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1.
World J Surg ; 35(7): 1643-8, 2011 Jul.
Article in English | MEDLINE | ID: mdl-21487852

ABSTRACT

BACKGROUND: The endoscopic totally extraperitoneal (TEP) mesh repair is nowadays a well-established tension-free method for inguinal hernia repair. Mainly based on animal studies and case reports, a concern about the risk of postoperative infertility was expressed. This clinical study aimed to evaluate the risk of infertility due to obstructive azoospermia in men of fertile age who underwent a bilateral hernia repair. METHODS: Over 3 years (2005-2008) 59 male patients, 18-60 years of age, underwent a bilateral TEP repair. Twenty-one of them were prospectively ("light mesh") and 38 retrospectively ("heavy mesh") evaluated for testicular volume and perfusion, serum levels of sexual hormones, ejaculate volume, and number of spermatic cells. Those parameters were determined preoperatively (prospective group) and not earlier than 3 months postoperatively (both groups). RESULTS: No significant difference between pre- and postoperative values was detected in the prospectively studied group. All postoperative parameters were within the normal range in the retrospective group. There was no evidence of impaired fertility in any patient due to the operation. CONCLUSION: The standardized TEP technique for simultaneous bilateral inguinal hernia repair in male patients was not associated with a higher risk for postoperative infertility after mesh implantation. The use of heavy-weight meshes had no negative effect on fertility.


Subject(s)
Azoospermia/etiology , Endoscopy/adverse effects , Endoscopy/methods , Hernia, Inguinal/surgery , Surgical Mesh/adverse effects , Adult , Humans , Male , Peritoneum , Polypropylenes , Prospective Studies , Retrospective Studies
2.
Chirurg ; 77(9): 844-55, 2006 Sep.
Article in German | MEDLINE | ID: mdl-16821051

ABSTRACT

BACKGROUND: Current German legislation ( (section sign) 115 b SGB V) allows groin hernia inpatient treatment only under particular circumstances. That allows the operative technique of first choice for outpatient groin hernia repair to be determined by basic market principles. The aim of this paper was to study the feasibility of outpatient minimally invasive hernia surgery with regard to complication rates, patient satisfaction, and economic considerations. METHODS: For 1 year, a total of 571 patients with inguinal hernias (131 male, eight female, mean age 46 years, all ASA I) were treated at two surgical centers. Twenty-four percent (139/571) underwent outpatient total extraperitoneal repair (TEP). Complication rates were recorded. Patient satisfaction with the procedure was evaluated by a standard questionnaire. Cost calculations were compared with revenues according to the EBM2000plus. RESULTS: Of the patients, 96.4% were discharged on the day of operation without subsequent rehospitalization, 84% had no fears of complications at home, 54% went back to work in less than 14 days, and 88.7% were willing to undergo TEP a second time if necessary. Calculated average total cost of euro 709 exceeded the revenue of euro 565 by 20%. CONCLUSION: For a carefully selected group, outpatient TEP is patient-friendly and safe. Despite these advantages, it still remains economically unattractive to hospital management because of the 20% cover shortage. Improvements in the current legislation are urgently desired.


Subject(s)
Ambulatory Surgical Procedures/legislation & jurisprudence , Hernia, Inguinal/surgery , Minimally Invasive Surgical Procedures/legislation & jurisprudence , National Health Programs/legislation & jurisprudence , Outcome Assessment, Health Care/legislation & jurisprudence , Adult , Ambulatory Surgical Procedures/economics , Ambulatory Surgical Procedures/statistics & numerical data , Costs and Cost Analysis , Female , Germany , Health Care Costs/legislation & jurisprudence , Health Care Costs/statistics & numerical data , Hernia, Inguinal/economics , Hernia, Inguinal/epidemiology , Humans , Male , Middle Aged , Minimally Invasive Surgical Procedures/economics , Minimally Invasive Surgical Procedures/statistics & numerical data , National Health Programs/economics , National Health Programs/statistics & numerical data , Outcome Assessment, Health Care/economics , Outcome Assessment, Health Care/statistics & numerical data , Patient Admission/economics , Patient Admission/legislation & jurisprudence , Patient Admission/statistics & numerical data , Patient Satisfaction , Postoperative Complications/economics , Postoperative Complications/epidemiology , Reoperation
3.
Int J Pharm ; 217(1-2): 161-72, 2001 Apr 17.
Article in English | MEDLINE | ID: mdl-11292552

ABSTRACT

Vesicular phospholipid gels (VPGs), highly concentrated phospholipid dispersions of semisolid consistency and vesicular morphology are under investigation as potential implantable depots for sustained release of drugs and as intermediates for subsequent dilution into 'conventional' liposome dispersions. It was investigated here if VPGs can be steam sterilised. VPGs prepared from 400 mg/g egg-phosphatidylcholine by high-pressure homogenisation retained their vesicular structure but showed a slight increase in vesicle size (freeze-fracture electron microscopy). However, autoclaving slowed down both, the in vitro release of the hydrophilic marker carboxyfluorescein and vesicles from VPGs. This was assumed to be due to bigger vesicle sizes and corresponding increase in packing density of the vesicular matrix. Upon dilution into a liposome dispersion both negative staining electron microscopy and dynamic laser light scattering analysis confirmed a distinct increase in liposome size, mainly due to fusion of small (20 nm) vesicles with unfavourable curvature. This was consistent with the observed increase in encapsulation efficiency of carboxyfluorescein. Phospholipid hydrolysis during autoclaving was negligible with lysophosphatidylcholine formation of less than 2% (thin layer chromatography). Despite significant change of their morphological and functional properties during autoclaving VPGs retained their main characteristics, such as vesicular structure, sustained release and dilutability to liposome dispersions, and are, therefore, considered as autoclavable.


Subject(s)
Phospholipids/chemistry , Steam , Sterilization , Fluoresceins/chemistry , Fluorescent Dyes/chemistry , Gels , Hydrolysis , Liposomes , Particle Size , Phosphatidylcholines/chemistry , Sterilization/methods
4.
Dtsch Med Wochenschr ; 125(15): 455-8, 2000 Apr 14.
Article in German | MEDLINE | ID: mdl-10800443

ABSTRACT

HISTORY AND ADMISSION FINDINGS: A 55-year-old woman had for 5 years been suffering from severe burning thoracic pain. She had typical risk factors for cardiovascular disease, namely hypertension, chronic smoking, obesity and hypercholesterolaemia. She had been hospitalized several times for suspected myocardial infarction, but coronary heart disease had been excluded by cardiac examination, including angiocardiography. The only contributory admission finding was epigastric pain on pressure. INVESTIGATION: Gastroscopy revealed a non-erosive duodenitis and chronic antral gastritis. The cardia was tightly closed and there were no signs of reflux oesophagitis. Manometry in the oesophagus showed frequent simultaneous contractions and marked increase in pressure amplitude, predominantly in the distal segment, indicating diffuse oesophageal spasms. TREATMENT AND COURSE: Drug treatment with calcium channel blockers gave only brief relief from the thoracic pain. But longitudinal oesophageal myotomy via thoracoscopy brought about complete pain relief, which has now persisted for 3 years. CONCLUSION: Thoracoscopic longitudinal oesophageal myotomy can provide a therapeutic alternative in patients with oesophageal spasms when drug therapy and pneumatic oesophageal dilatation have failed.


Subject(s)
Esophageal Spasm, Diffuse/surgery , Esophagus/surgery , Thoracoscopy , Chest Pain/etiology , Coronary Disease/diagnosis , Diagnosis, Differential , Esophageal Spasm, Diffuse/diagnosis , Female , Humans , Manometry , Middle Aged , Risk Factors
5.
Arch Surg ; 134(12): 1309-16, 1999 Dec.
Article in English | MEDLINE | ID: mdl-10593328

ABSTRACT

HYPOTHESIS: Perioperatively administered enteral immunonutrition will improve early postoperative morbidity and cost-effectiveness after gastrointestinal tract surgery. DESIGN: A prospective, randomized, double-blind, multicenter clinical trial. SETTING: Surgical departments in German university and teaching hospitals. PATIENTS: One hundred fifty-four patients with upper gastrointestinal tract malignant neoplasms who were eligible for analysis. INTERVENTION: Preoperatively, patients received 5 days of oral immunonutrition (an arginine-, RNA-, and omega3 fatty acid-supplemented diet) or an isoenergetic control diet (1 L/d). Early postoperative enteral feeding with immunonutrition or an isoenergetic, isonitrogenous control diet using a catheter jejunostomy was performed for 10 days. MAIN OUTCOME MEASURES: Postoperative infectious complications, their treatment costs, and cost-effectiveness of immunonutrition were analyzed. Plasma levels of the fatty acids eicosapentaenoic acid and docosahexaenoic acid were measured. RESULTS: In the immunonutrition group, significantly fewer infectious complication events occurred (14 vs 27; P = .05). The number of patients with complications was significantly lower in the supplemented diet group after postoperative day 3 (7 vs 16; P = .04). The treatment costs of complications in the supplemented diet group were suggestively lower than in the control diet group (DM 75172 vs DM 204273). Cost-effectiveness was DM 1503 in the experimental group vs DM 3587 in the control group, where DM denotes deutsche mark (German currency). CONCLUSION: The perioperative administration of an enteral immunonutrition significantly (P = .05) decreased the early occurrence of postoperative infections and reduced substantially the treatment costs of the complications after major upper gastrointestinal tract surgery.


Subject(s)
Adjuvants, Immunologic/administration & dosage , Enteral Nutrition/economics , Food, Formulated , Gastrointestinal Neoplasms/surgery , Aged , Docosahexaenoic Acids/blood , Double-Blind Method , Eicosapentaenoic Acid/blood , Fatty Acids, Omega-3/blood , Female , Gastrointestinal Neoplasms/mortality , Gastrointestinal Neoplasms/pathology , Humans , Male , Middle Aged , Neoplasm Staging , Prospective Studies
6.
J Chromatogr A ; 837(1-2): 117-28, 1999 Apr 02.
Article in English | MEDLINE | ID: mdl-10227179

ABSTRACT

The coupling of ion chromatography (IC) with electrospray mass spectrometry (ES-MS) opens new ways for the determination of polar organic micropollutants in water samples. The technique of conductivity suppression has been found to reduce the background signal in the range of about two orders of magnitude leading to a significant increase in sensitivity. In addition, the formation of salt adducts has been avoided. The usefulness of this method was proven on several polar and environmentally relevant micropollutants such as the herbicide glyphosate and its metabolite aminomethylphosphonic acid (AMPA), the chelating agent ethylenediamine tetraacetate (EDTA) and diacetonketogulonic acid (DAG). This present study has shown that IC-ES-MS is a simple, sensitive and quick method for the determination of these polar organic traces in water samples after separation on an anion-exchange column without any derivatization. In this work, several possibilities of applications of IC-ES-MS (with varying conditions) are presented. Analysis of glyphosate, AMPA, DAG and EDTA in ground and surface water has been achieved by IC-ES-MS without additional sample preparation at a concentration level of 1 microgram/l.


Subject(s)
Water Pollutants, Chemical/analysis , Chromatography, Ion Exchange , Edetic Acid/analysis , Fresh Water/analysis , Glycine/analogs & derivatives , Glycine/analysis , Herbicides/analysis , Indicators and Reagents , Mass Spectrometry , Solvents , alpha-Amino-3-hydroxy-5-methyl-4-isoxazolepropionic Acid/analysis , Glyphosate
7.
Eur J Pharm Biopharm ; 47(1): 61-71, 1999 Jan.
Article in English | MEDLINE | ID: mdl-10234528

ABSTRACT

Lauroyldextran (LD) and crosslinked galactomannan (XGM) were investigated as microbiologically degradable film coating materials for site-specific drug delivery to the colon. LD was used with degrees of substitution between 0.12 and 0.40, and swelling in aqueous media between 195 and 50%, XGM-batches showed swelling between 309 and 520%. Theophylline tablets were coated in a Hüttlin Kugelcoater with coating quantities of 4-17 mg/cm2. Sprayable coating formulations were obtained with 4% aqueous dispersions of XGM or 4% dispersions of LD in a 1:1 mixture of 1-propanol and water with 10% glycerol (based on the polymer) as a plasticizer. Theophylline dissolution was monitored in a USP XXIII paddle dissolution apparatus with buffer pH 5.5. After 4 h, which is an average small intestine transit time, colon conditions were simulated by adding galactomannanase or dextranase, respectively. Results showed similar dissolution rates for all XGMs and high-swelling LDs during the first 4 h and a relatively quick disintegration after enzyme addition. Both parameters decreased with increasing coating quantities. Dissolution from low-swelling lauroyldextrans was very low but no disintegration was observed after enzyme addition. The disintegration rate was found to be proportional to the square root of the enzyme activity. All swollen materials exhibited low mechanical stability. XGM coatings, especially at higher coating quantities, showed small transient ruptures at the edges not caused by enzyme addition. This behaviour was explained by internal stress due to the high degree of swelling. In principle, materials of both types proved to be suitable as degradable coating materials. The ideal zero-dissolution before and quick disintegration after enzyme addition, however, was not realized with the present materials.


Subject(s)
Colon/metabolism , Dextrans/chemistry , Drug Delivery Systems , Mannans/chemistry , Tablets, Enteric-Coated , Theophylline/administration & dosage , Biodegradation, Environmental , Cross-Linking Reagents , Dextranase , Drug Stability , Galactose/analogs & derivatives , Mannosidases
8.
Med Klin (Munich) ; 94 Suppl 1: 12-6, 1999 Feb 15.
Article in German | MEDLINE | ID: mdl-10194942

ABSTRACT

In this short review the fundamental differences between pH- and diffusion-controlled drug releases are outlined. In a following step the characteristics of single unit- and multiple units-dosage forms are discussed, and the predominantly used excipients for pH- and diffusion-controlled drug release are mentioned. Finally the influences of such special galenical designs for controlled drug release are explained in the light of some selected examples. The exact knowledge and consideration of these facts are extremely important in the development of optimal drug systems, in the interpretation of results, and with respect to interdisciplinary cooperation, e.g. between pharmaceutical technologists and pharmacologists.


Subject(s)
Cellulose/analogs & derivatives , Drug Delivery Systems , Excipients , Gastrointestinal Agents/administration & dosage , Administration, Oral , Delayed-Action Preparations , Diffusion , Dosage Forms , Gastrointestinal Agents/pharmacokinetics , Humans , Hydrogen-Ion Concentration , Polymethacrylic Acids
9.
Eur J Pharm Biopharm ; 46(2): 229-32, 1998 Sep.
Article in English | MEDLINE | ID: mdl-9867439

ABSTRACT

The intention of this study was to show under which conditions a film forming methacrylic acid copolymer coating excipient, corresponding to the requirements of pharmacopoeia, but obtained from different sources, can be substituted without severe problems. The mechanical properties of the film coats were investigated by dynamic-mechanical thermo-analysis (DMTA) experiments to determine with respect to the glass transition the storage modulus E', the loss modulus E'', and the loss factor tan delta. Further determinations concerned the surface tensions of the different coating dispersions. This attribute plays an important role in spreading, distribution and coalescence of the film forming preparations. Finally by a series of small experimental fluidized bed batches cores containing a model drug were coated with the different methacrylic acid copolymers. The resistance of these coated tablets in 0.1 N HC1 as well as their dissolution rates in artificial intestinal juice were tested. The coatings proved themselves so similar that in this case substitutions of products of different provenance are possible. The determinations of surface tension and the DMTA measurements seem to be useful and reliable preliminary applicability tests.


Subject(s)
Caffeine/chemistry , Citrates/chemistry , Methacrylates/chemistry , Glass , Hot Temperature , Surface Tension , Thermodynamics
10.
Zentralbl Chir ; 123(2): 163-6, 1998.
Article in German | MEDLINE | ID: mdl-9556890

ABSTRACT

The repair of multiple recurrences of inguinal hernias remains a surgical challenge. In 38 patients with a problematic recurrent inguinal hernia we implanted a polypropylene mesh (Prolene) in order to reinforce the transversalis fascia and to repair the inguinal hernia. 20 of these were medial and 14 lateral hernias; 4 patients had a combination of both types. All patients were prospectively included into this study and were seen in median follow-up periods of 3 and 6 months, as well as 4 and 9 years. As early complications hematoma of the wound (n = 3), scrotal edema (n = 1), temporary pain at the wound site (n = 12) and paresthesia (n = 13) occurred. Two patients (n = 2) developed a femoral hernia and one patient suffered from a persisting nerve injury of the ilioinguinal nerve. Due to the low complication and recurrency rate the tension free repair with polypropylene mesh is a effective method for treatment of problematic recurrent hernias.


Subject(s)
Hernia, Inguinal/surgery , Polypropylenes , Postoperative Complications/surgery , Surgical Mesh , Adult , Aged , Aged, 80 and over , Female , Follow-Up Studies , Humans , Male , Middle Aged , Recurrence , Reoperation , Treatment Outcome
11.
Zentralbl Chir ; 123(2): 199-201, 1998.
Article in German | MEDLINE | ID: mdl-9556897

ABSTRACT

This is a case report of a female patient who during a routine follow-up after a gastrectomy showed a tumor of the ileo-cecal valve, which--according to all radiologic diagnostic procedures--was highly suspected to be a malignant tumor. However, the histologic diagnosis was benign lipoma. The incidence and the characteristics of gastrointestinal lipomas in the actual literature will be reviewed.


Subject(s)
Ileal Neoplasms/diagnosis , Ileocecal Valve , Lipoma/diagnosis , Anastomosis, Surgical , Carcinoma/surgery , Female , Gastrectomy , Humans , Ileal Neoplasms/pathology , Ileal Neoplasms/surgery , Ileocecal Valve/pathology , Ileocecal Valve/surgery , Lipoma/pathology , Lipoma/surgery , Middle Aged , Neoplasms, Multiple Primary/diagnosis , Neoplasms, Multiple Primary/pathology , Neoplasms, Multiple Primary/surgery , Postoperative Complications/diagnosis , Postoperative Complications/pathology , Postoperative Complications/surgery , Stomach Neoplasms/surgery
12.
Zentralbl Chir ; 123(11): 1306-8, 1998.
Article in German | MEDLINE | ID: mdl-9880853

ABSTRACT

Gastrostomy or jejunostomy allow a safe and effective long-term enteral nutritional support. In patients with stenosis of the upper gastrointestinal tract the percutaneous endoscopic route is frequently not feasible. In these cases a laparoscopic approach is proposed. In 18 patients (n = 18) mostly with recurrent tumors of the upper gastrointestinal tract a laparoscopic catheter was placed into the jejunum without complications. Enteral feeding was started on the first day after catheter placement. One patient experienced a cathetersite infection. We describe a modified technique of laparoscopic jejunostomy the placement which is easy, effective and less invasive.


Subject(s)
Catheters, Indwelling , Enteral Nutrition/instrumentation , Jejunostomy/instrumentation , Laparoscopes , Gastrointestinal Neoplasms/therapy , Humans , Needles , Treatment Outcome
13.
Pharmazie ; 51(5): 283-7, 1996 May.
Article in English | MEDLINE | ID: mdl-8710952

ABSTRACT

New physiologically approached in vitro assays are presented which allow rather quick and uncomplicated determinations of the hemolytic activity of surfactants, intended mainly to solubilize poorly soluble drugs in parenteral dosage forms. The extent and the rates of the hemoglobin release from erythrocytes during the incubation of blood with increasing additions of surfactants is thought to be a very suitable and realistic estimation of the membrane damaging side effects of amphiphilic substances. In this study the extent of free hemoglobin released into the plasma is determined by a spectrophotometric method, as well as by an enzymatic determination measuring the lactate dehydrogenase (LDH) activity. LDH is released in a similar way from damaged erythrocytes. The results of these two methods are compared. They correspond satisfactorily.


Subject(s)
Hemolysis/drug effects , Surface-Active Agents/pharmacology , Adult , Erythrocytes/drug effects , Erythrocytes/enzymology , Hemoglobins/analysis , Humans , In Vitro Techniques , L-Lactate Dehydrogenase/blood , Spectrophotometry, Ultraviolet
14.
Clin Nutr ; 14(5): 275-82, 1995 Oct.
Article in English | MEDLINE | ID: mdl-16843943

ABSTRACT

Following severe trauma or major surgery patients develop functional alterations of host defense mechanisms which contribute an enhanced susceptibility towards microbial infections. Several studies have demonstrated that a specialized nutritional regimen may improve immune functions. We analyzed leukocyte functions from 40 patients undergoing major upper gastrointestinal surgery in a randomized placebo-controlled double-blind study. Patients were divided into two groups, one received 5 days pre-operatively an orally given experimental supplement enriched with omega-3-fatty acids, arginine, and ribonucleic acid (RNA), the other an isocaloric, control supplement. The experimental group generated significantly more leukotriene B(5) (LTB(5)) as compared to the control group. In contrast, the capacity to generate leukotriene B(4) (LTB(4)) as well as the synthesis of interleukin-8 (IL-8) was not significantly different in both groups. Additionally, lymphocyte/monocyte proliferation was analyzed and donor specific heterogeneities were observed; but no significant differences were found between the two nutritional regimens.

15.
Arch Pharm (Weinheim) ; 328(9): 645-53, 1995 Sep.
Article in English | MEDLINE | ID: mdl-7487421

ABSTRACT

The development of a galenical formulation for poorly water soluble dichloroplatinum(II) complexes suitable for the parenteral administration in cancer chemotherapy is described. The procedure, which we elaborated for [(+/-)-1,2-bis(4-fluorophenyl)ethylenediamine]dichloroplatinum(II) (rac-4F-PtCl2), is based on the reaction of a soluble diaquaplatinum(II) salt with sodium chloride in water in the presence of pluronic F 68 as stabilizer and results in a sufficiently stable colloidal solution (i.e. hydrosol). In contrast to the poorly water soluble synthetic rac-4F-PtCl2, which was ineffective towards the hormone sensitive MXT-M-3.2 breast cancer of the mouse, its hydrosol formulation proved to be highly active and was very well tolerated.


Subject(s)
Antineoplastic Agents/isolation & purification , Organoplatinum Compounds/isolation & purification , Animals , Antineoplastic Agents/administration & dosage , Antineoplastic Agents/pharmacology , Drug Stability , Female , Humans , Infusions, Parenteral , Mammary Neoplasms, Experimental/drug therapy , Mice , Organoplatinum Compounds/administration & dosage , Organoplatinum Compounds/pharmacology , Solubility , Tumor Cells, Cultured
16.
Pharmazie ; 50(7): 481-6, 1995 Jul.
Article in German | MEDLINE | ID: mdl-7675891

ABSTRACT

New amphiphilic polymer networks based on methacrylates with amphiphilic side-chains were prepared by cross-linking. Undecanol was the lipophilic part and tetraoxyethylen the hydrophilic part of the side-chain. The cross-linking was performed by a similarly derived amphiphilic dimethacrylate connecting structure. To characterize the relevant membrane features, like solvatation, degree of cross-linking, phase behavior and glass transition temperature, predominantly the swelling properties in water as well as in certain organic solvents, but also polarisation microscopic examinations were used. It was intented to assess the dependence of these parameters from the degree of cross-linking. For this reason the different systems were ranked accordingly to their cross-linking. Their swelling degree was determined in the indifferent dioxane as swelling medium. In the binary phase diagram with water the systems show a prominent laminary phase in the area with water contents of about 20-80% up to a maximum temperature of 35 degrees C. The phase behavior was also confirmed by thermal analysis, and the results of swelling measurements in water. Despite the relatively small hydrophilic part of the molecule, the swelling of the tested new cross-linked systems is more intensive in water than in nonpolar organic solvents. The swelling characteristics and phase behavior show a certain comparability to the human skin.


Subject(s)
Membranes, Artificial , Skin Absorption/physiology , Cross-Linking Reagents , Kinetics , Models, Biological , Polymethacrylic Acids , Temperature
17.
Pharmazie ; 50(6): 403-7, 1995 Jun.
Article in German | MEDLINE | ID: mdl-7544467

ABSTRACT

The solubilization of poorly water soluble drugs in surfactant solutions is still a problem in pharmaceutical technology. There doesn't exist any surfactant which can be applied unrestricted in parenteral dosage forms. For this reason, alkylpolyglycosides and fatty esters of dextran were investigated. Their solubilization behaviour and hemolytic activity was tested and compared to established surfactants. For solubilization, only water soluble surfactants can be used. That means, that only alkylpolyglycosides with two or more glucose units and dextran esters with a degree of substitution of 0.1 or less may be applied. The determination of the CMC of alkylpolyglycosides by solubilization of fluorescent substances shows a plot, typical for monomeric surfactants. The dextran esters show no CMC. They actually are polymeric surfactants and form monomolecular micelles. The differences in hemolytic activity of the alkylpolyglycosides run up to the factor 100. The hemolytic activity increase in this class of surfactants with the elongation of the alkyl chain and decreases with increasing degree of glycosylation. It doesn't exist any correlation between the CMC and the hemolytic activity. For diazepam the differences in solubilization behaviour are rather low. The solubilization behaviour is more effective than that of Solutol HS 15. The hemolytic activity of the dextran fatty esters is low, compared with the alkylpolyglycosides.


Subject(s)
Hemolysis/drug effects , Surface-Active Agents/chemistry , Surface-Active Agents/pharmacology , Chemical Phenomena , Chemistry, Physical , Dextrans , Fluorescence , Glycosides , Humans , In Vitro Techniques , Micelles , Spectrometry, Fluorescence
18.
Pharmazie ; 50(4): 263-9, 1995 Apr.
Article in German | MEDLINE | ID: mdl-7540763

ABSTRACT

In this paper production methods of certain colon-degradable dextran fatty acid esters and their relevant properties as excipients for colon-targeting dosage forms are reported. Such dextran fatty acid esters must be insoluble in, resp. resistant against, gastric and small intestinal fluids. But to a certain degree they must be swellable in aqueous liquids in order to allow an enzymatic attack of the colonic microflora. Furthermore, they must be adequately soluble in pharmaceutically accepted solvents to permit the technological application of film coatings. Otherwise, they can only be used as embedding excipients or matrices. As the most suitable excipients for film coatings, biodegradable by the colonic microflora, but resistant against gastric and small intestinal fluids, the dextran lauroyl esters were found. Their molecular weight have to be between 60,000 and 250,000, and their average degree of substitution (DS) between 0.06 and 0.2. Are the molecular weights higher the DS must be correspondingly lower.


Subject(s)
Colon/drug effects , Dextrans/pharmacology , Fatty Acids/pharmacology , Colon/microbiology , Dextrans/chemistry , Fatty Acids/chemistry , Molecular Weight , Solubility
19.
Pharmazie ; 50(3): 191-4, 1995 Mar.
Article in German | MEDLINE | ID: mdl-7732050

ABSTRACT

Up to now there is no excipient for the solubilization of poorly watersoluble drugs that can be used without limitations in pharmaceutical preparations for intravasal application. The available surfactants show considerable hemolytic activity, cause anaphylactic reactions are chemically instable or have no sufficient solubilizing capacity. By polymerisation of non-ionic surfactants amphiphilic side-chain-polymers are obtained which show in vitro the same solubilization capacity as the monomers but exhibit practically no hemolytic activity. The objective of this work was to investigate, if this findings are also true for ionic oligomers. For this purpose, polyacrylic acids were substituted with long-chain alkyl amines. The solubilization capacity of these oligomers exceeds that of non-ionic amphiphilic side-chain-polymers and that of other surfactants. The hemolytic activity of the oligomers was below that of common ionic surfactants. The solubilization capacity as well as the hemolytic activity depends on the oligomers degree of substitution. Considering their high solubilization capacity and their low hemolytic activity, these oligomers may be excipients in preparations for parenteral application.


Subject(s)
Electrolytes/chemistry , Excipients/chemistry , Polymers/chemistry , Diazepam/administration & dosage , Diazepam/pharmacokinetics , Diazepam/pharmacology , Electrolytes/pharmacology , Excipients/pharmacology , Hemolysis/drug effects , Humans , In Vitro Techniques , Injections, Intravenous , Micelles , Molecular Conformation , Polymers/pharmacology , Surface-Active Agents/pharmacology
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