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PubMed1989

Maternal hemodynamics after normal delivery and delivery complicated by postpartum hemorrhage.

Serial hemodynamic investigations were performed in 40 women at 38 weeks' gestation and then 1, 2, 6, 10, and 14 days after normal delivery. Cardiac output was measured by Doppler and cross-sectional echocardiography at the aortic valve. In 30 controls who received an average of 280 mL intravenous fluid during labor, the mean cardiac output remained elevated (7.15 L/minute) for 24 hours after delivery and then fell to 5.39 L/minute at 10 days as a result of decreases in both heart rate and stroke volume. Blood pressure fell during the first 2 days after delivery and thereafter increased to values not significantly different from those recorded at the end of pregnancy. In ten women who experienced postpartum hemorrhage, stroke volume decreased and heart rate increased, relative to the control group, during the first 48 hours after delivery. Blood pressure and cardiac output, however, were not significantly different from values in the control group.

Adult↗

PubMed1988

Brain-enhanced delivery of testosterone using a chemical delivery system complexed with 2-hydroxypropyl-beta-cyclodextrin.

Enhanced brain delivery of testosterone was suggested by application of a dihydropyridine in equilibrium pyridinium salt redox system. The drug delivery method is based upon the NAD+ in equilibrium NADH coenzyme system and utilizes the covalent attachment of testosterone to a dihydropyridine-type carrier. Upon administration of two such testosterone chemical delivery systems (T-CDS1 or T-CDS2), serum LH levels were suppressed by 71-87% after 24 hours and maintained through 5 days (28%) with T-CDS1. An equimolar dose of testosterone or testosterone propionate failed to suppress serum LH. Peripheral testosterone target tissues (seminal vesicles and prostate gland) were only slightly stimulated by T-CDS1. Complexation of T-CDS1 with 2-hydroxypropyl-beta-cyclodextrin allowed a lowering of the effective LH-suppressing dose of T-CDS1 from 25 mg/kg to 10 mg/kg, presumably by increasing the solubility of T-CDS1 in the blood. These findings suggest that testosterone can be effectively delivered to the central nervous system (CNS) with minimal peripheral effect, and the delivery of T-CDS1 to the CNS can be improved via complexation with 2-hydroxypropyl-beta-cyclodextrin.

Animals↗

PubMed1986

Improved delivery through biological membranes. Synthesis, distribution, and neurochemical effects of a tryptamine chemical delivery system.

Enhanced central delivery of tryptamine was proposed by application of a dihydropyridine in equilibrium pyridinium salt redox system. This drug delivery method, which relies on biochemistry similar to that which occurs in the NAD+ in equilibrium NADH coenzyme system, required synthetic derivatization of tryptamine. When the resulting tryptamine chemical delivery system (TCDS) was systematically administered, it passed the blood-brain barrier intact and then oxidized. The resulting quaternary form (TQ+) accumulated in the brain of rats relative to most peripheral organs. The only organ in which a more rapid efflux was not demonstrated was the heart. Intestinal administration of the TCDS showed the ability of the system to undergo absorption and to survive the first pass through the liver. The TCDS caused central neurochemical changes consistent with central delivery of tryptamine. Possible applications of the TCDS are discussed.

Animals↗

PubMed1983

Neonatal outcome in cesarean section under general anesthesia, related to gestational age, induction-delivery and uterus-delivery intervals.

Neonatal outcome after cesarean section under general anesthesia was studied in 568 women in whom no prior signs of fetal distress were evident. Low Apgar 1-minute scores were not related to induction-delivery and/or to uterus-delivery intervals, which were all within the accepted safe limits, but were related to the gestational age. Thus, Apgar scores less than 7 were found in 62% of newborns whose gestational age was less than 35 weeks, but in only 17% of those greater than or equal to 35 weeks. The importance of gestational age, in addition to the induction-delivery and uterus-delivery intervals, is discussed in relation to neonatal outcome following cesarean section.

Adolescent↗

PubMed1993

[How does the presence of normal vaginal delivery before and after a first cesarean section influence the outcome of a subsequent vaginal delivery].

The author has studied 740 cases of vaginal delivery after one or more caesarean operations over a period of 10 years (1980-1989) in the Clinic of Obstetrics and Gynaecology in Stara Zagora in his attempt to assess the effect of a normal delivery before or after the first caesarean operation on the outcome of the following vaginal delivery. The results obtained do not correlate with the data cited elsewhere. The author has established that the outcome of the next vaginal delivery is approximately 1% better in the latter group while elsewhere it is cited to be 6-7 times better.

Bulgaria↗

PubMed2005

Oral heparin delivery: design and in vivo evaluation of a stomach-targeted mucoadhesive delivery system.

Low molecular weight heparin (LMWH) is an agent of choice in the anti-coagulant therapy and prophylaxis of thrombosis and coronary syndromes. However, the therapeutic use is partially limited due to a poor oral bioavailability. It was therefore the aim of this study to design and evaluate a highly efficient stomach-targeted oral delivery system for LMWH. In order to appraise the influence of the molecular weight on the oral bioavailability, mini-tablets comprising 3 kDa (279 IU) and 6 kDa (300 IU) LMWH, respectively, were generated and tested in vivo in rats. The potential of the test formulations based on thiolated polycarbophil, was evaluated in comparison to hydroxyethylcellulose (HEC) as control carrier matrix. The plasma levels of LMWH after oral versus subcutaneous administration were determined in order to calculate the relative bioavailability. With the delivery system containing 3 kDa LMWH (279 IU) a relative bioavailability of 19.1% was achieved, offering a significantly (p < 0.05) better bioavailability than the control system displaying a relative bioavailability of 8.1% The 6 kDa LMWH (300 IU) formulation displayed a relative bioavailability of 10.7% in contrast to the control displaying a relative bioavailability of 2.1%. In conclusion, these results suggest that mucoadhesive thiolated polymers are a promising tool for the non-invasive stomach-targeted systemic delivery of LMWH as model for a hydrophilic macromolecular polysaccharide.

Acrylic Resins↗

PubMed2004

Evaluation of placental drainage as a method of placental delivery in vaginal deliveries.

METHODS: We describe a prospective study, done over a 2-year period in which a total of 958 women having a vaginal delivery were randomised to the drainage method (478 women) or controlled cord traction method (480 women) for placental delivery. RESULTS: The mean age, parity, gestation and birth weight were similar in the two groups. The mean duration of third stage of labor was 3.24 min and 3.2 min in the placental drainage group in contrast to 8.57 min and 6.20 min in controlled cord traction method in primigravida and multigravida respectively. CONCLUSION: Placental drainage significantly reduces the duration of third stage of labour in vaginal deliveries.

Adolescent↗

PubMed1991

Twin delivery: influence of the presentation and method of delivery on the second twin.

To ascertain the perinatal mortality and morbidity in the second twin as related to its presentation and method of delivery, we reviewed the data on 578 sets of twins delivered from 1980 to 1987 and included 397 sets in whom both twins were greater than or equal to 1000 gm, without lethal anomalies, and in whom the first twin presented as a vertex. The perinatal outcome comparing twin A (all vertex) with twin B (vertex or nonvertex) with cesarean section or vaginal delivery was analyzed. No statistically significant difference in perinatal mortality or morbidity was found in comparing the nonvertex second twin delivered vaginally or by cesarean section. The one perinatal death and significant perinatal morbidity occurred in infants weighing less than 1500 gm or at less than 32 weeks' gestational age. It is concluded that vaginal delivery, irrespective of the position of the second twin, is valid in selected cases as long as fetal weight is greater than 1500 gm and the gestational age is greater than or equal to 32 weeks.

Birth Order↗

PubMed1994

Successful antidote of multiple lethal infections using sustained delivery of difluoromethylornithine by means of ceramic drug delivery devices.

The objectives of this study were (1) to cure multiple infections of trypanosomiasis in rats by the sustained release of DFMO from biodegradable tricalcium phosphate (TCP) and aluminum-calcium-phosphorous oxide (ALCAP) delivery systems, and (2) to determine if the side effects associated with oral administration of DFMO can be avoided by using TCP and ALCAP capsules. Sixty-eight SD male albino rats (235-270 g) were divided randomly into five groups. Each rat in group I (n = 16) was implanted subcutaneously (s.c.) with four TCP capsules (two large TCP (L-TCP), one PLA-impregnated large TCP (IL-TCP) and one thin TCP capsule (TN-TCP)). Rats in group II (n = 16) were implanted s.c. with four ALCAP ceramics (two large ALCAP (L-ALCAP), one PLA-impregnated large ALCAP (IL-ALCAP) and one thin ALCAP capsule (TN-ALCAP)). Rats in groups III (n = 16), IV (n = 4) and V (n = 16) were left without implants. Rats in group III (n = 16) were given 4% (w/v) DFMO (pH 7) in drinking water at the day of inoculation and continued up to 7 days postinoculation. Rats in group IV (n = 4) served as a nontreated group. Rats in group V (n = 16) served as normal controls. The results showed that all rats implanted with with TCP or ALCAP implants had no intoxications symptoms or side effects such as diarrhea during the treatment period. In contrast, rats given DFMO in drinking water exhibited foul-smelling diarrhea during the treatment period. Microscopic evaluation of blood smears collected from rats receiving DFMO chemotherapy showed an occasional or limited number of stumpy shape (SS) trypanosomes. This study suggests that (1) ceramic drug delivery systems are capable of delivering DFMO in a sustained manner for two months, and were able to cure repeated infections of trypanosomiasis; (2) the use of ceramic implants avoided widely fluctuating, irregular levels of DFMO in the body by keeping sustained levels above minimal effective concentrations; (3) ceramic drug delivery systems provide a pharmacological potentiality for drugs such as DFMO which have been withheld from the market because of severe side effects when administered using conventional methods of drug administration; and (4) DFMO-filled ceramic devices can be implanted subcutaneously in animals that face a threat of lethal protozoal infections in highly infested areas of the world.

Administration, Oral↗

PubMed2006

Cyclodextrin-containing poly(ethyleneoxide) tablets for the delivery of poorly soluble drugs: potential as buccal delivery system.

The aim of this work was to develop a tablet for the buccal delivery of the poorly soluble drug carvedilol (CAR), based on poly(ethyleneoxide) (PEO) as bioadhesive sustained-release platform and hydroxypropyl-beta-cyclodextrin (HPbetaCD) as modulator of drug release. As first, PEO tablets loaded with CAR/HPbetaCD binary systems with different dissolution properties were tested for CAR and HPbetaCD release features and compared to PEO tablets containing only CAR. When the drug was incorporated as CAR/HPbetaCD freeze-dried product, all CAR content was released from the tablet in about 10 h, displaying a constant release regimen after a transient. The effect of HPbetaCD incorporation on the release mechanism, was rationalized on the basis of the interplay of different physical phenomena: erosion and swelling of the tablet, drug dissolution, drug counter-diffusion and complex formation. In the second part of the study, the potential of HPbetaCD-containing PEO tablets as buccal delivery system for CAR was tested. It was found that the incorporation of HPbetaCD in the tablet did not alter significantly its good adhesion properties. The feasibility of buccal administration of CAR was assessed by permeation experiments on pig excised mucosa. The amount of CAR permeated from PEO tablet was higher in the case of HPbetaCD-containing tablets, the maximum value being obtained for CAR/HPbetaCD freeze-dried system. Our results demonstrate that, when the tablet is employed as transmucosal system, the role of drug dissolution enhancement in the hydrated tablet is much more relevant than in solution for increasing the delivery rate.

2-Hydroxypropyl-beta-cyclodextrin↗

PubMed2004

An assessment of different DNA delivery systems for protection against respiratory syncytial virus infection in the murine model: gene-gun delivery induces IgG in the lung.

Immunization with plasmid DNA (pDNA) has the potential to overcome the difficulties of neonatal vaccination that may be required for protection against infection with respiratory syncytial virus (RSV); however, little is known about optimal delivery modalities. In this pilot study we compared mucosal delivery of pDNA encoding RSV F protein encapsulated in poly(DL-lactide-co-glycolide) with delivery of pDNA by gene-gun for the induction of immunity in mice. Intra-gastric or intra-nasal immunization with various doses of microparticles induced weak low levels of RSV-specific serum antibodies in a proportion of mice; in contrast, gene-gun vaccination led to protective immunity associated with a humoral response. Interestingly, RSV-specific antibody was detected in lung fragment cultures following intradermal vaccination with the gene-gun.

Animals↗

PubMed1998

First delivery after cesarean delivery for strictly defined cephalopelvic disproportion.

OBJECTIVE: To examine the outcome of trial second labor after a first cesarean performed because of cephalopelvic disproportion, defined according to strict diagnostic criteria. METHODS: Obstetric details of nulliparous women delivering at 37 or more weeks' gestation by cesarean for cephalopelvic disproportion, between 1975 and 1990, were recorded prospectively. The diagnostic criteria for cephalopelvic disproportion were cervical dilation arrested after 5 cm, unresponsive to oxytocin augmentation, after active dilatation of 2 cm or more in 2 hours. Fetal malpresentations and malpositions were excluded. The outcome of next delivery in our hospital by each woman enrolled was then examined. RESULTS: Eighty-four of 42,793 women met the criteria for disproportion, and 40 with cephalic presentations delivered their next baby in our hospital. All 40 underwent a trial of labor and 27 (68%) delivered vaginally, comprising seven (47%) women with larger second and 20 (80%) with smaller second babies. Of 15 women previously delivered by cesarean at full dilatation, 11 (73%) delivered vaginally with no serious maternal or neonatal morbidity. CONCLUSION: The strictly defined diagnosis of nulliparous cephalopelvic disproportion should not constitute an automatic "recurrent" indication for elective cesarean delivery, because 68% of patients in our series had successful vaginal deliveries in their next pregnancies. This rate is similar to those reported after all nulliparous cesareans for dystocia.

Cesarean Section↗

PubMed2001

Targeted drug delivery systems 6: Intracellular bioreductive activation, uptake and transport of an anticancer drug delivery system across intestinal Caco-2 cell monolayers.

We demonstrate transport across, intracellular accumulation and bioreductive activation of a conformationally constrained, anticancer drug delivery system (the CH(3)-TDDS) using Caco-2 cell monolayers (CCMs) as an in vitro model of the human intestinal mucosa. Reverse-phase High Performance Liquid Chromatography (HPLC) coupled with UV detection was used to detect CH(3)-TDDS, the bioreduction product (lactone) and the released drug (melphalan methyl ester; MME). Upon incubation of the CH(3)-TDDS with the apical (AP) surface of 21-day-old CCM, we observed rapid decrease in the AP concentration of the CH(3)-TDDS (60%/hr) as a result of cellular uptake. Rapid intracellular accumulation of the CH(3)-TDDS was followed by bioreductive activation to deplete the cellular levels of CH(3)-TDDS. The drug part (MME) and lactone, as well as CH(3)-TDDS, were detected in the basolateral (BL) chamber. Intracellular Caco-2 levels of TDDS and lactone were also detectable. Bioreductive activation of the CH(3)-TDDS was additionally confirmed by formation of lactone after incubation of the CH(3)-TDDS in the presence of freshly prepared Caco-2 cell homogenates. During transport studies of melphalan or MME alone (as control), the intact drug was not detected in the intracellular compartment or in the BL chamber. These observations demonstrate that CH(3)-TDDS has potential for improving intestinal delivery of MME. TDDS could be useful in facilitating oral absorption of MME as well as the oral delivery of other agents.

Antineoplastic Agents↗

PubMed1999

Persistent primary coronary dilation induced by transatrial delivery of nitroglycerin into the pericardial space: a novel approach for local cardiac drug delivery.

OBJECTIVES: We compared the effects of intrapericardial and intracoronary nitroglycerin on coronary cross-sectional area as assessed by intravascular ultrasound and demonstrated the feasibility of local cardiac drug delivery by a newly developed method to access the normal pericardial space through the right atrial appendage. BACKGROUND: Studies of nitric oxide (NO) donors have suggested that their antiarrhythmic and antiproliferative properties are more effective when administered by the intrapericardial rather than intravascular route. We postulated that NO donors delivered intrapericardially would also cause sustained coronary vasodilation without significant systemic hypotension. METHODS: Intrapericardial nitroglycerin (200 microg) was administered in five Yorkshire pigs. Coronary cross-sectional luminal area was measured with intravascular ultrasound at various time intervals. The effects of intracoronary nitroglycerin on coronary luminal area were used for comparison. RESULTS: Transatrial pericardial access required 1 to 3 min in all animals. Intrapericardial nitroglycerin was associated with a mean 31.7% increase in luminal area at 5 min (p < 0.001). Vasodilation peaked between 5 and 10 min and persisted for 15 min. In contrast, intracoronary nitroglycerin was associated with a smaller mean increase in luminal area (20.3% at 5 min, p < 0.01) that disappeared by 10 min. Significant systemic hypotension was observed at 3 min with intracoronary but not with intrapericardial nitroglycerin. CONCLUSIONS: Sustained coronary vasodilation can be achieved with intrapericardial delivery of nitroglycerin without systemic hypotension. Nitric oxide donors with longer half-lives could prove beneficial in the treatment of myocardial ischemic syndromes when administered through this route. Transatrial pericardial access offers a novel route for local cardiac drug delivery.

Animals↗

PubMed2003

Local methylprednisolone delivery using a BiodivYsio phosphorylcholine-coated drug-delivery stent reduces inflammation and neointimal hyperplasia in a porcine coronary stent model.

Phosphorylcholine (PC)-coated stents have shown excellent blood and tissue biocompatibility in porcine coronary arteries. The purpose of this study was to determine the efficacy of local methylprednisolone (MP) delivery using PC-coated stents to inhibit inflammatory response and in-stent neointimal hyperplasia in an overstretched porcine coronary model. BiodivYsio (Biocompatibles, Farnham, Surrey, UK) PC-coated drug delivery (DD) stents and DD stents loaded with a high dose of MP (269 microg) were implanted in the coronary arteries of 20 pigs with a balloon/artery ratio of 1.2 : 1. At five days the peri-strut inflammatory response score and thrombus score of the MP-loaded DD stents were lower than in the control stents. The neointimal hyperplasia of MP-loaded DD stents was significantly reduced (0.80 +/- 0.10 versus 0.48 +/- 0.10 mm(2), p < 0.01). At four-week follow-up, the inflammatory response of MP-loaded stents was lower than the control stents, but without significant difference. The MP-loaded stents showed decreased peri-strut arterial injury and in-stent neointimal hyperplasia (2.42 +/- 0.87 versus 1.62 +/- 0.71 mm(2), p < 0.05). It is concluded that local vascular delivery of a high dose of MP from PC-coated DD stents could effectively decrease inflammatory response and thrombus formation after oversized stent deployment and result in a significant reduction of neointimal hyperplasia.

Animals↗

PubMed2005

Design and development of multivesicular liposomal depot delivery system for controlled systemic delivery of acyclovir sodium.

The aim of the present study was to design a depot delivery system of acyclovir sodium using multivesicular liposomes (MVLs) to overcome the limitations of conventional therapies and to investigate its in vivo effectiveness for sustained delivery. MVLs of acyclovir were prepared by the reverse phase evaporation method. The loading efficiency of the MVLs (45%-82%) was found to be 3 to 6 times higher than conventional multilamellar vesicles (MLVs). The in vitro release of acyclovir from MVL formulations was found to be in a sustained manner and only 70% of drug was released in 96 hours, whereas conventional MLVs released 80% of drug in 16 hours. Following intradermal administration to Wistar rats, the MVL formulations showed effective plasma concentration for 48 hours compared with MLVs and free drug solution (12-16 hours). C(max) values of MVL formulations were significantly less (8.6-11.4 microg/mL) than MLV and free drug solution (12.5 microg/mL). The AUC(0-48) of the MVL formulations was 1.5- and 3-fold higher compared with conventional liposomes and free drug solution, respectively. Overall, formulations containing phosphatidyl glycerol as negatively charged lipid showed better results. The MVL delivery system as an intradermal depot offers the advantage of a very high loading and controlled release of acyclovir for an extended period of time. The increase in AUC and decrease in C(max) reflects that the MVL formulations could reduce the toxic complications and limitations of conventional iv and oral therapies.

Acyclovir↗

PubMed2006

Isolation of drug delivery from drug effect: problems of optimizing drug delivery parameters.

A recurring question in the treatment of malignant brain tumors has been whether treatment failure is due to inadequate delivery or ineffective drugs. To isolate these issues, we tested a paradigm in which the "therapeutic" agent was a toxin about which there could be no question of efficacy, provided it was delivered in adequate amounts; we used 10% formalin. We infused 10% formalin into 5- to 8-mm subcutaneous RG-2 and D54-MG gliomas at increasing rates until we achieved 100% tumor cell kill. In RG-2 gliomas, infusions of 10 microl/h x 7 days, and 2, 4, 6, and 8 microl/min x 2 h failed to kill tumors, although growth was delayed, while infusion rates of 12 microl/min x 60 min and 48 microl/min x 15 min produced 100% tumor kill. In D54-MG tumors, infusions of 4, 8, and 24 microl/min produced 100% tumor kill. 14C-Formalin autoradiographs showed a heterogeneous distribution after infusions of 2 microl/min x 2 h, whereas infusions of 48 microl/min x 15 min showed a homogeneous distribution within the tumor, but more than 95% of tissue radioactivity was found in tissue surrounding tumor. Drug delivery remains a major issue in brain tumor treatment: Distribution inhomogeneity, rapid efflux, and consequent treatment failures are likely due to high interstitial fluid pressure. Because the infusion rates being used in the treatment of human brain tumors are low and the tumors are larger, treatment failures can be expected on the basis of inadequate drug delivery alone, regardless of the effectiveness of the drug.

Animals↗

PubMed2006

Proprietary Rel-Ease drug delivery technology: opportunity for sustained delivery of peptides, proteins and small molecules.

Proprietary Rel-Ease (Praecis Pharmaceuticals) drug delivery technology uses biocompatible polymers as carriers to incorporate a drug into a polymer matrix through opposite charge interaction or complexation. The resulting low solubility complexes can be used to prepare sustained release depot injections or potentially sustained release formulations for oral administration. As a regulatory approved and commercialised drug delivery technology, Rel-Ease is used in abarelix for injectable suspension, a monthly depot injection for the treatment of patients with advanced prostate cancer. The technology offers high drug loading and minimal-to-no initial burst effect in vivo. It uses aqueous processes and is compatible for complexation with many peptide and protein therapeutics; its mechanism can also be applied to many small-molecule therapeutics and offers conventional and alternative methods for sustained release delivery via an oral route.

Delayed-Action Preparations↗