Super Porous Hydrogels: A Review

Super porous hydrogels (SPHs) basically developed initially create as a novel drug delivery system to absorb and continue to hold the drugs in the gastric medium which allows absorption in stomach and upper part of the gastrointestinal tract. These systems get swollen in the stomach instantly and in the harsh stomach environment they maintain their integrity, while the pharmaceutical active ingredient is being released. Instant and fast swelling property of hydrogel is based on water absorption through open porous structure by capillary force. SPHs have the poor mechanical strength which has got over by developing the second-generation SPH composites (SPHCs) and the third-generation SPH hybrids (SPHHs). The present review has been focused on the preparation, characterization and application of SPHs

Application value of different digestive tract reconstruction methods in laparoscopic distal gastrectomy / 中华消化外科杂志

Objective To investigate the application value of different digestive tract reconstruction methods in laparoscopic distal gastrectomy (LDG).Methods The retrospective cohort study was conducted.The clinicopathological data of 164 with early gastric cancer (GC) who were admitted to the First Affiliated Hospital of Fujian Medical University between June 2010 and April 2015 were collected.Of 164 patients undergoing LDG,45 receiving Billroth Ⅰ (B Ⅰ) anastomosis,39 receiving Billroth Ⅱ (B Ⅱ) anastomosis,44 receiving Roux-en-Y anastomosis and 36 receiving uncut Roux-en-Y anastomosis were allocated into the B Ⅰ group,B Ⅱ group,RY group and uncut RY group,respectively.Observation indicators:(1) surgical and postoperative recovery situations;(2) postoperative short-term complications situations;(3) follow-up situations.Follow-up using outpatient examination and telephone interview was performed to detect postoperative nutriology and long-term complications up to May 2017.Measurement data with normal distribution were represented as x±s.Comparison among groups was analyzed using the ANOVA,and pairwise comparisons were done by the Tukey hsd test.Count data were described as the frequency and percentage,and comparisons among groups were analyzed the chi-square test or Fisher exact probability.Ordinal data were analyzed by the Kruskal Wallis test.Results (1) Surgical and postoperative recovery situations:patients in 4 groups underwent successfully LDG.Cases undergoing total LDG and assisted LDG and digestive tract reconstruction time in the B Ⅰ,B Ⅱ,RY and uncut RRY groups were respectively 0,29,13,15 and 45,10,31,21 and (42±7)minutes,(55±8)minutes,(64±8)minutes,(51±6) minutes,with statistically significant differences among 4 groups (x2 =21.628,F=74.441,P＜0.05).(2)Postoperative short-term complications situations:2,2,3 and 1 patients in the B Ⅰ,B Ⅱ,Roux-en-Y and uncut Roux-en-Y groups had respectively postoperative short-term complications,showing no statistically significant difference among 4 groups (x2 =0.840,P＞0.05).(3) Follow-up situations:all patients were followed up,and follow-up time in the B Ⅰ,B Ⅱ,RY and uncut RY groups were respectively (10.8 ± 3.5) months,(10.9 ±3.4)months,(11.3±3.2) months and (11.2±2.2) months,with no statistically significant difference among 4 groups (F=0.200,P＞0.05).① Comparisons of postoperative 1-year nutritional indexes:rates of changes in body mass index (BMI),hemoglobin (Hb),total protein (TP) and albumin were respectively 93％±7％,91％±7％,90％±7％,90％±9％ and 94％±9％,97％±11％,95％±9％,97％±9％ and 101％±9％,99％±7％,98％±7％,99％±7％ and 101％±10％,103％±7％,100％±10％,103％±9％ in the B Ⅰ,B Ⅱ1,RY and uncut RY groups,showing no statistically significant difference among 4 groups (F=1.182,0.724,1.050,0.971,P＞0.05).②)Of 164 patients within 1 year postoperatively,47 were complicated with gastric retention (27,12,6 and 2 with severity in grade 1,2,3 and 4),87 with residual gastritis (53,24,10 and 0 with severity in grade 1,2,3 and 4),and 38 with bile reflux (severity in grade 1).Of 38 patients with bile reflux,33 were combined with residual gastritis,showing a correlation between residual gastritis and bile reflux (r=0.396,P＜0.05).Cases with gastric retention,residual gastritis and bile reflux within 1 year postoperatively were respectively 16,9,21,1and 35,30,13,9 and 16,18,3,1 in the B Ⅰ,B Ⅱ],RY and uncut RY groups,showing statistically significant differences among 4 groups (x2 =21.261,41.103,30.469,P＜ 0.05).There were statistically significant differences in gastric retention occurrence between uncut RY group and B Ⅰ group or B Ⅱ group or RY group (x2 =12.958,6.675,20.065,P＜0.05),and in residual gastritis occurrence between RY group and B Ⅰ group or B Ⅱ group (x2 =20.831,18.587,P＜0.05) and between uncut RY group and B Ⅰ group or B Ⅱ group (x2 =22.452,20.220,P＜0.05).There were statistically significant differences in bile reflux occurrence between RY group and B Ⅰ group or B Ⅱ group (x2 =10.942,16.926,P＜0.05),and between uncut RY group and B Ⅰ group or B Ⅱ group (x2 =12.958,18.620,P＜0.05).Conclusion Roux-en-Y and uncut Roux-en-Y anastomoses are superior to B Ⅰ and B Ⅱ anastomoses in improving residual gastritis and bile reflux in the postoperative digestive tract reconstruction of LDG,and uncut Roux-en-Y anastomosis can effectively reduce occurrence of postoperative gastric retention.

Formulation development and evaluation of gastroretentive floating beads with Brucea javanica oil using ionotropic gelation technology / 中国天然药物

In the present study, a gastric retention floating system for Brucea javanica oil, composed of alginate and carrageenan, was prepared using ionotropic gelation. Parameters for floatability, drug load, encapsulation efficiency, bead morphology, in vitro release, and in vivo gastric retention were evaluated. The optimized formulation via Box-Behnken design consisted of 1.7% alginate (W/V), 1.02% carrageenan (W/V), 1.4% CaCO (W/V), and a gelling bath of pH 0.8. The alginate-carrageenan-Brucea javanica oil beads had a porous structure and exhibited up to 24 h of in vitro floatability with a load capacity of 45%-55% and an encapsulation efficiency of 70%-80%. A 6-h sustained release was observed in vitro. The beads had a prolonged gastric retention (> 60% at 6 h) in fasted rats, compared to non-floating beads (15% at 6 h), as measured by gamma scintigraphy with single-photon emission tomography/computed tomography (SPET/CT). In conclusion, the alginate-carrageenan-Brucea javanica oil system showed enhanced oil encapsulation efficiency, excellent floating and gastric retention abilities, and a favorable release behavior.

Formulation development and evaluation of gastroretentive floating beads with Brucea javanica oil using ionotropic gelation technology / 中国天然药物

In the present study, a gastric retention floating system for Brucea javanica oil, composed of alginate and carrageenan, was prepared using ionotropic gelation. Parameters for floatability, drug load, encapsulation efficiency, bead morphology, in vitro release, and in vivo gastric retention were evaluated. The optimized formulation via Box-Behnken design consisted of 1.7% alginate (W/V), 1.02% carrageenan (W/V), 1.4% CaCO (W/V), and a gelling bath of pH 0.8. The alginate-carrageenan-Brucea javanica oil beads had a porous structure and exhibited up to 24 h of in vitro floatability with a load capacity of 45%-55% and an encapsulation efficiency of 70%-80%. A 6-h sustained release was observed in vitro. The beads had a prolonged gastric retention (> 60% at 6 h) in fasted rats, compared to non-floating beads (15% at 6 h), as measured by gamma scintigraphy with single-photon emission tomography/computed tomography (SPET/CT). In conclusion, the alginate-carrageenan-Brucea javanica oil system showed enhanced oil encapsulation efficiency, excellent floating and gastric retention abilities, and a favorable release behavior.

Preparation of Mifepristone Gastric Retention Sustained-Release Pellet System Tablets and Their Release Characteristics in Vitro / 中国药学杂志

OBJECTIVE: To prepare mifepristone gastric retentive multi-unit pellet system (MUPs), and study its release behaviors in vitro. METHODS: A sustained release layer and mucous adhesive layer were coated onto extrusion spherized mifepristone pellets. The gastric retentive sustained release pellets were mixed with granules which were wet granulated from micronized mifepristone and compressed into MUPs tablets. Investigation and evaluation of the in vitro release of mifepristone MUPs tablets were carried out from different aspects. RESULTS: The turning point of pH value for the solubility of mifepristone was 3.0.Micronized mifepristone showed higher dissolving rate and apparent solubility. The gastric retentive mifepristone MUPs tablets had faster release than marketed mifepristone tablets. The in vitro adhesive experiment with pig stomach showed that mucous adhesive mifepristone pellets could be entrapped into the gastric mucous and retained for a long time. The accelerated stability study showed that mifepristone MUPs tablets were as stable as marketed mifepristone tablets. CONCLUSION: Novel mifepristone gastric retentive MUPs tablets are successfully prepared. The release characteristics in vitro indicate that the product may have higher bioavailability than marketed mifepristone tablets with significantly lower variability.

Effectiveness of enteral nutrition support for stroke patients with gastric retention / 中国中西医结合急救杂志

ObjectiveTo observe the clinical curative effect of nasal jejunal nutrition support in stroke patients with gastric retention.Methods Forty-two patients with cerebral apoplexy combined with gastric retention admitted to Dingxing County Hospital in Hebei province from March 2012 to November 2015 and treated with enteral nutrition support were enrolled, and they were divided into observation group and control group according to the random number table method, 21 cases in each group. Under the guidance, routine treatment were given, the head of bed was raised to 30°- 45°, and gastrointestinal decompression was carried out in the two groups. In the observation group, a nasal jejunal tube was inserted and enteral nutrition was given, while in the control group, parenteral nutrition was firstly applied until the recovery of gastrointestinal function, then nasogastric enteral nutrition was carried out. Compared between the two groups, on the day of admission before treatment and 2 weeks after treatment, blood glucose levels, plasma total protein levels, albumin were detected; the triceps skinfold thickness (TSF), upper arm circumference (MAC), upper arm muscle circumference (AMC), etc were measured in the two groups to show the difference in nutritional status. Adverse reactions of diarrhea, stress ulcer, gastrointestinal tract infection, reverse flow, high blood sugar and central venous infection and complications in the two groups were observed.Results The levels of blood glucose, albumin, total protein content were not significantly different between the two groups before treatment (allP > 0.05). Blood glucose levels in the two groups after treatment were lower than those on admission, and the decrease in the observation group was more significant (mmol/L: 6.45±2.15 vs. 7.68±2.68,P < 0.05); the levels of albumin and total protein in the control group after treatment were lower than those on admission, while the observation group had no such significant changes, and the levels of the control group were significantly lower than those of the observation group [albumin (g/L): 30.78±4.12 vs. 38.20±4.67, total protein (g/L): 63.91±4.32 vs. 67.11±3.12, P < 0.05]. After treatment for 2 weeks, the nutritional indexes of TSF, MAC, AMC in the two groups were slightly lower than those on admission, but the degrees of descent in observation group were not as significant as those in the control group [TSF (mm): 11.91±1.29 vs. 10.13±1.37, MAC (cm): 24.19±3.12 vs. 23.74±2.08, AMC (cm): 22.64±2.05 vs. 21.73±2.15, allP < 0.05]. The incidences of adverse reactions and complications in the observation group were significantly lower than those in the control group [diarrhea: 9.5% vs. 38.1%, stress ulcer: 4.8% vs. 33.3%, regurgitation:4.8% vs. 28.6%, hyperglycemia: 9.5% vs. 38.5%,P < 0.05]; In the control group, the incidence of central venous infection was 4.8%.Conclusions Gastric jejunal nutrition support in patients with cerebral apoplexy combined with gastric retention can prevent occurrence of malnutrition, reduce the incidences of adverse reactions and complications and promote the rehabilitation of patients.

Microballoons: A better approach for gastro retention.

The purpose of this review is to accumulate the recent study on floating drug delivery system with special emphasis on microballoons as drug delivery. Microballoons are emerging as the most promising drug delivery as it overcome many limitations of conventional drug delivery system. As microballoons delivery system provides longer retention in gastric pH, hence longer is the residence time and therefore enhance the solubility of drugs that are less soluble in high pH environment. The formation of cavity inside the microsphere depends upon the preparation temperature and the surface smoothness determines the floatability and the drug release rate of the microballoons. The review includes the classification, advantages, disadvantages, method of preparation and future aspects of microballoons. Basic anatomy and physiology of stomach is also studied.

Preparation and Evaluation of Novel Expandable Drug Delivery System.

Aims: The purpose of this research is to develop a novel expandable gastroretentive dosage form (GRDF), based on unfolding mechanism. It consists of a drug loaded bilayer polymeric film, folded into a hard gelatin capsule. Gastric retention is achieved due to unfolding of the dosage form within 15-20 min. Furosemide is selected as the drug candidate for this work. Due to its narrow absorption window, Furosemide has to be administered to the upper parts of the intestine in order to maintain sustained therapeutic levels. This may be achieved by a GRDF. Methodology: Films were prepared by solvent-casting technique using Ethyl cellulose, HPMC E15 and Eudragit RLPO as polymers and dibutyl phthalate as the plasticizer in both layers. The film with zigzag folding in the capsule was shown to unfold in the gastric juice and provide drug release up to 12 h in the acidic medium. The films were evaluated for weight & thickness variation, mechanical properties, in vitro drug release and unfolding behavior based on the mechanical shape memory of polymers. Absence of drug polymer interaction and uniform drug dispersion in the polymeric layers was revealed by DSC, XRD studies and SEM. The GRDF location in the gastrointestinal tract was determined by X-ray studies. Results: X-ray studies revealed that the GRDF is retained in the stomach up to 6± 0.5 h in fasting condition and 8 h in fed state. Conclusion: The polymers used in the development of GRDFs were safe and proper combination of these polymers will yield a novel expandable GRDF with good in vitro drug release in acidic media, mechanical properties, and unfolding behaviour. These outcomes demonstrate that the GRDF may be used to improve furosemide therapy and can be applied to extend the absorption of other narrow absorption window drugs that require continuous input.

Síndrome de retención gástrica por Tricobezoar / Gastric retention syndrome due to tricobezoar

RESUMEN Los bezoares son masas sólidas compuestas por fibras, pelos o restos de comida ingeridos que generalmente permanecen en el estómago. Los tricobezoares, que están formados por pelos, son más comunes en el sexo femenino en edad pediátrica con antecedentes de tricotilomanía y tricofagia. Para el diagnóstico se utilizan imágenes como la radiografía simple de abdomen, la radiografía de abdomen con bario y la endoscopia digestiva alta que permite la visualización directa. El tratamiento del tricobezoar es quirúrgico, con gastrostomía anterior, además de apoyo psiquiátrico. Este caso corresponde a una paciente de 16 años con antecedentes de tricofagia, que consulta por un cuadro de dolor abdominal, vómitos y distensión abdominal. Se realiza estudios laboratoriales, imagenológicos y endoscópicos llegando al diagnóstico de obstrucción intestinal mecánica alta. Se indicó cirugía y se confirmó tricobezoar que es extraído por gastrotomía anterior. La evolución fue favorable, por lo cual egresó al quinto día del post operatorio, con recomendaciones de asistir a consultas externas de cirugía general y psicología.

ABSTRACT Bezoars are solid masses made up of fibers, hairs or food debris that usually remain in the stomach. Trichobezoars, which are formed by hairs, are more common in female patients with a history of childhood trichotillomania and trichophagia. For diagnosis, imaging techniques like plain abdominal radiography, barium contrast abdominal radiography and upper gastrointestinal endoscopy are used that allow direct visualization. Treatment for trichobezoar is surgical, consisting of anterior gastrostomy in addition to psychiatric support. Our case corresponds to a 16-year old patient with a history of trichophagia, that consulted for abdominal pain, vomiting and abdominal distension. Laboratory, imaging and endoscopic studies were conducted leading to the diagnosis of higher intestinal mechanical obstruction. Surgery was indicated confirming the trichobezoar that was removed by anterior gastrostomy. Evolution was favorable, whereby the patient egressed five days after surgery, with recommendations to attend outpatient general surgery and psychology.

Multiple myeloma associated with light-chain amyloidosis manifesting as gastric retention: a case report and review of the literature / Mielona múltiple asociado con amiloidosis de cadenas ligeras manifestada como retención gástrica: reporte de caso y revisión de la literatura

We report a case of multiple myeloma associated with light-chain amyloidosis in a 62-year old woman. The patient came to hospital with the main complaint of epigastric pain and gastroscopy showed gastric retention. The patient had been diagnosed with multiple myeloma associated with light-chain amyloidosis after biopsy of the gastric mucosa and bone marrow aspirate. A review of the literature was also performed.

Se reporta el caso de un mieloma múltiple asociado con amiloidosis de cadenas ligeras en una mujer de 62 años de edad. La paciente acudió al hospital aquejada principalmente por un dolor epigástrico y la gastroscopía mostró retención gástrica. A la paciente le había sido diagnosticado un mieloma múltiple asociado con una amiloidosis de cadenas ligeras luego de practicársele una biopsia de la mucosa gástrica y aspirado de la médula ósea. También se realizó una revisión de la literatura.

Effect of stearic acid on the properties of metronidazole/methocel K4M floating matrices / Efeito do ácido esteárico nas propriedades de metronidazol / Methocel K4M matrizes flutuante

The properties of metronidazole/Methocel K4M sustained release floating tablets have been studied varying the proportion of the lubricant, stearic acid, on formulations with and without sodium bicarbonate. The variables studied include technological properties of the tablets such as tablet hardness and ejection pressure, the drug release profile, the hydration kinetics and the floating behaviour. The presence of stearic acid and sodium bicarbonate improves the floating behaviour for more than 8 hours. The hydration volume, the tablet hardness and the ejection pressure decrease as the stearic acid content increases and the polymer content decreases. Drug dissolution increases with increasing proportions of stearic acid and decreasing proportions of the polymer in the tablets. The presence of sodium bicarbonate extends the differences in dissolution produced by stearic acid. These results are attributed to decreasing matrices coherence with an increasing quantity of stearic acid and a reducing polymer proportion. The carbon dioxide bubbles produced by sodium bicarbonate expand the matrices facilitating the dissolution, although their presence obstructs also the diffusion path through the hydrated gel layer.

Estudaram-se as propriedades de comprimidos flutuantes de metronidazol/Methocel K4M de liberação controlada, variando-se a proporção do lubrificante, ácido esteárico, nas formulações com e sem bicarbonato de sódio. As variáveis estudadas incluem propriedades tecnológicas dos comprimidos, tais como dureza, pressão de ejeção, perfil de liberação do fármaco, cinética de hidratação e comportamento de flutuação. A presença de ácido esteárico e do bicarbonato de sódio melhora o comportamento de flutuação para mais de 8 horas. O volume de hidratação, a dureza e a pressão de ejeção do comprimido decrescem à medida que o conteúdo de ácido esteárico e de polímero diminui. A dissolução do fármaco aumenta com o aumento das proporções de ácido esteárico e a diminuição das proporções de polímero nos comprimidos. A presença de bicarbonato de sódio amplia as diferenças na dissolução produzidas pelo ácido esteárico. Estes resultados são atribuídos à coesão decrescente das matrizes, com o aumento da quantidade de ácido esteárico e a redução da proporção de polímero. Bolhas de dióxido de carbono produzidas pelo bicarbonato de sódio expandem as matrizes, facilitando a dissolução, embora a presença delas obstrua, também, a difusão através da camada de gel hidratado.