Studies of a benzoporphyrin derivative with Pluronics
Bibliographic record
Abstract
The synthetic route for the benzoporphyrin derivatives produces two regioisomers in equimolar quantities (ring A and B isomers). A derivative of the A-ring product, BPD-MA (benzoporphyrin-derivative monoacid ring A, verteporfin), has recently been approved in North America and Europe for the treatment of age-related macular degeneration. The B-ring isomers, contrary to the A-ring isomers, exhibit high aggregation in many formulations, which results in inadequate drug delivery for clinical uses. To avoid aggregation, a non-ionic surfactant polymer such as a Pluronic poly(ethylene oxide)-poly(propylene oxide)-poly(ethylene oxide) may be used as a formulation excipient. The triblock polymer investigated here is designated P123 (or poloxamer 403). When used to formulate a monoacid benzoporphyrin B-ring derivative (2), a critical micelle concentration of P123 in water occurred at approximately 0.015 to 0.03%. The apparent pKa of compound 2 was dependent on its concentration in P123, and decreased as the molar ratio (P123:2) increased. High concentrations of P123 and neutral pH were found to be the best conditions to maintain the drug in its monomeric form. Kinetic studies suggest that the aggregate of 2 contains several molecules, and is formed by a catalyzed self-assembly process. Samples with 1 mg mL1 of drug, at pH = 7.4, and 4.8% of Pluronic showed satisfactory capacity to load and keep monomers stable. This formulation has potential PDT applications.Key words: Pluronic, poloxamers, block copolymers, photosensitizing drug, photodynamic therapy (PDT), formulation, micelles.
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.001 |
| Meta-epidemiology (narrow) | 0.001 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.001 |
| Insufficient payload (model declined to judge) | 0.001 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".