Pancreatin preparations used in the treatment of cystic fibrosis-- lipase content and in vitro release.

BACKGROUND: Pancreatic extracts are essential in the treatment of the majority of cystic fibrosis patients. The clinical response to different preparations is often unpredictable and at present there is no sure method of determining the best preparation for a particular patient. METHODS: Creon, Nutrizym GR, Pancrease and the high-lipase versions, Creon 25,000, Nutrizym 22 and Pancrease HL, were investigated for lipase content and resistance to simulated gastric conditions. The rates of lipase release in response to pH change, bile salts and duodenal solids were investigated. The stability of lipase and its binding to duodenal solids were also investigated. RESULTS: Declared values for lipase content were exceeded in all preparations. All preparations were acid resistant. The release of lipase in response to pH change showed notable differences in release rates. After 20 min at pH 5.5, Creon released three times the amount of lipase compared with Pancrease, the other preparations coming within the range. Above pH 5.75, the release rates were comparable amongst the preparations. Bile salts influenced release variably whilst release in a solid-rich duodenal fluid was much slower than in buffers. The released lipase was susceptible to proteolysis and pH-dependent binding to duodenal solids; these effects may compromise lipolysis. CONCLUSIONS: These results show some factors contributing to variable clinical responses to pancreatic supplements. Improvements may result if a patient is assessed on different preparations.     

Comparative in vitro enzyme activities of five commercially available pancreatic supplements

A comparative in vitro analysis was performed of the enzyme activities contained in five commercial pancreatic supplements available in New Zealand. there was considerable individual variation between each product. Lipase was regarded as the most important enzyme, as lipase deficiency is the most significant clinical factor in patients with exocrine pancreatic insufficiency. Viokase not only contained the most lipase per tablet, but was also the cheapest product.     

In vitro comparative study of three pancreatic enzyme preparations: dissolution profiles, active enzyme release and acid stability

Background  Various pancreatic enzyme preparations are used for the treatment of pancreatic insufficiency but their bioequivalence is often unknown.
Aim  To determine in vitro the pH-dependent release and acid resistance of enzymes from three commercially available pancreatin capsules, two containing enteric-coated (Creon 25000; Eurobiol 25000) and one uncoated (Eurobiol 12500) microspheres.
Methods  Dissolution experiments were performed at pH values ranging from 4.0 to 5.8. Lipase, chymotrypsin and amylase activities were measured in the solution as a function of time.
Results  Eurobiol 25000 started to release its enzymes significantly at pH 5.0 ( t _1/2 = 71 min), whereas the enzymes from Creon 25000 were only released at higher pH value (5.4; t _1/2 = 49.2 min). Unlike chymotrypsin, lipase and amylase were highly sensitive to acidic conditions at the lowest pH values tested. Both enzymes were also found to be sensitive to proteolytic inactivation at the highest pH values tested. Overall, Eurobiol 25000 released higher amounts of active amylase and lipase than Creon 25000 at the pH values usually found in duodenal contents. The uncoated Eurobiol 12500 preparation was, however, the only one that could immediately release rather high levels of active chymotrypsin and lipase at low pH (4.5).
Conclusion  These findings suggest that pH-sensitive enteric-coated pancreatin products containing similar amounts of enzymes might not be bioequivalent depending on the pH of duodenal contents.     

Fate of orally ingested enzymes in pancreatic insufficiency: comparison of two pancreatic enzyme preparations

The effect on steatorrhoea of a pH-sensitive enteric-coated pancreatic preparation (Eurobiol 25,000) was compared with a conventional pancreatic enzyme preparation (Eurobiol) in six adult patients with exocrine pancreatic insufficiency. In addition, the fate of orally ingested pancreatic enzymes in the upper digestive tract was evaluated by measuring gastric and duodenal pH, amount of enzymes in the stomach, duodenal enzyme output, and fat absorption at the angle of Treitz for the 4 hours following a standard meal. When compared with placebo, Eurobiol and Eurobiol 25,000 reduced daily faecal fat excretion by 24% (not significant) and 43% (P less than 0.05), respectively. With the conventional preparation, enzyme output and fat absorption at the duodeno-jejunal flexure were significantly improved (P less than 0.05). Marked inter-individual differences in duodenal enzyme recovery (lipase 3% to 80%; chymotrypsin 26% to 100%) and, consequently, in the reduction of steatorrhoea (0% to 67%) were observed, with the gastric emptying rate emerging as a key determinant factor. With the enteric-coated preparation, enzyme output and fat absorption at the duodenojejunal flexure were not significantly improved. Discrepancy between the marked reduction of faecal fat excretion and the low duodenal enzyme recovery could indicate that enzyme delivery from microtablets occurs further down in the small bowel. Efficacy of enteric-coated preparations could be enhanced by adding unprotected enzymes, especially in patients with rapid gastric emptying.     

Ultrase MT12 and Ultrase MT20 in the treatment of exocrine pancreatic insufficiency in cystic fibrosis: safety and efficacy

BACKGROUND: Cystic fibrosis causes exocrine pancreatic insufficiency, leading to malabsorption. Supplemental pancreatic enzyme therapy alleviates the concomitant malnutrition experienced by cystic fibrosis patients. It is recognized that patients experience variations in clinical response to different brands of enzymes. This has prompted the US Food and Drug Administration to require that enzyme supplements be subjected to New Drug Applications. AIM: To investigate the safety and efficacy of supplemental pancreatic enzyme therapy in cystic fibrosis subjects. METHODS: We compared two doses of one formulation of enteric-coated pancreatic enzymes: Ultrase MT12 (12,000 lipase units per capsule) and Ultrase MT20 (20,000 lipase units per capsule), to placebo in two separate safety and efficacy studies. RESULTS: Mean total fat, protein and carbohydrate intake did not differ significantly between the groups. A significant difference in both fat and protein absorption occurred with the enzyme therapy groups. The Ultrase MT12 and Ultrase MT20 groups experienced a mean fat and protein absorption 79.4% and 83.8%, and 87.3% and 88.6%, respectively. No adverse events related to study drug were reported. CONCLUSIONS: This study further supports the use of enzymes to treat pancreatic insufficiency in cystic fibrosis. Excellent fat and protein absorption was achieved with minimal adverse events and safe doses.     

Treatment of steatorrhoea in cystic fibrosis: a comparison of enteric-coated microspheres of pancreatin versus non-enteric-coated pancreatin and adjuvant cimetidine

Enteric-coated microspheres of pancreatin were compared with non-enteric-coated pancreatin combined with cimetidine taken 40 min before meals in the treatment of patients with cystic fibrosis. Fourteen adults with steatorrhoea due to cystic fibrosis were investigated in an open, randomized crossover study, over two consecutive 28-day treatment periods. Lipase intake was adjusted to each patient's previous requirements and was the same during both months; they were instructed to continue with their normal diet. Patients collected faeces for 72 h at the end of each month and completed diary cards daily throughout. Bowel actions were less frequent on enteric-coated microspheres of pancreatin than on non-enteric-coated pancreatin/cimetidine (1.7 vs. 2.4/day; P less than 0.001) and stool character was improved (P less than 0.001). Mean daily faecal weight was similar on enteric-coated microspheres of pancreatin to that on the combination (254 g vs. 291 g; N.S.), whereas daily faecal fat excretion tended to be less on enteric-coated microspheres of pancreatin (21 g vs. 27 g; N.S.), and percentage fat absorption tended to be greater (81% vs. 73%; N.S.). Mean body weight increased by 0.3 kg on enteric-coated microspheres of pancreatin and fell by 0.1 kg on the combination (N.S.). These data indicate that enteric-coated microspheres of pancreatin are at least as effective as non-enteric-coated pancreatin with cimetidine in the treatment of steatorrhoea in cystic fibrosis.     

Effect of oral pancreatic enzyme administration on digestive function in healthy subjects: comparison between two enzyme preparations

Background : Intraduodenal proteases exert a negative feedback on pancreatic secretion.
Aim : To investigate the effect of two pancreatic enzyme preparations (enteric-coated tablets, and capsules with enteric-coated microtablets) on postprandial pancreatic and bile acid secretion, gastroduodenal motility and release of gastrin and pancreatic polypeptide in healthy humans.
Methods : Twenty healthy males were studied on two different days one week apart. After an overnight fast a nine-lumen motility tube was positioned with the distal tip at the Treitz angle. On each study day, 30 min after an interdigestive migrating motor complex-phase III, a semi-liquid test meal was given either alone ( n =20) or with enzymes (3 tablets ( n =10) or 2 capsules with microtablets ( n =10); 40000 U lipase and 2000 proteases) in a randomized order, and the study continued over 2 h. Motility was continuously recorded with four ports in the antrum and three in the duodenum, using a low-compliance pneumohydraulic perfusion system. Secretion of human-specific pancreatic elastase and bile acids was measured by a standard duodenal intubation perfusion technique. Plasma concentrations of gastrin and pancreatic polypeptide were measured by specific radioimmunoassays.
Results : Postprandial pancreatic secretion was significantly reduced by administration of microtablets (median 82 mg/2 h vs. 70 mg/2 h, P <0.02) but not by tablets (median 59 mg/2 h vs. 58 mg/2 h, N.S.). No changes were observed in bile acid secretion, antroduodenal motility or release of gastrin and pancreatic polypeptide.
Conclusions : Oral administration of pancreatic enzymes at normal therapeutic doses significantly inhibits postprandial pancreatic secretion in healthy humans, when capsules with enteric-coated microtablets are given. Exogenous pancreatic enzymes have no significant effect on bile acid secretion, gastroduodenal motility and hormone release.     

Post-prandial intragastric and duodenal acidity are increased in patients with chronic pancreatitis

OBJECTIVES: Patients with chronic pancreatitis and exocrine insufficiency have lower intraduodenal pH compared to controls. It has been assumed that abnormal low intraduodenal pH in these patients not only results from impaired pancreatic bicarbonate secretion but also from an increased gastric acid load to the duodenum. METHODS: We have tested this hypothesis by combined intragastric and intraduodenal 24 h pH monitoring in nine chronic pancreatitis patients with exocrine pancreatic insufficiency and nine healthy control subjects during standardized test conditions. Postprandial gastrin and cholecystokinin release were also determined. RESULTS: Median 24-h intraduodenal pH (5.90 vs. 6.00) and intragastric pH (1.60 vs. 1.70) were not significantly different between patients and controls. However, in the 2-h postprandial periods intraduodenal pH was below five for a significantly higher percentage of time in chronic pancreatitis patients compared to controls (lunch: 14.5% vs. 0.17%, P=0.011; dinner: 24.1% vs. 5.75%, P=0.05). The post-dinner intragastric pH was below three for a significantly higher percentage of time in chronic pancreatitis patients vs. controls (72.2 vs. 48.9%, P=0.04). Postprandial gastrin release was not significantly different between the two groups. Postprandial secretion of cholecystokinin (CCK), as enterogastrone, was significantly (P < 0.01) reduced in chronic pancreatitis patients (78 +/- 13 pmol/L, 120 min) compared to controls (155 +/- 14 pmol/L, 120 min). CONCLUSIONS: Median intraduodenal and intragastric pH are not significantly decreased in patients with chronic pancreatitis and exocrine insufficiency but the postprandial time with an acidic pH in the duodenum (pH < 5) and in the stomach (pH < 3) is significantly (P 相似文献   

In vitro dissolution profiles of enteric-coated microsphere/microtablet pancreatin preparations at different pH values

Objectives : Enteric-coated microsphere/microtablet pancreatin should stay intact in the stomach and dissolve promptly on entering the duodenum. Post-prandial intraluminal pH in the distal duodenum is 5.75 and is lower in exocrine pancreatic insufficiency. The aim of the study was to measure in vitro dissolution times in buffer solutions with pH 4.0–6.0 for five currently available enteric-coated microsphere/microtablet pancreatin preparations.
Methods : The following preparations were tested: Creon, Creon Forte, Pancrease, Pancrease HL and Panzytrat. Two capsules were placed in the buffer solution at 37 °C in a USP dissolution testing apparatus. Buffer solutions with pH between 4.0 and 6.0 were used. Solutions were stirred at 125 r.p.m. and the rate of dissolution was monitored by taking 2-mL samples at regular intervals and measuring extinction at 280 nm. Measurements were repeated six times.
Results : All preparations failed to dissolve at pH 4.0. At pH 5.0 Pancrease HL showed 43% dissolution within 30 min, all other preparations 15% or less. Panzytrat and Pancrease HL showed more than 50% dissolution within 30 min at pH 5.2. Panzytrat, Pancrease HL and Creon Forte had more than 90% dissolution within 30 min at pH 5.6, and all preparations more than 90% dissolution within 30 min at pH 5.8 and higher.
Conclusions : For the treatment of exocrine panceatic insufficiency conventional strength enteric-coated microsphere/microtablet pancreatin preparations do not have an optimal dissolution profile. The newer, high lipase preparations such as Pancrease HL perform better, although still not optimally, at pH 5.4 and lower.     

Pancreatic enzyme pharmacotherapy

Supplemental pancreatic enzyme preparations are provided to patients with conditions of pancreatic exocrine deficiency such as chronic pancreatitis and cystic fibrosis. These patients frequently experience steatorrhea, which occurs from inadequate fat absorption. The delivery of sufficient enzyme concentrations into the duodenal lumen simultaneously with meals can reduce nutrient malabsorption, improve the symptoms of steatorrhea, and in some cases alleviate the pain associated with chronic pancreatitis. Current clinical practices dictate administration of lipase 25,000-40,000 units/meal by using pH-sensitive pancrelipase microspheres, along with dosage increases, compliance checks, and differential diagnosis in cases of treatment failure. Despite the large number of specialty enzyme replacements available commercially, many patients remain dissatisfied with standard therapy, and future developments are needed to optimize treatment in these individuals.     

A comparison of two pancreatin microsphere preparations in cystic fibrosis.

OBJECTIVES: to compare the efficacy and tolerance of Creon and Pancrease in children and young adults with cystic fibrosis. METHODS: a double blind, crossover study of two pH sensitive microsphere preparations of pancreatin (Creon, Pancrease), given in equivalent lipase dosage to 27 children with cystic fibrosis, was conducted. RESULTS: at similar lipase activity no significant difference was found in the following: coefficient of fat absorption (CFA), coefficient of nitrogen absorption (CNA), weight gain, mean adequate daily intake for energy, and subjective symptoms. Three children who had a CFA less than 70% while receiving Pancrease all improved on Creon. No children had a CFA less than 70% while receiving Creon. A significant reduction in the number of capsules required daily to achieve similar control was possible when changing from Pancrease (mean 25/day) to Creon (mean 15/day). Seventy percent of patients preferred Creon and this was likely to be related to a perceived reduction in abdominal pain and stool frequency, and need for less capsules per day. CONCLUSION: Creon and Pancrease are equally effective at doses providing equal lipase activity, however, the reduced number of capsules, fewer symptoms, and possible improvement of more severe steatorrhoea result in an increased patient preference for Creon.     

Cimetidine and postprandial pancreatic exocrine secretion in dogs

In dogs fitted with a pancreatic cannula and a duodenal cannula the intake of a standard meal induced a significant increase in the flow of pancreatic secretion and in the output of amylase, total protein, bicarbonate and chloride. The oral administration (200 mg/day) of cimetidine to dogs was seen to elicit a marked decrease in postprandial flow increase and bicarbonate output, coinciding with a significant increase in amylase and total protein output. At the same time the postprandial duodenal pH remained at levels similar to those obtained in basal periods. The implications of secretin, gastrin and cholecystokinin (CCK) on these effects are discussed.     

Free fatty acids and lipolytic activity of the pancreas of irradiated rats

The effect of X-ray irradiation (800 R) on the lipolytic activity of pancreas was studied in rats. Lipase activity was assayed in the granules of zymogenmitochrondial fraction and in the perfusion fluid and free fatty acids (FFA) content was determined in blood serum, pancreatic homogenates and in perfusion fluid. The irradiation caused a marked increase of the activity of lipase released from zymogen-mitochondrial fraction. In the perfusate the enhancement of lipase activity accompanied by a simultaneous increase of FFA content. Irradiation resulted in an increase of FFA in pancreatic homogenates and a decrease of their content in blood serum.     

龙马酶的固定化研究

研究龙马酶（ＥＣ ３． １． １． ３）固定化载体、固定化条件和固定化酶的性质。方法：固定化采用吸附法。结果：固定化最适条件：酶液ＰＨ９．０,吸附时间１．５ ｈ,酶浓度１．５ ｇ／１００ ｍｌ,在此条件下固定化酶活力５３ ｕ／ｇ载体,活力回收率７１％。固定化酶的最适作用温度和ｐＨ较游离酶高,范围较游离酶广,耐热性、酸碱稳定性比游离酶好。结论：固定化酶性能比游离酶得到提高。     

Postprandial pancreatic exocrine secretion in dogs after oral administration of pirenzepine dihydrochloride

The effect of orally administered 1,5-dihydroxy-11-(4-methyl-1-piperazinyl)- acetyl-6H-pyrido[2,3-b]-1,4-benzodiazepin-6-one dihydrochloride (pirenzepine dihydrochloride, LS-519 Cl, Gastrozepin) on the postprandial secretion of pancreatic juice and the duodenal pH was studied in conscious dogs. An inhibition of the normal increase of the postprandial pancreatic secretion was observed. A possible indirect role of endogenous secretin and a cholinergic enteropancreatic reflex was discussed.     

Leaky enteric coating on ranitidine hydrochloride beads: Dissolution and prediction of plasma data.

The present research is based on the hypothesis that leaky enteric-coated pellets formulations are able to provide sustained input for drugs that have an absorption window, such as ranitidine hydrochloride, without jeopardizing their bioavailability. Leaky enteric-coated pellets formulations are defined as enteric-coated pellets that allow some of the drug to be released from the formulation in gastric fluid. Different approaches to making leaky enteric-coated pellets were investigated using extrusion-spheronization followed by spray coating. Leaky enteric coats were formulated using a commonly used enteric polymer, Eudragit((R)) L 30 D-55, combined with soluble compounds including lactose, PEG 8000 and surfactants (Span 60 (hydrophobic) or Tween 80 (hydrophilic)). The rate of drug release from the formulations in simulated gastric fluid can be tailored by varying the additive's amount or type. All leaky enteric-coated formulations studied completely released the drugs within 30min after changing dissolution medium to phosphate buffer, pH 6. Predictions of plasma concentration-time profiles of the model drug ranitidine hydrochloride from leaky enteric-coated pellets in fasted conditions and from immediate-release formulations were performed using computer simulations. Simulation results are consistent with a hypothesis that leaky enteric-coated pellets formulations provide sustained input for drugs shown to have an absorption window without decreasing bioavailability. The sustained input results from the combined effects of the formulation and GI transit effects on pellets. The present research demonstrates a new application of knowledge about gastrointestinal transit effects on drug formulations. It also shows that enteric-coating polymers have new applications in areas other than the usual enteric-coated formulations. The hypothesis that a leaky enteric-coated pellets formulation may maintain or increase the bioavailability of drugs that have a window of absorption is still to be confirmed by further in vivo studies.     

Control of malabsorption in cystic fibrosis

Intestinal malabsorption is severe and of early onset in virtually all people who have cystic fibrosis. The main cause is deficiency of pancreatic enzymes, but bicarbonate deficiency, abnormalities of bile salts, mucosal transport and motility, and anatomical structural changes are other contributory factors. Appropriate pancreatic replacement therapy will achieve normal or near normal absorption in many patients. It is important to identify both malabsorption and evidence of a pancreatic lesion in all patients who are to receive pancreatic enzymes. All who have evidence of fat malabsorption are deemed pancreatic insufficient and candidates for enzyme replacement therapy. Effective treatment should allow a normal diet to be taken, control symptoms, correct malabsorption and achieve a normal nutritional state and growth. The occurrence of fibrosing colonopathy in some patients receiving very high doses of those enzymes that have the copolymer Eudragit L30 D55 in their covering has resulted in guidelines in the UK to avoid dosages greater than the equivalent of 10,000 IU lipase/kg/day for all patients and also to avoid preparations containing this copolymer in children and adolescents. For patients not responding to 10,000 IU lipase/kg/day, review of adherence to treatment, change of enzyme preparation, variation of the time of administration and reduction in gastric acid may improve absorption. The importance of excluding other gastrointestinal disorders as a cause of the patient's symptoms and the need for early investigations, rather than merely increasing the dosage of enzymes, is stressed. With modern enzymes, adequate control of gastrointestinal symptoms and absorption can be achieved at dosages of 10,000 IU lipase/kg/day or only slightly more, and a normal nutritional state and growth rate maintained in most patients with cystic fibrosis.     

Cystic fibrosis diagnosed in adult patients

AIM: To review the presentation, diagnosis and long-term, clinical follow-up of cystic fibrosis in adult patients diagnosed in adulthood at Green Lane Hospital. METHODS: A retrospective review of the case notes of patients with cystic fibrosis diagnosed in adulthood at Green Lane Hospital or referred there for management. Information was collected on diagnostic tests, including sweat tests and genotyping. Relevant family history was documented as were spirometry results and microbial colonisation. RESULTS: Six patients conclusively fulfilled the diagnostic criteria for cystic fibrosis. There was a wide range of ages at diagnosis (18-68) and half of the patients had a positive family history. A single mutation was identified in all, but in only one of the cases was the second mutation identified. All patients had evidence of bronchopulmonary suppuration and all had retained pancreatic function. Colonisation with P aeruginosa was associated with marked impairment in lung function. CONCLUSION: The patients at Green Lane Hospital represent part of the broad-spectrum disease in adult patients diagnosed with cystic fibrosis and highlight the differences between this group and those patients diagnosed in childhood with the more classical phenotype. Patients generally have less severe lung disease and retain pancreatic function. Sweat testing is useful diagnostically but gene testing is of limited value in making the diagnosis.     

Patterns of use of pancreatic enzyme supplements in fibrosing colonopathy: implications for pathogenesis

Sixteen pathologically confirmed and 14 suspected cases of a new disease entity, fibrosing colonopathy, have been described in the UK and the US in children with cystic fibrosis since 1991. The patterns of use of pancreatic enzyme supplements in cases were compared with use in controls and in the market, in the 2 years prior to surgery for fibrosing colonopathy or the equivalent date in controls. The disease was only found in children with cystic fibrosis who had received brands of pancreatic enzyme supplement coated with methacrylic acid copolymer, for a period of at least 6 months. The risk was dose-related. No cases could be identified in children who had only received other pancreatic enzyme formulations, irrespective of the strength of the formulation or the dose.     

Determination of erythromycin and related substances in enteric-coated tablet formulations by reversed-phase liquid chromatography

An isocratic method for the identification and quantitation of erythromycin and related substances in enteric-coated tablet formulations using high-performance liquid chromatography (HPLC) with ultraviolet (UV) detection at 205 nm is described. A novel method for sample preparation using a molecular weight centrifuge filter to reduce the interferences observed from polymeric tablet coating material is also presented. Erythromycin HPLC assays are best run at high pH; therefore, various polymer columns were evaluated. The resulting HPLC method that was developed has several advantages over current pharmacopeial assay methods for enteric-coated erythromycin tablets. Comparative data from both methods for the same batch of EryTab tablets are presented. The method can also be applied to various other erythromycin formulations, including particle-coated tablets, erythromycin stearate tablets, and erythromycin ethylsuccinate suspensions and fermentation broths. A C18 Polymeric column is used with a mobile phase composition of 0.02 M potassium phosphate dibasic buffer (pH 9): acetonitrile (60:40) and flow rate of 1 mL/min. This method is more sensitive, specific, and rugged than the pharmacopeial method.