PubMed Health⌕ Search

Biomedical subjects

T K Pal

Publications and source records attributed to T K Pal.

At least 19 recordsLinked to original sources
PubMed2004

Bioequivalence study of rabeprazole sodium on healthy human volunteers.

The newly developed proton pump inhibitor rabeprazole sodium is expected to have beneficial effects in the treatment of peptic ulcer. The pharmacokinetic parameters (C(max), AUC(o-t), t(max)) of this drug have been evaluated to compare the single dose (20 mg) bioavailability of rabeprazole sodium with the standard reference. High performance liquid chromatography (HPLC) coupled with UV detector set at 280 nm has been used to determine plasma concentration of 12 human volunteers as per Drugs Controller General of India (DCGI) guidelines. The method has been validated over a linear range of 20-480 ng/ml from plasma. The minimum quantifiable concentration was set at 10 ng/ml [co-efficient of variance (CV) < 10%]. By comparing AUC(o-t) the relative bioavailability of test preparation has been found to be 100.88% of that of reference preparation.

2-Pyridinylmethylsulfinylbenzimidazoles↗
PubMed2004

Bioequivalence study of sildenafil citrate tablets in healthy human volunteers.

Newly developed sildenafil citrate (SC), a selective inhibitor of cyclic guanosine monophosphate (c-GMP) specific phosphodiesterase type 5 (PDE 5) in the corpus cavernosum is used for the oral treatment of erectile dysfunction. A convenient, sensitive and simple method for the determination of sildenafil in human plasma is presented. The analytical technique was based on reversed-phase high-performance liquid chromatography coupled with UV detector set at 295 nm. Rofecoxib was used as internal standard (I.S). Liquid-liquid extraction using diethyl ether was performed to recover sildenafil and rofecoxib. The retention time of I.S and sildenafil were 5.5 minutes and 7.2 minutes respectively. The method was validated over a linear range of 10 to 1000 ng/ml from plasma. Separate stability study showed that sildenafil is stable under conditions of analysis. The extraction efficiency from plasma varied from 79.69% to 81.13 %. The minimum quantifiable concentration was set at 10 ng/ml. (%o CV<12.5%). The method was used for Bioequivalence Study of Two Brands of Sildenafil citrate 50 mg tablets in healthy human volunteers. All pharmacokinetic parameter were calculated along with statistical evaluation.

Area Under Curve↗
PubMed2004

Oral delivery system of insulin microspheres: effect on relative hypoglycemia of diabetic albino rats.

The aim of the present work was to investigate the effectiveness of a dosage form approach for monitoring both the inactivation and the absorption process by targeting insulin delivery to the upper region of small intestine. The dosage form is based on the incorporation of insulin with protease inhibitor and absorption enhancer into polyacrylic polymer Eudragit L-100. Insulin microspheres were prepared by solvent evaporation technique. And also study the effect of these microspheres upon the relative hypoglycemia (RH) effect in white diabetic albino rats has been studied in comparison to that produced after subcutaneous injection of bovine insulin solution. The oral administration of formulation with aprotinin and bile salts gave significant (p< 0.01) hypoglycemia when compared with formulation with insulin alone and with insulin and bile salts. However, the duration, course and the intensity of effect were different for each formulation. It was interesting to observe that the co-administration of aprotinin and bile salts produce prolonged and significant reduction of blood glucose level. A reduction of 4.47-36.81% in plasma glucose levels and RH of about 11.7% relative to subcutaneous injection of soluble insulin solution can be achieved by encapsulation along with protease inhibitor and bile salts.

Administration, Oral↗
PubMed2004

A study to determine the pharmacokinetics of gatifloxacin following a single oral dose.

Gatifloxacin is a broad spectrum fluoroquinolone that offers enhanced Gram-positive activity and anaerobic coverage to other fluoroquinolones. The pharmacokinetic parameters (Cmax, AUCo-t, tmax) of this drug have been evaluated to compare the single dose (400mg) bioavailability of gatifloxacin with the reference formulation. High performance liquid chromatography (HPLC) coupled with U-V detector set at 290 nm has been used to determine plasma concentration of 12 human volunteers as per DCGI (Drug Controller General of India) guidelines. The method has been validated over a linear range of 0.25 to 8 microg/ml from plasma. The minimum quantifiable concentration has been set at 0.25 microg/ml (% CV < 10%). The pharmacokinetic parameters are: Cmax = 4.366 +/- 0.44 microg/ml at tmax = 1.83 +/- 0.44 hour, AUCO0-t = 25.26 +/- 2.91 microg hour/ml, AUCo-inf = 33.68 +/- 4.31 microg hour/ml, Kel = 0.094 +/- 0.024/hour and t1/2 = 8.0 +/- 1.92 hour.

Administration, Oral↗
PubMed2003

Pellet coating by air suspension technique using a mini-model coating unit.

Air suspension coating is widely used in the pharmaceutical industry, as an attractive alternative to pan coating in that it can successfully coat small particles, pellets and tablets irrespective of size or shape with a wide variety of coating materials. The commercially available air suspension coating equipments require at least one kilogram of material for optimum efficiency of their working. Therefore, it is felt that there is a potential need for a small, compact air suspension coating instrument, which can work with gram quantities of material. The main objective of the present work is to design and evaluate a laboratory model top spray air suspension coating instrument. The performance of the instrument was evaluated for both, drug loading on to non-pareil pellets and coating of drug-loaded pellets. Terbutaline sulphate was selected as model drug, while Surelease (aqueous polymeric dispersion of ethyl cellulose) as representative coating material. The drug loading efficiency of the instrument was found to be around 82% with a pellet load of 10 g. The drug loading efficiency was found to be satisfactory and reproducible. Scanning electron micrographs of coated pellets indicated that coating was homogenous and uniform around the pellets. The maximum deviations observed in the in vitro drug release studies were +/- 2.7397% of the mean percent quantity of drug released, which is low enough for the coating to be considered uniform and reproducible. Reproducibility of the coating process was further confirmed by determining the 95% confidence interval for average difference in cumulative percentage drug release between two runs of each batch, which was found to be less than 5% set as the maximum allowable difference. The release data obtained were found to show best fit with first order kinetic model. A significant influence of coating thickness on the drug release rate was observed. From the results and observations of this work, it may be concluded that the mini-model air suspension coating instrument designed, may be a useful piece of equipment for preparing coated multiparticulate dosage forms in small quantities for sustained drug delivery, especially in research works.

Bronchodilator Agents↗
PubMed2003

High performance liquid chromatographic determination of cox-2 inhibitor rofecoxib in human plasma.

A convenient, sensitive and simple method for the determination of rofecoxib in human plasma is presented. The analytical technique is based on reversed phase high performance liquid chromatography coupled with UV detector (Knauer, Germany) set at 272 nm. The retention time of rofecoxib after recovery from plasma, was 8.9 minutes. The method has been validated over a linear range of 50-450 ng/ml from plasma. After validation the method was used to study the pharmacokinetic profile of rofecoxib in 6 healthy volunteers as per DCGI guidelines after administration of a single oral dose (50 mg). The extraction efficiency from plasma varied from 93.95-99.58%. The minimum quantifiable concentration was set at 50 ng/ml (% CV < 10%). The pharmacokinetic parameters were Cmax = 318.58 +/- 30.65 ng/ml at tmax = 2.66 +/- 0.25 hours, AUC0-t = 4007.88 +/- 438.32 ng hour/ml, AUC0-yen = 5454.66 +/- 822.29 ng hour/ml, Kel = 0.0433 +/- 0.0067/hour, and t1/2 = 16.36 +/- 2.89 hours.

Area Under Curve↗
PubMed1999

Evaluation of thermodynamic parameters for the activated charcoal-phenobarbitone adsorption system.

Poisoning with phenobarbitone is common occurrence all over the world. The removal efficiency of this drug by activated charcoal has been investigated. In vitro experiments were performed to determine the extent and duration of adsorption of phenobarbitone onto activated charcoal in solutions of various pH and at different temperatures. The results of studies supported the evidence of the effectiveness of charcoal as an adsorbent for phenobarbitone. With increasing the amount of activated charcoal, adsorption increases and was almost complete with 60 minutes. The adsorption of phenobarbitone onto activated charcoal was almost independent of pH. Thermodynamic parameters like change of enthalpy (delta H) and free energy (delta G) of the process were evaluated. The adsorption process follows the Langmuir isotherm model where b and n, Langmuir constants were also determined at different temperature and pH. A mathematical model has been established based on experimental data for adsorption of drug onto activated charcoal.

Adsorption↗
PubMed1997

Animal experimentation with tooth derived calcium hydroxyapatite based composites as bone-graft substitute biomaterials.

Calcium Hydroxyapatite (HA) has now been clinically accepted as one of the most important alloplastic bonegraft substitute in the management of oral surgical procedures including periodontal bony defects. HA can be synthetically prepared or derived from natural sources. Among the natural sources bovine bone is common but human source is also used. Of late Calcium Hydroxyapatite has been derived from extracted human tooth source. The present study involves the experiments using different varieties of HA in conjunction with chitosan, a binder, to know it's unique biological behaviour of bone bonding. The experiment was designed using 12(Twelve) New Zealand white rabbits on transcortical drilled hole tibial model and the observation was made under optical and scanning electron microscope. Result showed the osteoconductive and bioactive nature of tooth derived HA and biocompatibility of chitosan. The clinical problem of handling the particulate form of HA can be overcome by using chitosan which when mix with HA can stabilize the particle in surgical sites. This has tremendous clinical applications in dental regenerative surgery.

Animals↗
PubMed1992

Standardization of process parameters for salbutamol sulphate microcapsules coated with cellulose acetate phthalate and computation of in-vitro release kinetics.

Salbutamol sulphate, a bronchodilatatory drug for asthma, is encapsulated by Emulsion-Solvent-Evaporation technique using cellulose acetatephthalate as coating polymeric material. Different process parameters like Stirring Speed, Drug-Polymer Ratio, Solvent-Polymer Ratio, Internal Phase-External Phase Ratio, Effects of Temperature, and of Surfactants have been studied to standardise the process. At optimal condition of process parameters maximum encapsulation efficiency is obtained and microcapsules produced are free flowing and spherical. The dissolution of the microcapsules is carried out and the data obtained from in-vitro dissolution profile are computed in the light of different kinetic models. Diffusion coefficient (Da) and diffusivity rate constant (KBL) are evaluated with the help of Baker-Lonsdale model.

Albuterol↗
PubMed1992

In-vitro binary release kinetics of sulphamethoxazole and trimethoprim microcapsules.

Sulphamethoxazole and trimethoprim are separately microencapsulated with polyacrylic resin: Eudragit RS 100. The data so obtained from the drug release have been analyzed according to the different existing kinetic models (1) Zero order (2) First order and (3) Higuchi Matrix Kinetics. It is observed that in both the cases of single component and binary release of sulphamethoxazole (SMZ) and trimethoprim (TMP), Higuchi mechanism predominates. Lastly, a comparative study is made between The Single and Binary release kinetics to correlate the diffusivity rate constant (KBL) and diffusion Coefficient (Da) which have been estimated according to Baker-Lonsdale method at pH 1.2.

Capsules↗
PubMed1991

Computation of release kinetics of isoniazid microcapsules.

Isoniazid is a drug of choice for intermittent chemotherapy of tuberculosis. It has been microencapsulated by emulsification followed by solvent evaporation technique using Eudragit RS 100 as polymer where free flowing, spherical and discrete microcapsules have been formed as obtained by SEM. The drug release data have been computed in the light of various kinetic models, where it is found that the matrix release mechanism predominates over the first and zero order mechanism for isoniazid microcapsules, even if the sizes and drug polymer ratio of the microcapsules were varied.

Acrylic Resins↗
PubMed1991

Some prospective observations on recent outbreak of typhoid fever in West Bengal.

The present study was designed to study the clinical behaviour of a recent epidemic of typhoid fever in West Bengal. Of 46 cases studied, 67% (31) had chloramphenicol resistant typhoid fever. The chloramphenicol-resistant cases were comparatively severe in nature with higher complication and mortality rates. Salmonella typhi resistant to chloramphenicol were also resistant to ampicillin, cloxaxillin and cotrimoxazole. Strains of Salmonella typhi sensitive to chloramphenicol retained their sensitivity to these other antimicrobials.

Adult↗
PubMed1989

In-vitro diffusion kinetics of salbutamol sulphate from microcapsules coated with Eudragit RS 100.

Diffusion plays an important role in controlled release drug delivery system. Salbutamol sulphate, which is a bronchodilatory drug for asthma, was microencapsulated with a polyacrylic resin: Eudragit RS 100. Drug release data have been analyzed according to various release kinetics like Zero order, First order and Higuchi kinetics. Suice Higuchi mechanism seemed to predominate, the diffusivity rate constant (KBL) and the diffusion coefficient (Da) were estimated according to Baker-Lonsdale method at pH 1.2.

Acrylic Resins↗