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Record W1552995075 · doi:10.4212/cjhp.v57i5.394

Chemical Stability of 4-Aminopyridine Capsules

2004· article· en· W1552995075 on OpenAlexaffvenue
Ronald F Donnelly

Bibliographic record

VenueThe Canadian Journal of Hospital Pharmacy · 2004
Typearticle
Languageen
FieldMedicine
TopicOrthopaedic implants and arthroplasty
Canadian institutionsOttawa Hospital
Fundersnot available
KeywordsMicrocrystalline celluloseChromatographyVialChemistryAmpouleKraft paper4-AminopyridineChemical stabilityLactoseDiluentCelluloseNuclear chemistryMaterials scienceMedicineOrganic chemistry

Abstract

fetched live from OpenAlex

ABSTRACT Background: 4-Aminopyridine (4-AP) is a known potassium channel blocker that has been used to treat multiple sclerosis and spinal cord injury. 4-AP capsules must be prepared extemporaneously. Objective: To determine the chemical stability of 4-AP capsules containing 10 mg of active ingredient. Methods: Ten-milligram capsules were prepared from 4-AP obtained from 2 suppliers, with either lactose or microcrystalline cellulose as diluent. The hard gelatin capsules were stored in amber snap-top prescription vials at room temperature (20°C to 25°C) with protection from light. Two capsules were collected from each group on days 0, 14, 28, 62, 96, 125, 180, and 365 and stored in a rubber-stoppered glass test tube containing desiccant material at –70°C. On the day of analysis, solutions were prepared from the contents of the capsules, which had been accurately weighed and appropriately diluted; the solutions were assayed, in duplicate, by means of a stability-indicating high-pressure liquid chromatography assay. Results: Ten-milligram capsules of 4-AP, prepared from material obtained from each supplier and diluted with either lactose or microcrystalline cellulose, retained at least 94% of the initial content for 365 days when stored in plastic prescription vials at room temperature with protection from light. Conclusions: Extemporaneously prepared 10-mg capsules of 4-AP were considered stable for 365 days when stored in plastic prescription vials at room temperature with protection from light. RESUME Historique : La 4-aminopyridine (4-AP) est un inhibiteur des canaux potassiques connu, qui a ete utilise dans le traitement de la sclerose en plaques et des lesions medullaires. Les capsules de 4-AP doivent etre preparees extemporanement. Objectif : On a mene une etude pour determiner la stabilite chimique des capsules de 4-AP renfermant 10 mg de principe actif. Methodes : On a prepare des capsules de 10 mg avec de la 4-AP provenant de deux fournisseurs, et du lactose ou de la cellulose microcristalline comme excipient. Les capsules de gelatine dure ont ete conservees a la temperature de la piece (entre 20 et 25 oC) et protegees de la lumiere dans des flacons d’ordonnance de couleur ambre a bouchon pression. On a recueilli deux capsules de chaque groupe aux jours 0, 14, 28, 62, 96, 125, 180 et 365, qu’on a entreposees a -70 oC dans des eprouvettes de verre munies d’un bouchon de caoutchouc et contenant un dessicatif. Le jour de l’analyse, on a prepare des solutions a partir du contenu des capsules, qu’on a pese avec precision et dilue de facon appropriee; on les a ensuite soumises a un double dosage au moyen d’une epreuve de stabilite par chromatographie liquide a haute pression. Resultats : Les capsules de 10 mg de 4-AP, preparees a partir du produit de chaque fournisseur dilue avec du lactose ou de la cellulose microcristalline, ont conserve au moins 94 % de leur contenu initial pendant 365 jours, lorsqu’elles etaient conservees dans des flacons d’ordonnance de plastique a la temperature de la piece et a l’abri de la lumiere. Conclusions : Les capsules de 10 mg de 4-AP preparees extemporanement et conservees dans des flacons d’ordonnance de plastique a la temperature de la piece et a l’abri de la lumiere ont ete jugees stables pendant une periode de 365 jours.

Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.

How this classification was reachedexpand

Full frame machine prediction

Teacher imitation

Not 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.

metaresearch head score (Codex)0.000
metaresearch head score (Gemma)0.001
Version: metacan-v3-hybrid-931329e0061cValidation status: machine_predicted_unvalidated
Candidate categoriesnone
Consensus categoriesnone
DomainCandidate signal: none · Consensus signal: none
Study designCandidate signal: Bench or experimental · Consensus signal: Bench or experimental
GenreCandidate signal: Empirical · Consensus signal: Empirical
Teacher disagreement score0.002
Threshold uncertainty score0.008

Distilled classifier scores by category (both heads)

CategoryCodexGemma
Metaresearch0.0000.001
Meta-epidemiology (narrow)0.0000.000
Meta-epidemiology (broad)0.0000.000
Bibliometrics0.0000.000
Science and technology studies0.0000.000
Scholarly communication0.0000.000
Open science0.0000.000
Research integrity0.0000.000
Insufficient payload (model declined to judge)0.0020.001

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.

Opus teacher head0.022
GPT teacher head0.269
Teacher spread0.247 · how far apart the two teachers sit on this one work
Validation statusscore_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from it

Classification

machine, unvalidated

Machine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.

The models applied no category: nothing in the taxonomy fit this work.
Study designBench or experimental
Domainnot available
GenreEmpirical

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".

Quick stats

Citations8
Published2004
Admission routes2
Has abstractyes

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