lovibond R4.0 max. bead insol. in water sol. in oil elevated temps. m.p. 57-62 C HLB 3-4 acid no. 3.0 iodine no. 5.0 nonionic... 

Definition Mixture of ethanolamides of fatty acids derived from palm kernel oil Formula RC0-N(CH2CH20H)2, RCO- represents fatty acids derived from palm kernel oil Properties Nonionic Uses Emulsifier, emulsion stabilizer, surfactant, vise, control agent in cosmetics vise, builder, foam booster/stabilizer, emulsifier for shampoos, liq. soaps, dish detergents, bubble bath prods. emulsifier, solubilizer, thickener, wetting agent for dermatologicals, germicidal liq. soaps in food-pkg. adhesives... 

Definition Natural fat obtained from fruit of the Karite tree, Butyrospermum parkii Properties Gray-wh. solid dens. 0.9175 iodine no. 53-65 sapon. no. 178-190 Uses Emollient, consistency agent, lubricant, moisturizer, vehicle, carrier, vise, modifier, skin protectant, fatting agent for lotions, pharmaceutical dermatologicals, suppositories, o/w and w/o creams and emulsions skin conditioner, occlusive agent, solvent for suntan preps., body lotions, soaps, shampoos... 

Uses Emulsifier, opacifier, thickener, emulsion stabilizer, lubricant, conditioner, softener, pearlescent, dye carrier, gellant, lubricant in skin and hair care prods., dermatologicals, textiles, metal treatment antistat, vise, control agent in cosmetics petroleum anti-icing additive emulsifier/corrosion inhibitor in sol. cutting oils in food-pkg. adhesives in food-contact paper/paperboard in resin-bonded... 

PEG-2 laurate SE PEG-300 oleate PEG-300 stearate Propylene glycol myristate opacifier, depilatories Beeswax, synthetic opacifier, dermatologicals Stearamide DEA opacifier, detergents Sodium styrene/acrylates copolymer Styrene/acrylamide copolymer opacifier, dry cleaning PEG-2 stearate opacifier, dusting powders Zinc carbonate opacifier, emulsion shampoo Glycol distearate opacifier, enamels Stannic oxide opacifier, eye make up Titanium dioxide opacifier, fabrics... 

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