A validated stability-indicating LC method for estimation of etoposide in bulk and optimized self-nano emulsifying formulation: Kinetics and stability effects

The present investigation was aimed to establish a validated stability-indicating liquid chromatographic method for the estimation of etoposide (ETP) in bulk drug and self-nano emulsifying formulation. ETP was successfully separated from the degradation products formed under stress conditions on LiChrospher 100 C₁₈ reverse-phase column (a 250 mm × 4.6 mm i.d., 5-μm particle size) using 55:45 (v/v) acetonitrile–phosphate buffer saline (pH 4.5) as the mobile phase, at a flow rate of 1.0 mL min⁻¹ and detection at 283 nm. The response was a linear function of analyte concentration (R² > 0.9997) over the concentration range of 0.05–50 μg mL⁻¹. The method was validated for precision, accuracy, robustness, sensitivity and specificity. The % recovery of ETP at three different levels (50%, 100% and 150%) ranged between 93.84% and 100.06% in optimized self-nano emulsifying formulation, Etosid® soft-gelatin capsule and Fytosid® injection. First-order degradation kinetics of ETP were observed under acidic and alkaline conditions. The method was also applied for the stability assessment of self-nano emulsifying formulation under accelerated conditions, the formulation was found to be stable at all storage conditions with the shelf-life of 2.37 years at 25 °C. The method holds promise for routine quality control of ETP in bulk, pharmaceutical formulations as well as in stability-indicating studies.     

Inhalational System for Etoposide Liposomes: Formulation Development and In Vitro Deposition

Etoposide is a semisynthetic compound, widely used in treatment of non small cell lung cancer. However, frequent dosing and adverse effects remain a major concern in the use of etoposide. Liposomal systems for pulmonary drug delivery have been particularly attractive because of their compatibility with lung surfactant components. In the present investigation, pulmonary liposomal delivery system of etoposide was prepared by film hydration method. Various parameters were optimized with respect to entrapment efficiency as well as particle size of etoposide liposomes. For better shelf life of etoposide liposomes, freeze drying using trehalose as cryoprotectant was carried out. The liposomes were characterized for entrapment efficiency, particle size, surface topography, and in vitro drug release was carried out in simulated lung fluid at 37° at pH 7.4. The respirable or fine particle fraction was determined by using twin stage impinger. The stability study of freeze dried as well as aqueous liposomal systems was carried out at 2-8° and at ambient temperature (28±4°). The freeze dried liposomes showed better fine particle fraction and drug content over the period of six months at ambient as well as at 2-8° storage condition compared to aqueous dispersion of liposomes.     

Box-Behnken supported validation of stability-indicating high performance thin-layer chromatography (HPTLC) method: An application in degradation kinetic profiling of ropinirole

Stability-indicating high-performance thin-layer chromatographic (HPTLC) method for the analysis of ropinirole HCl was developed and validated as per the ICH guidelines. The method employed the mobile phase and toluene-ethyl acetate-6 M ammonia solution (5:6:0.5, v/v/v) was optimized with the help of a design expert. Densitometric analysis of ropinirole HCl was carried out in the absorbance mode at 250 and 254 nm. Compact spots for ropinirole HCl were found at R_f value of 0.58 ± 0.02. The linear regression analysis data for the calibration plots showed R² = 0.9989 ± 0.0053 with a concentration range of 100–3000 ng spot⁻¹. The method was validated for precision, accuracy, ruggedness, robustness, specificity, recovery, limit of detection (LOD) and limit of quantitation (LOQ). The LOD and LOQ were 12.95 and 39.25 ng spot⁻¹ respectively. Drug was subjected to acidic, alkaline, oxidative, dry heat, wet heat and photo degradation stress. All the peaks of degradation products were well resolved from the standard drug peak with significant difference of R_f. The acidic and alkaline stress degradation kinetics of ropinirole, were found to be in first order, showing high stability (t_1/2, 146.37 h⁻¹; t_0.9, 39.11 h⁻¹) in the acidic medium and low stability (t_1/2, 97.67 h⁻¹; t_0.9, 14.87 h⁻¹) in the alkaline environment.     

Stability of pantoprazole sodium in glass vials, polyvinyl chloride minibags, and polypropylene syringes

Background:

Pantoprazole sodium, a proton-pump inhibitor, is approved for the short-term treatment of several types of ulcer, Zollinger–Ellison syndrome, and gastroesophageal reflux disease.

Objective:

To determine the physical compatibility and chemical stability of ethylenediaminetetra-acetic acid (EDTA)–free pantoprazole in glass vials, polypropylene syringes, and polyvinylchloride (PVC) minibags, after storage at 2°C to 8°C with protection from light or at 20°C to 25°C with exposure to light.

Methods:

Solutions of pantoprazole 4 mg/mL reconstituted in 0.9% sodium chloride (normal saline [NS]) were stored in glass vials at 20°C to 25°C. Similar solutions were transferred to polypropylene syringes and stored at 2°C to 8°C. Stock solution was further diluted, in 5% dextrose in water (D5W) or NS, to 0.4 or 0.8 mg/mL, and samples were then packaged in PVC minibags for storage at 2°C to 8°C or at 20°C to 25°C. Samples collected on days 0, 2, 3, 7, 14, 21, and 28 were analyzed in duplicate with a stability-indicating high-performance liquid chromatography assay.

Results:

Pantoprazole 4 mg/mL was stable (i.e., retained at least 90% of initial concentration) for 3 days when stored in glass vials at 20°C to 25°C or for 28 days when stored in polypropylene syringes at 2°C to 8°C. Pantoprazole 0.4 mg/mL diluted in D5W and stored in PVC minibags was stable for 2 days at 20°C to 25°C or for 14 days at 2°C to 8°C. At 0.8 mg/mL, pantoprazole in D5W was stable for 3 days at 20°C to 25°C or 28 days at 2°C to 8°C. Pantoprazole diluted to either 0.4 or 0.8 mg/mL in NS and stored in PVC minibags was stable for 3 days at 20°C to 25°C or 28 days at 2°C to 8°C.

Conclusions:

The present study confirmed or extended previously reported expiry dates for pantoprazole sodium packaged in glass vials, polypropylene syringes, and PVC minibags.     

Development and Validation of a Stability-Indicating RP-HPLC Method for the Quantitative Analysis of Anagrelide Hydrochloride

A simple, rapid, and stability-indicating reverse-phase liquid chromatographic assay method was developed for Anagrelide Hydrochloride (ANG) in the presence of its degradation products generated from forced decomposition studies. The HPLC separation was achieved on a C18 Inertsil column (250 mm × 4.6 mm i.d. particle size is 5 μm), using solution A, a mixture of 0.03 M potassium di-hydrogen phosphate pH-adjusted to 3.0 using ortho-phosphoric acid (buffer): methanol: acetonitrile (90:5:5, v/v/v), and solution B, which contains a mixture of buffer: acetonitrile (10:90, v/v). The UV detector was operated at 251 nm while column temperature was maintained at 40°C, and the gradient program had the flow rate of 1.0 mL min⁻¹. The developed method was validated as per ICH guidelines with respect to specificity, linearity, precision, accuracy, robustness, and limit of quantification. The method was found to be simple, specific, precise, accurate, and reproducible. Selectivity was validated by subjecting the stock solution of ANG to acidic, basic, photolysis, oxidative, and thermal degradation. The calibration curve was found to be linear in the concentration range of 0.05–152 μg mL⁻¹ (R² = 0.9991). The peaks of degradation products did not interfere with that of pure ANG. The utility of the developed method was examined by analyzing the tablets containing ANG.     

A Stability-Indicating RP-HPLC Assay Method for 5-Fluorouracil

The present study describes the development of a validated RP-HPLC method for the determination of 5-fluorouracil in presence of its degradation products or other pharmaceutical excipients. Stress studies were performed on 5-fluorouracil and it was found that it degrades sufficiently in alkaline conditions, while negligible degradation was observed in acidic, neutral, oxidative and photolytic conditions. The peaks of the degradation products were not observed in the chromatogram due to the nonchromophoric nature of the degradation moiety formed. The separations were carried out on a C-18 reversed phase column (Phenomenex; Prodigy ODS3V, 250×4.6 mm, 5 μ) using 50mM KH₂PO₄ (pH, 5.0) as mobile phase at a flow rate of 1.2 ml/min and temperature of 30°. The wavelength of detection was 254 nm. A retention time of nearly 6 minutes was obtained. Analytical validation parameters such as specificity and selectivity, linearity, accuracy and precision were evaluated. The calibration curve for 5-fluorouracil was linear (r²=0.999±0.0005) from range of 10 μg/ml to 100 μg/ml. Relative standard deviation values for all the key parameters, was less than 2.0 %. The recovery of the drug after standard addition to the degraded sample was found to be 104.69%. Thus, the developed RP-HPLC method was found to be suitable for the determination of 5-fluorouracil in bulk as well as stability samples of the pharmaceutical dosage forms containing various excipients.     

Supersaturated Self-Nanoemulsifying Drug Delivery Systems (Super-SNEDDS) Enhance the Bioavailability of the Poorly Water-Soluble Drug Simvastatin in Dogs

This study investigates the potential of supersaturated self-nanoemulsifying drug delivery systems (super-SNEDDS) to improve the bioavailability of poorly water-soluble drugs compared to conventional SNEDDS. Conventional SNEDDS contained simvastatin (SIM) at 75% of the equilibrium solubility (S_eq). Super-SNEDDS containing SIM at 150 and 200% of S_eq were produced by subjecting the SNEDDS preconcentrates to a heating and cooling cycle. The super-SNEDDS were physically stable over 10 months. During in vitro lipolysis of SNEDDS and super-SNEDDS the SIM concentration in the aqueous phase increased for the first 30 min almost proportional to the drug loads and amounts of preconcentrate employed. The 200% drug-loaded super-SNEDDS generated an amorphous SIM precipitate at the end of in vitro lipolysis. In vivo, the relative bioavailability of SIM from super-SEDDDS increased significantly to 180 ± 53.3% (p = 0.014) compared to the dosing of two capsules of (dose equivalent) 75% drug-loaded SNEDDS. A significant increase in the terminal half-life of elimination was observed for super-SNEDDS (2.3 ± 0.6 h) compared to conventional SNEDDS (1.4 ± 0.3 h) as well as a decreased area under the curve ratio of the SIM metabolite simvastatin acid to the parent compound (0.57 ± 0.20 and 0.90 ± 0.3), possibly due to a combination of saturation effects on presystemic metabolising enzymes and prolonged absorption along the small intestine. In summary, this study demonstrated that super-SNEDDS are a viable formulation option to enhance the bioavailability of poorly water-soluble drugs such as simvastatin while reducing the pill burden by an increased drug load of SNEDDS.Key words: bioavailability, in vitro digestion, in vitro lipolysis, simvastatin, supersaturated self-nanoemusifying drug delivery systems (super-SNEDDS) poorly soluble drugs     

Kinetics of Autoxidation of an Oil Extract from Terminalia catappa

Soxhlet extractor was used in the extraction of oil from milled seeds of Terminalia catappa using petroleum ether (40-60°). The optimal oil yield was 56.71±1.66% with a viscosity of 40.79±1.05 centipoises. Other parameters of the oil were found as follows; specific gravity-0.9248, refractive index-1.4646, acid value-3.35, peroxide value-8.6, saponification value-166.2, and unsaponifiable matter-1.46. The crude oil extract was water-degummed, bleached and deodorized to generate what we called refined oil. Autoxidation of the crude and refined T. catappa oil extract was done at five different temperatures of 0±0.1°, 20±0.1°, 40±0.1°, 60±0.1° and 80±0.1° and also in the presence of pure α-tocopherol at a concentration of 1.0% (w/v) by measuring peroxide value variations over 96 h. In all evaluations, the refined oil exhibited lower tendency towards autoxidation but not at temperatures above 60±0.1°. The use of Arrhenius equation revealed generally very low activation energies of 0.0261 cal/deg×mol and 0.0122cal/deg×mol for crude oil and antioxidant-treated crude oil, respectively and 0.0690 cal/deg×mol and 0.0177 cal/deg×mol for the refined oil. This study indicates T. catappa seed oil to be potential pharmaceutical oil with excellent characteristics.     

Preparation and In Vitro Characterization of Mucoadhesive Hydroxypropyl Guar Microspheres Containing Amlodipine Besylate for Nasal Administration

Amlodipine besylate microspheres for intranasal administration were prepared with an aim to avoid first-pass metabolism, to achieve controlled blood level profiles and to improve therapeutic efficacy. Hydroxypropyl Guar, a biodegradable polymer, was used in the preparation of microspheres by employing water in oil emulsification solvent evaporation technique. The formulation variables were drug concentration, emulsifier concentration, temperature, agitation speed and polymer concentration. All the formulations were evaluated for particle size, particle shape and surface morphology by scanning electron microscopy, percentage yield, drug entrapment efficiency, in vitro mucoadhesion test, degree of swelling and in vitro drug diffusion through sheep nasal mucosa. The microspheres obtained were free flowing, spherical and the particles ranged in size from 13.4±2.38 μm to 43.4±1.92 μm very much suitable for nasal delivery. Increasing polymer concentration resulted in increased drug entrapment efficiency and increased particle size. Amlodipine besylate was entrapped into the microspheres with an efficiency of 67.2±1.18 % to 81.8±0.64 %. The prepared microspheres showed good mucoadhesion properties, swellability and sustained the release of the drug over a period of 8 h. The data obtained were analysed by fitment into various kinetic models; it was observed that the drug release was matrix diffusion controlled and the release mechanism was found to be non-Fickian. Stability studies were carried out on selected formulations at 5±3°, 25±2°/60±5% RH and 40±2°/75±5% RH for 90 days. The drug content was observed to be within permissible limits and there were no significant deviations in the in vitro mucoadhesion and in vitro drug diffusion characteristics.     

Formulation and in vitro evaluation of topical nanosponge-based gel containing butenafine for the treatment of fungal skin infection

In the current study, four formulae (BNS1-BNS4) of butenafine (BTF) loaded nanosponges (NS) were fabricated by solvent emulsification technology, using different concentration of ethyl cellulose (EC) and polyvinyl alcohol (PVA) as a rate retarding polymer and surfactant, respectively. Prepared NS were characterized for particle size (PS), polydispersity index (PDI), zeta potential (ZP), entrapment efficiency (EE) and drug loading (DL). Nanocarrier BNS3 was optimized based on the particle characterizations and drug encapsulation. It was further evaluated for physicochemical characterizations; FTIR, DSC, XRD and SEM. Selected NS BNS3 composed of BTF (100 mg), EC (200 mg) and 0.3% of PVA showed, PS (543 ± 0.67 nm), PDI (0.330 ± 0.02), ZP (−33.8 ± 0.89 mV), %EE (71.3 ± 0.34%) and %DL (22.8 ± 0.67%), respectively. Fabricated NS also revealed; polymer-drug compatibility, drug-encapsulation, non-crystalline state of the drug in the spherical NS as per the physicochemical evaluations. Optimized NS (BNS3) with equivalent amount of (1%, w/w or w/v) BTF was incorporated into the (1%, w/w or w/v) carbopol gel. BTF loaded NS based gel was then evaluated for viscosity, spreadability, flux, drug diffusion, antifungal, stability and skin irritation studies. BNS3 based topical gels exhibited a flux rate of 0.18 (mg/cm².h), drug diffusion of 89.90 ± 0.87% in 24 h with Higuchi model following anomalous non-Fickian drug release. The BNS3 based-gel could be effective against pathogenic fungal strains.     

Buffered lidocaine hydrochloride solution with and without epinephrine: stability in polypropylene syringes

Background:

Pain associated with infiltrating the skin with lidocaine can be reduced by buffering the solution with sodium bicarbonate.

Objectives:

To determine the physical compatibility and chemical stability of lidocaine hydrochloride solution buffered with 8.4% sodium bicarbonate, with and without epinephrine, packaged in polypropylene syringes and stored at 5°C with protection from light.

Methods:

Lidocaine solutions (1% and 2%), with and without epinephrine 1:100 000, were diluted 10:1 with 8.4% sodium bicarbonate, packaged in 3-mL polypropylene syringes, and stored at 5°C (range 3°C to 8°C). On each of days 0, 3, 7, 10, 14, 17, 21, 24, and 28, the contents of 3 syringes for each solution of lidocaine combined with epinephrine were collected separately in glass vials and frozen at −70°C for subsequent analysis. In addition, on days 0, 7, 14, 21, and 28, the contents of 3 syringes for each lidocaine solution without epinephrine were collected separately in glass vials and frozen at −70°C for subsequent analysis. Chemical stability was determined with a validated, stability-indicating high-performance liquid chromatography method. Changes in colour, clarity, and pH were used to determine physical compatibility of the solutions.

Results:

All buffered lidocaine solutions containing epinephrine (1:100 000) retained at least 93.3% of the original concentration of epinephrine and 97.5% of the lidocaine concentration for 7 days when stored at 5°C with protection from light. In contrast, the epinephrine-free solutions retained at least 94.7% of the initial concentration of lidocaine for the duration of the study (28 days). All samples remained clear, colourless, and free of precipitate throughout the study, and there were no significant changes in pH.

Conclusion:

Extemporaneously prepared buffered lidocaine (1% and 2%) packaged in polypropylene syringes remained stable for up to 28 days when properly refrigerated with protection from light. A 7-day expiry date was established for buffered lidocaine solutions containing epinephrine, packaged in polypropylene syringes, and stored with refrigeration and protection from light.     

Protective effects of aqueous and ethanolic extracts of Nigella sativa L. and Portulaca oleracea L. on free radical induced hemolysis of RBCs

Background and the purpose of the study

It has been shown that Nigella sativa L. and Portulaca oleracea L. have many antioxidant components. In the present study, the cytoprotective effect of ethanolic and aqueous extracts of N.sativa and P.oleracea against hemolytic damages induced by free radical initiator, AAPH [2, 2’ azobis (2- amidinopropane) hydrochloride] was evaluated.

Methods

Hemolysis was induced by addition of AAPH. To study the cytoprotective effect, aqueous (50, 200, 300, 400, 800 µg/ml) and ethanolic (25, 100, 150, 200 and 400 µg/ml) extracts of N. sativa and aqueous (25, 50, 100, 150, 200 and 400 µg/ml) and ethanolic (300, 600, 900, 1200 and 1800 µg/ml) extracts of P. oleracea were employed. RBCs were incubated with both extracts and AAPH at 37 °C for 6 hrs. In order to evaluate the impact of the time of addition, extracts were added one and 2 hrs after AAPH. Samples of suspensions were removed at different times and the degree of hemolysis was assessed spectrophotometrically by reading the absorption of supernatants at 540 nm.

Results

Aqueous (300, 400 and 800 µg/ml) and ethanolic (150, 200 and 400 µg/ml) extracts of N.sativa and also, aqueous (100, 150, 200 and 400 µg/ml) and ethanolic (1200, 1800 µg/ml) extracts of P.oleracea showed concentration-dependent cytoprotective effects. Addition of extracts one hour after AAPH reduced but did not eliminate protective activities of extracts.

Conclusion

Cytorotective effect of aqueous and ethanolic extracts of N. sativa and P. oleracea against AAPH- induced hemolysis may be related to antioxidant properties of these plants.     

The effect of Kö 1173, a new anticonvulsant agent on experimental cardiac arrhythmias

1. The effects of the intravenous injection of Kö 1173, a new anticonvulsant drug, phenytoin and procainamide were studied on three types of cardiac arrhythmia in dogs.2. Ventricular ectopic beats produced by intravenous injection of adrenaline in anaesthetized dogs respired with halothane were abolished by Kö 1173, 0·6 ± 0·1 mg/kg, phenytoin, 1·1 ± 0·3 mg/kg and procainamide, 4·1 ± 1.8 mg/kg.3. Ventricular tachycardia was produced in anaesthetized dogs by the intravenous injection of ouabain and the three drugs infused intravenously at 0·2 (mg/kg)/min until sinus rhythm returned. Kö 1173 was effective in 8 out of 9 dogs after a mean dose of 1·3 ± 0·3 mg/kg; phenytoin in all 3 dogs after 2·7 ± 0·6 mg/kg and procainamide in the 3 dogs tested after 16·6 ± 1·3 mg/kg.4. The intravenous injection of Kö 1173, 8·0 mg/kg, greatly reduced the number of ventricular ectopic beats occurring in conscious dogs 18-44 h after ligation of the anterior descending branch of the left coronary artery, with a resultant increase in the number of sinus beats. Phenytoin, 8·0 mg/kg, had a similar effect but procainamide was much less effective.5. These results indicate that Kö 1173 is effective in abolishing experimental cardiac arrhythmias and suggest that its effects should be studied in patients.     

Stability of ciprofloxacin in polyvinylchloride minibags

Background:

Ciprofloxacin is a fluoroquinolone antibiotic used to treat infections caused by both gram-positive and gram-negative organisms.

Objective:

To determine the physical and chemical stability of ciprofloxacin diluted in 5% dextrose in water (D5W) or 0.9% sodium chloride (normal saline [NS]) and stored in polyvinylchloride (PVC) minibags at various temperatures.

Methods:

Solutions of ciprofloxacin (1 and 2 mg/mL) were prepared by diluting a commercially available concentrate (10 mg/mL) with either D5W or NS. The prepared solutions were then packaged in PVC mini-bags. Three minibags of each concentration–diluent combination were stored at 2°C to 8°C with protection from light, at 21°C to 24°C with exposure to light, and at 29°C to 31°C with protection from light. Samples were collected from each minibag on days 0, 7, 14, and 30 and then analyzed. Colour, clarity, and pH were monitored when the samples were collected. On each day of analysis, the samples were accurately diluted before duplicate analysis with a stability-indicating high-performance liquid chromatography assay. A solution was considered stable if the concentration remained above 90% of the initial values.

Results:

There were no changes in the physical characteristics of any of the solutions. At both concentrations (1 and 2 mg/mL), the ciprofloxacin solutions prepared in D5W remained above 93.9% of the initial concentration over the 30-day study period under all 3 storage conditions. Similarly, at both concentrations, solutions diluted in NS remained above 95.9% of the initial concentration over the 30-day study period under all 3 storage conditions.

Conclusions:

Ciprofloxacin prepared in either D5W or NS and stored in PVC minibags was stable for 30 days under 3 separate storage conditions: 2°C to 8°C with protection from light, 21°C to 24°C with exposure to light, and 29°C to 31°C with protection from light.     

A Mass Balance-Based Semiparametric Approach to Evaluate Neonatal Erythropoiesis

Postnatal hemoglobin (Hb) production in anemic preterm infants is determined by several factors including the endogenous erythropoietin levels, allogeneic RBC transfusions administered to treat anemia, and developmental age. As a result, their postnatal Hb production rate can vary considerably. This work introduces a novel Hb mass balance-based semiparametric approach that utilizes infant blood concentrations of Hb from the first 30 postnatal days to estimate the amount of Hb produced and the erythropoiesis rate in newborn infants. The proposed method has the advantage of not relying on specific structural pharmacodynamic model assumptions to describe the Hb production, but instead utilizes simple mass balance principles and nonparametric regression analysis. The developed method was applied to the Hb data from 79 critically ill anemic very low birth weight preterm infants to evaluate the dynamic changes in erythropoiesis during the first month of life and to determine the inter-subject variability in Hb production. The estimated mean (±SD) cumulative amount of Hb produced by the infants over the first month of life was 6.6 ± 3.4 g (mean body weight, 0.768 kg), and the mean estimated body weight-scaled Hb production rate over the same period was 0.23 ± 0.12 g/day/kg. A significant positive correlation was observed between infant gestational age and the mean body weight-scaled Hb production rate over the first month of life (P < 0.05). We conclude that the proposed mathematical approach and its implementation provide a flexible framework to evaluate postnatal erythropoiesis in newborn infants.KEY WORDS: anemic preterm infants, neonatal erythropoiesis, pharmacodynamic, postnatal hemoglobin production, very low birth weight     

Development and Characterization of Pharmacokinetic Parameters of Fast-Dissolving Films Containing Levocetirizine

A fast-dissolving film containing levocetirizine, a non-sedative antihistamine drug, was developed using pullulan, xanthan gum, propylene glycol, and tween 80 as the base materials. The drug content of the prepared films was within an acceptable limit as prescribed by the USP. The film exhibited excellent stability for four months when stored at 40 °C and 75% humidity. In vitro dissolution studies suggested a rapid disintegration, in which most of levocetirizine (93.54 ± 3.9%) dissolved within 90 seconds after insertion into the medium. Subsequently, Sprague–Dawley rats were used to compare the pharmacokinetic properties of the film preparation administered to the oral cavity, to those with oral administration of the pure drug solution. The pharmacokinetic parameters were similar between the two groups in which AUC_0–t (ng h/ml), AUC_0–∞ (ng h/ml) C_max (ng/ml), T_max (min), K_el (h⁻¹), and t_1/2 (h) of the reference were 452.033 ± 43.68, 465.78 ± 48.16, 237.16 ± 19.87, 30, 0.453 ± 0.051, and 1.536 ± 0.118, respectively, for the film formulation 447.233 ± 46.24, 458.22 ± 46.74, 233.32 ± 17.19, 30, 0.464 ± 0.060, and 1.496 ± 0.293, respectively. These results suggest that the present levocetirizine containing fast-dissolving film is likely to become one of the choices to treat different allergic conditions.     

In Vitro Cutaneous Application of ISCOMs on Human Skin Enhances Delivery of Hydrophobic Model Compounds Through the Stratum Corneum

This study aimed to investigate the effect of a novel kind of immune-stimulating complexes (ISCOMs) on human skin penetration of model compounds in vitro to evaluate their potential as a delivery system, ultimately for transcutaneous vaccination. Special focus was on elucidating the mechanisms of penetration. Preparation of ISCOMs was done by dialysis and subsequent purification in a sucrose density gradient. The penetration pathways of acridine-labeled ISCOMs were visualized using confocal laser scanning microscopy (CLSM). Transmission electron microscopy (TEM) was used to evaluate the ultrastructural changes in the skin after application of the ISCOMs with or without hydration. Transcutaneous permeation of the model compound, methyl nicotinate, was evaluated in diffusion cells. The prepared ISCOMs were 42–52 nm in diameter as evaluated by dynamic light scattering with zeta potentials of −33 to −26.1 mV. TEM investigations verified the presence of ISCOM structures. Penetration of acridine into skin was greatly increased by incorporation into ISCOMs as visualized by CLSM. Permeation of methyl nicotinate was enhanced in the presence of ISCOMs. Ultrastructural changes of the intercellular space in the stratum corneum after exposure of ISCOMs were observed on micrographs, especially for hydrated skin. In conclusion, cutaneous application of ISCOMs leads to increased penetration of hydrophobic model compounds through human stratum corneum and thus shows potential as a transcutaneous delivery system. The increased penetration seems to be reflected by a change in the intercellular space between the corneocytes, and the effect is most likely caused by the components of the ISCOMs rather than intact ISCOMs.Key words: CLSM, penetration, Posintro™, TEM, vaccine     

Determination of drug-like properties of a novel antileishmanial compound: In vitro absorption, distribution, metabolism, and excretion studies

In drug discovery research, the compounds should not only to be potent and selective but also must possess acceptable pharmacokinetic properties such as absorption, distribution, metabolism, and excretion (ADME) to increase success rate in clinical studies.

Objective:

Exploration of drug-like properties of 2-(2-methylquinolin-4-ylamino)-N-phenyl acetamide, a potent antileishmanial compound by performing some in vitro ADME experiments along with validation of such studies.

Materials and Methods:

Experimental protocols were established and validated for stability (in PBS pH7.4, simulated gastric and intestinal fluid), solubility, permeability, distribution coefficient (Log D), plasma protein binding and metabolism by rat liver microsomes by using spectrophotometer or HPLC. Methods were considered valid if the results of the standard compounds matched with reported results or within acceptable range or with proper ranking (high-medium-low).

Results:

The compound was found to be stable (>95% remaining) in all stability studies and aqueous solubility was 299.7 ± 6.42 μM. The parallel artificial membrane permeability assay (PAMPA) indicated its medium permeability (Log Pe = −5.53 ± 0.01). The distribution coefficients (Log D) in octanol/PBS and cyclohexane/PBS systems were found to be 0.54 and −1.33, respectively. The plasma protein binding study by the equilibrium dialysis method was observed to be 78.82 ± 0.13% while metabolism by Phase-I enzymes for 1 hour at 37°C revealed that 36.07 ± 4.15% of the compound remained after metabolism.

Conclusion:

The methods were found to be very useful for day-to-day ADME studies. All the studies with the antileishmanial compound ascertained that the compound bears optimum pharmacokinetic properties to be used orally as a potential drug for the treatment of leishmaniasis.     

A validated capillary electrophoresis method for simultaneous determination of ezetimibe and atorvastatin in pharmaceutical formulations

A simple, precise, and sensitive capillary electrophoresis technique coupled with a diode array detector has been developed for the separation and simultaneous determination of ezetimibe and atorvastatin in pharmaceutical formulations. Separation of both ezetimibe and atorvastatin was achieved utilizing fused silica capillary (58 cm × 75 μm ID) and background electrolyte solution that consisted of phosphate buffer (2.5 mM, pH 6.7): methanol (70:30 v/v). The proposed method was validated by testing its specificity, linearity, precision, accuracy, recovery, and detection limit/quantitation limit values. The method was linear over the range 2.5–50 μg/ml for ezetimibe (r = 0.9992) and 1–100 μg/ml for atorvastatin (r = 0.9999). Within-day and between-day RSD for ezetimibe and atorvastatin were ⩽5.6% and ⩽2.9%, respectively. The detection limit was 0.07 μg/ml for ezetimibe and 0.06 μg/ml for atorvastatin. The validated method was successfully employed for the determination of ezetimibe and atorvastatin in tablets with no interfering peaks from common pharmaceutical excipients. The percentage recoveries of the two drugs from their tablets were 99.80 ± 1.76 and 100.19 ± 1.83, respectively.