Design and Evaluation of Ethyl Cellulose Based Matrix Tablets of Ibuprofen with pH Modulated Release Kinetics

Controlled release preparations have been reported to reduce the gastro irritant and ulcerogenic effects of non steroidal antiinflammatory drugs. In the present study, an attempt was made to develop matrix tablet-based controlled release formulations of ibuprofen, using ethyl cellulose as the rate-controlling polymer. In order to prevent initial release of the drug in the acidic environment of the stomach, cellulose acetate phthalate was incorporated in the matrix in varying amounts. It was found that with increasing the proportion of ethyl cellulose in the matrix, the drug release was extended for 14-16 h. Incorporation of cellulose acetate phthalate in ethyl cellulose matrix provided very low initial release of the drug in the first 2-3 h followed by enhanced release rate in alkaline medium owing to the high solubility of cellulose acetate phthalate at basic pH which led to creation of a porous matrix. It was concluded that combination of cellulose acetate phthalate with ethyl cellulose in the matrix base can be an effective means of developing a controlled release formulation of ibuprofen with very low initial release followed with controlled release up to 14-16 h.

Retinoid-independent motor neurogenesis from human embryonic stem cells reveals a medial columnar ground state

A major challenge in neurobiology is to understand mechanisms underlying human neuronal diversification. Motor neurons (MNs) represent a diverse collection of neuronal subtypes, displaying differential vulnerability in different human neurodegenerative diseases. The ability to manipulate cell subtype diversification is critical to establish accurate, clinically relevant in vitro disease models. Retinoid signalling contributes to caudal precursor specification and subsequent MN subtype diversification. Here we investigate the necessity for retinoic acid in motor neurogenesis from human embryonic stem cells. We show that activin/nodal signalling inhibition, followed by sonic hedgehog agonist treatment, is sufficient for MN precursor specification, which occurs even in the presence of retinoid pathway antagonists. Importantly, precursors mature into HB9/ChAT-expressing functional MNs. Furthermore, retinoid-independent motor neurogenesis results in a ground state biased to caudal, medial motor columnar identities from which a greater retinoid-dependent diversity of MNs, including those of lateral motor columns, can be selectively derived in vitro.

Study of optimal temperature, pH and stability of dragon fruit (Hylocereus polyrhizus) peel for use as potential natural colorant

The peel of Hylocereus polyrhizus is often regarded as a waste hence this study was aimed at exploring the feasibility of using the peel as a natural colorant using simple water extraction method. Samples were subjected to a series of temperatures: Room temperature (RT), 50, 80 and 100 degrees C; varied length of heating time from 1, 2, 3, 4, 5 and 10 min and a varied range of pH using 1 M of citric acid solution. The best condition to obtain highest betacyanin content was heating samples at 100 degrees C for 5 min in a pH 5 citric acid solution. The next part of this study involved the stability test of the pigments obtained through the best method determined earlier. The pigments were dried and resuspended in distilled water. The samples were then exposed to light to monitor pigment changes. Initial resuspension of the dried pigments yielded a comparable high content of betacyanins to its juice counterpart. The results showed that resuspended pigments had high pigment retention and were stable up to 7 days. These initial findings must be further studied in more controlled conditions to understand the stability of betacyanin. Nevertheless, the results show that betacyanin obtained from the peel of dragon fruit has a high potential to be used as a natural dye.

Effects of direct transplantation of multipotent mesenchymal stromal/stem cells into the demyelinated spinal cord

The adult bone marrow contains a population of multipotent mesenchymal stromal cells (MSCs), defined by plastic adherence, expression of stromal cell surface markers, and differentiation into mesenchymal lineages. There has been much interest in the possible therapeutic use of MSCs in the treatment of demyelinating diseases of the central nervous system. One therapeutic possibility is that these cells may be able to remyelinate when directly injected into the demyelinated spinal cord. Here we examine the effects of direct transplantation of green fluorescent protein (GFP)-labeled MSCs into a model of focal spinal cord demyelination induced by ethidium bromide. We demonstrate that direct intralesional injection of undifferentiated MSCs does not lead to remyelination. Furthermore, we report that transplanted MSCs migrate into areas of normal tissue, deposit collagen, and are associated with axonal damage. These findings support the need for further experimental evaluation of the safety and efficacy of direct parenchymal injection of MSCs into demyelinated lesions and highlight an important issue regarding potential clinical consequences of culture heterogeneity of MSCs between centers.

Design and evaluation of pH modulated controlled release matrix systems for colon specific delivery of indomethacin

Indomethacin, a potent non steroidal anti-inflammatory drug (NSAID), is indicated for the local treatment of colorectal carcinoma. The aim of the present study was to design and investigate various matrix systems for controlled and site specific delivery of indomethacin to the colon. Various pH sensitive and hydrophobic polymers were investigated for their effect on drug release and site specificity. Effect of proportion of Eudragit L100 and Eudragit S100 in matrix either alone or in combination was evaluated. Effect of hydrophobic non-swellable polymer ethyl cellulose on the release pattern of drug from the Eudragit bases was also investigated. Matrix tablets prepared with Eudragit showed pH dependent release profile with the formulations of Eudragit L100 showing faster rate of drug release than Eudragit S100 in alkaline pH. The release profile from matrix tablets containing Eudragit L100 and Eudragit S100 in combination or with ethyl cellulose correlated well with the relative proportion of the two polymer types in the matrix base. Selected formulations when evaluated in simulated gastric fluid pH without enzymes showed negligible to low drug release (less than 10%) in the first 4-6 h followed with controlled release for 14-16 h. It was concluded that pH sensitive matrix bases in combination with a hydrophobic polymer like ethyl cellulose canbe ideal for site specific delivery of drugs to colon with controlled release profile.

Abnormally phosphorylated tau is associated with neuronal and axonal loss in experimental autoimmune encephalomyelitis and multiple sclerosis

The pathological correlate of clinical disability and progression in multiple sclerosis is neuronal and axonal loss; however, the underlying mechanisms are unknown. Abnormal phosphorylation of tau is a common feature of some neurodegenerative disorders, such as Alzheimer's disease. We investigated the presence of tau hyperphosphorylation and its relationship with neuronal and axonal loss in chronic experimental autoimmune encephalomyelitis (CEAE) and in brain samples from patients with secondary progressive multiple sclerosis. We report the novel finding of abnormal tau phosphorylation in CEAE. We further show that accumulation of insoluble tau is associated with both neuronal and axonal loss that correlates with progression from relapsing-remitting to chronic stages of EAE. Significantly, analysis of secondary progressive multiple sclerosis brain tissue also revealed abnormally phosphorylated tau and the formation of insoluble tau. Together, these observations provide the first evidence implicating abnormal tau in the neurodegenerative phase of tissue injury in experimental and human demyelinating disease.

Primary splenic flexure volvulus

Primary splenic flexure volvulus is a rare entity. We report an acute presentation of primary splenic flexure volvulus with gangrene in a 24-year-old man. Radiograph showed a massively-dilated large bowel loop with a coffee-bean sign. At emergency laparotomy, a distended and gangrenous splenic flexure was found, with absence of all three ligamentous attachments of the splenic flexure.

Comparison of various international guidelines for analytical method validation

Analytical method validation is the systematic process of establishing that an analytical method is acceptable for its intended purpose. In general the developer or user of the method generates evidence on specificity, linearity range, accuracy, precision, detection limit, quantitation limit, ruggedness and robustness of the method for regulatory submissions or in-house application. The iterative process of method development and validation has a direct impact on the quality of the above data. Such validated analytical methods for qualitative or quantitative testing of drug molecules assume greater importance when they are employed to generate quality and safety compliance data during development and post-approval of drug products. The present paper aims to discuss salient points of the analytical method development and validation cycle. It also attempts to compare and summarize guidelines issued by different agencies for validation of analytical methods used for analysis of drug substances in the pure form and in pharmaceutical formulations.

Comparison of various international guidelines for analytical method validation

Analytical method validation is the systematic process of establishing that an analytical method is acceptable for its intended purpose. In general the developer or user of the method generates evidence on specificity, linearity range, accuracy, precision, detection limit, quantitation limit, ruggedness and robustness of the method for regulatory submissions or in-house application. The iterative process of method development and validation has a direct impact on the quality of the above data. Such validated analytical methods for qualitative or quantitative testing of drug molecules assume greater importance when they are employed to generate quality and safety compliance data during development and post-approval of drug products. The present paper aims to discuss salient points of the analytical method development and validation cycle. It also attempts to compare and summarize guidelines issued by different agencies for validation of analytical methods used for analysis of drug substances in the pure form and in pharmaceutical formulations.

Stability indicating ultraviolet spectroscopic method for the estimation of ezetimibe and carvedilol

In this study, new and rapid stability indicating ultraviolet spectroscopic methods were developed and validated for the estimation of ezetimibe and carvedilol in pure form and in their respective formulations. Since both the drugs are poorly water soluble, 20% v/v acetonitrile in triple distilled water was selected as the solvent system for both the drugs. This ensured adequate drug solubility and maximum assay sensitivity. The linearity range for ezetimibe and carvedilol at their respective wavelength of detection of 232 nm and 238 nm was obtained as 2-50 microg/ml and 2-20 microg/ml respectively. The linear regression equations obtained by least square regression method, were Y = 0.0443 x (X) + 0.0106 for ezetimibe and Y = 0.1080 x (X) + 0.034 for carvedilol, where Y is the absorbance and X is the concentration (in microg/ml) of pure drug solution. The detection and quantitation limit as per the error propagation theory were found to be 0.4 microg/ml and 1.3 microg/ml respectively for ezetimibe and 0.7 microg/ml and 2.1 microg/ml respectively for carvedilol. The methods were employed with high degree of precision and accuracy for the estimation of total drug content in two commercial tablet formulations of each of the two drugs. It was concluded that both the developed methods are accurate, sensitive, precise, and reproducible. They can be applied directly for the estimation of drug content in pharmaceutical formulations.

Physical, psychosocial and economic impact of rheumatoid arthritis: a pilot study of patients seen at a tertiary care referral centre

BACKGROUND

Rheumatoid arthritis is associated with marked physical disability. In addition, it has an impact on patients' psyche and social well-being, and entails a major financial burden. The impact of the disease in different cultural and social backgrounds is varied. Limited data are available from India on this aspect.

METHODS

Patients with rheumatoid arthritis satisfying the 1987 modified American College of Rheumatology criteria were included. Besides demographic data, functional impact was assessed using the Health Assessment Questionnaire (HAQ). The psychosocial impact was measured using the medical outcomes study short form 36 (SF-36) with minor modifications. Data on direct and indirect health costs were collected by direct interview.

RESULTS

The mean age of 101 patients (90 women) was 43.2 years and mean duration of disease was 8 years. Their mean (SD) HAQ score was 0.97 (0.69) with 8 patients having scores > 2. On the SF-36 scale (0-100) the mean (SD) score for various domains were: physical functioning 49.90 (28.55), social functioning 55.51 (20.59), role limitation due to physical problems 32.67 (41.34), role limitation due to emotional problems 47.54 (40.08), mental health 47.36 (7.99), general health perception 52.38 (8.30), energy and vitality 58.56 (6.09), and bodily pain 49.26 (18.87). The summary score for the physical component was 37.95 (9.03) and for the mental component it was 47.71 (4.81). While the physical component summary score had excellent negative correlation with the HAQ score (r = -0.84), correlation with the mental component summary score was poor (r = 0.32). The annual average total cost burden per patient was Rs 16 758, of which Rs 11 617 (67%) was spent on health services and the rest on non-health services (travel, home help and loss of wages).

CONCLUSION

Rheumatoid arthritis causes significant physical and social disability besides being an economic burden. Indian patients had good scores for mental and social health suggesting good family support systems or reluctance to express their feelings despite physical disability.

Astrocytes promote neurogenesis from oligodendrocyte precursor cells

The oligodendrocyte precursor cell (OPC) has until recently been regarded as a lineage-restricted precursor cell. Considerable interest has been generated by reports suggesting that OPCs may possess a wider differentiation potential than previously assumed and thus be considered a multipotential stem cell. This study examined the neuronal differentiation potential of rat, postnatal cortical OPCs in response to extracellular cues in vitro and in vivo. OPCs did not exhibit intrinsic neuronal potential and were restricted to oligodendrocyte lineage potential following treatment with the neural precursor mitogen fibroblast growth factor 2. In contrast, a postnatal hippocampal astrocyte-derived signal(s) is sufficient to induce functional neuronal differentiation of cortical OPCs in vitro in population and single cell studies. Co-treatment with Noggin, a bone morphogenetic protein antagonist, did not attenuate neuronal differentiation. Following transplantation to the adult rat hippocampus, cortical OPCs expressed doublecortin, a neuroblast-associated marker. The present findings show that hippocampal, astrocyte-derived signals can induce the neuronal differentiation of OPCs through a Noggin-independent mechanism.

Low prevalence of IgA deficiency in north Indian population

BACKGROUND AND OBJECTIVES

IgA deficient patients are at risk of severe anaphylactic reaction on being transfused blood and blood products, and its prevalence varies in different parts of the world. No data are available from India. We did a blood donor survey to look for prevalence of IgA deficiency in north India.

METHODS

A sensitive enzyme linked immunosorbent assay developed in-house was used to detect IgA deficiency in a total of 3818 blood donors. Complete IgA deficiency was defined as value less than 5 mg/dl whereas partial IgA deficiency was defined as value between 5-30 mg/dl.

RESULTS

Of the 3818 blood donors screened, 3640 (95.3%) were males with a mean age of 31.2 yr. No donor was found to have complete IgA deficiency; however, 257 (6.7%) had partial IgA deficiency.

INTERPRETATION AND CONCLUSION

Our study shows that IgA deficiency is rare in north India.

Ruptured left gastric artery aneurysm successfully treated by thrombin injection: case report and literature review

This short report describes the successful use of a new minimally invasive technique for the treatment of acute gastric artery aneurysm rupture. It emphasises the importance of persistence and multiple imaging modalities in the presence of gastrointestinal bleeding. The photographs and case history clearly illustrate the nonoperative management and highlight learning points for experienced surgeons and trainees alike in the management of this potentially fatal condition.

Effect of active acromegaly and its treatment on parathyroid circadian rhythmicity and parathyroid target-organ sensitivity

CONTEXT

Patients with active acromegaly have increased bone turnover and skeletal abnormalities. Biochemical cure of acromegaly may represent a functional GH-deficient state and result in cortical bone loss. Reduced PTH target-organ sensitivity occurs in adult GH deficiency and may underlie the associated development of osteoporosis.

OBJECTIVE

We examined the effect of active and treated acromegaly on PTH concentration and target-organ sensitivity.

PATIENTS

Ten active acromegalic subjects (GH nadir > 0.3 mug/liter after 75-g oral glucose load and IGF-I above age-related reference range) and 10 matched controls participated in the study.

DESIGN

Half-hourly blood and 3-h urine samples were collected on patients and controls for 24 h. Samples were analyzed for PTH, calcium (Ca), nephrogenous cAMP (NcAMP, a marker of PTH renal activity), beta C-telopeptide (bone resorption marker), and procollagen type-I amino-terminal propeptide (bone formation marker). Serum calcium was adjusted for albumin (ACa). Eight acromegalic subjects who achieved biochemical cure (GH nadir < 0.3 mug/liter after 75-g oral glucose load and IGF-I within reference range) after standard surgical and/or medical treatment reattended and the protocol repeated.

RESULTS

Active acromegalic subjects had higher 24-h mean PTH, NcAMP, ACa, urine Ca, beta C-telopeptide, and procollagen type I amino-terminal propeptide (P < 0.05), compared with controls. Twenty-four-hour mean PTH increased (P < 0.001) in the acromegalic subjects after treatment, whereas NcAMP and ACa decreased (P < 0.05).

CONCLUSION

Increased bone turnover associated with active acromegaly may result from increased PTH concentration and action. Biochemical cure of acromegaly results in reduced PTH target-organ sensitivity indicated by increased PTH with decreased NcAMP and ACa concentrations. PTH target-organ sensitivity does not appear to return to normal after successful treatment of acromegaly in the short term and may reflect functional GH deficiency.

A missing denture's misadventure!

We report a late onset, benign, tracheoesophageal fistula in a 51-year-old man, due to an accidentally swallowed denture. In view of the extensive peri-esophageal sepsis and fibrosis, he was managed by a subtotal esophagectomy and a cervical esophagogastric anastomosis. The tracheal defect was closed with the help of an intercostal muscle flap. This report also highlights the difficulty in identifying swallowed prosthetic dental material radiologically, when no metallic component is present. This fact was also responsible for the delay in diagnosis, eventually leading to the rare complication of a tracheoesophageal fistula.

Cost-effective laparoscopic TEP inguinal hernia repair: the Portsmouth technique

NICE (UK) has not recommended unilateral primary laparoscopic inguinal hernia repair because of its expense. A two-port technique without balloon inflator or routine tacking was developed, which helped reduce costs to just Pounds 35 more than day-case open hernia repair. Over a 6-month period, 40 patients underwent 60 TEP repairs with a 6-month follow up. Zero degree laparoscope (10 mm) and blunt graspers (5 mm) created the pre-peritoneal space, identified landmarks and completed the dissection. Trimmed 15 x 15 cm mesh was placed over each defect. Operating times for unilateral and bilateral hernias for consultants and supervised trainees were 30*, 42.5* and 40*, 55* min (*: Median) respectively. Verbal rating pain scores at 24 and 72 h were 1* (0-3) and 0* (0-2) respectively. Patients returned to activity, driving and work in 5*, 7* and 14* days respectively. Cost of laparoscopic hernia repair was calculated at Pounds 105. A two-port laparoscopic hernia repair can be performed effectively and safely, in reasonable time and at a low cost. These data support the use of this technique in primary unilateral inguinal hernia.

Torted and ruptured wandering spleen presenting as a surgical emergency in pregnancy

Wandering spleen (WS) is characterised by incomplete fixation of the spleen to its supporting linorenal and gastrosplenic ligaments. It can predispose to life-threatening complications due to torsion of its vascular pedicle, splenic infarction, portal hypertension, and haemorrhage. A 27-year-old, 36-week prima gravida underwent emergency caesarean section for tachycardia and hypotension. A healthy baby girl was delivered. However, she remained shocked despite aggressive fluid therapy and intraoperatively it was noted that there was significant intraperitoneal bleeding and the on-call surgical team was summoned. Midline laparotomy revealed a lacerated, infarcted, hypermobile spleen found with free intraperitoneal bleeding. The unsalvageable spleen was resected and the patient went on to make an excellent recovery. The aetiology of WS is contentious. With an increased frequency among multiparous females of reproductive age, some suggest the hormonal effects of pregnancy as contributing factors. Clinical presentations range from an asymptomatic abdominal mass to acute abdominal pain with hypovolaemic shock. WS poses a serious threat to life due to thrombosis, bleeding, or infarction. Ultrasound scan and CT scan are equally effective in the diagnosis. Patients with asymptomatic WS should be treated with elective splenopexy, however, in the acute presentation, splenectomy is the procedure of choice.