Topical formulation is a medication that is applied directly to the body or a particular place where it is required. They are available in various forms such as creams, ointments, gels, lotions, and foams.
Most of these medications can be directly applied to the skin while some may also be inhaled, for example, asthma medications. Additionally, they can be applied to eyes in the form of eye drops, or ear drops for the ears or tooth. There are many companies that provide formulation development services.
What Are The Common Types Of Topical Formulations?
It is an emulsion of water and oil. The emulsions are mainly classified into two types. One is oil in water, and the other is water in oil. The oil in water creams spread easily across the skin and do not make the skin sticky or greasy. For example, vanishing creams. The water in creams are greasy and make the skin feel sticky — for example, cold creams. Creams may sometimes cause contact allergy due to the presence of emulsifiers and preservatives.
They semi-solid preparations of hydrocarbons such as paraffin, petrolatum, synthetic hydrocarbons, oil, mineral oil. The presence of strong emollient in the ointments makes them beneficial for treating dry skin.
The occlusive effect of the ointments enhances the penetration of active drug and also improves efficacy. This is useful for thick skin. They act as a protective layer to the skin.
Further, they are sticky, greasy, and retains sweat.
Hence, they are not suitable for hot weather conditions, hairy areas of the skin, skin prone to folliculitis, or wet, weepy dermatitis. Ointments neither contain water nor preservatives.
Pastes are a mixture of powder and ointments. For example, zinc oxide 20% paste. The main factor powders are used in the making of pastes are because they improve porosity and help the skin breathe without any difficulty.
Further, its addition to converting an ointment into a paste adds to the consistency which makes it difficult for the person to rub it off: example, anthralin paste for the treatment of psoriasis.
The lotion is the most common term used these days. It is a mixture in which active or inert medications are either suspended or dissolved. In other words, it is a liquid preparation. Lotions often are the oil in water emulsion with high water content to give it the liquid consistency.
They are aqueous or hydroalcoholic systems. Small amounts of alcohol are added to support solubilization of the active or inert ingredients to quicken the evaporation of the solvent from the skin surface. In other words, the addition of alcohol helps the solvent evaporate immediately when it is applied to the skin.
Further, lotions are non-sticky and drying depending on the water content in the emulsions. They can be easily applied even on a large portion of the skin. They are suitable for skin prone to folliculitis or acne, hairy areas, and intertriginous areas.
Gels are transparent preparations that contain cellulose ethers or carbomer either in water or a mixture of water and alcohol. When applied on the skin, they leave a liquified effect, dry off and stay as a thin film of active medication. They can be applied to hairy areas as well and cosmetically acceptable. Check out the pharma manufacturing companies.
What The Advantages And Disadvantages Of Topical Preparation?
The medicine can be applied in increased dose where and when needed.
Fewer side effects of toxicity to other organs of the body while compared to systemic medications.
Takes time to apply; time-consuming.
The regimes may be complicated at times due to the prescription of various formulations.
It can get messy or cause discomfort while applying.