Formulation development and characterization of lumefantrine nanosuspension for enhanced antimalarial activity

Variable and low oral bioavailability (4-11%) of lumefantrine (LUF), an anti-malarial agent, is characterized by very low solubility in aqueous vehicle. Thus, the present study was intended to formulate lyophilized nanosuspensions of LUF to resolve its solubility issues for the improvement of oral bioavailability. A three level 3² factorial design was applied to analyze the influence of independent variables, concentration of polysorbate 80 (X₁) and sonication time (X₂) on the responses for dependent variables, particle size (Y₁) and time to 90% release of LUF (t₉₀) (Y₂). Optimized formulation (F3) has shown to possess lowest particle size (95.34 nm) with minimum t₉₀ value (⁓3 mins), which was lyophilized to obtain the dry powder form of the nanosuspension. The characterization parameters confirmed the amorphous form of LUF with good stability and no chemical interactions of the drug with the incorporated components. Further, saturation solubility study revealed increased solubility of the LUF nanosuspension (1670 µg/mL) when compared to the pure drug (212.33 µg/mL). Further, rate of dissolution of LUF from the nanosuspension formulations were found to be significantly (p < 0.05) higher when compared to the pure drug. Fabricated lyophilized nanosuspension was found to be stable at 25 ± 2 °C/60 ± 5% RH and 40 ± 2 °C/75 ± 5% RH for the duration of three months. In conclusion, lyophilized nanosuspension showed ∼8-folds increase in drug release, which indicated a better way to offer higher release of LUF in controlling malaria.

Protective Effect of Eichhornia Crassipes Against Cerebral Ischemia Reperfusion Injury in Normal and Diabetic rats

Eichhornia crassipes (EC) is well reported to modify inflammatory response, oxidative stress which are key pathophysiological finding of cerebral reperfusion injury, alongside it is reported to reduce cholesterol and blood glucose levels, and therefore present work was designed to investigate the effect of EC on cerebral reperfusion injury in normal and diabetic rats. Each protocol comprised cerebral ischemia (CI) for 30 min followed by reperfusion(R) for 1 h. Animals were treated with EC (100 mg/kg p.o) for seven days. At the end of the experiment, brain tissue was utilized for the measurement of oxidative stress markers, inflammatory response, infarct size and histopathological findings. EC treated rats demonstrated a significant reduction in infarct sizes when compared with CI/R and Diabetic CI/R (DCI/R) group of rats. EC treatment demonstrated a significant decreased in malondialdehyde, nitric oxide and blood glucose levels and a significant increase in the level of reduced glutathione, superoxide dismutase catalase and insulin levels, showed modification in oxidative stress. EC treatment confirmed a significant decrease in myeloperoxidase, C - reactive protein and TNF-α levels indicated a change in the inflammatory response. Histopathological findings revealed a reversal of damage in EC treated rats. EC treatmen reduced DNA fragmentation of brain tissue in treated animals. EC was found to be cerebroprotective against CI/R along with DCI/R group of rats by anti-inflammatory and antioxidant activities.

Novel bio analytical method development, validation and application for simultaneous determination of nebivolol and S-amlodipine in human plasma using ultra performance liquid chromatography-tandem mass spectrometry

A sensitive and specific ultra-performance liquid chromatography tandem mass spectrometric (UPLC-MS/MS) method has been developed, validated and applied for the assay of Nebivolol and S-amlodipine in human plasma. Sample extraction was carried out through hybrid extraction method from 250 μL of human plasma sample. Linearity of the method was (r ≥ 0.9996) was found to be dynamic for both the analytes over concentration range of 25.0-4000 pg/mL. Chromatographic separation was achieved on UPLC column {Waters Acquity UPLC BEH C18 (50 mm × 2.1 mm, 1.7 micrometer)} with the mobile phase composition of 0.1% (v/v) formic acid in 5 mM Ammonium formate in water-acetonitrile (20:80, %v/v). Analytes Stability was assured under different requisite conditions in human plasma, reconstitution solution and diluents. Inter and intra-day assay precision and relative error (accuracy) were within ±5% for both analytes. The method was applied and reproduced to support a pharmacokinetic study of 5 mg Nebivolol (NEB) and 2.5 mg S-amlodipine (LAM) tablet on 9 healthy subjects.

The simultaneous UPLC-MS/MS determination of emerging drug combination; candesartan and chlorthalidone in human plasma and its application

A novel, precise, sensitive and accurate ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) method has been developed for the simultaneous determination of a novel drug combination, candesartan (CAN) and chlorthalidone (CHL), in human plasma. Chromatographic separation was achieved on Waters Acquity UPLC BEH C₁₈ (50 × 2.1 mm, 1.7 μm). Mobile phase consisting of 1 mm ammonium acetate in water-acetonitrile (20:80 v/v) was used. The total chromatographic runtime was 1.9 min with retention times for CAN and CHL at 0.7 and 1.1 min respectively. Ionization and detection of analytes and internal standards was performed on a triple quadrupole mass spectrometer, operating in the multiple reaction monitoring and negative ionization mode. Quantitation was done to monitor protonated precursor → product ion transition of m/z 439.2 → 309.0 for CAN, 337.0 → 189.8 for CHL and 443.2 → 312.1 for candesartan D4 and 341.0 → 189.8 for chlorthalidone D4. The method was validated over a wide dynamic concentration range of 2.0-540.0 ng/mL for candesartan and 1.0-180.0 ng/mL for chlorthalidone. The validated method was successfully applied for the assay of CAN and CHL in healthy volunteers.

Effect of fruits of Opuntia elatior Mill on mast cell degranulation

Background:

The presence of potentially active nutrients and their multifunctional properties make prickly pear a perfect candidate for the production of phytopharmaceutical products. Among the numerous Opuntia species, bioactive compounds have been isolated and characterized primarily from Opuntia ficus-indica, Opuntia polycantha, Opuntia stricta, Opuntia dilleni for various medicinal properties.

Objective:

Based on the traditional use of prickly pear for enhancement of immune function, the objective of the present study to evaluate the effect of prickly pear on mast cell degranulation function.

Materials and Methods:

The Opuntia fruit juice (OFJ) (10-200 μl/ml) were studied for the effect on sensitized rat peritoneal mast cell degranulation induced by immunological (egg albumin), and nonimmunological (compound 48/80) stimuli and compared with that of the reference standard, sodium cromoglycate and ketotifen (10 μg/ml).

Results and Conclusion:

The OFJ exhibited significantly (P < 0.001) concentration dependent inhibition of mast cell degranulation. The IC₅₀ value of OFJ was found 12.24 and 18 μl/ml for immunological and nonimmunological induced mast cell degranulation, respectively. The betacyanin is an active principle compound in prickly pear that may responsible for mast cell stabilizing action.

HPTLC Method for the Simultaneous Estimation of Valsartan and Hydrochlorothiazide in Tablet Dosage Form

A simple, precise, accurate and rapid high performance thin layer chromatographic method has been developed and validated for the simultaneous estimation of valsartan and hydrochlorothiazide in combined dosage forms. The stationary phase used was precoated silica gel 60F₂₅₄. The mobile phase used was a mixture of chloroform: methanol: toluene: glacial acetic acid (6:2:1:0.1 v/v/v/v). The detection of spots were carried out at 260 nm. The method was validated in terms of linearity, accuracy, precision and specificity. The calibration curve was found to be linear between 300 to 800 ng/spot for valsartan and 100 to 600 ng/spot for hydrochlorothiazide. The limit of detection and the limit of quantification for the valsartan were found to be 100 and 300 ng/spot respectively and for hydrochlorothiazide 30 and 100 ng/spot respectively. The proposed method can be successfully used to determine the drug content of marketed formulation.

Stability-indicating Simultaneous HPTLC Method for Olanzapine and Fluoxetine in Combined Tablet Dosage Form

A rapid, selective and stability-indicating high performance thin layer chromatographic method was developed and validated for the simultaneous estimation of olanzapine and fluoxetine in combined tablet dosage form. Olanzapine and fluoxetine were chromatographed on silica gel 60 F₂₅₄ TLC plate using methanol:toluene (4:2 v/v) as the mobile phase and spectrodensitometric scanning-integration was performed at a wavelength of 233 nm using a Camag TLC Scanner III. This system was found to give compact spots for both olanzapine (R_f value of 0.63±0.01) and fluoxetine (R_f value of 0.31±0.01). The polynomial regression data for the calibration plots showed good linear relationship with r²=0.9995 in the concentration range of 100-800 ng/spot for olanzapine and 1000-8000 ng/spot for fluoxetine with r²=0.9991. The method was validated in terms of linearity, accuracy, precision, recovery and specificity. The limit of detection and the limit of quantification for the olanzapine were found to be 30 and 100 ng/spot, respectively and for fluoxetine 300 and 1000 ng/spot, respectively. Olanzapine and fluoxetine were degraded under acidic, basic and oxidation degradation conditions which showed all the peaks of degraded product were well resolved from the active pharmaceutical ingredient. Both drugs were not further degraded after thermal and photochemical degradation. The method was found to be reproducible and selective for the simultaneous estimation of olanzapine and fluoxetine. As the method could effectively separate the drugs from their degradation products, it can be employed as a stability-indicating method.

Development and Validation of a HPTLC Method for the Estimation of Sumatriptan in Tablet Dosage Forms

A simple, precise, accurate and rapid high performance thin layer chromatographic method has been developed and validated for the estimation of sumatriptan in tablet dosage forms. The stationary phase used was precoated silica gel 60F254. The mobile phase used was a mixture of methanol:water:glacial acetic acid (4.0:8.0:0.1, v/v/v). The detection of spots was carried out at 230 nm. The method was validated in terms of linearity, accuracy, precision and specificity. The calibration curve was found to be linear between 200 to 800 ng/spot. The limit of detection and the limit of quantification for the sumatriptan were found to be 63.87 and 193.54 ng/spot, respectively. The proposed method can be successfully used to determine the drug content of marketed formulation.

Simultaneous determination of losartan and hydrochlorothiazide in combined dosage forms by first-derivative spectroscopy and high-performance thin-layer chromatography

Losartan (LST) is the first orally active nonpeptide angiotensin-II receptor antagonist with an improved safety and tolerability profile. It is prescribed alone or in combination with hydrochlorothiazide (HCTZ) for the treatment of moderate-to-severe hypertension. This paper describes the development of 2 methods that use different techniques, first-derivative spectroscopy and high-performance thin-layer chromatography (HPTLC), to determine LST and HCTZ in the presence of each other. LST and HCTZ in combined preparations were quantitated by using the first-derivative responses at 271.6 nm for LST and 335.0 nm for HCTZ in spectra of their solutions in water. The linearity ranges are 30-70 microg/mL for LST and 7.5-17.5 microg/mL for HCTZ with correlation coefficients of 0.9998 and 0.9997, respectively. In the HPTLC method, a mobile phase of chloroform-methanol-acetone-formic acid (7.5 + 1.5 + 0.5 + 0.03, v/v) and a prewashed Silica Gel G60 F254 TLC plate as the stationary phase were used to resolve LST and HCTZ in a mixture. Two well-separated and sharp peaks for LST and HCTZ were obtained at Rf values of 0.61+/-0.02 and 0.41+/-0.02, respectively. LST and HCTZ were quantitated at 254.0 nm. The linearity ranges obtained for the HPTLC method are 400-1200 and 100-300 ng/spot with corresponding correlation coefficients of 0.9944 and 0.9979, for LST and HCTZ, respectively. Both methods were validated, and the results were compared statistically. They were found to be accurate, specific, and reproducible. The methods were successfully applied to the estimation of LST and HCTZ in combined tablet formulations.

Estimation of individual sennosides in plant materials and marketed formulations by an HPTLC method

Senna is a well-known drug, used in the Ayurvedic and Allopathic systems of medicine, and is a treatment for constipation. The purgative action of senna and its formulations is due to the presence of sennosides A and B. An HPTLC method has been developed for the determination of individual sennosides (A, B, C, D) without any derivatization in marketed formulations (three tablet formulations, two granule formulations and one liquid formulation) and plant materials (senna leaf and pod). The methanolic solution of a sample was applied on a pre-coated silica gel G60 F254 TLC plate (E. Merck.) and was developed using n-propanol : ethyl acetate : water : glacial acetic acid (3 : 3 : 2 : 0.1 v/v) as the mobile phase. The relative band speeds (Rf values) obtained were 0.35, 0.25, 0.61, 0.46 for sennosides A, B, C and D, respectively. The densitometric response was monitored at 366nm. Calibration curves were found to be linear in the concentration ranges 193-1356, 402-2817, 71-497 and 132-927 ng per spot for sennosides A, B, C, and D, respectively. The correlation coefficients were found to be 0.9978, 0.9987, 0.9939 and 0.9983 respectively for sennosides A, B, C and D. The result obtained with the HPTLC method for total sennoside content was compared with the results using the pharmacopoeial methods (spectrophotometric (British Pharmacopoeia) and spectrofluorimetric (United States Pharmacopeia) using the 'F' test). The results revealed no significant difference in the three different methods for estimation of total sennoside. The proposed HPTLC method was found to be simple, specific, precise, accurate and rapid. It can be used for routine quality control of sennosides or senna-containing formulations for individual sennosides.