Development and validation of a LC-MS/MS method for quantitation of recombinant human growth hormone in rat plasma...

Area of Science:

• Biochemistry
• Analytical Chemistry
• Pharmacology

Background:

• Recombinant human growth hormone (rhGH) is a 191-amino acid peptide crucial for pediatric growth and possesses anti-aging properties.
• Accurate quantification of rhGH in biological matrices is essential for pharmacokinetic and therapeutic monitoring.

Purpose of the Study:

• To develop and validate a simple, sensitive, and rapid LC-MS/MS method for quantifying rhGH in rat plasma.
• To assess the method's suitability for pharmacokinetic studies.

Main Methods:

• Establishment of a quantitative LC-MS/MS assay using enzymatic digestion of plasma samples.
• Selection of two surrogate peptides (LFDNAMLR and FPTIPLSR) for targeted analysis.
• Validation of linearity, accuracy, and precision across a wide calibration range.

Main Results:

• The method demonstrated good linearity from 10-2000 ng/mL.
• Quality control accuracy ranged from -13.8% to 14.3%, with LLOQ accuracy between -12.9% and 19.0%.
• Intra-day and inter-day precision were within acceptable limits (1.7-13.6% and 4.0-7.0%, respectively).

Conclusions:

• The developed LC-MS/MS method is simple, sensitive, and efficient for rhGH quantification in rat plasma.
• The method's advantages include a short processing time (3.5 h), wide linear range, small plasma volume requirement (35 μL), and a low LLOQ (10 ng/mL).
• This validated assay is suitable for intravenous and subcutaneous pharmacokinetic studies of rhGH in rats.