Search

Aim: To develop nanoemulsions (NEs) loading amphotericin B (AmB) and to evaluate the influence of different excipients on the stability and the supramolecular organization, retention and toxicity of AmB. Materials & methods: The NEs were developed from different oils, surfactants, external media and anionic lipids (disteaoryl phosphatidylglycerol [DSPG] and dioleoyl phosphatidylglycerol [DOPG]). Their impact on the size, pH, zeta potential, AmB encapsulation efficiency, AmB retention and hemolytic potential of the NEs was evaluated. Results & conclusion: The use of soybean oil (lipid matrix), Span 80 (surfactant), phosphate buffer (external phase) and DSPG or DOPG (hydrophobic ion pair) provided better NE stability, higher AmB retention within the NEs and a safer formulation profile in hemolysis tests. Disteaoryl phosphatidylglycerol and dioleoyl phosphatidylglycerol form a hydrophobic ion pair with amphotericin B in nanoemulsions, enhancing drug retention after dispersion and decreasing its toxicity. [ABSTRACT FROM AUTHOR]

The substance 4-Aminobenzamidine dihydrochloride (4-AD) is one of the degradation products of diminazene aceturate and has demonstrated antiglaucomatous potential. Glaucoma is the second leading cause of blindness worldwide; thus, new therapeutic alternatives must be studied, for example, the molecule 4-AD vehiculated into polymeric inserts for prolonged release. The present work aims to develop and validate an analytical method to quantify 4-AD in pharmaceutical ophthalmic forms. A HPLC was used with UV-Vis detector, at 290 m and ACE® C18 column (125 × 4.6 mm, 5 µm), in which the mobile phase consists of phosphate buffer (pH 7.4) and triethylamine (30 mmol/L), under an isocratic flow of 1.0 mL/min. The retention time of 3.2 minutes was observed. The method was developed and validated in accordance with ANVISA recommendations and ICH guides. The linearity range was established between the concentrations 5 and 25 µg/mL (correlation coefficient r = 0.993). The accuracy, repeatability, and intermediate precision tests obtained a relative standard deviation less than or equal to 5%. In addition, the method was considered selective, exact. and robust, with pH being its critical factor. Therefore, the HPLC analysis method is robust and can be used to quantify 4-AD in pharmaceutical forms for ocular application. [ABSTRACT FROM AUTHOR]