Isoxsuprine Hydrochloride Research Articles

Spectrophotometric Determination of Ritodrine and Isoxsuprine Hydrochlorides Using 4-Aminoantipyrine

A simple, accurate, and rapid method for the quantitative determination of ritodrine hydrochloride (RTH) and isoxsuprine hydrochloride (ISH) in both pure and dosage forms, is described. The method is based on the development of pink colored product as a result of the condensation of 4-aminoantipyrine with phenols in the presence of an alkaline oxidizing agent. The resulting products are measured at 510 nm for both drugs, with molar absorptivities of 0.98 x 10(4) and 1.20 x 10(4) L/mol x cm for RTH and ISH, respectively. A study of the effect of commonly associated excipients revealed that they did not cause interference.

Determination of Phenolic Sympathomimetic Drugs in Pharmaceutical Samples and Biological Fluids by Flow-Injection Chemiluminescence

A rapid and highly sensitive flow-injection chemiluminometric method was developed for determination of 3 sympathomimetic drugs, namely, etilefrine hydrochloride, isoxsuprine hydrochloride, and prenalterol hydrochloride. The method is based on chemiluminescence induced by oxidation of drugs with acidified potassium permanganate in the presence of formic acid as a carrier. The calibration graphs were linear over the concentration ranges 0.2-9, 0.2-12.5, and 0.025-1.25 microg/mL for the 3 compounds, respectively. The method was applied successfully in determining the drugs in dosage forms and in biological fluids. A proposal for the reaction pathway is suggested.

Isoxsuprine in the Treatment of Sickle Cell Painful Crises: A Double-Blind Comparative Study with Narcotic Analgesic

Isoxsuprine is a tocolytic agent which improves erythrocyte deformability. It was accidentally found to be effective in the management of sickle cell disease (SCD) painful crises. The experience with the drug in the treatment of sickle cell disease is limited. This double-blind randomized comparative study was undertaken to test its efficacy and safety in the treatment of SCD painful crises. Forty-three SCD patients (33 males and 10 females) with 44 episodes of pain were included in the study (i.e., one patient was included twice). Only those with painful crises requiring hospital admission were included. Patients were randomized to receive either isoxsuprine 5-10 mg, or meperidine 50100 mg intramuscularly, according to body weight, every four hours. A random selection of 23 patients received isoxsuprine, and 21 received meperidine. Pain score, duration of crisis, hospital stay, and side effects were monitored. No significant difference was found in any parameter except for pain score at 30 and 60 minutes. We conclude that isoxsuprine appears to be effective in the treatment of sickle cell painful crises. Confirmation of its efficacy in studies involving a larger number of patients is warranted.

Effects of acepromazine maleate, isoxsuprine hydrochloride and prazosin hydrochloride on laminar microcirculatory blood flow in healthy horses

Laser Doppler flowmetry was used to determine the effects of acepromazine maleate, isoxsuprine hydrochloride, and prazosin hydrochloride on laminar microcirculatory blood flow. Five adult horses, weighing 450–500 kg and free of evidence of laminitis or other inflammatory conditions of the lower limb were used. Holes were drilled on the dorsum of each front hoof to the depth of the junction of the sensitive and insensitive laminae. Temperature, pulse rate and respiratory rate were obtained before begining the measurements. Pulse rate was measured at 15-minute intervals throughout the measurement period. A laser Doppler probe was placed in each hole. Baseline Doppler flow measurements were obtained. Following baseline determinations either acepromazine maleate (0.066 mg/kg), isoxsuprine hydrochloride (0.6 mg/kg) or prazosin hydrochloride (0.025 mg/kg) were administered intravenously. Drugs were randomly assigned and repeated 3 times in each horse. Laminar microcirculatory blood flow was then measured continuously for 180 minutes. These data were analyzed using univariate (mixed model) repeated measures analysis. None of the drugs evaluated had any significant effect on laminar microcirculatory blood flow. Acepromazine maleate, isoxsuprine hydrochloride and prazosin hydrochloride have no laminar microcirculatory blood flow effect in standing, healthy horses at dosages used. Efficacy in the use of these 3 drugs for the treatment of laminitis is questionable. However, this study was performed in healthy horses and the results may not be applicable in horses with laminitis.

Spectrophotometric Determination of Etilefrine, Ritodrine, Isoxsuprine and Salbutamol by Nitration and Subsequent Meisenheimer Complex Formation

Abstract A simple and sensitive colorimetric method has been developed for the determination of four phenolic drugs, namely, etilefrine hydrochloride, ritodrine hydrochloride, isoxsuprine hydrochloride and salbutamol sulphate. The method is, mainly, based on the nitration of the drug molecule followed by the subsequent formation of meisenheimer complex with a nucleophilic reagent (acetone) in alkaline medium. The experimental conditions leading to optimum chromogen intensity and stability were carefully studied and incorporated in the general procedure. Under the proposed conditions, the method was applicable over the concentration range of 4.8–16 μg ml−1 for the four drugs. The suggested method was further applied for the determination of the studied drugs in bulk and pharmaceutical dosage forms. The results of the analysis were found to agree statistically with those obtained with either the official or the referee methods. The procedure is characterized by its simplicity with accuracy and precision.

Diagnostic value of radionuclide phallography with intravenous vasodilator stress in the evaluation of arteriogenic impotence

Arteriogenic impotence is a major cause of organic erectile dysfunction. We evaluated the diagnostic value of quantitative radionuclide phallography with intravenous pharmacological stress in screening impotent patients for penile arterial inadequacy. Using technetium-99m labelled autologous erythrocytes, dynamic scintigraphy of the penile blood pool was performed. Penile haemodynamic changes following intravenous injection of the vasodilator isoxsuprine hydrochloride were assessed by quantitation of penile blood flow and volume. Forty-seven impotent patients (11 psychogenic, 24 arteriogenic, 10 venogenic, 2 endocrine) were studied. Arteriogenic impotent patients demonstrated a lesser degree of increase in penile blood flow and volume than impotent patients with uncompromised penile arterial inflow. Quantitation of penile blood flow and volume yielded a high diagnostic accuracy (> 90%). Radionuclide phallography with intravenous vasodilator stress forms a simple and accurate method for evaluating the functional integrity of penile arterial inflow.

The evaluation of isoxsuprine hydrochloride for the treatment of navicular disease: a double blind study

The evaluation of isoxsuprine hydrochloride for the treatment of navicular disease: a double blind study

A Comparative Analysis of the Ability of Five Classes of Pharmacological Agents to Augment Skin Flap Survival in Various Models and Species: An Attempt to Standardize Skin Flap Research

There is a myriad of research in the pharmacological manipulation of skin flap survival. However, skepticism exists as to whether any of these drugs is clinically useful. We evaluated the efficacy of five categories of agents in improving skin flap survival in five different rat flap models. Diltiazem, isoxsuprine hydrochloride, nitroglycerin, prazosin hydrochloride (two doses), and methyldopa were compared in a double-blind, randomized fashion. Their benefits were assessed in a musculocutaneous flap, axial flap, and three types of random flaps. The "best" drug was determined to be nitroglycerin. Its efficacy was verified in a primate model.

Reactivity of equine palmar digital arteries and veins to vasodilating agents.

Palmar digital arteries and veins removed surgically from healthy horses under general anesthesia were cut into 4 mm vascular rings, suspended in tissue baths, and attached to force displacement transducers for continuous measurement of vascular tension. In vitro vascular responses were determined for acetylcholine, acepromazine, isoxsuprine hydrochloride (isoxsuprine), prostaglandin E2 (PGE2), and prostaglandin I2 (prostacyclin). After preconstriction with norepinephrine hydrochloride (norepinephrine), or prostaglandin F2 alpha (PGF2 alpha), the concentrations needed to produce 50% maximum relaxation (EC50) and the maximum percentage of relaxation were determined for each drug. Acetylcholine was the most potent arterial vasodilator (smallest EC50 value) and PGE2 was the least potent. Prostacyclin was the least potent venodilator (highest EC50 value); there were no differences between acetylcholine, acepromazine, isoxsuprine, and PGE2. Isoxsuprine produced greater arterial relaxation than all other agents. Isoxsuprine and acepromazine produced significantly greater venous relaxation than did acetylcholine and PGE2. Prostacyclin produced minimal vasodilation of arteries or veins. Acepromazine and isoxsuprine relaxed the veins significantly more than the arteries. When PGF2 alpha was used instead of norepinephrine to preconstrict the arteries and veins, the potency and effectiveness of acepromazine and isoxsuprine to produce vasodilation were significantly decreased. Results indicate that acepromazine and isoxsuprine can relax the equine digital vasculature but their effectiveness varies depending on the origin of the constriction.

Diagnosis and Treatment of the Navicular Syndrome in Horses

Navicular syndrome can be treated in a variety of ways. This is related to the fact that it has a variety of causes. Prognostically, most horses will improve with treatment. One can expect about 50 per cent of the horses to become useably sound for 1 year, no matter what treatment is used. The disease is progressive, and affected horses eventually will need to be retired because of lameness. The author's therapeutic approach is to utilize shoeing as the primary therapy. Shoeing is performed to correct structural problems and to ensure that shoeing is physiologically sound. Nonsteroidal anti-inflammatory drugs are not used unless radical changes have been made in the shoeing. In cases of confirmed distal interphalangeal joint synovitis, either sodium hyaluronate or polysulfated glycosaminoglycans will be used in conjunction with shoeing. In cases where decreased circulation is documented, isoxsuprine hydrochloride will be administered if shoeing alone has not improved the horse within 6 weeks. If therapy does not improve the horse within 6 to 12 weeks, palmar digital neurectomy is recommended.

A simple spectrophotometric method for determination of isoxsuprine hydrochloride in pharmaceuticals

A spectrophotometric method has been developed for the determination of isoxsuprine hydrochloride and its dosage forms, based on its coupling reaction with diazotized sulphanilic acid. The yellow chromophore has an absorption maximum at 440 nm. Beer's law holds over the range 0.8–8 μ/ml in the final solution.

Circulatory and blood gas changes accompanying the development and treatment of induced laminitis

Summary A peripheral vasodilatory agent, isoxsuprine hydro-chloride, was evaluated in a controlled study for its efficacy in the treatment of acute equine laminitis. Eight healthy, adulthorses of variable age and sex were used in the trial. Acute laminitis was induced in 5 of the horses by oral carbohydrate overload. Intravenous isoxsuprine therapy (1.8 mg/kg) was initiated in 3 of the horses receiving carbohydrate overload at first sign of clinical lameness and repeated at 12-hour intervals. Intravenous saline placebos were administered on a similar schedule to 2 control horses which also received a carbohydrate overload. The remaining 3 horses served as further controls. Local and systemic responses to induction of laminitis and isoxsuprine administration were assessed by subjective evaluation of clinical lameness in a double blind trial; nuclear scintigraphy and radiography of the distal forelimbs; and assessment of physical, hematological and biochemical parameters. Pronounced tachycardia, hypotension and sweating accompanied the intravenous infusion of isoxsuprine. The 3 horses treated with isoxsuprine following the induction of laminitis showed a more rapid improvement in soundness than horses receiving saline placebos. No horse developed rotation of the third phalanx in response to the diet Nuclear scintigraphy indicated that blood perfusion patterns within the hoof of laminitic horses altered with isoxsuprine therapy, but an overall increase or decrease in perfusion was not apparent. Alterations in serum enzyme and electrolyte profiles with the onset of laminitis generally concurred with findings previously reported for this model of the disease. No change in coagulation profiles accompanied the onset of laminitis or isoxsuprine administration. Blood gas analysis indicated an increase in median palmar vein oxygen partial pressure (PO 2 ) levels with onset of laminitis. A concurrent decrease in the median palmar arteriovenous oxygen partial pressure difference (AVO 2 ) was significant at the P 2 values between thoseanimals receiving isoxsuprine and those receiving saline placebo therapy. Results of the trialindicated that isoxsuprine may be beneficial in the treatment of acute laminitis. Further controlled studies are appropriate.

A simple spectrophotometric method for the determination of nylidrin hydrochloride, isoxsuprine hydrochloride and salbutamol sulphate in pharmaceutical preparations

A simple spectrophotometric method for the determination of nylidrin hydrochloride, isoxsuprine hydrochloride and salbutamol sulphate is described, based on measurement of the orangeyellow species produced when the drugs are coupled with diazotized benzocaine ( p-aminoethyl benzoate) in trimethylamine medium. The method is applicable over the range 1–12 μg ml for isoxsuprine hydrochloride and nylidrin hydrochloride and 1–8 μg ml for salbutamol sulphate. The method is a modification of the Bratton-Marshall reaction and is simple, reproducible, accurate and more sensitive than those cited in the literature.

Myotonic muscular dystrophy associated with ritodrine tocolysis

A patient thought to be normal was admitted with premature labor at 29+ weeks' gestation. Treatment with the β-mimetic ritodrine hydrochloride appeared to provoke symptoms of myotonic muscular dystrophy. Neurological history and examination confirmed the presence of previously unsuspected myotonic dystrophy in the patient, her father, and paternal grandfather. Discontinuation of the drug led to improvement in myotonia symptoms but worsening premature labor. Magnesium sulfate did not provoke the same symptoms but was unsuccessful in controlling premature contractions. Long-term management with bed rest, phenytoin, and isoxsuprine hydrochloride resulted in term delivery. Subsequently, maternal symptoms of myotonia disappeared. Congenital myotonia was suspected in the fetus because of the ultrasonic demonstration of polyhydramnios and reduced fetal movements. This was confirmed at delivery. The mechanism by which ritodrine unmasked the myotonia is unclear but may be related to changes in the cell membrane (chloride conductance, the sodium-potassium pump, or membrane polarization).

Fetal movements in isoxsuprine-treated patients

Fetal activity expresses fetal condition in utero. Daily monitoring of fetal movements provides a good criterion for estimating fetal well-being. I The number of fetal movements per day is inAuenced by gestational age a nd other factors . I It has been suggested that drugs, such as barbiturates and diaze pam, reduce fetal movements. ~ Isoxsuprine hydrochloride (Duvadilan) is a ,a-adrenergic drug generally used in prevention of premature labor by inhibition of uterine contraction. It is known that uterine contractions are associated with fetal movements.

熱電効果による麻酔下ラットの皮膚血流測定条件の検討

The experimental conditions to measure accurately the changes of dermal blood flow (DBF) in rats were studied according to the thermoelectrical element method, which was uninterfered with muscle blood flow and arteriovenous shunt in the precapillary regions. Main factors affecting the stability and the sensitivity to drugs of DBF were the body weight and the treatment to immerse into the water bath. The most suitable conditions were as follows. 1. The body weight was 245-257g. 2. The anesthetized rats were immersed into the water bath at 15°C to the depth of xiphoid process for 10 min. Under these conditions, the changes of DBF by the application of the reference drugs (norepinephrine, dl-α-tocopheryl nicotinate, inositol hexanicotinate, isoxsuprine hydrochloride) were measured accurately.

Pulmonary edema associated with the use of betamimetic agents in preterm labor

A case report of pulmonary edema associated with the use of a betamimetic agent in preterm labor is reported. A 31-year-old, black multigravida woman, 28 weeks pregnant, was admitted to the hospital with dysuria, vaginal bleeding, and uterine contractions. She had experienced premature labor in her previous pregnancies, and she had a history of kidney stones, confirmed by pyelography, and repeated urinary tract infections. Eighteen hours after admission, the contractions were occurring every five minutes. Terbutaline sulfate constant infusion (10-20 micrograms/min) was started. By hospital day 2, the uterine contractions were occurring every 1-2 minutes and lasting 50 seconds. The terbutaline therapy was discontinued, and isoxsuprine hydrochloride infusion was started at 240 micrograms/min and gradually increased to 800 micrograms/min. The patient complained of smothering and became tachypneic after one hour and 40 minutes of therapy. The shortness of breath and tachypnea continued in spite of the administration of oxygen and positional changes. The isoxsuprine was discontinued. The diagnosis of pulmonary edema was confirmed by abnormal findings in the chest roentgenogram, bilateral rales, and a decrease in arterial blood oxygen pressure. A literature review of pulmonary edema associated with the administration of beta sympathomimetic drugs is presented, which suggests this adverse effect is multifactorial in origin. Precipitating factors may include corticosteroids, fluid overload, low levels of serum potassium, twin gestations, a sustained tachycardia greater than 140 beats per minute, undiagnosed cardiopulmonary disease, or catecholamine-induced cardiac injury. Patients requiring betamimetics for the delay of premature labor should be monitored closely to obviate this complication.

Effects of some drugs on ripening of uterine cervix in nonpregnant castrated and pregnant rats.

The stimulating effect of some drugs on the ripening of the uterine cervix in rats was studied by measuring the wet weight of the uterine cervix and by both light and electron microscopy in nonpregnant castrated and pregnant conditions. Since the light and electron microscopic findings after estrogen (E) administration to castrated rats were similar to those found in the uterine cervix of rats at the end of pregnancy, it was concluded that E (E2 greater than or equal to E3 greater than or equal to E1) plays a major role in the ripening mechanism. It was also found that DHA-S, progesterone and relaxin had stimulating effects on cervical ripening. Oxytocin and PG (PGE2 greater than PGF2 alpha) showed the ripening activity only in pregnant condition. Moreover, oxytocin, PGE2 and PGF2 alpha potentiated the estrogen action. The effects on the increase in wet weight of the uterine cervix and microscopic findings due to DHA-S were different from E in castrated rats. It is therefore postulated that the effect of DHA-S might be mainly due to the secondary increase in E converted from DHA-S in the ovary and, in addition, to a direct effect of this medicament on the uterine cervix. There was essentially no difference in ultrastructure between the cervix of control (nonpregnant, castrated or pregnant) rats and that of rats treated with HCG, isoxsuprine hydrochloride, dihydroergotoxine, diazepam or n-butylscopolammonium bromide.

High-Performance Liquid Chromatography of two Peripheral Vasodilators, Nylidrin Hydrochloride and Isoxsuprine Hydrochloride, in Pharmaceutical Dosage Forms

A reliable and selective high-pressure liquid chromatographic (HPLC) procedure for the quantitative determination of nylidrin hydrochloride or isoxsuprine hydrochloride in pharmaceutical dosage forms is described. The specificity of the stability-indicating HPLC procedure is presented for nylidrin hydrochloride.

Solubility characteristics of weak bases and their hydrochloride salts in hydrochloric acid solutions.

The pH-solubility profiles of four basic drugs were studied at 37°. The solubility of papaverine hydrochloride in acetate buffer showed a typical pH-profile, which increased with decrease in pH. On the other hand, the pH-solubility profile of the hydrochloride in HCl-sodium acetate buffer was not as simple as that in acetate buffer, showing as solubility maximum at approximately 3.7. Similar pH-profiles of solubility were observed for trihexyphenidyl hydrochloride, isoxsuprine hydrochloride, and oxyphencyclimine hydrochloride. The decrease in the solubility of these drugs at more acidic pH values could be rationalized on the basis of the common ion effect. The dissolution behavior of the free bases and that of the hydrochloride salts of papaverine, trihexyphenidyl, and isoxsuprine were compared in dilute hydrochloric acid solutions, in the pH range from 1.0 to 1.8. It was confirmed that a much higher solution concentration and dissolution rate could be obtained using the free bases than from the hydrochloride salts in the pH range of the stomach (pH 1.0-1.2 for papaverine, and pH 1.2-1.4 for trihexyphenidyl and isoxsuprine) due to the common ion effect. It is suggested that salt formation does not always result in an enhancement of solubility characteristics.