Analgesic medicated stick for arthritis treatmentDear Colleagues; Rheumatoid arthritis, characterized by inflammation of a joint or joints and commonly known as “inflammatory rheumatism,” is a chronic joint disease lasting longer than 6 weeks that primarily involves small joints (hand joints, wrist, and foot joints) and causes disability in the affected joint. The disease can also involve and cause damage to multiple organs and systems, such as the lungs, kidneys, skin, and digestive system. Exactly what causes rheumatoid arthritis is not fully known. However, it is thought that various environmental factors, such as an individual’s genetic predisposition, smoking, and certain past infections, may trigger it. Seen in one out of every 100 people at some point in their lives, rheumatoid arthritis occurs three times more frequently in women than in men. Hormonal factors are believed to play a role in this. Fortunately, thanks to early diagnosis and appropriate treatments, it is possible to prevent the damage and disability that may develop in the joint.
This week, we will examine together a formulation in the form of a medicated stick used for its analgesic effect in the treatment of arthritis.Rp.
Methyl salicylate 35 g
Menthol 15 g
Sodium stearate 13 g
Purified water 12 g
Propylene glycol 25 g
Ingredients in the formula:
Methyl salicylate-Salicylate de méthyle- Methylum salicylicum:According to the European Pharmacopoeia (Ph Eur. 7), methyl salicylate is a colorless or light yellow liquid. It is slightly soluble in water; miscible with alcohol, fatty oils, and essential oils. It should be protected from light. According to the Merck Index 13, its melting point is -8.6°C and its boiling point is 220-224°C (101.325 kPa). According to the Merck Index 13, it is slightly soluble in water (1:1500); soluble in chloroform and diethyl ether; soluble in ethanol; and miscible with acetic acid, fatty oils, and essential oils. Its refractive index n20D is between 1.535 and 1.538 (Merck Index 13). Its density d2525 is 1.184; the density of its natural ester is approximately 1.180. It is a colorless, yellowish, or reddish liquid. It possesses the characteristic odor of Gaultheria procumbens. It is slightly soluble in water; soluble in alcohol and glacial acetic acid. It must be stored in airtight containers. Methyl salicylate is an essential oil of natural origin with an ester structure. In addition to natural sources, it is also synthesized starting from salicylic acid and methyl alcohol. Natural methyl salicylate is obtained from the leaves of the plant Gaultheria procumbens (Ericaceae) and the bark of Betula lenta (Betulaceae). It is widely used as a counterirritant in analgesic preparations due to the irritant effect it exerts on the skin. Its main indications are injuries seen in musculoskeletal, joint, and soft tissues, and perniosis. It is also used by inhalation in the symptomatic treatment of upper respiratory tract diseases. In most countries, it can be defined as a safe and effective drug sold over the counter. Because it has a pleasant taste and odor, it is also used at low concentrations (0.04%) as a flavoring agent in oral preparations; it is included in the composition of confectionery, cough lozenges, chewing gums, toothpastes, and mouthwashes. It is also used for the preparation of some formulations used in the treatment of hemorrhoids. Swallowing large amounts is harmful due to its high salicylate content. It is rapidly absorbed through intact skin and exhibits effects characteristic of systemically administered salicylates. The exact mechanism of action of methyl salicylate is unknown. When applied topically to the skin, it causes redness and irritation at the application site, which is followed by its analgesic effect. It is readily absorbed from intact skin and can exhibit effects characteristic of systemically administered salicylates. Methyl salicylate is rapidly absorbed from the site of application on the skin.Menthol- Levomenthol [ABDATA-SK; ASK; BAN1999; BP; FP; INN]- Pfefferminzcampher:It is a powder with a characteristic odor and taste, occurring as free-flowing or agglomerated crystals. It can also be found as colorless, prismatic, or needle-like shiny crystals. Its melting point is approximately 34°C. According to the British Pharmacopoeia (BP), menthol is practically insoluble in water; very soluble in alcohol, ether, and petroleum ether; freely soluble in fatty oils and liquid paraffin; and very slightly soluble in glycerol. The estimated acceptable daily intake of menthol has been reported as 200 µg/kg body weight. It is an antiseptic substance that produces a cooling sensation when applied to the skin and exhibits a mild analgesic effect, which is why it is used against urticaria. It produces a cooling sensation and exerts an analgesic effect by dilating blood vessels on the skin.Sodium stearate- Octadecanoic acid sodium salt- Sodium octadecanoate- Sodium Caprylate:It is the chemical name of commercially known white soap. Aside from soap, it is found in solid deodorants, rubbers, and certain specialty inks. The hydrophilic part is sodium, and the hydrophobic part is the chain portion.Propylene glycol- Methyl ethylene glycol- Glicol propilenico- Propylenglycol [ASK; Ph.Eur.]:Propylene glycol is a clear, colorless, odorless or practically odorless, hygroscopic liquid with a slightly characteristic taste. It is miscible with water, acetone, alcohol, and chloroform; soluble in ether; immiscible with fixed oils, but dissolves some essential oils. It should be stored in airtight containers in a cool place, protected from light and moisture.
Propylene glycol is an excipient used for various purposes in pharmaceutical preparations. It is particularly used as a solvent and vehicle for drugs that are unstable or insoluble in aqueous media. It is a better solvent than glycerin. It is an excellent solvent for corticosteroids, phenols, sulfa drugs, barbiturates, vitamins A and D, alkaloids, and local anesthetics. In addition to being used as a stabilizer in vitamin preparations, it is also useful as a plasticizer and preservative. It is used as a vehicle for emulsifying agents in cosmetic products and the food industry. It is preferred over ethanol for carrying flavoring agents. Due to its humectant properties, it is used instead of glycerin in topical moisturizing preparations.
Propylene glycol may cause local irritation on the skin and mucous membranes. Hypersensitivity reactions have been reported. Particularly in patients with renal failure, it can cause hyperosmolality, lactic acidosis, and central nervous system depression. The estimated maximum acceptable daily intake of propylene glycol has been reported as 25 mg per kg of body weight.
At high temperatures, it tends to oxidize to yield degradation products such as propionaldehyde, lactic acid, pyruvic acid, and acetic acid. It is incompatible with oxidizing agents such as potassium permanganate. It is recommended not to be used as a solvent in ear drops containing chloramphenicol.Preparation of the formulation:Sodium stearate, purified water, and propylene glycol are mixed and melted under heat. The melted mass is allowed to cool for a short period. Menthol is dissolved in methyl salicylate, added to the melted mass, and mixed thoroughly. The mass is allowed to cool until it begins to thicken. It is poured into stick-shaped containers and left to solidify. It is packaged and labeled.
Source:
1- MESUT ARICI ASSOCIATE PROFESSOR Ege University Faculty of Pharmacy Department of Pharmaceutical Technology Division of Pharmaceutical Technology (Examples of Compounded Formulations Used in the Treatment of Arthritis)
2-RxMediaPharma®2016 Interactive Drug Information Resource.
Specialist Pharmacist Ahmet Nezihi Pekcan
Pekcan Pharmacy – Konya
[email protected]
Tel: (332) 3520657http://www.majistralformul.com/
