{
  "abstract": "Background and Importance Losartan is an angiotensin II receptor antagonist used off-label as eye drops for corneal haze and is being investigated for corneal scarring and other eye disorders. This effect is driven via antifibrotic TGF-β pathway inhibition, reducing myofibroblast differentiation and survival. Given the lack of robust published stability data supporting the use of this extemporaneous preparation, establishing a period of validity is essential to ensure its quality and patient safety.Aim and Objectives To evaluate the physicochemical stability of Losartan 0.8 mg/mL eye drops over a 56-day period under refrigerated storage (2-8 °C) and establish a period of validity for its use in clinical practice.Material and Methods The active pharmaceutical ingredient concentration was determined using an Ultraviolet-Visible spectrophotometric method at a wavelength of 227 nm. Method validation included the design of a calibration curve where Losartan standards were prepared from a 100 µg/mL stock solution, dissolved in Balanced Salt Solution (BSS), and measured across six concentrations (2-25 µg/mL). All dilutions were prepared in 0.01 N Hydrochloric Acid (HCl), and the curve demonstrated linearity (R 2 = 0.9997).For the stability study, three independent batches of Losartan 0.8 mg/mL in BSS were prepared with an initial pH between 6.7-7.0. Solutions were aseptically prepared by sterile filtration under a biological safety cabinet, filled in low-density polyethylene containers, and stored refrigerated. Triplicate samples from each batch were analysed on Days 0, 7, 14, 28, 42 and 56. All measurements were performed using a 0.01 N HCl blank after a 1:100 dilution in 0.01 N HCl.Results Mean initial concentration of the diluted sample was 8.28 µg/mL (corresponding to 0.828 mg/mL in the original solution). The concentration remained highly stable throughout the study, exhibiting no significant change or degradative trend over the 56-day period. At Day 56, the mean residual concentration was 8.14 µg/mL, representing 98.32% of the initial concentration.Conclusion and Relevance Losartan 0.8 mg/mL eye drops formulation demonstrated excellent physicochemical stability over the 56-day period under refrigeration, with the active ingredient concentration remaining highly stable (98.32%). These robust analytical findings provide strong evidence to support a 56-day period of validity. Further studies include monitoring pH and osmolarity throughout the validity period.References and/or Acknowledgements 1. Rathee P, Rathee S, Chaudhary H, Rathee D. Development and validation of a stability indicating UV-spectrophotometric method for the estimation of losartan potassium in bulk and tablet dosage form. Journal of Pharmacy Research 2008;1(2):188–191.2. Wilson SE. Topical losartan: practical guidance for clinical trials in the prevention and treatment of corneal scarring fibrosis and other eye diseases and disorders. Journal of Ocular Pharmacology and Therapeutics 2023;39(3).Conflict of Interest No conflict of interest",
  "authors": [
    {
      "affiliations": [
        "Hospital Clínico San Carlos, Farmacia, Madrid, Spain"
      ],
      "name": "JA Domínguez Cháfer"
    },
    {
      "affiliations": [
        "Complejo Hospitalario Universitario De Toledo, Análisis Clínicos, Toledo, Spain"
      ],
      "name": "M Cháfer Rudilla"
    },
    {
      "affiliations": [
        "Hospital Clínico San Carlos, Farmacia, Madrid, Spain"
      ],
      "name": "V Puebla García"
    },
    {
      "affiliations": [
        "Hospital Clínico San Carlos, Farmacia, Madrid, Spain"
      ],
      "name": "MÁ Campos Fernández"
    },
    {
      "affiliations": [
        "Hospital Clínico San Carlos, Farmacia, Madrid, Spain"
      ],
      "name": "A Aparicio Carmena"
    },
    {
      "affiliations": [
        "Hospital Clínico San Carlos, Farmacia, Madrid, Spain"
      ],
      "name": "J Corazón Villanueva"
    },
    {
      "affiliations": [
        "Hospital Clínico San Carlos, Farmacia, Madrid, Spain"
      ],
      "name": "M De La Torre Ortiz"
    },
    {
      "affiliations": [
        "Hospital Clínico San Carlos, Farmacia, Madrid, Spain"
      ],
      "name": "L Ybáñez García"
    },
    {
      "affiliations": [
        "Hospital Clínico San Carlos, Farmacia, Madrid, Spain"
      ],
      "name": "N Sánchez-Ocaña Martín"
    },
    {
      "affiliations": [
        "Hospital Clínico San Carlos, Farmacia, Madrid, Spain"
      ],
      "name": "I Muñóz Delgado"
    },
    {
      "affiliations": [
        "Hospital Clínico San Carlos, Farmacia, Madrid, Spain"
      ],
      "name": "A Retamosa Escolar"
    }
  ],
  "title": "3PC-018 Stability assessment of extemporaneous losartan 0.8 mg/ml eye drops",
  "uid": "be92f5ce-15d1-5e14-b38f-8f0dbe04a53e"
}