Sustained In-Vivo Release of Triptorelin Acetate from a Biodegradable Silica Depot: Comparison to Pamorelin^® LA.

Forsback AP, Noppari P, Viljanen J, Mikkola J, Jokinen M, Leino L, Bjerregaard S, Borglin C, Halliday J

Nanomaterials (Basel, Switzerland)16 Jun 2021Cited by 13 (Europe PMC)

PMID34208450PMCIDPMC8233906DOI10.3390/nano11061578PepBankPUB-34208450

Summary

Triptorelin acetate was encapsulated into silica microparticles by spray-drying a mixture of colloidal silica sol and triptorelin acetate solution. The resulting microparticles were then combined with another silica sol containing silica nanoparticles, which together formed an injectable silica-triptorelin acetate depot. The particle size and surface morphology of the silica-triptorelin acetate microparticles were characterized together with the in vitro release of triptorelin, injectability and rheology of the final injectable silica-triptorelin acetate depot. In vivo pharmacokinetics and pharmacodynamics of the silica-triptorelin acetate depot and Pamorelin^® were evaluated and compared in Sprague-Dawley male rats after subcutaneous administration. Serum samples up to 91 days were collected and the plasma concentrations of triptorelin and testosterone were analyzed with ultraperformance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). In vivo pharmacokinetics showed that injections of the silica-triptorelin acetate depot gave 5-fold lower Cmax values than the corresponding Pamorelin^® injections. The depot also showed a comparable sustained triptorelin release and equivalent pharmacodynamic effect as the Pamorelin^® injections. Detectable triptorelin plasma concentrations were seen with the depot after the 91-day study period and testosterone plasma concentrations remained below the human castration limit for the same period.

CC BYText from Europe PMC. Highlighted sentences are the source of results.

Results from this study5

No result from this study comes from a test of the peptide.

Studies that did not test the peptide alone5

In this study, Triptorelin (Trelstar, Decapeptyl) was a lab tool or a carrier, part of a mix, or the subject of a lab method. These results are not evidence about taking Triptorelin (Trelstar, Decapeptyl).

01AnimalNot a test of Triptorelin (Trelstar, Decapeptyl) aloneAnimal study (in vivo)Pharmacokinetics
In rats, the silica-triptorelin depot produced lower peak triptorelin concentrations than Pamorelin injections.
In plain wordsIn rats, the silica-triptorelin depot produced lower peak drug concentrations than Pamorelin injections.
Peptide
Triptorelin (Trelstar, Decapeptyl)
Outcome
DecreasePeak triptorelin concentration
Study
ratn: not reported in source
male Sprague-Dawley rats
Comparator
Pamorelin injections
Outcome group
Pharmacokinetics · Pharmacology
Measurements
Cmax reduction
5 fold
silica depot versus Pamorelin
Source sentences
Summary
In vivo pharmacokinetics showed that injections of the silica-triptorelin acetate depot gave 5-fold lower Cmax values than the corresponding Pamorelin^® injections.
1 context sentence(design, population, supporting numbers)
Summary · context
In vivo pharmacokinetics and pharmacodynamics of the silica-triptorelin acetate depot and Pamorelin^® were evaluated and compared in Sprague-Dawley male rats after subcutaneous administration.
In this study, Triptorelin (Trelstar, Decapeptyl) was a lab tool or a carrier, part of a mix, or the subject of a lab method. This result is not evidence about taking Triptorelin (Trelstar, Decapeptyl).
Show in the study text Report a problemFND-3420845001
02AnimalNot a test of Triptorelin (Trelstar, Decapeptyl) aloneAnimal study (in vivo)Pharmacokinetics
In rats, the silica-triptorelin depot showed sustained release comparable to Pamorelin injections.
In plain wordsIn rats, the silica-triptorelin depot released the drug over time comparably to Pamorelin injections.
Peptide
Triptorelin (Trelstar, Decapeptyl)
Outcome
No significant changeSustained triptorelin release
Study
ratn: not reported in source
male Sprague-Dawley rats
Comparator
Pamorelin injections
Outcome group
Pharmacokinetics · Pharmacology
Source sentences
Summary
The depot also showed a comparable sustained triptorelin release and equivalent pharmacodynamic effect as the Pamorelin^® injections.
1 context sentence(design, population, supporting numbers)
Summary · context
In vivo pharmacokinetics and pharmacodynamics of the silica-triptorelin acetate depot and Pamorelin^® were evaluated and compared in Sprague-Dawley male rats after subcutaneous administration.
In this study, Triptorelin (Trelstar, Decapeptyl) was a lab tool or a carrier, part of a mix, or the subject of a lab method. This result is not evidence about taking Triptorelin (Trelstar, Decapeptyl).
Show in the study text Report a problemFND-3420845002
03AnimalNot a test of Triptorelin (Trelstar, Decapeptyl) aloneAnimal study (in vivo)Activity measurement
In rats, the silica-triptorelin depot showed a pharmacodynamic effect equivalent to Pamorelin injections.
In plain wordsIn rats, the silica-triptorelin depot showed an equivalent biological effect compared with Pamorelin injections.
Peptide
Triptorelin (Trelstar, Decapeptyl)
Outcome
No significant changePharmacodynamic effect
Study
ratn: not reported in source
male Sprague-Dawley rats
Comparator
Pamorelin injections
Outcome group
Pharmacokinetics · Pharmacology
Source sentences
Summary
The depot also showed a comparable sustained triptorelin release and equivalent pharmacodynamic effect as the Pamorelin^® injections.
1 context sentence(design, population, supporting numbers)
Summary · context
In vivo pharmacokinetics and pharmacodynamics of the silica-triptorelin acetate depot and Pamorelin^® were evaluated and compared in Sprague-Dawley male rats after subcutaneous administration.
In this study, Triptorelin (Trelstar, Decapeptyl) was a lab tool or a carrier, part of a mix, or the subject of a lab method. This result is not evidence about taking Triptorelin (Trelstar, Decapeptyl).
Show in the study text Report a problemFND-3420845003
04AnimalNot a test of Triptorelin (Trelstar, Decapeptyl) aloneAnimal study (in vivo)Pharmacokinetics
In rats, plasma triptorelin remained detectable with the silica depot after the 91-day study period.
In plain wordsIn rats, drug levels remained detectable with the silica-triptorelin depot after the 91-day study period.
Peptide
Triptorelin (Trelstar, Decapeptyl)
Outcome
Not applicableDetectable plasma triptorelin
Study
ratn: not reported in source
male Sprague-Dawley rats
Outcome group
Pharmacokinetics · Pharmacology
Source sentences
Summary
Detectable triptorelin plasma concentrations were seen with the depot after the 91-day study period
1 context sentence(design, population, supporting numbers)
Summary · context
In vivo pharmacokinetics and pharmacodynamics of the silica-triptorelin acetate depot and Pamorelin^® were evaluated and compared in Sprague-Dawley male rats after subcutaneous administration.
In this study, Triptorelin (Trelstar, Decapeptyl) was a lab tool or a carrier, part of a mix, or the subject of a lab method. This result is not evidence about taking Triptorelin (Trelstar, Decapeptyl).
Show in the study text Report a problemFND-3420845004
05AnimalNot a test of Triptorelin (Trelstar, Decapeptyl) aloneAnimal study (in vivo)Activity measurement
In rats, testosterone concentrations with the silica-triptorelin depot remained below the human castration limit over the 91-day study period.
In plain wordsIn rats, testosterone with the silica-triptorelin depot remained below the human castration limit during the 91-day study.
Peptide
Triptorelin (Trelstar, Decapeptyl)
Outcome
DecreaseTestosterone suppression
Study
ratn: not reported in source
male Sprague-Dawley rats
Comparator
human castration limit
Outcome group
Sex hormones and fertility · Endocrine and hormones
Source sentences
Summary
Detectable triptorelin plasma concentrations were seen with the depot after the 91-day study period and testosterone plasma concentrations remained below the human castration limit for the same period.
1 context sentence(design, population, supporting numbers)
Summary · context
In vivo pharmacokinetics and pharmacodynamics of the silica-triptorelin acetate depot and Pamorelin^® were evaluated and compared in Sprague-Dawley male rats after subcutaneous administration.
In this study, Triptorelin (Trelstar, Decapeptyl) was a lab tool or a carrier, part of a mix, or the subject of a lab method. This result is not evidence about taking Triptorelin (Trelstar, Decapeptyl).
Show in the study text Report a problemFND-3420845005

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Version history

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Version 2Current
22 Oct 2026, 02:26 UTC
Study results updated
Version 1
21 Oct 2026, 18:59 UTC
First added · source update from Europe PMC

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