Optimizing the storage of chemotherapeutics for ophthalmic oncology: stability of topotecan solution for intravitreal injection.

BACKGROUND: . Intravitreal administration of topotecan shows activity against tumor vitreous seeding in the conservative treatment of retinoblastoma, a malignant tumor originated in the retina of small children. Adequate storage of the intravitreal topotecan solution would allow immediate availability for patients at health care institutions. The goal of the work was to address the stability of the intravitreal topotecan formulation upon reconstitution. MATERIALS AND METHODS: . Intravitreal topotecan solutions were reconstituted (at a concentration of 0.2 mg topotecan in 1 mL saline solution vehicle, aliquoted in 1 mL plastic syringes) and stored either frozen or at room temperature for different times. Topotecan content was analyzed at time zero and at different conditions using a high performance liquid chromatography method to quantify topotecan lactone (active) and to detect its pH-dependent hydrolysis product, the open carboxylate. RESULTS: . We found that intravitreal topotecan syringes remained stable at room temperature at least for 24 h, at least for 167 days upon stored frozen at -20°C, and up to 8 h after thawing at day 6. The degradation carboxylate product did not appear in the analyzed thawed samples during the whole study. CONCLUSIONS: . This study confirms the stability of frozen intravitreal topotecan syringes and will help optimize the use of this chemotherapy modality at institutions with low resources. Storage of aliquots will also help reduce personnel exposure to chemotherapy at hospital pharmacies.

Constraints to microbial food safety policy: opinions from stakeholder groups along the farm to fork continuum.

This exploratory qualitative study was conducted to identify constraints to microbial food safety policy in Canada and the USA from the perspective of stakeholder groups along the farm to fork continuum. Thirty-seven stakeholders participated in interviews or a focus group where semi-structured questions were used to facilitate discussion about constraints to policy development and implementation. An emergent grounded theory approach was used to determine themes and concepts that arose from the data (versus fitting the data to a hypothesis or a priori classification). Despite the plurality of stakeholders and the range of content expertise, participant perceptions emerged into five common themes, although, there were often disagreements as to the positive or negative attributes of specific concepts. The five themes included challenges related to measurement and objectives of microbial food safety policy goals, challenges arising from lack of knowledge, or problems with communication of knowledge coupled with current practices, beliefs and traditions; the complexity of the food system and the plurality of stakeholders; the economics of producing safe food and the limited resources to address the problem; and, issues related to decision-making and policy, including ownership of the problem and inappropriate inputs to the decision-making process. Responsibilities for food safety and for food policy failure were attributed to all stakeholders along the farm to fork continuum. While challenges regarding the biology of food safety were identified as constraints, a broader range of policy inputs encompassing social, economic and political considerations were also highlighted as critical to the development and implementation of effective food safety policy. Strategies to address these other inputs may require new, transdisciplinary approaches as an adjunct to the traditional science-based risk assessment model.