Anti-glaucoma latanoprost-loaded ocular implants provide prolonged delivery and enhanced bioavailability relative to the conventional eye drops. This study aims at the development and validation of a reversed-phase high-performance liquid chromatography method for quantitative analysis of nanogram levels of latanoprost in the eye, and for the first time, compares the use of fluorescence vs ultraviolet (UV) detectors in latanoprost quantification. The mobile phase was composed of acetonitrile:0.1% v/v formic acid (60:40, v/v) with a flow rate of 1 mL/min and separation was done using a C18 column at temperature 40°C. The fluorescence excitation and emission wavelengths were set at 265 and 285 nm, respectively, while the UV absorption was measured at 200 nm. The latanoprost concentration-peak area relationship maintained its linearity (R2 = 0.9999) over concentration ranges of 0.063-10 μg/mL and 0.212-10 μg/mL for the fluorescence and UV detectors, respectively. The UV detector showed better precision, while the fluorescence detector exhibited higher robustness and greater sensitivity, with a detection limit of 0.021 μg/mL. The fluorescence detector was selected for quantification of latanoprost released from ocular implants in vitro and in porcine ocular tissues. The developed method is a robust, rapid and cost-effective alternative to liquid chromatography-mass spectrometry for routine analysis of latanoprost released from ocular implants.
Bevacizumab is a full-length human monoclonal antibody used to treat various neovascular diseases such as wet age-related macular degeneration (AMD), diabetic eye disease and other problems of the retina. Monthly intravitreal injections of bevacizumab (Avastin®) are effective in the treatment of wet AMD. However, there is a growing demand in the development of sustained release ophthalmic formulations. Therefore, this study aims, for the first time, to develop a rapid, simple, and sensitive method using size exclusion chromatography coupled with fluorescence detection for routine quantification of bevacizumab in ophthalmic formulations and during in vitro release studies. The selected chromatographic conditions included an aqueous mobile phase composed of 35 mM sodium phosphate buffer and 300 mM sodium chloride (pH 6.8), a flow rate of 0.5 mL/min, and the fluorescence detector was operated at excitation and emission wavelengths of 280 and 340 nm, respectively. The peak area-concentration relationship maintained its linearity over concentration range of 0.1-20 μg/mL (R2 = 0.9993), and the quantitation limit was 100 ng/mL. The method was validated for specificity, accuracy, precision, and robustness. The developed method had a run time of 6 min at temperature 25 °C, making it a unique validated method for rapid and cost-effective quantification of bevacizumab.
Meaningful communication between health service users and providers is essential. However, when stakeholders are unfamiliar with new health services, innovative communication methods are necessary to engage them. The aim of the study was to create, validate, and evaluate a video-vignette to enhance stakeholders' (physicians, pharmacists, and laypeople) engagement and understanding of an innovative pharmacy-based diabetes screening and prevention program. Also, to assess the video-vignette's capacity to measure appetite and appeal for such preventive programs. This mixed-methods study consisted of two phases. In phase one, a video-vignette depicting the proposed screening and prevention program was developed and validated following established international guidelines (n = 25). The video-vignette was then evaluated by stakeholders (n = 99). In phase two, the video-vignette's capacity as a communication tool was tested in focus groups and interviews to explore stakeholders' perspectives and engagement on the proposed service (n = 22). Quantitative data were analyzed descriptively, while qualitative data underwent thematic analysis. In total, 146 stakeholders participated. The script was well-received, deemed credible, and realistic. Furthermore, the video-vignette received high ratings for its value, content, interest, realism, and visual and audio quality. The focus groups and interviews provided valuable insights into the design and delivery of the new service. The video-vignette compellingly portrayed the novel pharmacy-based diabetes screening and prevention service. It facilitated in-depth discussions among stakeholders and significantly enhanced their understanding and appreciation of such health services. The video-vignette also generated significant interest in pharmacy-based diabetes screening and prevention programs, serving as a powerful tool to promote enrollment in these initiatives.