Formulation Development and Characterization of Nanoemulsion-Based Formulation for Topical Delivery of Heparinoid.

Heparinoid is commonly used for the treatment of superficial thrombophlebitis, a condition wherein inflammation and clotting occurs in the veins below the skin surface. However, stratum corneum is a major barrier that limits the delivery of hydrophilic heparinoid, in and across the skin. The aim of the present study was to develop a nonirritant topical formulation for heparinoid incorporating chemical penetration enhancers and investigate the delivery of heparinoid across the human epidermis using in vitro vertical Franz diffusion cells. The developed oil-in-water nanoemulsions (NEs; NE-1 and NE-2) delivered higher amount of heparinoid (91.58 ± 25.75 µg/sq.cm and 62.67 ± 5.66 µg/sq.cm, respectively) after 72 h compared with the other developed formulations, which in turn also delivered significantly higher amount compared with commercial formulations: cream (1.78 ± 0.07 µg/sq.cm), ointment (9.95 ± 4.41 µg/sq.cm), and gel (0 µg/sq.cm) (p <0.05). Transmission electron microscopy, polarizing light microscopy, and dynamic light scattering studies were performed to characterize the microstructure of these NEs with chemical enhancers. NE-1 was tested to be nonirritant with cell viability greater than 50% and a minimal release of IL-1α by using the "in vitro Epiderm tissue" model. Our results demonstrate that NE formulations represent a potential strategy for providing a localized therapy for the treatment of superficial thrombophlebitis.

Efficacy of Heparinoid PSS in Treating Cardiovascular Diseases and Beyond-A Review of 27 Years Clinical Experiences in China.

Propylene glycol alginate sodium sulfate (PSS) is the world's first oral heparinoid approved by Chinese Food and Drug Administration in 1987. Propylene glycol alginate sodium sulfate is produced by modifying partially hydrolyzed alginate, one of the most abundant marine polysaccharides isolated from brown algae, by epoxypropane esterification and by chemical sulfation. It is used for treating and preventing cardiovascular-related diseases. The low cost (US$1.29/100 tablets, ∼4 tablets/day), remarkable clinical effects, and convenient oral administration make PSS an ideal long-term prevention drug. Propylene glycol alginate sodium sulfate is available in most drug stores in China, and millions of patients take PSS routinely during the past 27 years. The 22 784 reported clinical cases as well as the structure, preparation, clinical efficacy, adverse reactions, pharmacokinetics, pharmacodynamics, and future perspectives of PSS based on the results of peer-reviewed publications will be discussed. This review should bring the knowledge of PSS gained in China to the world to stimulate in depth academic and clinical studies of PSS.

Release profiles of dexamethasone dipropionate from admixtures of steroid and heparinoid ointments prepared by different mixing methods.

Characterization and release profiles of commercial dexamethasone dipropionate (DDP) from an innovator and 2 generic ointments (Methaderm (IM), Promethasone (GP), and Mainvate (GM)) and their admixtures with heparinoid ointment (Hirudoid Soft) were investigated. The admixtures were prepared using 2 mixing methods (slab or rotation/revolution mixer). Microscopic and FT-Raman spectrometric analyses revealed that the ointments, except for IM, contained DDP crystals. A silicone membrane was used for the evaluation of the DDP permeation. The permeated DDP amounts from GP and GM were lower than that from IM, indicating that DDP solubility in the ointment vehicle affected the release of DDP from the ointment. No significant differences were observed in DDP release between IM alone and its admixture prepared using a slab; however, DDP release from the admixture prepared using a rotation/revolution mixer was significantly lower than those from IM alone and its admixture by slab. In the GP system, DDP release from the admixtures by the 2 mixing methods was higher than that from GP alone, whereas no significant difference in DDP release between the 2 mixing methods was observed. No significant differences were observed between the GM and admixtures. The apparent solubility of DDP in the admixtures as determined by the ultracentrifugal separation method indicated that the DDP amount in the liquid phase of admixtures with GP was 6 times higher than that of admixtures with IM or GM. Therefore, the apparent solubility of DDP in the liquid phase in the GP system might influence the DDP release in admixtures.

Pharmacokinetic studies of dalteparin (Fragmin), enoxaparin (Clexane), and danaparoid sodium (Orgaran) in stable chronic hemodialysis patients.

BACKGROUND: Low molecular weight heparins (LMWHs) and danaparoid are an alternative to unfractionated heparin (UH) for anticoagulation during hemodialysis. Few data are available concerning their duration of action and whether drug accumulation occurs with continued use. We performed a prospective randomized study of the pharmacokinetics of dalteparin and enoxaparin plus danaparoid in 21 hemodialysis patients. METHODS: Patients were randomly assigned to administration of enoxaparin, 40 mg; dalteparin, 2,500 U; or danaparoid, 34 U/kg, for 4 weeks. Antifactor Xa levels were measured at the end of weeks 1 and 4 immediately before the injection and at prescribed intervals up to 48 hours postinjection. RESULTS: No bleeding or thrombotic episodes occurred during the study. Mean antifactor Xa activities 4 hours postinjection were 0.2 +/- 0.035 (SEM), 0.38 +/- 0.028, and 0.54 +/- 0.051 U/mL week 1 and 0.26 +/- 0.038, 0.40 +/- 0.055, and 0.64 +/- 0.050 U/mL week 4 for dalteparin, enoxaparin, and danaparoid, respectively. Both weeks 1 and 4, antifactor Xa activity 3 hours postdose was significantly greater for danaparoid sodium compared with enoxaparin and dalteparin. There were no significant differences between antifactor Xa activity week 4 versus week 1 for enoxaparin and dalteparin; however, danaparoid sodium levels during dialysis were significantly greater after 4 weeks of treatment (P = 0.0328, 1 hour; P = 0.003, 2 hours; P = 0.0128, 3 and 4 hours). CONCLUSION: Dalteparin and enoxaparin provide adequate anticoagulation for hemodialysis using single bolus injections at relatively low doses. Danaparoid sodium at the current recommended dosage resulted in greater anticoagulation than enoxaparin or dalteparin and may have an

Autoradiography reveals regional metabolic differences in the endometrium of pregnant and nonpregnant mice.

The rodent endometrium undergoes remarkable modifications during pregnancy, resulting from a redifferentiation of its fibroblasts. During this modification (decidualization), the fibroblasts transform into large, polyhedral cells that establish intercellular junctions. Decidualization proceeds from the subepithelial stroma towards the deep stroma situated next to the myometrium and creates regions composed of cells in different stages of differentiation. We studied by autoradiography whether cells of these different regions have different levels of macromolecular synthesis. Radioactive amino acids or radioactive sulfate were administered to mice during estrus or on different days of pregnancy. The animals were killed 30 min after injection of the precursors and the uteri were processed for light microscope autoradiography. Silver grains were counted over cells of different regions of the endometrium and are reported as the number of silver grains per area. Higher levels of incorporation of amino acids were found in pregnant animals as compared to animals in estrus. In pregnant animals, the region of decidual cells or the region of fibroblasts transforming into decidual cells showed the highest levels of synthesis. Radioactive sulfate incorporation, on the other hand, was generally higher in nonpregnant animals. Animals without decidual cell transformation (nonpregnant and 4th day of pregnancy) showed a differential incorporation by subepithelial and deep stroma fibroblasts. This study shows that regional differences in synthetic activity exist in cells that are in different stages of transformation into decidual cells as well as in different regions of the endometrium of nonpregnant mice.

Autoradiography reveals regional metabolic differences in the endometrium of pregnant and nonpregnant mice

The rodent endometrium undergoes remarkable modifications during pregnancy, resulting from a redifferentiation of its fibroblasts. During this modification (decidualization), the fibroblasts transform into large, polyhedral cells that establish intercellular junctions. Decidualization proceeds from the subepithelial stroma towards the deep stroma situated next to the myometrium and creates regions composed of cells in different stages of differentiation. We studied by autoradiography whether cells of these different regions have different levels of macromolecular synthesis. Radioactive amino acids or radioactive sulfate were administered to mice during estrus or on different days of pregnancy. The animals were killed 30 min after injection of the precursors and the uteri were processed for light microscope autoradiography. Silver grains were counted over cells of different regions of the endometrium and are reported as the number of silver grains per area. Higher levels of incorporation of amino acids were found in pregnant animals as compared to animals in estrus. In pregnant animals, the region of decidual cells or the region of fibroblasts transforming into decidual cells showed the highest of synthesis. Radioactive sulfate incorporation, on the other hand, was generally higher in nonpregnant animals. Animals without decidual cell transformation (nonpregnant and 4th day of pregnancy) showed a differential incorporation by subepithelial and deep stroma fibroblasts. This study shows that regional differences in synthetic activity exist in cells that are in different stages of transformation into decidual cells as well as in different regions of the endometrium of nonpregnant mice.

Danaparoid. A review of its pharmacology and clinical use in the management of heparin-induced thrombocytopenia.

Danaparoid, a low molecular weight heparinoid consisting of a mixture of heparan, dermatan and chondroitin sulfates, has well established antithrombotic activity. The drug has a high antifactor Xa to antifactor IIa (thrombin) activity ratio, a low tendency to cause bleeding and minimal effects on the fibrinolytic system. Danaparoid has a low cross-reactivity rate with heparin-associated antiplatelet antibodies (0 to 20%; mean approximately 10%). This represents a significant advantage over low molecular weight heparins (LMWHs) as a potential replacement agent for unfractionated heparin (UFH) in patients with immune-mediated (type II) heparin-induced thrombocytopenia (HIT). In a worldwide compassionate-use programme involving a total of 667 patients with HIT to date, 93% of danaparoid treatment courses were considered to be successful. Thrombocytopenia resolved in 91% of episodes. In a multicentre randomised comparative trial of danaparoid and dextran in patients with HIT plus thrombosis (HITT), significantly more danaparoid than dextran recipients had resolution of thromboses, and an effective clinical response was achieved in significantly more danaparoid recipients. Results of a retrospective case-controlled study of danaparoid and ancrod in patients with HITT showed significantly fewer new or progressive thromboses with danaparoid. In the compassionate-use programme, danaparoid was associated with a mortality rate of 10.4% during treatment (up to 3.5 years) and 7.8% during the follow-up period (3 months). 14 of 114 deaths during the follow-up period were considered to be related to danaparoid therapy. A mortality rate of 23.5% was reported in patients accepted for but not treated with, danaparoid. Mortality rates with danaparoid, ancrod and dextran in the comparative studies were similar (7, 11 and 12%, respectively). Severe bleeding was reported in 3.1% of patients in the compassionate-use programme, persistent or recurrent thrombocytopenia in 2.6% and new thromboembolic events/extension of existing thrombosis in 1.7%. The incidence of bleeding was similar with danaparoid and dextran in a comparative trial. Although in vitro cross-reactivity does not always translate into clinical cross-reactivity, testing is currently recommended, when possible, before initiation of danaparoid therapy. Thus, danaparoid appears to be an effective and well tolerated replacement agent for UFH in many patients with HIT who require further anticoagulation. The drug has low cross-reactivity with HIT-associated antibodies. Further comparative trials are needed to confirm these promising findings.

-Anticoagulant drugs-. / Gerinnungshemmende Substanzen.

In todays medicine, anticoagulant drugs like heparin and coumadin derivatives have become indispensable for the treatment of thrombo-embolic diseases. Heparin, consisting of long poly-sulfated polysaccharide chains of variable length and sequences is mostly derived from porcine mucosa. Its bioavailability by other than the parenteral way of administration is almost negligible. Therefore, with only few exceptions, it is almost exclusively applied in hospitalized patients (short-term therapy) or to bridge 2 phases of treatment with oral anticoagulant drugs. Today, besides the conventional high-molecular weight heparins, new fractionated heparins are gaining more and more attention. They offer the advantage of a more reliable resorption from the subcutaneous tissue and thus warrant reliable plasma levels. In many recent randomized trials of deep vein thrombosis and pulmonary embolism, those fractionated heparins have proven to successfully substitute for intravenously applied, aPTT-controlled unfractionated heparin. It remains however open, whether this also translates into the prevention of arterial thrombo-embolic diseases. Heparin may not pass through the placental barrier nor into the milk and is regarded non-teratogenic. Therefore, it may be regarded the ideal anticoagulant for pregnant women and lactating mothers. Those women, however, still carry the heparin-associated risk of bleeding and osteoporosis. In comparison: Coumadin derivatives interfere with the carboxylation of the clotting factors II, VII, IX, and X as well as proteins C and S. By inhibiting the synthesis of these proteins they shift the haemostatic balance to a lower level. In addition, they are almost completely bioavailable by the enteral pathway. They are, therefore, regarded the drugs of choice for long-term anticoagulant therapy in patients at particular thromboembolic risk. For their therapeutic range, being extremely narrow, meticulous drug monitoring by repeated INR-measurements as well as a reliable compliance of the patient to drug intake and dietary restrictions are mandatory to exclude phases with over- or under-anticoagulation. Above all, coumadin therapy is characterized by numerous drug interactions. Thus, whenever the basal medication is changed, for whatever reason, more intense care must be laid to drug monitoring, and the intervals for INR determinations must transiently be shortened. Coumadin derivatives do pass through the placental barrier and in minor amounts also into the milk of breast feeding mothers. Furthermore, they are highly teratogenic. If taken during pregnancy, malformations of the central nervous system are reported to occur in some 10% to 30% of the infants. Thus during pregnancy and in the lactation period, coumadin therapy should be avoided. Bleeding episodes of different severity are the most frequent adverse effects of anticoagulant therapy, no matter whether heparin or coumadin is given. There is a direct relation between the intensity of anticoagulant therapy and the frequency of bleeds. Luckily, most bleeding episodes do not create major therapeutic problems. In case of severe bleeds, however, the anticoagulant therapy must immediately be suspended. In case of coumadin therapy the immediate administration of 4 packs of PPSB (prothrombin-complex-concentrates) or FFP (fresh-frozen-plasma) with concomitant low doses of heparin is additionally advised. Allopecia diffusa, urticartia and allergic reactions are known side effects of anticoagulant therapy. Patients on long-term heparin may also suffer from severe osteoporosis. On the other hand, heparin treatment raises the hazzards of a HAT-Syndrome (heparin-associated thrombocytopenia) (estimated frequency 0.01% to 0.1% of treated patients), giving rise to severe and life-threatening thrombo-embolic side effects predominantly in the arterial tree. In these cases, heparin must be suspended despite those severe thrombo-embolic episodes.

Pharmacokinetic considerations on Orgaran (Org 10172) therapy.

Pharmacokinetic investigations on Orgaran (Org 10172) have been conducted by monitoring the following biological effects: plasma anti-Xa, anti-IIa and IIa-generation-inhibiting (IIaGI) activities. In addition, a limited number of studies were conducted on the basis of concentrations of the No-affinity glycosaminoglyc(uron)an (NoA-GAG) fraction as determined by a competitive binding assay. In humans, widely different pharmacokinetic profiles for various biological effects were observed, with relatively short elimination half-lives for the anti-IIa and IIaGI activities of 4.3 +/- 3.5 and 6.7 +/- 3.2 h, respectively, but a relatively long elimination half-life of anti-Xa activity of 24.5 +/- 9.6 h. These differences in half-life mainly reflect differences in the rate of elimination of individual components of Orgaran. Rapid elimination of some of these components may explain why twice daily dosing is required for optimal thrombosis prophylaxis with Orgaran. In a comparative study in healthy male volunteers, the pharmacokinetics of the following low molecular weight heparin(oid)s were determined after intravenous administration: Orgaran (3,750 anti-Xa units), Fragmin (5,000 anti-Xa units), Fraxiparine (7,500 IC units) and Clexane (40 mg). Between these products, wide differences in pharmacokinetics were observed. Particularly, the half-lives of anti-Xa activity and IIaGI activity were much longer for Orgaran than for the other products. At the same time, a relatively low area under the curve of anti-IIa activity was observed. The absolute bioavailability of Orgaran following subcutaneous administration was determined on the basis of plasma anti-Xa and IIaGI activities and the NoA-GAG fraction concentrations. Absorption from subcutaneous tissues was found to be close to 100%, which is significantly higher than of heparin; a finding which indicates that the subcutaneous route is reliable for the administration of Orgaran. The elimination of Orgaran components occurs by renal and possibly non-renal routes. With respect to anti-Xa activity, about 50% of the total clearance can be accounted for by urinary excretion. Therefore, in severe renal failure, a reduction of the maintenance dose of Orgaran would seem to be indicated. Studies on the influence of enzyme induction as a result of treatment with pentobarbital suggest that the pharmacokinetics of Lomoparan are relatively insensitive to changes in hepatic function. In a number of studies, the influence of conditions such as age, body weight and drug interactions were studied. Generally, only minor changes in the pharmacokinetic parameters of Orgaran were observed.(ABSTRACT TRUNCATED AT 400 WORDS)

Influence of chlorthalidone on the pharmacokinetics and pharmacodynamics of Org 10172 (Lomoparan), a low molecular weight heparinoid, in healthy volunteers.

The influence of chlorthalidone (100 mg PO) on the pharmacokinetics and pharmacodynamics of Org 10172 (IV bolus injection of 3250 anti-Xa units), a low molecular weight heparinoid, was studied in six healthy male volunteers using an open randomized two-way crossover design. Chlorthalidone produced a slight decrease in clearance of anti-Xa activity from 7.1 +/- 1.0 to 6.6 +/- 0.8 mL/min and a decrease of the volume of distribution from 0.20 +/- 0.05 to 0.16 +/- 0.04 L/kg, whereas the volume of distribution of antithrombin activity increased from 0.14 +/- 0.05 to 0.26 +/- 0.10 L/kg (all differences P less than .05). During the entire study period no adverse events occurred. In summary, chlorthalidone showed separate effects on different fractions of Org 10172. The clinical implication of the slight change observed in plasma anti-Xa activity is likely to be limited, whereas the 80% increase in distribution volume of plasma antithrombin activity can not be defined as yet in terms of clinical relevance.

Interaction of the combined medication with the new low-molecular-weight heparinoid Lomoparan (Org 10172) and acenocoumarol.

A high intravenous dose of the low-molecular-weight heparinoid Lomoparan (Org 10172) was administered to 6 healthy males in a steady state of anticoagulation (Thrombotest) by acenocoumarol. Prothrombin time, activated partial thromboplastin time and Stypven time were prolonged to a degree which was greater than that expected on the base of the summation of the effects by each drug alone. This effect was observed for a period of up to 1 h. The Thrombotest was affected for up to 5 h after the intravenous administration of Org 10172, therefore it is deemed unsuitable for monitoring the combined effects of these two anticoagulants during this period. Acenocoumarol did not affect the pharmacokinetic parameters of Org 10172 with the exception of a slight reduction of the clearance of plasma anti-Xa activity.

Safety and pharmacokinetics of the low molecular weight heparinoid Org 10172 administered to healthy elderly volunteers.

1. In a cross-over study a new low molecular weight heparinoid Org 10172 was administered to 12 elderly male and female volunteers. It was well tolerated and no adverse effects occurred. 2. The absolute bioavailability of Org 10172 as measured by plasma anti-Xa activity, glycosaminoglycuronans with no affinity to antithrombin III (NoA-GAG) and thrombin generation inhibiting activity approached 100% in both sexes. 3. The half-life of elimination of its anti-Xa activity (19.2 +/- 6.1 h) was similar to that found previously in young volunteers. Org 10172 was further characterised by a rapid disappearance from the circulation of its anti-thrombin activity (t1/2 1.8 +/- 0.6 h) and of the NoA-GAG (t1/2 3.5 +/- 2.1 h). 4. Its thrombin generation inhibiting activity was of intermediate duration (t1/2 elimination 6.2 +/- 4.0 h).

[Percutaneous reabsorption of Tc 99m heparinoid]. / Untersuchungen zur perkutanen resorption von Tc-99 m Heparinoid.

The transcutaneous absorption of Tc-99 m Heparinoid was tested by animal experimental investigations. The quantified results showed only a small absorption of Tc-99 m Heparinoid (0.002%). This one has not any pharmacologic effect certainly.