Absorption, Distribution and Excretion
The absorption is done directly in the alveolus into the lung tissue. As the lung surfactant is distributed in the bronchi, bronchioles and alveoli, its highest concentration is at the alveolar air-fluid interface where it remains as a monolayer.
After 5 days, most of the administered dose (56%) is distributed throughout the body with renal and fecal excretion being the minor elimination pathway representing the 4 and 2% of the eliminated dose respectively. The major route of elimination is by expelled air which accounts for 28% of the administered dose.
Colfosceril palmitate is distributed uniformly to all lobes of the lung, distal airways and alveolar spaces. It will not enter the systemic circulation in healthy lungs, however when the integrity of the tissue is distrupted colfosceril can reach systemic circulation. Even 5 days after administration, there are traces of colfosceril palmitate retained in the body that represented 72% of the administered dose which by then have entered pathways of lipid metabolism to become tissue associated.
After 5 days of drug administration, the lung and liver would contain 10% of the administered dose and the elimination via renal excretion accounts only for 8% of the administered dose. This proved a very small renal clearance and confirmed that the major elimination route is by expired air.

---

Metabolism / Metabolites
Colfosceril palmitate is catabolized and reutilized for further synthesis and secretion in lung tissues.

---

Biological Half-Life
The half-life of colfosceril palmitate is registered to be in the range of 20-36 hours.

Protein Binding
Colfosceril palmitate stays and gets metabolized in the pulmunar tissue, thus it is not able to bind to plasma proteins.

1,2-dihexadecanoyl-sn-glycero-3-phosphocholine is a phosphatidylcholine 32:0 in which the 1- and 2-acyl groups are specified as hexadecanoyl (palmitoyl). A synthetic phospholipid used in liposomes and lipid bilayers to study biological membranes. It is also a major constituent of pulmonary surfactants. It has a role as a surfactant and a mouse metabolite. It is a phosphatidylcholine 32:0 and a 1-acyl-2-hexadecanoyl-sn-glycero-3-phosphocholine. It is functionally related to a hexadecanoic acid. It is a conjugate base of a 1,2-di-O-palmitoyl-sn-glycero-3-phosphocholine.
Colfosceril palmitate is a synthetic pulmonary surfactant administered in infants with respiratory distress syndrome. It was part of the first generation of commercially available artificial surfactants. It was developed by Burroughs Wellcome and it was FDA approved on August 6, 1990. Nowadays colfosceril palmitate is under the state of canceled post-marketing.
Colfosceril palmitate has been reported in Homo sapiens, Lycoris radiata, and Trypanosoma brucei with data available.
Colfosceril Palmitate is a lung surfactant agent that is used as a replacement for endogenous lung surfactant. Colfosceril palmitate is effective in reducing the surface tension of pulmonary fluids, thereby increasing lung compliance properties to prevent alveolar collapse and improve breathing. This drug is used in the treatment of neonatal respiratory distress.
PC(16:0/16:0) is a metabolite found in or produced by Saccharomyces cerevisiae.

---

Drug Indication
Colfosceril palmitate is indicated for the treatment of respiratory distress syndrome (RDS) in premature infants. The official label is referred as a intratracheal suspension for prophylactic treatment of infants of less than 1350 grams of birth weight under risk of developing RDS, or in infants with birth weight greater than 1350 grams with pulmonary immaturity, or as rescue treatment of infants that already developed RDS. The central feature of RDS is a surfactant deficiency due to lung immaturity. This lung condition is more frequently presented due to risk factors like prematurity, delayed lung maturation caused by maternal diabetes or male gender, or surfactant dysfuntion due to perinatal asphyxia, pulmonary infection or delivery without labor.

---

Mechanism of Action
Treatment with colfosceril palmitate aims to reinflate a collapsed area of the lung, improve compliance and reduce intrapulmonary shunting. The actions of colfosceril palmitate are perfomed by replacing the defficient or innefective endogenous lung surfactant and thus, reducing the tension and stabilizing the alveoli from collapsing. Colfosceril palmitate will form a very thin film that will cover the surface of the alveolar cells and therefore it will reduce surface tension.

---

Pharmacodynamics
Colfosceril palmitate has shown to significantly reduce the risk of pneumothoraces, pulmonary interstitial emphysema and mortality. Unlike naturals surfactants, colfosceril palmitate reduces the risk of bronchopulmonary dysplasia, intraventricular hemorrhage and patent ductus arteriosus. In clinical placebo-controlled trials, there was a significant reduction in the number of deaths attributed to hyaline membrane disease, the incidence of pulmonary air leaks, oxygen requirements and mean airway pressure. Some reports have indicated a lack of therapeutic effect due to the absence of surfactant protein.

C40H80NO8P

734.0389

733.562

63-89-8

DPPC-d9;DPPC-d62;25582-63-2;DPPC-d9-1;77165-56-1;DPPC-d4;326495-33-4;DPPC-d13;86531-55-7;DPPC-d66;326495-34-5;DPPC-d71;474943-49-2;DPPC-d75;181041-62-3

452110

White to off-white solid powder

229-229.5 °C

10.88

0

8

40

50

826

1

P(=O)([O-])(OC([H])([H])[C@@]([H])(C([H])([H])OC(C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])[H])=O)OC(C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])[H])=O)OC([H])([H])C([H])([H])[N+](C([H])([H])[H])(C([H])([H])[H])C([H])([H])[H]

KILNVBDSWZSGLL-KXQOOQHDSA-N

InChI=1S/C40H80NO8P/c1-6-8-10-12-14-16-18-20-22-24-26-28-30-32-39(42)46-36-38(37-48-50(44,45)47-35-34-41(3,4)5)49-40(43)33-31-29-27-25-23-21-19-17-15-13-11-9-7-2/h38H,6-37H2,1-5H3/t38-/m1/s1

[(2R)-2,3-di(hexadecanoyloxy)propyl] 2-(trimethylazaniumyl)ethyl phosphate

2934.99.9001

Powder      -20°C    3 years

                     4°C     2 years

In solvent   -80°C    6 months

                  -20°C    1 month

Note: Please store this product in a sealed and protected environment, avoid exposure to moisture.

Room temperature (This product is stable at ambient temperature for a few days during ordinary shipping and time spent in Customs)

Ethanol : ~25 mg/mL (~34.06 mM)
DMSO :< 1 mg/mL
H2O : < 0.1 mg/mL

Solubility in Formulation 1: 2.5 mg/mL (3.41 mM) in 10% EtOH + 40% PEG300 + 5% Tween80 + 45% Saline (add these co-solvents sequentially from left to right, and one by one), suspension solution; with sonication.
For example, if 1 mL of working solution is to be prepared, you can add 100 μL of 25.0 mg/mL clear EtOH stock solution to 400 μL PEG300 and mix evenly; then add 50 μL Tween-80 to the above solution and mix evenly; then add 450 μL normal saline to adjust the volume to 1 mL.
Preparation of saline: Dissolve 0.9 g of sodium chloride in 100 mL ddH₂ O to obtain a clear solution.

---

Solubility in Formulation 2: ≥ 2.5 mg/mL (3.41 mM) (saturation unknown) in 10% EtOH + 90% Corn Oil (add these co-solvents sequentially from left to right, and one by one), clear solution.
For example, if 1 mL of working solution is to be prepared, you can add 100 μL of 25.0 mg/mL clear EtOH stock solution to 900 μL of corn oil and mix evenly.

---

 (Please use freshly prepared in vivo formulations for optimal results.)