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Biomedical subjects

N Udupa

Publications and source records attributed to N Udupa.

At least 37 records · Page 2Linked to original sources
PubMed1999

Rapid and sensitive method for determination of nimesulide in human plasma by high-performance liquid chromatography.

A rapid and sensitive high-performance liquid chromatographic method for determination of nimesulide in human plasma has been developed. The chromatographic system uses a reversed-phase C18 column with UV-Vis detection at 230 nm. Mobile-phase consisted of phosphate buffer (pH 5.5)-methanol-acetonitrile (50:20:30, v/v) at a flow-rate of 1.4 ml/min. Nimesulide was extracted in a single step into dichloromethane. The overall mean extraction recoveries were above 98% for both inter- and intra-assay reproducibility, with CVs from 0.3 to 1%. The calibration curve was linear in the concentration range of 0.05-5 microg/ml, and the lower limit of detection was 30 ng/ml. This simple and sensitive method allows for determination of the range of plasma concentrations that is observed after administration of clinically relevant doses of nimesulide.

Analgesics, Non-Narcotic↗
PubMed1999

Evaluation of anti-tumor efficacy of injectable Centchroman in mice bearing Ehrlich ascites carcinoma.

Anti-tumor efficacy of Centchroman formulated as niosomes and gel implant was evaluated in Swiss albino mice bearing Ehrlich ascites carcinoma at 10 mg/kg body weight dose given subcutaneously. Median day of death, percentage increase in host life span and changes in body weight were studied. Centchroman significantly (P < 0.05) increased the median day of death both in free and formulated systems. Also, injectable formulations exhibited a significant (P < 0.05) increase in host life span compared to free drug, hence, enhanced anti-tumor efficacy against Ehrlich ascites carcinoma.

Animals↗
PubMed1999

Development and evaluation of transdermal formulations containing metronidazole and norfloxacin for the treatment of burn wound.

In an attempt for better treatment of partial thickness burn wounds topical ointments containing metronidazole and norfloxacin in different bases were prepared and in vitro release was conducted in phosphate buffer pH 6. It was found that, diffusion of the metronidazole and norfloxacin from the lanolin petrolatum base with 0.25% w/w dimethyl sulfoxide was maximum through hairless rat abdominal skin. Antimicrobial activity of different prepared formulations was found to be more effective both against aerobic and anaerobic bacteria than marketed formulation (1% silver sulfadiazine cream USP). Formulations were significantly effective as compared to that of marketed formulation in wound contraction of the partial thickness burn wound. Histopathological reports supported effectiveness of formulations. It was found that 1% metronidazole and 1% norfloxacin ointments are suitable for treating the partial thickness burn wound.

Administration, Cutaneous↗
PubMed1999

Biodegradable dental implants of ciprofloxacin beta-cyclodextrin inclusion complex in the treatment of periodontitis.

Dental implants of ciprofloxacin beta-cyclodextrin inclusion complex were formulated using poly (epsilon-caprolactone), a biodegradable polymer and evaluated. Clinical evaluation was carried out in ten patients with acute peridontitis. Various clinical parameters, viz. gingival index, plaque score, attachment gain, reduction in pocket depth were evaluated at 10, 20, 30, 40 days of treatment and compared with placebo as control. A significant (P < 0.0001) improvement in the healing of periodontal pockets treated with ciprofloxacin beta-cyclodextrin implant was observed in most of the clinical parameters. Estimation of gingival crevicular fluids (GCF) for the drug content revealed that drug levels above the minimum inhibitory concentration (10.2 micrograms/mg) for many of the periodontal pathogens were maintained throughout the period of study (40 days). This confirms the clinical efficacy of the dose and the duration of the study. It was found that biodegradable carrier was better accepted than the non-biodegradable carriers reported earlier.

Adult↗
PubMed1998

High-performance liquid chromatographic determination of insulin in rat and human plasma.

A rapid and simple isocratic chromatographic procedure for the determination of insulin in human and rat plasma using reversed-phase (RP) high-performance liquid chromatography with an ultraviolet/visible detector is described. The method includes extraction of insulin from human and rat plasma into dichloromethane, followed by back-extraction into 0.05 N hydrochloric acid. The organic phase was evaporated under a stream of nitrogen. The aqueous phase was filtered and a 100 microliters aliquot was analyzed on a RP-C18 column eluted with a mobile phase consisting of a mixture of 74 vol of 0.2 M sodium sulfate anhydrous adjusted to pH 2.3 with phosphoric acid and 26 vol of acetonitrile. The flow rate was 1.2 ml/min and the wavelength was set at 214 nm. The calibration curve was linear over the range of 75-800 microIU/ml. The precision of the assay expressed as coefficients of variation was less than 6% over the entire concentration range. The recovery for insulin ranged from 79 to 81% from human and rat plasma, with coefficients of variation less than 6%. The intra- and interassay coefficients of variation were less than 5.7%. The limit of detection was 50 microIU/ml.

Adult↗
PubMed1998

Cytotoxic and anticancer activities of some 1-aryl-2-dimethylaminomethyl-2-propen-1-one hydrochlorides.

A series of 1-aryl-2-dimethylaminomethyl-2-propen-1-one hydrochlorides demonstrated marked cytotoxicity towards approximately 55 human tumour cell lines from different neoplastic diseases. In general they were more potent than melphalan and displayed selective toxicity towards human leukemic cells. A representative compound, 1-phenyl-2-dimethyl-aminomethyl-2-propen-1-one hydrochloride (2a), had similar cytotoxicity as melphalan towards murine P388 and L1210 leukemic cells. In addition, 2a reduced the sizes of a number of human tumour xenografts including colon, prostatic and melanotic cancers passaged in athymic mice. Compound 2a showed excellent activity towards Ehrlich ascites carcinoma and B16F1 melanoma in mice which was enhanced using niosomes. One may conclude from the data generated that 1-aryl-2-dimethylaminomethyl-2-propen-1-one hydrochlorides are a novel series of cytotoxic and anticancer agents.

Allylamine↗
PubMed1997

In vitro characterization of methotrexate loaded poly(lactic-co-glycolic) acid microspheres and antitumor efficacy in Sarcoma-180 mice bearing tumor.

Methotrexate (MTX) loaded poly (lactic-co-glycolic) acid (PLGA) microspheres were prepared by emulsion solvent evaporation technique. The mean diameter of the microspheres was affected by the type of emulsion stabilizer, polymer concentration, aqueous and organic phase volume and stirring speed. The in vitro release was triphasic and was dependent on copolymer composition and molecular weight of the polymer. Antitumor efficacy in Sarcoma-180 tumor bearing mice exhibited increased volume doubling time (18 +/- 2.7 days) compared to plain subcutaneous injection of methotrexate (8 +/- 0.7 days). Preliminary pharmacokinetic studies following subcutaneous administration of MTX loaded PLGA microspheres illustrated the controlled release of the drug. The studies demonstrated the feasibility of employing PLGA as an effective carrier for antineoplastic drug like methotrexate.

Animals↗
PubMed1997

Absorption of ciprofloxacin and norfloxacin when administered as niosome-encapsulated inclusion complexes.

An attempt has been made to design suitable niosome-encapsulated drug delivery system for ciprofloxacin and norfloxacin. Encapsulation of ciprofloxacin and norfloxacin in niosomes was investigated and the nasal and intestinal absorption of the products studied. More than 80% of the drugs were successfully encapsulated to give products with sustained release characteristics. Encapsulation in niosomes also improved the stability of the antibacterial compounds. Although the systemic availability of these niosome-encapsulated antibacterial compounds was not increased after nasal administration, intestinal absorption was significantly higher in comparison with that of plain inclusion complexes.

Absorption↗
PubMed1997

Antitumor and antifertility activities of plumbagin controlled release formulations.

With a view to increase efficiency and reduce toxicity of Plumbagin, an attempt was made to formulate plumbagin as a controlled release preparation using various carriers and test for their antitumor and antifertility activities. Niosomes and albumin microspheres were used as carriers. In vitro data showed promising results for these formulations thus they were taken up for in vivo assessment. Given at a dose of 5 mg/kg, ip the albumin microspheres showed promising antitumor and antifertility activity when compared to the niosomes on control. Animal survival data also indicated slight improvement in survival rate and thus antitumoral activity. Also, an interesting point was that the antifertility activity was affected through an antiovulatory action as seen from histopathological studies.

Animals↗
PubMed1996

Niosomal plumbagin with reduced toxicity and improved anticancer activity in BALB/C mice.

Plumbagin niosome were prepared using a lipid layer hydration method, and drug entrapment was measured. The acute toxicity studies were conducted following treatment with free and niosomal plumbagin. The antitumour activity of niosomal plumbagin in a solid tumor (sarcoma-180) and Ehrlich ascites model was evaluated. Niosome-encapsulated plumbagin was less toxic than free drug. The antitumour activity of the drug was also better after encapsulation. The better anticancer activity can be justified with the help of LD50 survival studies and study of tumour volume doubling time.

Animals↗
PubMed1996

Biodegradable injectable implant systems for long term drug delivery using poly (lactic-co-glycolic) acid copolymers.

Poly (lactide-co-glycolide) (PLG), is one of the most widely employed biodegradable synthetic polymers for sustained-release preparations. In the present work, PLG (50:50) copolymer has been used to deliver diclofenac sodium in the form of microspheres and in situ gel-forming systems, both of which can be injected subcutaneously. The pharmacodynamic and pharmacokinetic studies in the adjuvant-induced arthritic rats showed that the microspheres offered steady therapeutic levels of the drug in the plasma for about 16 days following a single subcutaneous injection. However, the in situ gel-forming system provided a significantly higher maximum plasma concentration and increased inhibition of inflammation, maintained for about 10 days. Injectable microspheres and in situ gel-forming implant systems of PLG (50:50) copolymer may therefore be considered as prospective implantable controlled-release dosage forms to deliver drugs in long-term therapy of chronic ailments.

Animals↗
PubMed1996

Antitumor and radiosensitizing effects of withaferin A on mouse Ehrlich ascites carcinoma in vivo.

The antitumor and radiosensitizing effects of withaferin A (WA), a steroidal lactone from Withania somnifera, was studied on Ehrlich ascites carcinoma in vivo. The acute LD50(14) for WA in Swiss mice was approximately 80 mg/kg. Twenty-four hours after i.p. inoculation of 10(6) tumor cells, WA was injected i.p. at different dose fractions (5 or 7.5 mg/kg x 8, 10 mg/kg x 5, 20 or 30 mg/kg x 2) with or without abdominal gamma irradiation (RT, 75. Gy) after the first drug dose. Increase in life span and tumor-free survival were studied up to 120 days. The drug inhibited tumor growth and increased survival, which was dependent on the WA dose per fraction rather than the total dose. Combination of RT with all the drug schedules increased tumor cure and tumor-free survival, the best effect seen after 2 fractions of 30 mg/kg each. In another experiment WA was given as 2 (40 mg/kg x 2), 3 (30 mg/kg x 3) or 4 (20 mg/kg x 4) fractions at 5, 7 or 10 days after tumor inoculation with or without RT after the first drug dose. At 7 and 10 days after inoculation the drug was effective only at 40 mg/kg x 2, but with RT 30 mg/kg x 3 produced an equal effect (20% survival) on 7 day old tumors.

Abdominal Neoplasms↗
PubMed1996

Altered biological distribution and decreased neuromuscular toxicity of niosome encapsulated vincristine.

Effects of encapsulation within niosomes (nonionic surfactant vesicles) on the biological distribution and toxicity of vincristine-a widely used anticancer drug have been investigated. Plasma kinetics, tissue distribution profile and neuromuscular toxicity of niosomal vincristine (NVCR) were compared with those of free vincristine (FVCR). NVCR was cleared from the plasma much more slowly [t1/2(beta) = 1.388 hr] than FVCR [t1/2(beta) = 0.74 hr]. Over the 48 hr period of experiment, the niosome formulation delivered significantly more drug to the plasma compartment than FVCR and resulted in reduced accumulation of drug in gut and skeletal muscle. Encapsulation caused a marked alteration in the tissue disposition of the drug. NVCR was less toxic both in terms of mortality and morbidity. Importantly, histopathological studies of skeletal muscle, spinal cord and sciatic nerve of NVCR treated albino wistar rats demonstrated the less toxic potential of encapsulated vincristine. Further, the biochemical studies, estimation of enzymes plasma creatine phosphokinase and lactate dehydrogenase, confirmed the safety profile of NVCR. The decreased partitioning of NVCR to non active sites resulted in a significant amelioration of the toxic side effects, gastrointestinal and myological in particular, of the drug. The results indicate that the delivery of vincristine by encapsulating it in niosomes offer an efficient means of decreasing its toxic effects.

Animals↗
PubMed1996

Toxicity and antitumor activity of niosomal bleomycin in tumor bearing mice.

Niosomal encapsulation of bleomycin enhanced the antitumor activity against Ehrilich ascites and sarcoma-180 models. The niosomal/free drug mean survival time values of 1.28 was achieved in Ehrlich ascites infected animals. Niosomal bleomycin considerably increased the 40 days survival rate in mice. Tumor volume doubling time of S-180 tumor was also increased significantly in niosomal treated animals. Histopathological studies of lung and jejunum of Niosomal bleomycin treated mice, confirmed the less toxic potential of encapsulated bleomycin. The suppression of peripheral and bone marrow WBC counts upon niosomal bleomycin treatment was not substantial.

Animals↗
PubMed1994

Niosome encapsulated of vincristine sulfate: improved anticancer activity with reduced toxicity in mice.

Nonionic surfactant vesicles (niosomes) are promising drug carriers for anticancer drugs. Niosome encapsulated vincristine sulfate prepared by transmembrane pH gradient drug uptake process (remote loading method) was evaluated for toxicity and antitumour activity after administration to tumour bearing mice. The toxicity of vincristine sulfate was reduced after niosome encapsulation and anticancer activity improved, which may be due to better delivery of vincristine at the tumour site.

Animals↗
PubMed1993

Effect of macrophage activation on plasma disposition of niosomal 3H-methotrexate in sarcoma-180 bearing mice.

Methotrexate niosomes were formed by reverse phase evaporation technique using sorbitan monostearate (Span 60) surfactant. The pharmacokinetic parameters of methotrexate (MTX) after macrophage activation via muramyl dipeptide gelatin conjugate were studied and the results compared with those obtained after free MTX and MTX niosomes without macrophage activation. In mice MTX concentrations and tumour regression were higher after macrophage activation.

Animals↗
PubMedDate not supplied

Poly(DL-lactide-co-glycolide) microporous microsphere-based depot formulation of a peptide-like antineoplastic agent.

In the present investigation, a poly(DL-co-glycolide) (PLGA)-based, microspheric depot system for bleomycin (BLM) has been formulated, and the same has been evaluated in-vivo in C57BL/6J mice bearing transplantable melanoma B16F1 murine solid tumour. The microparticulate delivery systems were formulated employing a water-in-oil-in-water (W/O/W) emulsion-solvent evaporation technique and characterized in-vitro. The microspheres were injected subcutaneously to form a drug depot at the site of injection in mice bearing experimental tumours and the drug was continuously infused into the systemic circulation with progressive biodegradation. The drug-loaded microspheres exhibited improved pharmacodynamic efficacy, as evidenced by retarded tumour growth kinetics. Preliminary pharmacokinetic studies illustrated controlled release of the drug into the systemic circulation over the study period to exert an anti-neoplastic action. These studies demonstrated the feasibility of employing a PLGA-based microparticulate system as an effective biodegradable, injectable, depot-forming therapeutic system for long-term administration of anti-neoplastic agents.

Animals↗