Protargol

PROTARGOL (Protargol, Argentum proteinicum), a colloidal silver preparation in which the protective colloid consists of protein cleavage products. It is a light brown, odorless powder, colloidally soluble in water and in glycerin diluted with water (50%); it is insoluble in organic liquids that do not dissolve albumoses (alcohol, ether, chloroform, paraffin, etc.). It contains not less than 8% silver (Pharmacopoeia VII), and not more than 3% moisture. To dissolve Protargol, its powder is sprinkled onto the surface of the water; due to its high specific gravity, Protargol gradually sinks, forming a colloidal solution. Unlike silver salts, Protargol solutions are not precipitated by a 1% sodium chloride solution, nor by alkalis, sulfide alkalis, etc. The reaction of the solutions is weakly alkaline. Protargol was proposed as a silver preparation free from the disadvantages of silver nitrate—its caustic effect and shallow depth of penetration; in reality, Protargol, containing 8 times less silver than lunar caustic (AgNO₃), proved to be less caustic (corrosive), but also significantly less bactericidal. Cushny notes that in Protargol, a significant amount of silver is in an ionizable form. This explains the antiseptic, anti-inflammatory, and astringent effect of Protargol in its therapeutic use. Pronounced argyria, observed in patients after prolonged internal use of significant doses of Protargol, also confirms that the action of the silver ion occurs in the body. As for Protargol solutions, they easily penetrate deep into tissues, since silver is not precipitated from Protargol solutions by proteins or by weak solutions of table salt, hydrochloric acid, or sodium hydroxide. This property of Protargol, together with its significant antiseptic effect, especially on gonococci, is the reason for the frequent use of Protargol in the treatment of acute and chronic gonorrhea, with Protargol being prescribed in the form of solutions for douching in concentrations from 0.25% to 1%, and in chronic forms—up to 5%. In cases of suspicious coitus, Protargol is used prophylactically in 20% solutions with the addition of glycerin. Many authors recommend Protargol for the treatment of lacerated and crushed wounds, leg ulcers, paronychia, burns, and chronic eczema; in such cases, Protargol is used in a 5% solution for moistening applied dressings, or in the form of powders or ointments. For bladder irrigation, Protargol is taken in the form of 1–2% solutions. In ophthalmic practice, Protargol is successfully used for ophthalmia neonatorum and acute catarrhal conjunctivitis in the form of 5–10% solutions; for ulcerative blepharitis—in the form of compresses with a 5–10% Protargol solution or a 10–15% ointment. For ulcerating eczema of the eyelid margins, an ointment with Protargol is prescribed: Rp. Argenti proteinici 1.5; Zinci oxydati, Amyli aa 0.5, Vaselini albi 10.0. M.S. Ointment for the eyelid margin. For prophylactic purposes, 1–2 drops of a 1–5% Protargol solution are instilled into newborns. For chronic catarrh of the nose and nasopharynx and for chronic laryngitis, Protargol is prescribed in 0.5–1% solutions for swabbing. Internally, Protargol is given in pills of 0.1 for ulcerative processes in the stomach and intestines, and for childhood diarrhea caused by acute intestinal catarrh, in solutions: 0.05–0.1 Protargol per 50.0 of water, one teaspoonful. In Western Europe and the USSR, a huge number of preparations analogous to Protargol have been released: Albargin (15% silver; also prepared in the USSR), Argentaminalbumosa (7% silver, in combination with ethylenediamine), Argonin (10% silver, with casein as a protective colloid), Argyrol (30% silver), Choleval (10% silver, with sodium salts of bile acids), Hegonon (7% silver), Largin (11% silver), Nargol (10% silver, nuclein), Novargan (10% silver), Sophol (20% silver, nuclein treated with formaldehyde), and many others.

I. Oberhard.