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Picibanil (OK-432) is a sclerosing agent derived from a low-virulence strain of Streptococcus pyogenes that induces regression of macrocystic lymphangiomas. This report describes a prospective, nonrandomized trial to evaluate the efficacy of Picibanil in the treatment of 13 affected children ranging in age from 1 to 94 months. On average, 4.1 fluoroscopically guided intracystic injections were performed per child, with an average total dose of 0.56 mg of Picibanil. As judged by physical examination and radiographic studies, 5 children (42%) showed a complete or substantial response, and 2 children (16%) showed an intermediate response. No response was seen in 5 children (42%), 2 of whom had massive craniofacial lymphangioma. Factors that contribute to failure with Picibanil sclerotherapy are the presence of a significant microcystic component to the lesion, massive craniofacial involvement, and previous surgical resection. Macrocystic lymphangiomas of the infratemporal fossa or cervical area have the best response to therapy.

The effects of pH, mixed solvent systems, and divalent metal ions on oxytetracycline (OTC) solubility and the interactions between OTC and metal ions in aqueous and mixed solvent systems were investigated. OTC solubility profiles were obtained for pH 4-9. The cosolvents studied were glycerin, propylene glycol, PEG 400, and 2-pyrrolidone with the following metal ions: magnesium, calcium, and zinc. OTC and its interactions with these metal ions were evaluated by solubility, NMR, circular dichroism (CD), and electron diffraction (ED) methods. At pH 5.6, no complexation occurred with these metal ions, but OTC zwitterion formed aggregates in aqueous solutions as shown by NMR spectra. The hydration of the metal ions was observed to affect OTC aggregation, with Mg+2 causing the greatest OTC aggregation. At pH 7.5, OTC aggregation and metal-OTC complexation were observed in solutions with Ca+2 and Mg+2. Zinc ion was found to decrease OTC solubility because of zincate formation, which caused anionic OTC to precipitate. Electron diffraction revealed a relationship between OTC and metal-OTC complex crystallinity and solubility behavior. The zinc-OTC complex exhibited the highest crystallinity and lowest solubility at pH 8.0. Various cosolvents generally enhanced OTC solubility, with 2-pyrrolidone having the best solubility power. In OTC-metal-2-pyrrolidone and OTC-Zn(+2)-PEG 400 systems, circular dichroism provided evidence for the formation of soluble ternary complexes.

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