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Biomedical subjects

K A Mehta

Publications and source records attributed to K A Mehta.

At least 19 recordsLinked to original sources

Release performance of a poorly soluble drug from a novel, Eudragit-based multi-unit erosion matrix.

Mechanisms governing the release of drugs from controlled delivery systems are mainly diffusion, osmosis and erosion. For poorly soluble drugs, the existing mechanisms are limited to osmosis and matrix erosion, that are commonly observed in single unit matrix dosage forms. This study reports formulation and dissolution performance of Eudragit L 100 55 and Eudragit S 100 based multi-unit controlled release system of a poorly soluble thiazole based leukotriene D(4) antagonist, that was obtained by an extrusion/spheronization technique. Effect of triethyl citrate, that was incorporated in the matrix, on the dissolution performance of the drug was also evaluated. In vitro matrix erosion and drug release from the pellets were determined by the use of USP Dissolution Apparatus I, pH 6.8 phosphate buffer, gravimetry and UV spectrophotometry, respectively. Results obtained demonstrated that matrix erosion and drug release occurred simultaneously from the pellets. Pellets eroded with a consequent reduction in size without any change in the pellet geometry for over 12 h. Matrix erosion and drug release followed zero order kinetics. Data obtained strongly suggested a polymer controlled, surface erosion mechanism.

Acrylic Resins↗

Characterization of the interactions between polymethacrylate-based aqueous polymeric dispersions and aluminum lakes.

Instability in film coating formulations can arise from interactions between aluminum lake pigments and aqueous polymeric dispersions. The purpose of this study was to characterize the interactions between three polymethacrylate-based aqueous polymeric dispersions (Eudragit RS 30 D, Eudragit L 30 D-55, and Eudragit NE 30 D) and aluminum lakes. Particle size measurements, pH stability profiles, zeta potential measurements, and microscopy were used to study mixed dispersions of the polymeric latices and the lakes. Interactions leading to dispersion instability were related to the surface charge of the components in the formulation. Interactions between the ionic polymers and the lakes arose from instability of the lakes outside a certain pH range resulting in the release of electrolytes, which led to aggregation of the polymeric particles. Interactions between the nonionic polymer and the lakes were related to the polymer modifying the surface charge of the lakes, resulting in aggregation of the pigment particles.

Aluminum Compounds↗

Effect of formulation and process variables on porosity parameters and release rates from a multi unit erosion matrix of a poorly soluble drug.

The effect of drug loading, water required for granulation and spheronization time on porosity parameters (intrusion-extrusion isotherms, pore size distribution, total pore surface area, mean pore diameter, shape and morphology of pores) and drug release rates from pellets of a poorly soluble drug was investigated. Porosity parameters were determined by mercury intrusion porosimetry. The drug loading was found to have a profound effect on the porosity parameters. Pellets with low drug loading showed increased pore surface area with small mean pore diameters and an increased number of total pores. On the other hand, pellets with high drug loading had decreased pore surface areas with larger mean pore diameters and a reduction in the total number of pores. With high drug loading, the drug release rate decreased. Water required for granulation had a direct effect on the total porosity of the pellets. Spheronization time from 2 to 10 min had a pronounced effect on porosity parameters and release rates. No changes in porosity parameters and release rates were observed from 10 to 20 min of spheronization time. It was shown that each porosity parameter investigated was well correlated with drug release rates and thus it is important to study the effect of porosity parameters in evaluating the in vitro performance of the multi-unit erosion matrix for the controlled release of a poorly soluble drug.

Chemistry, Pharmaceutical↗

Oxygen desaturation of selected term infants in car seats.

OBJECTIVES: Premature infants are known to be at risk for oxygen (O2) desaturation and/or apnea in car seats. Since 1990, the American Academy of Pediatrics has recommended a period of monitoring in car seats before hospital discharge for infants born at < 37 weeks gestation. The objective of this report is to determine if selected term infants are also at risk for O2 desaturation, apnea, or bradycardia while in an infant car seat. METHODS: MetroWest Medical Center is a community hospital with a level II neonatal unit. Term infants who in the judgment of their pediatrician were felt to be at risk for O2 desaturation or apnea were monitored for a 90-minute period in a car seat and observed for transcutaneous O2 desaturation, apnea, or bradycardia. In addition, several infants who were admitted to the pediatric inpatient unit after discharge from the nursery were monitored in a similar fashion. RESULTS: Eight of 28 monitored infants (28.6%) had a period of O2 desaturation < 90%. In addition, five of 28 monitored infants (17.8%) had borderline results (O2 saturation, 90 to 93%). All four infants monitored because of genetic syndromes had abnormal results. O2 desaturation was also observed in two term infants who had been observed to be apneic by a parent after discharge from the nursery. CONCLUSIONS: In selected circumstances (eg, genetic disorders or observed apnea) term infants may be at risk for O2 desaturation in an upright car seat and monitoring these infants in car seats before nursery discharge should be considered. Because not all infants at risk for O2 desaturation can be identified at birth, an alternative approach would be to recommend, unless medically contraindicated (eg, gastroesphogeal reflux when supine), that infants should routinely be transported in a supine position car seat in the early months of life.

Apnea↗

Monitoring premature infants in car seats: implementing the American Academy of Pediatrics policy in a community hospital.

OBJECTIVES: In 1990, the American Academy of Pediatrics (AAP) Committee on Injury and Poison Prevention issued a policy statement which recommended that all infants born at less than 37 weeks gestational age be monitored in their car seat before discharge to identify infants at risk for apnea associated with car seat use. The objective of this report is to summarize the experience of a community hospital in implementing this recommendation, including: education of health professionals about the problem and its management, development of an effective hospital policy and procedure for testing at-risk infants, overcoming logistical difficulties for nursing staff who implement the policy, overcoming liability concerns, and summarizing the clinical results which we observed during a 15-month period. METHODS: MetroWest Medical Center, Framingham Union Campus is a community hospital with a Level II Neonatal Unit with approximately 2200 deliveries annually. Hospital procedures and policies were developed to implement the AAP policy for safe transportation of premature infants. Consequently, infants less than 37 weeks gestation at birth were monitored for a 90-minute observation period for oxygen saturation, apnea, or bradycardia in the car seat that they would be going home in from the nursery. RESULTS: Policies and procedures for car seat monitoring were instituted successfully during 15-month period. Sixteen of 87 (18.4%) monitored infants 26 to 36 weeks gestation had abnormal results. In addition, one 37-week gestational newborn who was monitored because of duskiness during feeds also became apneic and bradycardic in the car seat. CONCLUSIONS: A car seat monitoring program can be incorporated effectively into a Level II community hospital nursery discharge plan provided that appropriate medical staff policies, nursing procedures, and administrative support to deal with the logistics of the program is established. Our monitoring results are consistent with previous reports that premature infants are at risk of desaturation in a car seat. In addition, we have demonstrated that a full-term neonate may also be at risk if other evidence of desaturation (eg, duskiness during feedings) is observed.

Apnea↗

Parasitology screening of Latin American children in a primary care clinic.

A screening program based in a Massachusetts community hospital primary care clinic, which included 124 children from 12 different Latin American countries, demonstrated that nearly 35% were carriers of pathogenic parasites. The large majority (83.7%) of these children were asymptomatic at the time of the examination. Although there may be considerable variation based on country of origin, the present results, as well as a review of the literature, suggest this is likely to be a common finding among children born in most regions of Latin America. Compliance with the screening process was significantly higher in groups with higher infection rates and the successive yield in those patients who submitted two or more stool samples revealed that most pathogens were identified in the first sample. School-age children were found to have the highest risk for both roundworm infections and multiple parasitic infections. For those children with identified pathogens, nearly 90% received treatment. Current trends in immigration, international adoptions, and special circumstances including day care, family shelters, and increasing numbers of human immunodeficiency virus-infected children have made an appreciation of the extent of parasitosis, and awareness of possible management approaches, an important consideration for primary care physicians in the United States.

Adolescent↗

Pediatric problems in a suburban shelter for homeless families.

The experience of an affiliation between a hospital-based clinic and a family shelter is presented. The medical implications of family shelter residence include special issues related to the spread of infectious diseases, particularly to the neonate. Preentry medical evaluation revealed that a large proportion of children and their parents had one or more medical problems. Of 67 children screened before entrance, 13% [corrected] had Giardia lamblia detected in the stool. In addition to carriage of enteric pathogens, the range of pediatric problems encountered included a variety of acute and chronic medical conditions, unmet primary care needs, and developmental and school difficulties. Fifty-eight percent of shelter residents were found to be "medically homeless." Formal liaison between a hospital-based clinic and a family shelter was found to be an effective way to promote a healthy environment in the family shelter and to provide needed medical services to shelter families.

Adolescent↗

Asymptomatic toxocariasis in children. A prospective study and treatment trial.

Screening of 153 Hispanic children attending a Hospital-based primary care clinic revealed a 16 percent prevalence of Toxocara canis infection. Infections were found in other household occupants for half of these children. Follow-up of 20 children (for periods of up to 7 years) with asymptomatic T. canis infection failed to demonstrate any clinical sequelae. However, longer periods would be necessary to entirely discount the possibility of latent ocular disease. Treatment with thiabendazole did not appear to alter the course of the infection in a controlled 1-year evaluation as measured by eosinophil counts and specific T. canis antibody titers.

Adult↗

Injuries to adolescents and young adults.

Death rates in adolescents are on the rise--the only age group for which this is true. Unintentional injuries, homicide, and suicide account for 80 per cent of all deaths in this group. The authors summarize the available morbidity and mortality data.

Accidents, Home↗

Educating parents about injury prevention.

Pediatricians usually spend very little time counseling parents about childhood safety. The Framingham Safety Surveys (FSS) were developed for pediatricians to use in counseling on childhood injury prevention. The use of FSS and supplemental safety instruction are reviewed. This study found increased preventive behaviors in homes after safety counseling by pediatricians using FSS.

Accident Prevention↗

Unintentional injuries among adolescents and young adults: a review and analysis.

Unintentional injury is the leading cause of mortality and an important cause of morbidity in adolescents and young adults. A review of the literature suggests that the male gender and substance abuse are important contributors to many accidents. One recent study has identified some significant teenage educational needs regarding accident prevention; others report paradoxical outcomes following untargeted educational programs for teenagers. It appears that the greatest potential for success in the prevention of unintentional injury in this age group is regulatory and legislative measures.

Accident Prevention↗

Residency training in community pediatrics.

A required PL-3 rotation in community pediatrics, including assignments to preschool and school settings, private pediatric offices, and in-hospital responsibilities, is described. A university-affiliated community hospital provides the organizational base for the program. After 14 PL-3 rotations, analysis of program content, as well as resident and community response, shows the experience to be a practical and workable model for incorporating community pediatrics into residency training.

Boston↗