Alpha-glucosidase (IC50 = 11 nM)

The proliferation and migration of VSMC generated by TNF-α were reduced by acarbose (1, 2, and 3 μM) when dose and time were coupled. Acarbose (1, 2 and 3 μM) dose coupling decreased β-galactosidase and Ras expression while increasing p-AMPK expression in TNF-α-cleaved A7r5 [5].

Rather than lowering body weight, acarbose (300 mg/60 kg body weight) lowers fasting blood pressure and modifies diabetic readings by supplementation. Acarbose dramatically reduces TNF-α and DM serum IL6[4]. Neointimal p-AMPK staining was dramatically raised while neointimal IL-6, TNF-α, and iNOS staining was significantly and dose-dependently lowered by acarbose (2.5 and 5.0 mg/kg). In HCD-fed rabbits, neointimal Ras and β-galactosidase expression were dramatically and dose-dependently decreased by acarbose (2.5 and 5.0 mg/kg) without causing weight loss [5].

The inhibitory effects of natural and synthetic inhibitors on the intestinal membrane-bound hydrolase, alpha-glucosidase (AGH), were evaluated by using an immobilized cyanogen bromide-activated Sepharose 4B support. Immobilized AGH (iAGH) inhibition study by synthetic inhibitors (acarbose and voglibose) revealed that the magnitude of inhibition differed from that in the free AGH (fAGH) study: IC50 value of acarbose in iAGH-maltase assay system, 340-430 nM; fAGH, 11 nM. iAGH-maltase inhibition by both inhibitors was influenced by blocking reagents with different functional groups (COOH, OH, CH3, and NH2 groups). On the other hand, significant iAGH-sucrase inhibitory activity was observed only when using the negatively charged support induced by 0.1 M beta-alanine. The Km values obtained in the iAGH assay system were similar to those from the fAGH method. With natural inhibitors, the iAGH-sucrase inhibitory activity of D-Xylose, with in vivo glucose suppression, increased twice compared to that in fAGH. Green tea extract gave almost the same inhibition for both AGH assay systems. [3]

Cell viability analysis [5]
Cell viability was determined using the 3-(4,5-dimethylthiazol-2-yl)-2,5- diphenyltetrazolium bromide (MTT) assay44. Cells were seeded in 24-well culture plates at a density of 2 × 104 cells/well, incubated for 48 h, treated with acarbose at varying concentrations (0.5, 1.0, 2.0, 3.0, and 5.0 μM) for 24 h; or pre-treated with TNF-α (20 ng/ml) for either 24 h or 48 h to evaluate the dose-dependent effects of acarbose on VSMC growth and viability, cultured with 0.5 mg/ml MTT at 37 °C in a humidified atmosphere of 5% CO2 for another 4 h, and solubilized with isopropanol. The viable cell number varied directly with the concentration of formazan product measured spectrophotometrically at 563 nm.

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Wound healing [5]
A7r5 cells were seeded at a density of 1 × 106 ml in 6-well culture plates and incubated for 48 h. A sterile 100-μl pipette tip was used to make a straight scratch in the cell monolayer in each well45. The non-adhering cells were washed out with PBS, and the remaining cells were treated with TNF-α (0, 10, 20, 50 and 100 ng/ml) at 37 °C in a humidified atmosphere of 5% CO2. Under a 40X lens, images of the linear wound (9 fields per well) were taken at 24 and 48 h. Migrated cells were counted per well and the counts were averaged.

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Western blot analysis [5]
Western blot analysis46 was used to assess the expressions and/or activities of these migration-related proteins and thereby the mechanisms underlying the anti-migratory effects of acarbose on VSMCs. Specific antibodies were used to evaluate the expressions of iNOS, Ras, p-AMPK, AMPKα1/2, and TNF-α and β-galactosidase. After pre-treatment with TNF-α (20 ng/ml) for 24 h, the cells were treated with acarbose (0, 1, 2, and 3 μM) for 24 h and lysed. Cell lysates (50 μg of protein) were separated by electrophoresis on 8–12% SDS polyacrylamide gels and transferred to nitrocellulose membranes. The membranes were incubated with Tris-buffered saline (TBS) containing 1% (w/v) nonfat-milk and 0.1% (v/v) Tween-20 (TBST) for 1 h to block non-specific binding, washed with TBST for 30 min, incubated with the appropriate primary antibody for 2 h, incubated with horseradish peroxidase-conjugated second antibody for 1 h, developed using ECL chemiluminescence, and analyzed by densitometry using AlphaImager Series 2200 software. Compound C (an AMPK inhibitor, 5 μM) and L-NAME (iNOS inhibitor, 0.5 mM) were used to confirm AMPK and iNOS expression in TNF-α-pretreated acarbose-treated (1, 2 and 3 μM for 24 h) cells. Results are representative of at least 3 independent experiments.

Animal Models, Grouping, and Treatment [4]
Male Sprague-Dawley rats (280–320 g) were used. As previously described, diabetic rats were fed a high-fat diet (40% of calories as fat) for 4 weeks, and then were administered a single dose of streptozotocin (STZ, 50 mg/kg, tail vein) formulated in 0.1 mmol/L citrate buffer, pH 4.5. One week after the STZ injection, the random blood glucose level of the diabetic rats was measured to confirm hyperglycemia. Random blood glucose above 16.7 mmol/L was used to define rats as diabetic. Diabetic rats were fed a high-fat diet throughout the experiment. Diabetic rats with a similar degree of hyperglycemia were randomly divided into three groups: vehicle, low dose acarbose (AcarL), and high dose acarbose (AcarH) groups (n = 10, in each group). The typical human daily dose of acarbose is 300 mg/60 kg body weight. According to the formula: drat = dhuman × 0.71/0.11, the corresponding dose of acarbose for rats is 32.28 mg/kg per day. Therefore, we selected 30 and 60 mg/kg per day as low and high dosages, respectively. The control (n = 10) and the diabetic group received 0.5% saline, whereas the AcarL and AcarH groups were given acarbose at doses of 30 and 60 mg/kg in a 0.5% saline solution, respectively. The drug was administered once daily for 8 weeks using a gastric gavage. All animals were housed in an environmentally controlled room at 25°C with a 12 h light-dark cycles and were given free access to food and water throughout the experimental period. Fasting animals were allowed free access to water. After 6 weeks of treatment, an oral glucose tolerance test (OGTT) was performed. After 8 weeks of treatment, blood samples were taken from rats after anesthesia. The rats were then sacrificed. Some terminal ileums were collected for performing the microarray and quantitative real-time reverse transcription PCR (qRT-PCR) analysis. Other terminal ileums were fixed in 10% neutralized formalin for immunohistochemical staining.

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Animals and diets [5]
Twenty-four male New Zealand white rabbits, weighing 2500 g were used. They were individually housed in metal cages in an air-conditioned room (22 ± 2 °C, 55 ± 5% humidity), under a 12 h light/12 h dark cycle with free access to food and water. All rabbits were randomly assigned to four groups of 6 animals each and were fed either standard chow (Group I), high cholesterol diet (HCD; containing 95.7% standard Purina chow + 3% lard oil + 0.5% cholesterol) (Group II), HCD diet and 2.5 mg kg−1 per day acarbose (Group III), or HCD diet and 5.0 mg kg−1 per day acarbose (Group IV). At the end of the 25 weeks, all rabbits were sacrificed by exsanguination under deep anesthesia with pentobarbital (30 mg kg−1 i.v.) injected via the marginal ear vein. Serum was stored at −80 °C prior to measurement of serum values. The aortic arch and thoracic aortas were carefully removed to protect the endothelial lining, and were collected and freed of adhering soft tissue.

Absorption, Distribution and Excretion
The oral bioavailability of acarbose is extremely minimal, with less than 1-2% of orally administered parent drug reaching the systemic circulation. Despite this, approximately 35% of the total radioactivity from a radiolabeled and orally administered dose of acarbose reaches the systemic circulation, with peak plasma radioactivity occurring 14-24 hours after dosing - this delay is likely reflective of metabolite absorption rather than absorption of the parent drug. As acarbose is intended to work within the gut, its minimal degree of oral bioavailability is therapeutically desirable.
Roughly half of an orally administered dose is excreted in the feces within 96 hours of administration. What little drug material is absorbed into the systemic circulation (approximately 34% of an orally administered dose) is excreted primarily by the kidneys, suggesting renal excretion would be a significant route of elimination if the parent drug was more readily absorbed - this is further supported by data in which approximately 89% of an intravenously administered dose of acarbose was excreted in the urine as active drug (in comparison to <2% following oral administration) within 48 hours.
In a study of 6 healthy men, less than 2% of an oral dose of acarbose was absorbed as active drug, while approximately 35% of total radioactivity from a 14C-labeled oral dose was absorbed. An average of 51% of an oral dose was excreted in the feces as unabsorbed drug-related radioactivity within 96 hours of ingestion. Because acarbose acts locally within the gastrointestinal tract, this low systemic bioavailability of parent compound is therapeutically desired.
Following oral dosing of healthy volunteers with 14C-labeled acarbose, peak plasma concentrations of radioactivity were attained 14-24 hours after dosing, while peak plasma concentrations of active drug were attained at approximately 1 hour. The delayed absorption of acarbose-related radioactivity reflects the absorption of metabolites that may be formed by either intestinal bacteria or intestinal enzymatic hydrolysis.
Acarbose is metabolized exclusively within the gastrointestinal tract, principally by intestinal bacteria, but also by digestive enzymes. A fraction of these metabolites (approximately 34% of the dose) was absorbed and subsequently excreted in the urine.
The fraction of acarbose that is absorbed as intact drug is almost completely excreted by the kidneys. When acarbose was given intravenously, 89% of the dose was recovered in the urine as active drug within 48 hours. In contrast, less than 2% of an oral dose was recovered in the urine as active (i.e., parent compound and active metabolite) drug. This is consistent with the low bioavailability of the parent drug.
For more Absorption, Distribution and Excretion (Complete) data for Acarbose (6 total), please visit the HSDB record page.

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Metabolism / Metabolites
Acarbose is extensively metabolized within the gastrointestinal tract, primarily by intestinal bacteria and to a lesser extent by digestive enzymes, into at least 13 identified metabolites. Approximately 1/3 of these metabolites are absorbed into the circulation where they are subsequently renally excreted. The major metabolites appear to be methyl, sulfate, and glucuronide conjugates of 4-methylpyrogallol. Only one metabolite - resulting from the cleavage of a glucose molecule from acarbose - has been identified as having alpha-glucosidase inhibitory activity.
Acarbose is metabolized exclusively within the gastrointestinal tract, principally by intestinal bacteria, but also by digestive enzymes. ... At least 13 metabolites have been separated chromatographically from urine specimens. The major metabolites have been identified as 4-methylpyrogallol derivatives (i.e., sulfate, methyl, and glucuronide conjugates). One metabolite (formed by cleavage of a glucose molecule from acarbose) also has alpha-glucosidase inhibitory activity. This metabolite, together with the parent compound, recovered from the urine, accounts for less than 2% of the total administered dose.

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Biological Half-Life
In healthy volunteers, the plasma elimination half-life of acarbose is approximately 2 hours.
The plasma elimination half-life of acarbose activity is approximately 2 hours in healthy volunteers.

Hepatotoxicity
In several large clinical trials, serum enzyme elevations above 3 times the upper limit of normal were more common with acarbose therapy (2% to 5%) than with placebo, but all elevations were asymptomatic and resolved rapidly with stopping therapy. These studies reported no instances of clinically apparent liver injury. Subsequent to approval and with wide clinical use, however, at least a dozen instances of clinically apparent liver injury have been linked to acarbose use. The liver injury typically arises 2 to 8 months after starting therapy and is associated with a hepatocellular pattern of serum enzyme elevations with marked increases in serum ALT levels, suggestive of acute viral hepatitis. Immunoallergic features and autoantibody formation are not typical. While most cases are mild, some are associated with marked jaundice and cases with a fatal outcome have been reported to the sponsor. No cases of chronic liver injury or vanishing bile duct syndrome have been linked to acarbose use, and most large series of cases of drug induced liver injury and acute liver failure have not identified cases due to acarbose. Rechallenge has been carried out in several instances and resulted in recurrence with a shortening of the time to onset.
Likelihood score: B (rare but likely cause of clinically apparent liver injury).

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Effects During Pregnancy and Lactation
◉ Summary of Use during Lactation
Because less than 2% of a dose of acarbose is absorbed from the mother's gastrointestinal tract, it is unlikely that any drug reaches the infant through breastmilk.
◉ Effects in Breastfed Infants
Relevant published information was not found as of the revision date.
◉ Effects on Lactation and Breastmilk
Relevant published information was not found as of the revision date.

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Protein Binding
As only 1-2% of an orally administered dose is absorbed into the circulation, acarbose is unlikely to be subject to clinically relevant protein binding.

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Interactions
... A possible interaction between digoxin and acarbose was reported. In these reports, absorption of digoxin was decreased dramatically by coadministration of acarbose. The hypoglycemic action of acarbose stems from the reversible and competitive inhibition of alpha-glucosidase that hydrolyzes oligosaccharides absorbed later as glucose molecules. Acarbose functions exclusively in intestine, and most of it appears unchanged in feces. Digoxin is a well-known medication used in the treatment of heart failure and/or chronic atrial fibrillation. Acarbose delays the digestion of sucrose and starch in humans; as a result, a disturbance of gastrointestinal transit, causing loose stools, follows. Therefore, it is possible that gastrointestinal motility is increased, and absorption of digoxin decreased, by coadministration with acarbose. It is also possible that acarbose interferes with the hydrolysis of digoxin before its absorption, resulting in alteration in the release of the corresponding genine and thus affecting the reliability of the digoxin laboratory test. These case reports indicate that the absorption of digoxin is decreased by the administration of acarbose. ...
In a single-centre, placebo-controlled, clinical study, the influence of an antacid containing magnesium hydroxide and aluminium hydroxide (Maalox 70; 10 mL) on the pharmacodynamics of the oral antidiabetic drug acarbose (Glucobay 100, Bay g 5421, CAS 56180; 100 mg) was tested in 24 healthy male volunteers. The drugs were given alone or in combination and were compared with placebo. Volunteers were randomized into four different treatment groups. The daily medication over 4 days was 1 x 1 placebo tablet, or 1 x 1 tablet containing 100 mg acarbose, or 1 x 1 tablet containing 100 mg acarbose plus 10 mL antacid suspension, or 1 x 1 placebo tablet plus 10 ml antacid suspension, interrupted by wash-out phases of 6-10 days between successive treatments. Efficacy was assessed on the basis of postprandial blood glucose and serum insulin levels after administration of 75 g sucrose, and was measured as maximal concentrations and 'area under the curve' (0-4 hr). No influence of the antacid on the blood glucose and insulin-lowering effect of acarbose could be detected. Hence, there does not appear to be a significant interaction between acarbose and the antacid tested. Antacids similar to that tested do not need to be classified as a contraindication when used in combination with acarbose.
To investigate whether treatment with acarbose alters the pharmacokinetics (PK) of coadministered rosiglitazone. Sixteen healthy volunteers (24-59-years old) received a single 8-mg dose of rosiglitazone on day 1, followed by 7 days of repeat dosing with acarbose [100 mg three times daily (t.i.d.) with meals]. On the last day of acarbose t.i.d. dosing (day 8), a single dose of rosiglitazone was given with the morning dose of acarbose. PK profiles following rosiglitazone dosing on days 1 and 8 were compared, and point estimates (PE) and associated 95% confidence intervals (CI) were calculated. Rosiglitazone absorption [as measured with peak plasma concentration (Cmax) and time to peak concentration (Tmax)] was unaffected by acarbose. The area under the concentration-time curve from time zero to infinity [AUC(0-infinity)] was on average 12% lower (95% CI-21%, -2%) during rosiglitazone + acarbose coadministration and was accompanied by an approximate 1-hr (23%) reduction in terminal elimination half-life (4.9 hr versus 3.8 hr). This small decrease in AUC(0-infinity) appears to be due to an alteration in systemic clearance of rosiglitazone and not changes in absorption. These observed changes in AUC(0-infinity) and half-life are not likely to be clinically relevant. Coadministration of rosiglitazone and acarbose was well tolerated. Acarbose administered at therapeutic doses has a small, but clinically insignificant, effect on rosiglitazone pharmacokinetics.

[1]. A review of the safety and efficacy of acarbose in diabetes mellitus. Pharmacotherapy. 1996;16(5):792-805.

[2]. Acarbose: oral anti-diabetes drug with additional cardiovascular benefits [published correction appears in Expert Rev Cardiovasc Ther. 2009 Mar;7(3):330]. Expert Rev Cardiovasc Ther. 2008;6(2):153-163.

[3]. Evaluation of alpha-glucosidase inhibition by using an immobilized assay system. Biol Pharm Bull. 2000;23(9):1084-1087.

[4]. Acarbose Reduces Blood Glucose by Activating miR-10a-5p and miR-664 in Diabetic Rats. PLoS One. 2013 Nov 18;8(11):e79697.

[5]. Pleiotropic effects of acarbose on atherosclerosis development in rabbits are mediated via upregulating AMPK signals. Sci Rep. 2016 Dec 7;6:3864.

Therapeutic Uses
Enzyme Inhibitors; Hypoglycemic Agents
Acarbose tablets are indicated as an adjunct to diet and exercise to improve glycemic control in adults with type 2 diabetes mellitus./Included in US product label/
THERAPEUTIC CATEGORY: Antidiabetic

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Drug Warnings
Acarbose is contraindicated in patients with known hypersensitivity to the drug and in patients with diabetic ketoacidosis or cirrhosis. Acarbose is also contraindicated in patients with inflammatory bowel disease, colonic ulceration, partial intestinal obstruction or in patients predisposed to intestinal obstruction. In addition, acarbose is contraindicated in patients who have chronic intestinal diseases associated with marked disorders of digestion or absorption and in patients who have conditions that may deteriorate as a result of increased gas formation in the intestine.
Because of its mechanism of action, acarbose when administered alone should not cause hypoglycemia in the fasted or postprandial state. Sulfonylurea agents or insulin may cause hypoglycemia. Because acarbose given in combination with a sulfonylurea or insulin will cause a further lowering of blood glucose, it may increase the potential for hypoglycemia. Hypoglycemia does not occur in patients receiving metformin alone under usual circumstances of use, and no increased incidence of hypoglycemia was observed in patients when acarbose was added to metformin therapy. Oral glucose (dextrose), whose absorption is not inhibited by acarbose, should be used instead of sucrose (cane sugar) in the treatment of mild to moderate hypoglycemia. Sucrose, whose hydrolysis to glucose and fructose is inhibited by acarbose, is unsuitable for the rapid correction of hypoglycemia. Severe hypoglycemia may require the use of either intravenous glucose infusion or glucagon injection.
Gastrointestinal symptoms are the most common reactions to acarbose. ... In a one-year safety study, during which patients kept diaries of gastrointestinal symptoms, abdominal pain and diarrhea tended to return to pretreatment levels over time, and the frequency and intensity of flatulence tended to abate with time. The increased gastrointestinal tract symptoms in patients treated with acarbose are a manifestation of the mechanism of action of acarbose and are related to the presence of undigested carbohydrate in the lower GI tract. If the prescribed diet is not observed, the intestinal side effects may be intensified. If strongly distressing symptoms develop in spite of adherence to the diabetic diet prescribed, the doctor must be consulted and the dose temporarily or permanently reduced.
In long-term studies (up to 12 months, and including acarbose doses up to 300 mg t.i.d.) conducted in the United States, treatment-emergent elevations of serum transaminases (AST and/or ALT) above the upper limit of normal (ULN), greater than 1.8 times the ULN, and greater than 3 times the ULN occurred in 14%, 6%, and 3%, respectively, of acarbose-treated patients as compared to 7%, 2%, and 1%, respectively, of placebo-treated patients. Although these differences between treatments were statistically significant, these elevations were asymptomatic, reversible, more common in females, and, in general, were not associated with other evidence of liver dysfunction. In addition, these serum transaminase elevations appeared to be dose related. In US studies including acarbose doses up to the maximum approved dose of 100 mg t.i.d., treatment-emergent elevations of AST and/or ALT at any level of severity were similar between acarbose-treated patients and placebo-treated patients (p >/= 0.496).
For more Drug Warnings (Complete) data for Acarbose (16 total), please visit the HSDB record page.

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Pharmacodynamics
Acarbose is a complex oligosaccharide that competitively inhibits the ability of brush-border alpha-glucosidase enzymes to break down ingested carbohydrates into absorbable monosaccharides, reducing carbohydrate absorption and subsequent postprandial insulin levels. Acarbose requires the co-administration of carbohydrates in order to exert its therapeutic effect, and as such should be taken with the first bite of a meal three times daily. Given its mechanism of action, acarbose in isolation poses little risk of contributing to hypoglycemia - this risk is more pronounced, however, when acarbose is used in conjunction with other antidiabetic therapies (e.g. sulfonylureas, insulin). Patients maintained on acarbose in addition to other antidiabetic agents should be aware of the symptoms and risks of hypoglycemia and how to treat hypoglycemic episodes. There have been rare post-marketing reports of the development of pneumatosis cystoides intestinalis following treatment with alpha-glucosidase inhibitors - patients experiencing significant diarrhea/constipation, mucus discharge, and/or rectal bleeding should be investigated and, if pneumatosis cystoides intestinalis is suspected, should discontinue therapy.

C25H43NO18

645.6048

645.247

C, 46.51; H, 6.71; N, 2.17; O, 44.61

56180-94-0

Acarbose sulfate;1221158-13-9

444254

White to light yellow solid powder

1.7±0.1 g/cm3

971.6±65.0 °C at 760 mmHg

165-170ºC

541.4±34.3 °C

0.0±0.6 mmHg at 25°C

1.689

-4.16

14

19

9

44

962

19

C[C@@H]1[C@H]([C@@H]([C@H]([C@H](O1)O[C@@H]2[C@H](O[C@@H]([C@@H]([C@H]2O)O)O[C@@H]3[C@H](O[C@H]([C@@H]([C@H]3O)O)O)CO)CO)O)O)N[C@H]4C=C([C@H]([C@@H]([C@H]4O)O)O)CO

CEMXHAPUFJOOSV-XGWNLRGSSA-N

InChI=1S/C25H43NO18/c1-7-13(26-9-2-8(3-27)14(33)18(37)15(9)34)17(36)20(39)24(41-7)44-23-12(6-30)42-25(21(40)19(23)38)43-22(11(32)5-29)16(35)10(31)4-28/h2,4,7,9-27,29-40H,3,5-6H2,1H3/t7-,9+,10+,11-,12-,13-,14-,15+,16-,17+,18+,19-,20-,21-,22-,23-,24-,25-/m1/s1

(2R,3R,4R,5R)-4-(((2R,3R,4R,5S,6R)-5-(((2R,3R,4S,5S,6R)-3,4-dihydroxy-6-methyl-5-(((1S,4R,5S,6S)-4,5,6-trihydroxy-3-(hydroxymethyl)cyclohex-2-en-1-yl)amino)tetrahydro-2H-pyran-2-yl)oxy)-3,4-dihydroxy-6-(hydroxymethyl)tetrahydro-2H-pyran-2-yl)oxy)-2,3,5,6-tetrahydroxyhexanal

BAY-g-5421; BAY-g 5421; acarbose; Precose; CAS-56180-94-0; BAY g-5421; Acarbose; Glucobay; Prandase; Precose

2934.99.9001

Powder      -20°C    3 years

                     4°C     2 years

In solvent   -80°C    6 months

                  -20°C    1 month

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

H2O : ~100 mg/mL (~154.89 mM)

Solubility in Formulation 1: 100 mg/mL (154.89 mM) in PBS (add these co-solvents sequentially from left to right, and one by one), clear solution; with sonication (<60°C).

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