Investigation on the chemical stability of erythromycin in solutions using an optimization system

Abstract

Erythromycin, an antibiotic commonly used topically in the treatment of acne, is unstable in solution. The stability is influenced by the pH and by the presence of water. The influence of the pH on the stability of erythromycin was investigated even with the use of dimethyl isosorbide as co-solvent instead of water. The addition of zinc was attempted to ameliorate erythromycin stability as suggested in the literature. To investigate these three factors and their interactions, an optimization technique was carried out consisting of a 2(3) factorial analysis and a rotative central composite design. The erythromycin solutions were analysed with an HPLC method. The pH and the concentration of dimethyl isosorbide had a significant influence on the stability of erythromycin but the addition of zinc was not a significant factor. Moreover, there was a significant interaction between the pH and dimethyl isosorbide.

Silk constructs for delivery of musculoskeletal therapeutics

“…Numerous studies support the feasibility of SF for localized delivery of chemical entities, including antibiotics such as doxycyclin [53, 54], rifampicin, erythromycin [55], or tetracycline (unpublished results). Known instabilities of these drugs were overcome by entrapment within silk films or 3D scaffold material e.g.…”

Alkylated hyperbranched polymers as molecular nanosponges for the purification of water from polycyclic aromatic hydrocarbons

“…Preservation of bioactivity during carrier fabrication and drug release was also confirmed for sponges loaded with rifampicin and erythromycin. The latter, though highly unstable in aqueous media,93 continued to inhibit S. aureus growth up to 35 days despite being incubated at 37°C for over a month in a hydrated silk sponge (Pritchard et al, in preparation) 90. Tetracycline bioactivity was also preserved during fabrication of silk microneedle arrays and subsequent in vitro release studies in Staphylococcus aureus lawns 41…”

Comparative Study on the Photostability of Arbutin and Deoxy Arbutin: Sensitivity to Ultraviolet Radiation and Enhanced Photostability by the Water-Soluble Sunscreen, Benzophenone-4

“…20,21) Benzophenone-4 is used in a wide range of cosmetics and personal care products and, as a water-soluble UV filter, provides a broad spectrum of protection. 22,23) We therefore utilized benzophenone-4 in this study with equivalent concentrations to arbutin and deoxy arbutin to improve the photostability of both.…”