Clodronate Research Articles

The effects of clodronate on increased bone turnover and bone loss due to ovariectomy in rats.

The present study was carried out to investigate the ability of clodronate to inhibit ovariectomy-induced bone loss and increased bone turnover in rats. Estradiol was administered as a reference compound. Seventy Sprague-Dawley rats were ovariectomized (OVX) or sham-operated (Sham) at the age of 90 days and divided into seven groups. Two Sham and two OVX groups received subcutaneously either the vehicle of clodronate or the vehicle of estradiol. Other OVX groups were given s.c. either disodium clodronate at two dose levels (5 mg/kg or 12.5 mg/kg twice a week) or 17 beta-estradiol (10 micrograms/kg five times a week) for 8 weeks. Femur length, volume, dry weight, and ash weight were determined, and proximal ends of tibiae were used for bone histomorphometry. Markers of bone metabolism were measured from urine and serum. A significant loss of 54% of trabecular bone area of proximal tibial metaphysis was found at 8 weeks after ovariectomy. Clodronate and estradiol inhibited (p < 0.001) this osteopenia. Both drugs prevented the decrease in ash weight/volume of the femur. The inhibitory effect of clodronate and estradiol on bone resorption in OVX rats could be detected also in decreased urinary excretion of hydroxyproline and lysylpyridinoline (p < 0.001). Clodronate and estradiol decreased (p < 0.001) the ovariectomy-induced enhanced tibial endocortical mineral apposition rate (Ec.MAR) on the lateral cortex to the level of the Sham group. In contrast, periosteal MAR analyzed on the medial side of tibial cortical bone did not change significantly in the OVX/Veh group. Estradiol decreased periosteal MAR to below the level in the Sham group (p < 0.01). These results suggest that ovariectomy of growing rats resulted in tibial and femoral osteopenia two months later. Clodronate as well as estradiol can suppress bone resorption and turnover in ovariectomized rats, inhibiting the development of osteopenia. Both clodronate doses (5 and 12.5 mg/kg) had beneficial effects in ovariectomized animals.

Pharmacokinetics of clodronate in renal failure.

The pharmacokinetic parameters describing the fate of one intravenous clodronate (disodium dichloromethane diphosphonate) dose was studied in 24 normal subjects and in 24 patients with different degrees of renal insufficiency. The aim of the study was to derive data for adjustment of dosage in relation to renal function. Disodium clodronate in serum and urine samples was analyzed by capillary gas chromatography with mass-selective detection. The renal clearance (CLR) of clodronate was highly dependent on renal function and declined successively with declining glomerular filtration rate (GFR). Plasma clearance (CLP) declined, too, but to a lesser degree than CLR. The impairment of renal function resulted in decreased cumulative urinary elimination of clodronate and increased total areas under the serum concentration-time curve (AUC0-infinity). Hence, as the renal elimination of clodronate diminishes with decreasing GFR, there is a related retention of the substance. As a result of the present study, the following dosages are recommended: creatinine clearance (CLCr) from 50 to 80 ml/minute, 75-100% of normal dose; CLCr 12-50 ml/minute, 50-75% of normal dose; and ClCr < 12 ml/minute, 50% of normal dose. The results must be interpreted with caution in patients with malignancy and severe skeletal disease, in whom the nonrenal clearance may vary markedly.

Determination of bisphosphonate drugs in pharmaceutical dosage formulations by ion chromatography with indirect UV detection.

Application of ion chromatography (IC) to the analysis of non-chromophoric bisphosphonate drugs in pharmaceutical dosage formulations is described. The method is based on the use of single-column ion chromatography in conjunction with indirect UV detection that obviates the need for tedious chemical derivatization procedures. Diluted drug samples are chromatographed directly on a Waters IC-Pak HR anion-exchange column with dilute nitric acid (1.6-12 mM) as the mobile phase which exhibits a UV absorption maximum near 220 nm. Analyte detection is monitored by measuring the decrease in absorption of the mobile phase. The IC method has been validated and shown to be precise, accurate, specific and rugged for routine assay. Application of the method to the determination of alendronate sodium tablets, etidronate disodium injectable (which requires an eluent pH control for chromatographic resolution of active drug from chloride ions) and clodronate disodium injectable is presented. The performances of the Waters IC-Pak HR and several equivalent columns are also discussed.

Effect of clodronate on established adjuvant arthritis.

The rat adjuvant arthritis model was used to study the effect of disodium clodronate on inflammation and destruction of tarsal bones and joints. Male Lewis rats were given an intradermal injection of mycobacteria. Fourteen days after immunization, rats with similar scores were assigned to the different experimental groups. They were treated subcutaneously either with saline (controls) or with clodronate at doses of 12.5 and 25 mg/kg/day five times a week for 2 weeks. Clinical signs of arthritis including the severity of paw swelling were assessed weekly. At the time of sacrifice, histological features of the non-decalcified tarsus with ankle, intertarsal and tarsometatarsal joints were assessed for inflammatory soft-tissue, articular and bone changes. The total histological score of the hindpaw indicated that 58% of the control rats developed moderate arthritis and 42%, severe arthritis. The treatment with clodronate (25 mg/kg) decreased clinical signs of arthritis and the activity of the collagen-degrading lysosomal enzyme, beta-N-acetylglucosaminidase, in inflamed hindpaw tissue. Histological evaluation indicated moderate arthritis in 83%, but no severe arthritis. The lower dose of clodronate also decreased the severity of the disease; the decrease was, however, statistically insignificant. The results show that clodronate given therapeutically to adjuvant arthritic rats suppresses the intensity of the inflammation and prevents secondary articular and bone lesions in the tibiotarsal region.

Effect of iron on the absorption and distribution of clodronate after oral administration in rats.

The effect of iron on the absorption and distribution of disodium clodronate in rats after oral administration was studied. Disodium clodronate (300 mg/25 microCi/kg) was given both alone and with an equivalent amount of ferrous sulphate. The radioactivity in plasma and various tissue was measured. Concentration of clodronate in plasma was also determined with the GC-mass-selective detection method and the values compared with those measured with the isotope method. After administration, clodronate was rapidly cleared from plasma. Most of the dose was taken up by bone and only small amounts were found in non-calcified tissues. Concurrent ingestion of iron caused a marked decrease in the absorption of clodronate.

Determination of disodium clodronate in bulk material and pharmaceuticals by ion chromatography with post-column derivatization

A validated ion chromatographic method for the determination of disodium clodronate in bulk material and pharmaceuticals is described. Separations are performed on a poly(styrene-divinylbenzene) copolymer column using 40 mM nitric acid as mobile phase at a flow rate of 0.5 ml min −1. The analyte is detected by UV absorption at 300 nm after post-column derivatization with acidic iron(III) solution (0.25 ml min −1). The proposed ion chromatographic method is validated in terms of selectivity, precision, linearity, accuracy and ruggedness.

Pharmacokinetics of Clodronate after Single Intravenous, Intramuscular and Subcutaneous Injections in Rats

The pharmacokinetics of clodronate was studied in rats after single intravenous, intramuscular and subcutaneous doses of a mixture of unlabelled and 14C-labelled disodium clodronate (25 mg/5 muCi/kg). The peak clodronate concentration in plasma was reached within 5 min., and the drug was eliminated with a half-life of about 1.5 hr regardless of administration route. Bioavailabilities after intramuscular and subcutaneous administration were 105% and 89%, respectively. During the 72 hr collection period, the mean share of clodronate recovered from the urine was about 53% of the dose regardless of administration route. Most of the drug was excreted during the first 24 hr. The amount of clodronate in bone (femur) was 186 micrograms/g tissue at 2 hr after intravenous administration, 188 micrograms/g after intramuscular administration and 157 micrograms/g after subcutaneous administration. It is concluded that absorption of clodronate after intramuscular and subcutaneous administration is rapid and good, and that the concentrations of the drug in bone after 2 hr are about the same as after intravenous administration.

Level of Clodronate in Bone after Single and Repeated Subcutaneous Injections in Rats

The levels of clodronate in bone and plasma were determined in rats after subcutaneous injection of a mixture of unlabelled and 14C-labelled disodium clodronate as a single dose (25 mg/5 muCi/kg or of 125 mg/25 muCi/kg), and as repeated doses (25 mg/5 muCi/kg) once or five times a week for five weeks. The level of clodronate in bone increased dose-dependently. However, during repeated administration some saturation in bone was observed. The accumulation of clodronate in femur was higher than in ankle. No clear differences in concentration of clodronate in bone could be seen after different dosage schedules when the total doses were the same.

Solid state decomposition studies on some isopropyl clodronate sodium salts

Thermal decomposition of four isopropyl clodronate sodium salts were interpreted from the TG and DTG curves with help of mass spectrometry. The compounds studied were {[hydroxy(1-methylethoxy)phosphino] dichloromethyl} phosphonic acid trisodium salt or monoisopropyl clodronate trisodium salt (compound 1), {[bis(1-methylethoxy)phosphino]dichloro-methyl}phosphonic acid disodium salt or P,P-diisopropyI clodronate disodium salt (compound 2), (dichloromethylene)bisphosphonic acid P,P'-bis(1-methylethyl) ester disodium salt or P,P'-diisopropyl clodronate disodium salt (compound 3), {[bis(1-methylethoxy)phosphino]dichloro-methyl}phosphonic acid mono(1-methylethyl) ester monosodium salt or triisopropyl clodronate monosodium salt (compound 4)

Disodium clodronate concentrations in serum, urine and bone after single and repeated subcutaneous administration in rabbits

Disodium clodronate concentrations in serum, urine and bone after single and repeated subcutaneous administration in rabbits

Drug treatment of primary hyperparathyroidism: use of clodronate disodium.

Clodronate disodium (dichloromethylene diphosphonate), a specific inhibitor of bone resorption, was given by mouth (1.0-3.2 g daily) to nine patients with primary hyperparathyroidism for two to 32 weeks so that its clinical and metabolic effects could be evaluated. Bone resorption decreased in all patients as judged by a fall in the fasting urinary calcium to creatinine and hydroxyproline to creatinine ratios. Serum calcium concentration was increased in all patients before treatment and fell in response to treatment to values near the upper end of the normal range. Hypercalcaemia and hypercalciuria recurred when treatment was stopped. In three patients treated for longer than 19 weeks clodronate failed to sustain the reduction in serum calcium concentration but the concentration remained below pretreatment values. These results suggest that clodronate may be of use in the medical management of primary hyperparathyroidism, particularly in patients in whom suppression of bone disease is desirable before surgery or in whom surgery is contraindicated.

Clodronate kinetics and bioavailability.

Carbon 13-labeled clodronate disodium was given to healthy adult men by intravenous infusion and orally in a crossover design. Serum and urine levels were determined as a function of time by isotope-ratio mass spectrometry. Clodronate disodium (Cl2/MDP) is primarily excreted unchanged by the kidney; more than 80% of the intravenous dose was recovered within 48 hr. The serum concentrations-time curve over the first 8 hr after intravenous dosing appears biexponential with the disposition phase having a harmonic mean half-life (t 1/2) of 2 hr. The mean serum clearance was found to be 1.4 ml min-1 kg-1 and the apparent volume of distribution was approximately 25% of body weight. Simulations and computer fitting of the cumulative urinary excretion and urinary excretion rates based on the biexponential serum decay curve demonstrated the presence of a slow disposition component with a t 1/2 of 12.8 hr. Thus, the disposition kinetics of Cl2MDP appear to be triexponentials, although the slowest component is not of major significance after a single dose and could not be verified because of a lack of serum data after 8 hr. Cl2MDP is poorly absorbed with an absolute bioavailability of only 1% to 2%.

Biochemical and clinical responses to dichloromethylene diphosphonate (Cl2MDP) in Paget's disease of bone.

Dichloromethylene diphosphonate (Cl2MDP, or clodronate disodium) is one of the most potent of the known diphosphonates as an inhibitor of bone resorption and differs from EHDP in that it does not inhibit skeletal mineralization. It is one of the second generation diphosphonates now undergoing clinical evaluation. In the study described here Cl2MDP was given by mouth (800-1600 mg/day for 6 months) to 35 patients with symptomatic Paget's disease of bone. Cl2MDP induced a marked fall in serum alkaline phosphatase and urinary hydroxyproline to normal or near normal values in all patients. This was accompanied by clinical improvement in all but 4 patients. Cl2MDP appears to be another effective oral drug for the treatment of Paget's disease of bone and compares favorably with the calcitonins and EHDP.

EFFECT OF DICHLOROMETHYLENE DIPHOSPHONATE IN PAGET'S DISEASE OF BONE AND IN HYPERCALCÆMIA DUE TO PRIMARY HYPERPARATHYROIDISM OR MALIGNANT DISEASE

30 patients with disorders of calcium metabolism were treated with dichloromethylene diphosphonate (Cl 2MDP, or clodronate disodium), an inhibitor of bone resorption. 13 patients with Paget's disease of bone were given Cl 2MDP by mouth (1·6 g/day). Serum-alkaline-phosphatase and urinary hydroxyproline fell to normal or near-normal within 3-7 months, and there was a clinical improvement in all but 1 patient. Cl 2MDP (0·8-3·2 g/day) also reduced plasma-calcium and urinary calcium in 17 patients with hypercalcæmia due to primary hyperparathyroidism or secondary to malignant disease. Cl 2MDP seems to be an effective oral drug for inhibiting excessive bone resorption in man.