Zofenopril calcium

Zofenopril Calcium(SQ26991) is an antioxidant that acts as an angiotensin-converting enzyme inhibitor. Target: ACE Zofenopril is a pro-drug designed to undergo metabolic hydrolysis yielding the active free sulfhydryl compound zofenoprilat, which is an angiotensin converting enzyme (ACE) inhibitor [1]. Zofenopril promotes the regeneration of peripheral nerve injuries in rat models [2]. Zofenopril increases SR calcium cycling and stimulates active calcium uptake into the SR [3].

References:
[1]. Dal Bo, L., P. Mazzucchelli, and A. Marzo, Assay of zofenopril and its active metabolite zofenoprilat by liquid chromatography coupled with tandem mass spectrometry. J Chromatogr B Biomed Sci Appl, 2000. 749(2): p. 287-94. [2]. Kalender, A.M., et al., Effect of Zofenopril on regeneration of sciatic nerve crush injury in a rat model. J Brachial Plex Peripher Nerve Inj, 2009. 4: p. 6. [3]. Frascarelli, S., et al., Effects of zofenopril on cardiac sarcoplasmic reticulum calcium handling. J Cardiovasc Pharmacol, 2009. 54(5): p. 456-63.

Disposition of zofenopril calcium in healthy subjects.[Pubmed:2292772]

J Pharm Sci. 1990 Nov;79(11):970-3.

Zofenopril calcium (1) is a prodrug that is hydrolyzed in vivo to the active angiotensin-converting enzyme (ACE) inhibitor SQ 26,333 (2). In a two-way crossover study, six healthy male subjects (age range 25-36 years) each received an iv 11.2-mg dose of [14C]SQ 26,703 (14C-3; the L-arginine salt of 2) and an oral 10-mg (equimolar) dose of 14C-1. After the iv dose of 14C-3, the 0-96-h recovery of radioactivity averaged 76 and 16% of the dose in urine and feces, respectively, indicating substantial biliary secretion. After the oral dose of 14C-1, excretion of radioactivity averaged 70% (urine) and 26% (feces). Negligible amounts of 1 were present in urine, indicating complete hydrolysis of the orally administered prodrug. The oral absorption of 1 was almost complete and the oral bioavailability of 2 averaged approximately 70%. The terminal elimination half-life for 2 after the iv dose averaged 5.5 h. Whole body clearance, renal clearance, nonrenal clearance, and Vdss averaged 11.4, 3.1, and 8.3 mL/min/kg and 1.3 L/kg, respectively. These data indicated that 2 is eliminated by the kidney as well as the liver, is extensively metabolized, and is distributed extensively into extravascular sites.

Sites of first-pass bioactivation (hydrolysis) of orally administered zofenopril calcium in dogs.[Pubmed:2052527]

Pharm Res. 1991 Mar;8(3):370-5.

The relative contribution of the gut, liver, and lungs as sites of first-pass bioactivation (hydrolysis) of the orally administered ester prodrug, Zofenopril calcium (SQ 26,991), to the active angiotensin converting enzyme (ACE) inhibitor, SQ 26,333, was determined. With a five-way study design, two dogs each received a single 1.6-mg/kg dose of zofenopril [as its soluble potassium salt (SQ 26,900)] via the following routes of administration: intraarterial, intravenous, intraportal, and oral. Each dog also received an equimolar oral dose of Zofenopril calcium (1.5 mg/kg). Concentrations of zofenopril in plasma were quantitated with a GC/MSD assay. Extraction ratios (E) for zofenopril by the gut, liver, and lungs were calculated based on the ratios of the area under the curve (AUC) values of zofenopril in arterial plasma after administration by the various routes. As individual eliminating organs, the gut and liver each had a high intrinsic capability to hydrolyze zofenopril; E values ranged from 45 to 89%. The lungs were found to have low, but measurable, hydrolytic activity with estimated E values that ranged from 5 to 26%. Overall, about 95% of the orally administered dose of Zofenopril calcium was hydrolyzed during the first pass. Because the prodrug is sequentially exposed to the gut, liver, and lungs, the contribution of the gut to the overall first-pass hydrolysis (ca. 87%) was estimated to be significantly greater than that of the liver (less than 10%) or lungs (less than 2%). Zofenopril was rapidly eliminated after parenteral administration; mean residence time values were 2 min and the elimination half-life values (intraarterial route only) were 9 min.(ABSTRACT TRUNCATED AT 250 WORDS)

Effects of zofenopril on cardiac sarcoplasmic reticulum calcium handling.[Pubmed:19738489]

J Cardiovasc Pharmacol. 2009 Nov;54(5):456-63.

Isolated rat hearts were perfused for 120 minutes in the presence or in the absence of 10 microM zofenoprilat, the active metabolite of zofenopril. At the end of perfusion, cardiac tissue was used to assay sarcoplasmic reticulum (SR) (45)Ca uptake and SR calcium release, which was determined by automatized quick filtration technique after SR vesicle loading with (45)Ca. The expression of genes involved in the control of calcium homeostasis was evaluated by polymerase chain reaction after reverse transcription. In chronic experiments, SR (45)Ca uptake and gene expression were measured in hearts derived from rats treated with 15 mg*kg(-1)*day(-1) zofenopril for 15 days. Acute or chronic zofenopril administration did not produce any change in contractile performance. In acute experiments, SR (45)Ca uptake was significantly increased after exposure to zofenoprilat. The rate constant of calcium-induced calcium release was slightly although not significantly higher, and the calcium leak measured under conditions promoting SR channel closure was significantly increased. In the chronic model, significant increase in the rate of SR (45)Ca uptake was confirmed. Gene expression was not modified, except for decreased phospholamban expression, which is observed in the acute but not in the chronic model. In conclusion, zofenopril increases SR calcium cycling and stimulates active calcium uptake into the SR.

Temperature, pH and agitation rate as dissolution test discriminators of zofenopril calcium tablets.[Pubmed:8003543]

J Pharm Biomed Anal. 1994 Feb;12(2):173-7.

Comparative in vitro dissolution studies were performed on several tablet batches of Zofenopril calcium, an ACE inhibitor, to determine if they could be differentiated on the basis of their release rates. The samples included six batches produced at Site 1 and one batch produced at Site 2. Using regular dissolution conditions (USP paddle method at a 50-rpm agitation speed in phosphate buffer, pH 7.5, at 37 degrees C), release rates of all the tablet batches were similar. By independently altering one of the dissolution test parameters, either a lower pH or a slower agitation rate, discrimination between the Site 1 and Site 2 tablets was enhanced. Discrimination was only slightly enhanced when a lower dissolution medium temperature was used. Tablets made from different polymorphs of Zofenopril calcium could not be differentiated by their dissolution profiles, even with the more discriminating conditions. The dissolution profiles of certain other Zofenopril calcium tablets (including film-coated vs uncoated tablets, and tablets made with micronized vs unmicronized drug particles) were indistinguishable using a 50-rpm agitation rate, but they could be clearly differentiated using a 40-rpm agitation rate.