Dear colleagues, during these days when the weather gets very hot, I would like to share with you a formula prescribed for pruritic skin conditions frequently encountered due to allergic disorders or insect bites.
Crème antiprurigineuse
Mentholum …………………………. 0.50 g
Lidocaini hydrochloridum …. 0.06 g
Propyleneglycolum …..…….. 1.00 g
Cremor non ionicus aquosus F.N.V q.s..ad.. 60.00 g
Ingredients in the formula
Menthol-levomenthol-Peppermint camphor-2-isopropyl-5-methylcyclohexanol: It is a powder with a characteristic odor and taste, free-flowing or found as agglomerated crystals. It can also occur as colorless prismatic or needle-shaped brilliant crystals. Its melting point is approximately 34°C. According to the British Pharmacopoeia (BP), menthol is practically insoluble in water; freely soluble in alcohol, ether, and petroleum ether; easily soluble in fixed oils and liquid paraffin; and very slightly soluble in glycerin. The estimated acceptable daily intake of menthol has been reported as 200 µg/kg body weight. It is an antiseptic substance that produces a sensation of coolness and exhibits a mild analgesic effect when applied to the skin, and because of this property, it is used against urticaria. It produces a cooling effect and exhibits an analgesic action by dilating the blood vessels in the skin.
Lidocaine-lignocaine-lidocainum; Lidocaine is a widely used antiarrhythmic and local anesthetic. Lidocaine is generally used to relieve itching, soothe burning sensations or skin infections, and as an anesthetic in minor surgical procedures or dentistry.
Propylene glycol-Methylethylene glycol-Methyl glycol-Propylene glycol; It is an excipient used for various purposes in pharmaceutical preparations. It is used as a vehicle for cosmetic products. Due to its moisturizing properties, it is used instead of glycerin in topical moisturizing preparations. Propylene glycol may cause local irritation to the skin and mucous membranes. It is miscible with water, acetone, alcohol, and chloroform; soluble in ether; immiscible with fixed oils, but sometimes dissolves essential oils. It should be stored in a cool place and in airtight containers. It must be protected from light and moisture.
Cremor non ionicus aquosus; Non-ionic aqueous cream. It is an ointment base in the O/W phase. You will see how this vehicle is prepared at the end of the article.
Preparation of the formula – (Modus operandi); Menthol and lidocaine are first crushed in a mortar to expand their contact surface with the solvent, dissolved in propylene glycol, and mixed with the vehicle.
Cremor non ionicus aquosus – non-ionic water-containing cream – Crème aqueuse non ionique
Cera emulsificans cetomacrogolis F.N.V… 15.0 g
Cera liquida ………………………………….. 10.0 g
Propyleneglycolum …………………………. 10.0 g
Acidum sorbicum …………………………….. 0.2 g
Aqua ad ……………………………………….. 100.0 g
Preparation of the formula
Emulsifying wax and cera liquida are melted in a water bath at 70°C. Separately, sorbic acid is dissolved in propylene glycol and mixed with distilled water previously heated to 70°C. Finally, the oily phase (emulsifying wax + cera liquida = cetiol V) is added to the distilled water phase containing the preservative substance like sorbic acid in propylene glycol under vigorous stirring. Finally, the cream is stirred until cool.
Dear colleagues, for preparations in the form of creams, ointments, and lotions to be effective, the quality and characteristics of the vehicles carrying the active ingredients are extremely important. While drug delivery into the body via the transdermal route is discussed around the world as an alternative to the oral and intravenous routes, unfortunately, in our country, we have still not moved beyond preparing cream formulations with lanolin and petrolatum bases. Undoubtedly, for drugs of various structures to be administered percutaneously and to achieve adequate absorption, the structure of the skin and the characteristics of the skin layers acting as a barrier to drug penetration must be taken into account. While it is known that the percutaneous absorption of a drug is influenced by biological factors related to the skin, factors related to the active substance, and factors related to the vehicle, formulation designers worldwide are working rapidly to develop vehicle formulas that ensure optimum percutaneous absorption of the drug by considering all influencing factors.
Dear colleagues, in the coming weeks, I would like to draw attention to the importance of this topic by writing an article aimed at highlighting why vehicles are important and encouraging the inclusion of modern vehicles in formulations instead of conventional carriers.
Wishing you healthy days…
Spec. Pharm. Ahmet Nezihi Pekcan
Pekcan Pharmacy – Konya
[email protected]
Tel: (332) 3520657
