SEARCH · PubMed Health

Results for “Capsules”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 361 records · Page 20Linked to original sources

PubMed1990

[A pathological and histochemical study of capsules of impacted teeth with special reference to keratin immunohistochemistry in the lining epithelium].

The purpose of this study was to examine and understand the nature of capsules consisted of fifty cases of unerupted wisdom teeth using radiological, pathological and immunohistochemical methods. Radiologically, the pericoronal space was measured with slide caliper and divided into three groups (-0.9 mm, 1.0-1.9 mm, 2.0mm). Pathologically, all specimens were examined by the routine paraffin method and were stained with hematoxylin.eosin and PAS-alcian blue pH 2.5 stainings. Immunohistochemically, PAP (peroxidase-antiperoxidase) method using various keratin antibodies, such as, anti-keratin K 528 (40-68 KD), anti-cytokeratin PKK 1 (40, 45, 52.5 KD), anti-cytokeratin PKK 2 (40, 46, 48, 54 KD), anti-keratin A 575 (56, 64 KD) and anti-cytokeratin high molecular weight (68 KD), and other various antibodies of anti-EMA, anti-IgA and anti-SC was used in order to study the nature of the epithelium of capsule of impacted teeth. The following results were obtained; 1. Radiologically, the width of the capsules was 1.6 mm in the average. Histopathologically, the inner surface of the capsule was covered with two types of epithelium which were composed of non-typical epithelium with cuboidal (basal layer) and columnar (superficial layer) cells, and typical stratified squamous epithelium. The epithelium lining was observed in 74% of all cases. Among the cases, cyst like structure was more often seen in the cases with typical squamous epithelial lining and with pericoronal space more than 1.0 mm width. 2. In the connective tissue's findings of capsules of impacted teeth, fibrosis was found in almost all the cases. Inflammatory and myxomatous changes were recognized in ca. half cases. Epithelial rest and calcification with dystrophy and epithelial product were observed in about one third of the cases. The epithelial proliferation in the capsule was also rarely seen in the specimens. 3. Immunohistochemically, keratins of 56 KD and 64 KD were identified in the superficial layer of non-typical epithelium and basal, intermediate and superficial layers of the typical squamous epithelium of the capsules of imparted teeth. Keratin of 68 KD was only observed in superficial layer of squamous epithelium. 4. Epithelial membrane antigen was positive in the intermediate and superficial layers of typical squamous cell epithelium. However, it was not seen in the non-typical epithelium of capsule of impacted teeth. 5. Immunoglobulin A and secretory component were negative in the epithelia of capsules.

Epithelium↗

PubMed1990

Capsules and virulence in the HAP group of bacteria.

Many species in the genera Haemophilus, Actinobacillus, and Pasteurella produce serotype-specific, negatively-charged, polysaccharide capsules. In pure form, these capsules are nontoxic, relatively inert biologically, and some are poorly immunogenic. The capsule forms the outer-most surface of the bacterium, and prior to the development of specific antibody, inhibits the bactericidal and opsonic activity of normal serum. In contrast, noncapsulated isogenic mutants are generally avirulent, and are quickly cleared by host defenses. In conjunction with the bacterial cell, or through covalent conjugation to a protein carrier, relatively high titers of antibody to capsule can be produced in immunocompetent hosts. For some pathogens (such as H. influenzae type b) antibody to capsule alone is bactericidal, opsonic, and adequate for complete protection against disease. For pathogens that produce potent exotoxins, however, (such as P. haemolytica and A. pleuropneumoniae) antibody to capsule alone may provide only partial protection. The composition or structure of the capsule may also influence the relative virulence of a particular organism. Molecular analysis of the interaction between capsules and host defenses will be required to understand more fully how capsules influence bacterial virulence.

Animals↗

PubMed1984

Interaction of metastatic tumor cells with bovine lens capsule basement membrane.

The use of bovine lens capsule basement membrane as a model substratum for studies of invasion and extravasation by metastatic tumor cells is described. The abilities of three independently isolated pairs of metastatic variant cell lines to digest the purified substrates, laminin, type IV collagen, and type I collagen, were compared with their abilities to solubilize isotope from 125I-labeled lens capsule basement membrane matrix. The cell lines used were +SA and -SA mouse mammary adenocarcinoma cells, RT7-4bs and RT7-4b-Ls rat hepatocarcinoma cells, and B16-F1 and B16-F10 mouse melanoma cells. In general, imperfect correlations of lytic activity with metastatic ability were found for the purified substrate digestions, but, for each pair of variants, the more metastatic tumor cell line was always able to solubilize more surface-bound isotope from the lens capsule. Visual evidence of tumor cell-associated digestion of lens capsule basement membrane was obtained using transmission electron microscopy. Mouse mammary carcinoma cells attached more rapidly to lens capsule than to endothelial cell monolayers or tissue culture plastic. We next added endothelial cells to the model substrate. Aortic endothelial cells grew well on lens capsules without apparent synthesis of additional basement membrane matrix. In additional studies, the lens capsule was used in a chamber apparatus to demonstrate that cellular invasion of the full thickness of this basement membrane structure could be demonstrated and readily quantitated. Our results indicate that bovine lens capsule is a particularly versatile basement membrane structure useful for studies of tumor cell invasion and extravasation. In addition, the comparison of purified substrate digestions with lens capsule matrix digestion indicates the desirability of also using a matrix digest when correlating lytic abilities of tumor cells with their metastatic abilities.

Adenocarcinoma↗

PubMed1978

Thyroid capsule changes during the development of thyroid hyperplasia in the rat.

Young adult male Fischer rats were fed 0.25% thouracil in a low-iodine diet to produce hyperplasia of the thyroid gland. The capsule of the thyroid gland increased in thickness from approximately one cell in controls to a substantial multilayered structure. Increase in capsule thickness was noted by 3 days. The cell population of the capsule was largely fibroblasts, but during a period within the interval from 14 to 28 days, the capsule tended to be exceptionally thick and contained many mononuclear leukocytes. At later times the capsule was not quite as thick and the leukocytes largely disapproved. Capillaries developed in the capsule probably by sprouting. The capsule growth was so extensive that certain neighboring tissues were often incorporated into the capsule, including arteries, veins, nerves, striated muscle, and lymph nodes. There was some regional specificity in the development of capsular hyperplasia. Connective tissue increased around the thyroid and parathyroid glands but not between them. Connective tissue in partitions with the thyroid gland also increased in thickness, although the extent of accumulation of cells and intercellular matrix was much less than in the capsule.

Animals↗

PubMed2006

The risk of retention of the capsule endoscope in patients with known or suspected Crohn's disease.

OBJECTIVES: Capsule endoscopy (CE) allows visualization of the mucosa of the entire small bowel and is therefore a potentially important tool in the evaluation of patients with known or suspected Crohn's disease (CD). However, small bowel strictures, which are not uncommon in Crohn's, are considered to be a contraindication to CE for fear of capsule retention. Our goal was to determine the risk of capsule retention in patients with suspected or known CD. METHODS: We retrospectively reviewed the records of 983 CE cases performed at three private gastroenterology practices between December 2000 and December 2003, and selected those with suspected or proven Crohn's. RESULTS: A total of 102 cases were identified in which CE was used in patients with suspected (N = 64) or known (N = 38) CD. Only one of 64 patients (1.6%) with suspected CD had a retained capsule. However, in five of 38 (13%) patients with known Crohn's, the capsule was retained proximal to a stricture. Of the five cases of retained capsules, three strictures were previously unknown. In four cases, the obstructing lesions were resected without complications, leading to complete resolution of the patient's underlying symptoms. One patient chose not to undergo surgery and has remained without an episode of small bowel obstruction for over 38 months. CONCLUSIONS: Capsule retention occurred in 13% (95% CI 5.6%-28%) of patients with known CD, but only in 1.6% (95% CI 0.2%-10%) with suspected Crohn's. A retained capsule may indicate unsuspected strictures in Crohn's that may require an unexpected, but therapeutic, surgical intervention. Patients and physicians should be aware of these potential risks when using CE in CD.

Adolescent↗

PubMed2006

Biocompatibility of subsieve-size capsules versus conventional-size microcapsules.

Biocompatibility of cell-enclosing capsules, defined as suppression of pericapsular cellular reactions, is one of the factors governing the success of enclosed cell transplantation in in vivo cell therapy. Agarose capsules of subsieve size, less than 100 microm in diameter, and conventional size, approximately 300-1,000 microm in diameter, were implanted into the peritoneal cavity and epididymal fat pads of mice and rats, respectively, to determine the effect of a reduction in diameter to subsieve size. The degree of cellular reaction to the subsieve-size capsules was much lower than that of the conventional-size microcapsules, independent of implantation site. The frequency of overgrown subsieve-size capsules retrieved from the peritoneal cavities was less than 5% in contrast to approximately 20% for capsules 387 microm in diameter. In addition, no increase in floating cells, which are generated through capsule stimulation, was observed in the peritoneal cavity only with subsieve-size capsules. From these results, we concluded that subsieve-size capsules are more biocompatible than microcapsules of conventional size.

Adipose Tissue↗

PubMed2006

Ileus secondary to wireless capsule enteroscopy.

Wireless capsule enteroscopy, being a novel, painless investigative technique, is reported to be significantly superior to push enteroscopy in its ability to find bleeding abnormalities in the small intestine. Here we report a case of acute jejunal obstruction following wireless capsule endoscopy. The patient had a 1-month history of gastrointestinal bleeding of unknown source. Further evaluation including gastroscopy and colonoscopy, angiography and computed tomography (angio-CT), and radio-labeled erythrocytes scan failed to reveal a source of bleeding. Therefore, wireless capsule enteroscopy was performed. Before capsule endoscopy, there was no clinical or imaging evidence of strictures or stenosis. At readmission it could be shown that there were two inflamed strictures of the small intestine. The capsule was detected at a stricture of the small intestine detected by abdominal ultrasonography and conventional computed tomography. The patient underwent a medical treatment with steroidal and other anti-inflammatory drugs for a total of 23 days and was discharged without complaints. Acute laparotomy after readmission with jejunal ileus proofed the capsule occluding two highly inflamed jejunal stenosis caused by Crohn disease. The present case demonstrates the potential for complications when wireless capsule enteroscopy is performed in the presence of intestinal strictures. Any history of inflammatory bowel disease, abdominal irradiation, cancer, obstruction, and abdominal surgery must be elicited in detail and may exclude the use of wireless capsule enteroscopy.

Adult↗

PubMed1995

Localization of "lost" Norplant capsules using compression film screen mammography.

BACKGROUND: The complications of Norplant removal relate primarily to the length of time and amount of dissection required for removal of the capsules. Complications include swelling and pain at the removal site and, at times, capsule fracture. The inability to locate one or more of the capsules is a rare complication. Recommended methods for locating the capsules include plain film radiography and ultrasound imaging. However, in circumstances where neither of these techniques succeeds, no specific recommendations exist to enhance visibility of the capsules. CASE: We used compression film screen mammographic techniques of the soft tissue at the site of insertion to locate a "lost" Norplant capsule after both plain films and ultrasound images failed to reveal the location of the capsule. CONCLUSION: Film screen mammographic techniques may help locate "lost" Norplant capsules that are not visualized with either plain film radiography or ultrasound imaging of the insertion site.

Adolescent↗

PubMed2004

Comparison of the pharmacokinetics of lansoprazole 15- and 30-mg sachets for suspension versus intact capsules.

OBJECTIVE: The pharmacokinetic profiles of single doses of lansoprazole 15- and 30-mg sachets for suspension were compared with those of corresponding doses of lansoprazole oral capsules. METHODS: Healthy adult male and female subjects were randomized (1:1 ratio) into 2 Phase 1, open-label, single-dose, 2-sequence, 2-period complete crossover studies. In the first study, each subject received 1 lansoprazole 15-mg sachet mixed with water and 1 lansoprazole 15-mg oral capsule; in the second study, each subject received 1 lansoprazole 30-mg sachet mixed with water and 1 lansoprazole 30-mg oral capsule. Administration of the 2 formulations was separated by a washout period of > or =7 days. Blood samples were collected before and after each administration to assess the pharmacokinetic parameters of lansoprazole and bioequivalence between suspension and capsule. RESULTS: Thirty-six subjects (19 males, 17 females) with a mean (SD) age of 32.0 (9.6) years and mean (SD) body weight of 68.6 (10.5) kg received lansoprazole 15 mg. Thirty-six subjects (22 males, 14 females) with a mean (SD) age of 38.0 (8.3) years and mean (SD) body weight of 75.1 (9.7) kg received lansoprazole 30 mg. The pharmacokinetic parameters of the 15- and 30-mg lansoprazole sachets for suspension were similar to those of the corresponding doses of the oral capsules. The mean (SD) values for C(max) and AUC from time 0 to infinity (AUC(0-infinity) for the lansoprazole 15-mg sachet (591.9 [242.3] ng/mL and 1614 [2065] ng.h/mL, respectively) did not differ significantly from those for the lansoprazole 15-mg capsules (578.6 [275.2] ng/mL and 1620 [2290] ng.h/mL, respectively). These parameters also did not differ significantly between the lansoprazole 30-mg sachet and 30-mg capsule: mean (SD) C(max), 1103 (428.3) and 1077 (465.6) ng/mL, respectively; mean (SD) AUC(0-infinity), 2655 (1338) and 2669 (1311) ng.h/mL, respectively. The 90% Cls for C(max) and AUC(0-infinity) ratios were contained within the 0.80 to 1.25 equivalence range, supporting bioequivalence. CONCLUSIONS: These findings suggest that the 15- and 30-mg lansoprazole sachets for suspension are bioequivalent to the corresponding doses of oral capsules. The sachet for suspension may provide an alternative route of administration to patients who have difficulty swallowing solid oral formulations.

2-Pyridinylmethylsulfinylbenzimidazoles↗

PubMed2006

Capsule endoscopy: an alternative to duodenal biopsy for the recognition of villous atrophy in coeliac disease?

BACKGROUND: Villous atrophy present on a duodenal biopsy remains the 'gold standard' diagnostic test for coeliac disease. However, endoscopic biopsy may cause morbidity and discomfort. Our aim was to evaluate wireless capsule endoscopy as an alternative test for the recognition of villous atrophy. METHOD: Twenty-one patients with a positive endomysial antibody referred for endoscopy and duodenal biopsy were also offered a wireless capsule endoscopy to evaluate their small bowel. Concurrently, other patients (n=23) referred for a wireless capsule endoscopy acted as controls. Wireless capsule endoscopy reports were assessed for the presence of villous atrophy by one blinded investigator. RESULTS: Twenty endomysial antibody positive patients subsequently had villous atrophy on duodenal biopsy. The controls all had normal duodenal biopsies (with a negative endomysial antibody) and no evidence of villous atrophy noted on their wireless capsule endoscopy. Of the 20 endomysial antibody positive patients with confirmed villous atrophy on biopsy, 17 had villous atrophy also detected by wireless capsule endoscopy. The sensitivity, specificity, positive and negative predictive values for wireless capsule endoscopy recognising villous atrophy were 85%, 100%, 100%, 88.9%, respectively. CONCLUSION: Wireless capsule endoscopy may be an option to recognise villous atrophy in patients with a positive endomysial antibody who are unwilling, or unable to have a gastroscopy. However, a negative test should be followed by a biopsy if coeliac disease is to be excluded.

Adult↗

PubMed2006

Clinical outcome of patients examined by capsule endoscopy for suspected small bowel Crohn's disease.

BACKGROUND: Capsule endoscopy has a greater diagnostic yield than radiology for detecting subtle inflammatory changes of the small bowel mucosa, but the clinical significance of these abnormalities is still uncertain because of the lack of long-term follow-ups. AIM AND METHODS: To verify the accuracy of capsule endoscopy in a cohort of patients with suspected Crohn's disease of the small bowel, taking as 'gold standard' the final diagnosis made after a long follow-up. From April 2002 to March 2005, we enrolled and examined by capsule endoscopy 27 consecutive patients with abdominal pain and diarrhea lasting more than 3 months and at least one of the following: anaemia, weight loss, fever, extra-intestinal manifestation(s) of inflammatory bowel disease. All patients already had an unremarkable pan-endoscopy, serology for celiac disease and intestinal radiology inconclusive for small bowel abnormality. On the basis of capsule endoscopy findings, patients were distributed in three groups; Group A had severe stricturing lesions requiring surgery; Group B, moderate inflammatory lesions further investigated invasively; Group C, minimal inflammatory changes or normal findings, clinically observed every 3 months (median 21 months, range 15-29). RESULTS: Small bowel inflammatory lesions were found in 16 of the 27 patients (diagnostic yield 59%). Three had surgery (Group A) and Crohn's disease was confirmed in two; the remainder had ileal adenocarcinoma in a pathological context of chronic inflammation. Crohn's disease was histologically confirmed in four of the five patients in Group B. Group C comprised 19 patients; Crohn's disease was confirmed in seven out of eight with positive capsule endoscopy, while only one of the patients with normal findings later developed overt ileal Crohn's disease. Sensitivity, specificity, positive and negative likelihood ratio were, respectively, 93%, 84%, 5.8 and 0.08. Assuming a 50% pre-test probability of disease, capsule endoscopy gave a post-test probability of 85%. CONCLUSIONS: In our selected cohort, capsule endoscopy was highly sensitive in detecting small bowel inflammatory changes, enhancing by nearly 35% the pre-test probability of structural small bowel disease. Focal erythema and luminal debris may limit the specificity of capsule endoscopy.

Adult↗

PubMed2005

Production of enteric capsules by means of hot-melt extrusion.

The aim of this study was to develop an alternative technique for enteric coating consisting of the hot-melt extrusion of coating polymers. An enteric coating polymer (PVAP or HPMC AS), premixed with a plasticizer, was extruded into hollow cylinders. The hollow pipes were filled with a model drug and both open ends of the cylinders were closed, yielding hot-melt extruded enteric capsules. Main advantages of this new technology are the continuity of the process and its application for the formulation of moisture sensitive active ingredients. The enteric capsules showed excellent gastro-resistance, since no drug release was observed after 2 h 0.1N HCl. The influence of wall thickness (0.15, 0.3, 0.5, 0.8, and 1.0 mm) of the capsules on drug release was investigated. Enteric capsules with a wall thickness of 1.0 mm were subjected to a pH gradient dissolution method, simulating passage through the gastro-intestinal tract, in order to evaluate their suitability for ileal or colonic drug targeting. Storing the capsules for 1 month at high relative humidity (RH) (60 and 75% RH) revealed that the HPMC AS capsules were superior to the PVAP capsules. It can be concluded that hot-melt extruded capsules seem suitable as an alternative for enteric coating.

Capsules↗

PubMed2006

What we have learned from 5 cases of permanent capsule retention.

BACKGROUND: Capsule endoscopy allows the direct visualization of the entire small bowel. There is limited data on the clinical significance of permanent capsule retention. OBJECTIVE: Our purpose was to document the frequency, findings, risk factors, management, and outcomes of permanent capsule retention. DESIGN: Retrospective, case series. SETTING: Single tertiary referral center, outpatient. RESULTS: Permanent capsule retention occurred in 2% of our cases (5/245). The following pathologies caused insufficient capsule passage: adenocarcinoma in a patient with hereditary nonpolyposis colorectal cancer (1), idiopathic stenosis (1), stricturing Crohn's disease (2), and adhesions (1). Capsule retention lead to a symptomatic small-bowel obstruction in only 1 of these cases (0.4%). As a consequence, 2 cases had successful endoscopic retrieval; 3 cases required surgical intervention. Four of 5 patients had a clear clinical benefit resulting from the capsule findings or the secondary procedure. CONCLUSIONS: Permanent capsule retention is rare. Even though this event may lead to the necessity of an endoscopic or surgical intervention, a clear benefit for the patient in respect to the underlying disease resulted in 4 of 5 patients.

Aged↗

PubMed2005

Trials of clear aceclofenac-loaded soft capsules with accelerated oral absorption in human subjects.

To develop an effective oral drug delivery system with accelerated absorption in human subjects for a poorly water-soluble acelofenac, five aceclofenac-loaded soft capsule preparations containing various ratios of different solubilizers were prepared and their dissolution tests were carried out. Among five preparations tested, a preparation with ethanolamine was selected as a formula of aceclofenac soft capsule (Korea United Pharm. Co. Ltd., Clanza S, since it was clear in appearance and showed the fastest dissolution rate due to the solubility-enhancing effect of aceclofenac. To evaluate and compare the pharmacokinetics of acelofenac-loaded soft capsules with the conventional aceclofenac tablets (Dae-Woong Pharm. Co. Ltd., Airtal) in human subjects; 14 normal healthy male volunteers (age 20-25 years old) were divided into two groups and a randomized 2 x 2 cross-over study was performed. Following oral administration of one tablet or capsule, each containing 100mg of aceclofenac, blood samples were collected at the predetermined time intervals and the concentration of aceclofenac in plasma was determined by HPLC method using UV detector. The AUC, Cmax, MRT, t1/2 and Kel of aceclofenac delivered from soft capsule were not significantly different from those from aceclofenac-loaded conventional tablet. However, soft capsule gave significantly higher initial concentration and significantly faster Tmax of aceclofenac than did conventional tablet, suggesting that the soft capsule with ethanolamine showed the faster absorption of aceclofenac in human subjects. Thus, the clear aceclofenac-loaded soft capsule with ethanolamine was a more effective oral dosage form with fast absorption for poorly water-soluble aceclofenac.

Absorption↗

PubMed2004

Biomechanical changes in the anterior lens capsule after trypan blue staining.

PURPOSE: To examine the effect of trypan blue staining on the biomechanical behavior of the porcine anterior lens capsule. SETTING: Department of Ophthalmology, Technical University of Dresden, Dresden, Germany. METHODS: Fifty-five anterior lens capsules from porcine cadaver eyes were used. Two parallel 8.0 mm x 4.0 mm large capsule strips were prepared from each capsule. After trypan blue staining for various time intervals combined with exposure to white light (6000 lux) or with no light exposure, biomechanical stress-strain measurements were performed using an automated material tester. Untreated specimens and specimens treated with glutaraldehyde 0.1% were used as controls. The absorption spectrum of trypan blue 0.1% solution and the emission spectrum of the light source were measured. RESULTS: After treatment with light and trypan blue, at 25% strain, there was a statistically significant increase in stress of up to 70.1% and in elastic stiffness of 47% and a decrease in the ultimate mechanical strain of up to 13%. There were no biomechanical changes in capsules with trypan blue staining in the absence of light or after a short illumination time of 30 seconds, indicating a light-dependent process. After 30 minutes of glutaraldehyde 0.1% treatment, there was an increase in stress of 321.6% at 25% strain and a decrease in the ultimate strain of 47.6%. The emission spectrum of the light source included the absorption peak for trypan blue at 580 nm. CONCLUSIONS: Trypan blue staining of the lens capsule combined with light irradiation for at least 1 minute led to an increase in elastic stiffness at 25% strain and a reduction in the ultimate extensibility. This effect is probably due to the photosensitizing action of trypan blue, leading to light-induced collagen crosslinking of the capsule collagen similar to age-related crosslinking. Nucleus expression might be impeded by the increased capsule stiffness. Continuous curvilinear capsulorhexis is facilitated.

Animals↗

PubMed2003

Investigating the coating-dependent release mechanism of a pulsatile capsule using NMR microscopy.

Chronopharmaceutical capsules, ethylcellulose-coated to prevent water ingress, exhibited clearly different release characteristics when coated by organic or aqueous processes. Organic-coated capsules produced a delayed pulse release, whereas aqueous-coated capsules exhibited less delayed and more erratic release behaviour. Nuclear magnetic resonance microscopy was used to elucidate the internal mechanisms underlying this behaviour by studying the routes of internal water transport and the timescale and sequence of events leading to the pulse. Images showed that the seal between the shell and the tablet plug is a key route of water penetration in these dosage forms. There is evidence for a more efficient seal in the organic-coated capsule, and although some hydration of the contents was evident, erosion of the tablet plug is most probably the controlling factor in timed release. The premature failure of the aqueous-coated capsule appears to be a result of rapid influx of water between plug and capsule with hydration of the low substituted hydroxypropylcellulose expulsion agent. As a result of this, the tablet plug remains intact, but appears unable to be ejected. The resulting significant pressure build-up causes premature release by distortion and splitting of the capsule shell. These events may be aided by a weakening of the aqueous-coated gelatin shell by hydration from the inside, and at the mouth of the capsule where previous electron microscope studies have shown incomplete coating of the inside by the aqueous process.

Calcium Phosphates↗

PubMed1998

Crosslinked dextran--a new capsule material for colon targeting of drugs.

In the work presented here we have studied the application of glutaraldehyde crosslinked dextran as a capsule material for colon-specific drug delivery. A reaction mixture containing dextran, MgCl2, glutaraldehyde and polyethyleneglycol 400 in water was applied onto molding pins of nylon producing capsule caps and bodies. The capsule materials were characterized by measuring of the mechanical strength in compression and equilibrium degree of swelling. Based on these results an optimal composition for the capsule material was selected. The dextran capsules were loaded with hydrocortisone and subsequently, drug release was studied. The release was found to be about 10% during the initial 3 h in a buffer solution. Over a period of 24 h the release was about 35%. However, when the dextran capsules were challenged with a dextranase solution, simulating the arrival of the drug delivery system to the colon, the capsules quickly broke and the drug was released as a dose dump. The study shows that the dextran capsules are promising candidates for providing a colon-specific drug delivery.

Capsules↗

PubMed2002

Enteric coated HPMC capsules designed to achieve intestinal targeting.

The enteric coating of HPMC capsules containing paracetamol was investigated. Two enteric polymers, Eudragit L 30 D-55 and Eudragit FS 30 D were studied, which are designed to achieve enteric properties and colonic release, respectively. The capsules were coated in an Accela Cota 10, and, as shown by optical microscopy, resulted in capsules with a uniform coating. Scanning electron microscopy of the surface of the capsules illustrate that, in contrast to gelatin, HPMC has a rough surface, which provides for good adhesion to the coating. Dissolution studies demonstrated that capsules coated with Eudragit L 30 D-55 were gastro resistant for 2 h at pH 1.2 and capsules coated with Eudragit FS 30 D were resistant for a further 1 h at pH 6.8. The product visualisation technique of gamma scintigraphy was used to establish the in vivo disintegration properties of capsules coated with 8 mg cm(-2) Eudragit L 30 D-55 and 6 mg cm(-2) Eudragit FS 30 D. For HPMC units coated with Eudragit L 30 D-55, complete disintegration occurred predominately in the small bowel in an average time of 2.4 h post dose. For HPMC capsules coated with Eudragit FS 30 D, complete disintegration did not occur until the distal small intestine and proximal colon in an average time of 6.9 h post dose.

Capsules↗