ABSTRACT
The present study was aimed to develop an analytical method for quantification of memantine (MEM) hydrochloride in dissolution samples using high-performance liquid chromatography with refractive index (RI) detector. The chromatographic separation was achieved on C18 (250 × 4.5 mm, 5 µm) column using isocratic mobile phase comprises of buffer (pH 5.2):methanol (40:60 v/v) pumped at a flow rate of 1.0 mL/min. The column effluents were monitored using RI detector. The retention time of MEM was found to be ~6.5 ± 0.3 min. The developed chromatographic method was validated and found to be linear over the concentration range of 5.0-45.0 µg/mL for MEM. Mean recovery of MEM was found to be 99.2 ± 0.5% (w/w). The method was found to be simple, fast, precise and accurate, which can be utilized for the quantification of MEM in dissolution samples.
Subject(s)
Chromatography, High Pressure Liquid/methods , Memantine/analysis , Refractometry/methods , Linear Models , Memantine/chemistry , Reproducibility of Results , Sensitivity and Specificity , SolubilityABSTRACT
The objective of present work was to develop novel sunscreen creams containing polymeric nanoparticles (NPs) of morin. Polymeric NPs containing morin were prepared and optimized. The creams containing morin NPs were also prepared and evaluated. Optimized NPs exhibited particle size of 90.6 nm and zeta potential of -31 mV. The entrapment efficiency of morin, within the polymeric NPs, was found to be low (12.27%). Fourier transformed infrared spectroscopy and differential scanning calorimetry studies revealed no interaction between morin and excipients. Transmission electron microscopy and atomic force microscopy revealed that the NPs were spherical in shape with approximately 100 nm diameter. Optimized NPs showed excellent in vitro free radical scavenging activity. Skin permeation and deposition of morin from its NPs was higher than its plain form. Different sunscreen creams (SC1-SC8) were formulated by incorporating morin NPs along with nano zinc oxide and nano titanium dioxide. SC5 and SC8 creams showed excellent sun protection factor values (≈40). In vitro and in vivo skin permeation studies of sunscreen creams containing morin NPs indicated excellent deposition of morin within the skin. Morin NPs and optimized cream formulations (SC5 and SC8) did not exhibit cytotoxicity in Vero and HaCaT cells. Optimized sunscreen creams showed excellent dermal safety. SC5 and SC8 creams demonstrated exceptional in vivo antioxidant effect (estimation of catalase, superoxide dismutase, and glutathione) in UV radiation-exposed rats. The optimized sunscreen creams confirmed outstanding UV radiation protection as well as antioxidant properties.
Subject(s)
Flavonoids/chemistry , Flavonoids/pharmacology , Nanoparticles/chemistry , Ultraviolet Rays/adverse effects , Animals , Antioxidants/chemistry , Antioxidants/metabolism , Antioxidants/pharmacology , Capsules , Cell Line , Chemistry, Pharmaceutical , Drug Evaluation, Preclinical , Flavonoids/metabolism , Humans , Male , Microscopy, Electron, Transmission , Particle Size , Permeability , Polymers/chemistry , Rats , Skin/drug effects , Skin/metabolism , Skin/radiation effects , Sunscreening Agents/chemistry , Sunscreening Agents/metabolism , Sunscreening Agents/pharmacology , Titanium/chemistry , Zinc Oxide/chemistryABSTRACT
The aim of the current study was to prepare binary amorphous forms of Talinolol (TLN) by using Naringin (NRG) as a stabilizing agent. The secondary objective of this study was to study the effect of P-gp inhibitor NRG on the P-gp probe drug TLN. The binary amorphous samples were prepared by quench cooling technique in the molar ratios TLN:NRG (1:1), TLN:NRG (1:2), TLN:NRG (2:1). The prepared samples were characterized by DSC, FTIR and XRD. Amorphicity of the prepared binary amorphous samples was confirmed by spotting diffuse halo in the diffractograms and further corroborated by detecting glass transition event (Tg) in the thermograms of the respective samples. The Tgs for all prepared systems were found above room temperature, the highest being 45.43 °C. The systems were found physically stable at 25 °C and 40 °C at dry conditions for 60 days. The temperature stability of prepared amorphous forms may be attributed to strong intermolecular hydrogen bond interaction between TLN and NRG, which was confirmed by Gordon-Taylor calculations and FTIR data. The solubility of TLN in amorphous form was increased by approximately 9-fold as compared to its crystalline counterpart. The in-vivo bioavailability study conducted on wistar rats demonstrated 5.4-fold increase in the AUC0-t value for TLN as compared to its crystalline counterpart. Further to learn the contribution of P-gp inhibition by NRG on the permeability of TLN, In-vitro single pass perfusion studies were conducted on the ileum of wistar rats. The permeability of TLN in rat ileum in the presence of NRG was significantly increased to 3.16×10(-5) cm/s as compare to control value 2.48×10(-5) cm/s. The current study demonstrated the ability of binary amorphous technology to simultaneously overcome both the BCS barriers i.e. solubility and permeability.
Subject(s)
Flavanones , Propanolamines , Administration, Oral , Animals , Biological Availability , Drug Stability , Flavanones/chemistry , Flavanones/pharmacokinetics , Flavanones/pharmacology , Ileum/metabolism , Male , Permeability , Phase Transition , Propanolamines/blood , Propanolamines/chemistry , Propanolamines/pharmacokinetics , Propanolamines/pharmacology , Rats, Wistar , Solubility , Transition TemperatureABSTRACT
AIM: To assess the intraocular penetration of 0.5% moxifloxacin hydrochloride into aqueous humour after oral and topical administration. METHODS: A prospective, interventional study of 42 patients scheduled to undergo cataract surgery was carried out. Out of the 42 subjects, 21 were randomly categorised into Group I and received one drop of 0.5% topical moxifloxacin four times, at 15â min intervals starting 75â min before the surgery. Another 21 subjects were categorised into Group II and all subjects in this group were administered a single tablet of 400â mg of moxifloxacin, 12â h before the surgery. Estimation of moxifloxacin in aqueous samples was carried out using high-performance liquid chromatography. Results were analysed using Student unpaired 't' test and analysis of variance. The value of p<0.05 was considered to be significant. RESULTS: Mean aqueous concentration of moxifloxacin attained in the oral group (n=21) was 0.504±0.30â µg/mL while that in the topical group (n=21) was 2.04±0.72â µg/mL, and this difference in levels was statistically significant (p<0.005). The levels attained by both the groups well exceeded the MIC90 (minimum inhibitory concentration of antibiotic required to inhibit growth of 90% of bacteria strains) levels for most of the organisms causing endophthalmitis. Penetration of moxifloxacin in aqueous in both the groups was not affected by gender, intraocular pressure or comorbidities significantly. However, aqueous levels were found to be higher among the younger subjects within the topical group. CONCLUSIONS: Moxifloxacin has an impressive spectrum of coverage and this pharmacokinetic study reinforces its potential as a prophylactic drug against intraocular infections, given the high aqueous levels post topical administration.
Subject(s)
Anti-Bacterial Agents/pharmacokinetics , Aqueous Humor/metabolism , Fluoroquinolones/pharmacokinetics , Administration, Oral , Administration, Topical , Adult , Aged , Aged, 80 and over , Analysis of Variance , Anti-Bacterial Agents/administration & dosage , Cataract Extraction/methods , Chromatography, High Pressure Liquid , Endophthalmitis/prevention & control , Female , Fluoroquinolones/administration & dosage , Humans , Male , Middle Aged , Moxifloxacin , Ophthalmic Solutions/pharmacokinetics , Prospective StudiesABSTRACT
In the current study, Quercetin (QRT) was characterized for thermodynamic and kinetic parameters and found as an excellent glass former. QRT was paired with Ritonavir (RTV) (BCS class-IV antiretroviral) to form stable amorphous form and pharmacologically relevant combination. Binary amorphous forms of RTV and QRT in molar ratios 1:1, 1:2 and 2:1 were prepared by solvent evaporation technique and characterized by XRPD, DSC and FTIR. The prepared binary phases were found to become amorphous after solvent evaporation which was confirmed by disappearance of crystalline peaks from X-ray diffractograms and detecting single Tg in DSC studies. The physical stability studies at 40 °C for 90 days found RTV:QRT 1:2 and RTV:QRT 2:1 phases stable, while trace crystallinity was detected for 1:1M ratio. The temperature stability of RTV:QRT 1:2 and RTV:QRT 2:1 amorphous forms can be attributed to phase solubility of both components where the drug in excess acts as a crystallization inhibitor. Except for RTV:QRT 1:2 ratio, there was no evidence of intermolecular interactions between two components. Almost 5 fold increase in the saturation solubility was achieved for RTV, compared to crystalline counterpart. While for QRT, the solubility advantage was not achieved. In vivo oral bioavailability study was conducted for 1:2 binary amorphous form by using pure RTV as a control. Cmax was improved by 1.26 fold and Tmax was decreased by 2h after comparing with control indicating improved absorption. However no significant enhancement of oral bioavailability (1.12 fold after comparing with control) was found for RTV.
Subject(s)
Quercetin/chemistry , Quercetin/metabolism , Ritonavir/chemistry , Ritonavir/metabolism , Administration, Oral , Animals , Biological Availability , Calorimetry, Differential Scanning/methods , Crystallization/methods , Drug Stability , Glass/chemistry , Kinetics , Rats , Rats, Wistar , Solubility , Solvents/chemistry , Temperature , X-Ray Diffraction/methodsABSTRACT
The aim of this study was to stabilize the amorphous form of Ritonavir (RTV) a BCS class-II drug with known amorphous stabilizing small molecule Indomethacin (IND) by co-amorphous technology. The co-amorphous samples were prepared by solvent evaporation technique in the molar ratios RTV:IND (2:1), RTV:IND (1:1), RTV:IND (1:2) and their amorphous nature was confirmed by XRPD, DSC and FT-IR. Physical stability studies were carried out at temp 25°C and 40°C for maximum up to 90 days under dry conditions. Solubility and dissolution testing were carried out to investigate the dissolution advantage of prepared co-amorphous systems. The amorphous mixtures of all tested molar ratios were found to become amorphous after solvent evaporation. The same was confirmed by detecting halo pattern in diffractograms of co-amorphous mixtures. The Tg values of all three systems were found to be more than 40°C, the highest being 51.88°C for RTV:IND (2:1) system. Theoretical Tg values were calculated by Gordon-Taylor equation. Insignificant deviation of theoretical Tg values from that of practical one, corroborated by FT-IR studies showed no evidence of intermolecular interactions between RTV and IND. Almost 3-folds increase in the solubility for both amorphous RTV and IND was found as compared to their respective crystalline counterparts. The study demonstrated significant increase in the dissolution rate as well as increase in the total amount of drug dissolved for amorphous RTV, however it failed to demonstrate any significant improvement in the dissolution behavior of IND.
Subject(s)
Indomethacin/chemistry , Ritonavir/chemistry , Calorimetry, Differential Scanning , Crystallization , Drug Stability , Glass , Powder Diffraction , Solubility , Solvents , Spectroscopy, Fourier Transform Infrared , Transition Temperature , X-Ray DiffractionABSTRACT
A simple, precise, accurate, rapid, and sensitive reverse phase high performance liquid chromatography (RP-HPLC) method with UV detection has been developed and validated for quantification of naringin (NAR) in novel pharmaceutical formulation. NAR is a polyphenolic flavonoid present in most of the citrus plants having variety of pharmacological activities. Method optimization was carried out by considering the various parameters such as effect of pH and column. The analyte was separated by employing a C18 (250.0 × 4.6 mm, 5 µm) column at ambient temperature in isocratic conditions using phosphate buffer pH 3.5: acetonitrile (75 : 25% v/v) as mobile phase pumped at a flow rate of 1.0 mL/min. UV detection was carried out at 282 nm. The developed method was validated according to ICH guidelines Q2(R1). The method was found to be precise and accurate on statistical evaluation with a linearity range of 0.1 to 20.0 µg/mL for NAR. The intra- and interday precision studies showed good reproducibility with coefficients of variation (CV) less than 1.0%. The mean recovery of NAR was found to be 99.33 ± 0.16%. The proposed method was found to be highly accurate, sensitive, and robust. The proposed liquid chromatographic method was successfully employed for the routine analysis of said compound in developed novel nanopharmaceuticals. The presence of excipients did not show any interference on the determination of NAR, indicating method specificity.
ABSTRACT
The purpose of present study was to design, optimize and evaluate osmotically controlled pulsatile release capsule (PRC) of montelukast sodium (MKS) for the prevention of episodic attack of asthma in early morning and associated allergic rhinitis. Assembly of the capsular systems consisted of push, active and plug tablet arranged from bottom to top in hard gelatin capsule. The capsule system was coated with a semi-permeable membrane of cellulose acetate and drilled towards plug side in cap. A three-factor, three-level central composite design (CCD) with α = 1 was introduced to execute the experiments and quadratic polynomial model was generated to predict and assess the independent variables with respect to the dependent variables. The composition of optimal formulation was determined as weight of push tablet 138 mg (coded value: +0.59), plug tablet 60 mg (coded value: +0.49) and coating weight gain of 8.4 mg (coded value: -0.82). The results showed that the optimal formulation of PRCs had lag time of 4.5 h, release at 6 and 12 h are 61.95% and 96.29%, respectively. The X-ray radiographic imaging study was carried out to monitor the in vivo behavior of developed barium sulfate-loaded PRCs in rabbits under fasting conditions. In vivo pharmacokinetic study revealed Tmax of 2 h for marketed tablets; however 7 h for PRCs with initial lag time of 4 h. Thus designed capsular system may be helpful for patients with episodic attack of asthma in early morning and associated allergic rhinitis.
Subject(s)
Acetates/administration & dosage , Acetates/pharmacokinetics , Chronotherapy/methods , Osmosis , Quinolines/administration & dosage , Quinolines/pharmacokinetics , Animals , Capsules , Cyclopropanes , Delayed-Action Preparations/administration & dosage , Delayed-Action Preparations/pharmacokinetics , Drug Evaluation, Preclinical/methods , Intestinal Absorption/drug effects , Intestinal Absorption/physiology , Rabbits , SulfidesABSTRACT
Informed consent is an ethical and legal requirement for research involving human participants. It is the process where a participant is informed about all aspects of the trial, which are important for the participant to make a decision and after studying all aspects of the trial the participant voluntarily confirms his or her willingness to participate in a particular clinical trial and significance of the research for advancement of medical knowledge and social welfare. The concept of informed consent is embedded in the principles of Nuremberg Code, The Declaration of Helsinki and The Belmont Report. Informed consent is an inevitable requirement prior to every research involving human being as subjects for study. Obtaining consent involves informing the subject about his or her rights, the purpose of the study, procedures to be undertaken, potential risks and benefits of participation, expected duration of study, extent of confidentiality of personal identification and demographic data, so that the participation of subjects in the study is entirely voluntary. This article provides an overview of issues in informed consent: The obligations of investigator, sponsor and Institutional Review Board to protect rights and welfare of human research subjects. It discusses about the basic elements of informed consent and the process to be followed while obtaining informed consent. Some of the circumstances under which informed consent can be waived and ethical challenges faced by physicians in obtaining informed consent from subjects are also highlighted in this article.
ABSTRACT
OBJECTIVE: To develop a liquid-liquid extraction based reverse phase liquid chromatography method for estimation of montelukast in rabbit plasma. METHODS: Chromatographic separation was carried out using Phenomenex Luna C18 column (250 mm × 4.6 mm × 5 µm) with mobile phase composed of ammonium acetate buffer (20 Mm), pH 5.5 and acetonitrile in 20:80, v/v ratio. The analyte was monitored with UV detector at 345 nm. The developed method was validated with respect to linearity, accuracy, precision, specificity and stability. RESULTS: The peak area ratio of montelukast (MKS) to that of internal standard was used for the quantification of samples. Calibration curves were linear in the concentration range of 20-2000 ng mL(-1). The LOD and LLOQ of present method were found out to be 10 ng mL(-1) and 20 ng mL(-1) respectively. The intra-day and inter-day %CV values for MKS were below 6.06% and 8.43%. Intra-day and inter-day accuracies were within 95.81% and 110.90%, respectively. Extraction recoveries of drug from rabbit plasma were >66.47%. CONCLUSION: A simple, alternative, reproducible and sensitive HPLC-UV method was developed for MKS that can be used in preclinical pharmacokinetics.
ABSTRACT
Ziprasidone (ZRS) is among the various antipsychotic drugs indicated for treating schizophrenia. The determination of the pharmacokinetic behavior of this drug is of utmost importance in evaluating its bioavailability. The objectives of the present study are: (1) to develop and validate a sensitive, specific, accurate and precise reverse-phase high performance liquid chromatographic method for quantification of ZRS in the plasma of rats; and (2) to apply the developed method to study the pharmacokinetic profile of ZRS in rats after oral administration. The method uses a C18 (250.0 × 4.6 mm, 5 µm) column and ultraviolet detector with wavelength set at 210.0 nm. The mobile phase is acetonitrile-phosphate buffer (pH 3.6) 28:72% v/v at a flow rate of 1.0 mL/min. The internal standard (IS) is escitalopram. The extraction procedure for ZRS and IS from the biological matrix (plasma) employs liquid-liquid extraction technique using a mixture of methyl tert-butyl ether-dichloromethane (70:30% v/v). The results show good accuracy and precision over a linearity range of 20.0-3,000.0 ng/mL with r(2) ≥ 0.9986. The mean recoveries of ZRS and IS are 79.32 ± 1.16 and 84.10 ± 3.2%, respectively. The method has been successfully utilized to study the pharmacokinetic profile of ZRS in rats after oral administration.
Subject(s)
Chromatography, High Pressure Liquid/methods , Piperazines/blood , Thiazoles/blood , Animals , Drug Stability , Female , Linear Models , Piperazines/chemistry , Piperazines/pharmacokinetics , Rats , Rats, Wistar , Reproducibility of Results , Sensitivity and Specificity , Thiazoles/chemistry , Thiazoles/pharmacokineticsABSTRACT
The need for a reliable bioanalytical method is of primary importance during preclinical studies. The aim of the present study was simultaneous determination of pioglitazone (CAS 111025-46-8) (PIO) and glimepiride (CAS 93479-97-1) (GLM) in plasma of rats. A high-performance liquid chromatographic method has been developed and validated using C18 column and UV detector. A mobile phase composed of acetonitrile and ammonium acetate buffer pH 4.5 in the ratio of 55:45%. The plasma samples clean-up was carried out using solid phase cartridges. The method was in the linear range of 50-8000 ng/mL for PIO and 50-2000 ng/mL for GLM. The coefficient of regression was found to be > or = 0.99. Precision and accuracy were within the acceptable limits, as indicated by relative standard deviation varying from 1.5 to 6.1% for PIO and 3.1 to 7.0% for GLM whereas the accuracy ranged from 97.0 to 106.4% for PIO and 96.5 to 106.4% for GLM. The mean extraction recovery was found to be 90.2 +/- 4.5, 76.8 +/- 2.8 and 85.2 +/- 5.2% for PIO, GLM and internal standard, respectively. Moreover, PIO and GLM were stable in plasma, up to 30 days of storage at -70 degrees C and after being subjected to bench top, auto-sampler, and three freeze-thaw cycles. The developed method was applied for preclinical pharmacokinetic studies.
Subject(s)
Hypoglycemic Agents/blood , Hypoglycemic Agents/pharmacokinetics , Sulfonylurea Compounds/blood , Sulfonylurea Compounds/pharmacokinetics , Thiazolidinediones/blood , Thiazolidinediones/pharmacokinetics , Animals , Area Under Curve , Calibration , Chromatography, High Pressure Liquid , Drug Evaluation, Preclinical/methods , Drug Interactions , Half-Life , Male , Pioglitazone , Rats , Rats, Wistar , Reference Standards , Reproducibility of Results , Solid Phase Extraction , Spectrophotometry, UltravioletABSTRACT
BACKGROUND: A simple HPLC-UV method with a high reproducibility and sensitivity for the determination of talinolol in rat plasma was developed in this study. METHOD: After liquid-liquid extraction, the compounds were separated on a Vydac(®) C18 monomeric column (250 × 4.6 mm inner diameter × 5-µm particle size) using a mobile phase composed of acetonitrile and potassium dihydrogen phosphate buffer (34:66 v/v), delivered isocratically at a flow rate of 1.0 ml min(-1). Escitalopram was used as an internal standard. The chromatographic peak-area ratio, based on UV absorbency at 245 nm, was used for quantitative analysis. RESULTS: Calibration standards with concentrations over the range of 10-1000 ng ml(-1) were validated for routine sample analysis to support pharmacokinetic studies with talinolol in rats. The intra- and inter-day precision studies showed good reproducibility with coefficients of variation of less than 11.49%. The developed method is simpler and more sensitive than previously reported methods. DISCUSSION: The analytical sensitivity and accuracy of this assay were adequate for characterization of talinolol in rat plasma and the assay has been applied successfully to the in vivo kinetic study of talinolol in rats. After talinolol (10 mg kg(-1)) was given orally, the maximum concentration and the AUC(0-∞) were 341.8 ± 99.4 ng ml(-1) and 976.26 ± 173.37 ng h ml(-1), respectively. The oral bioavailability was approximately 52.14 ± 9.26%. CONCLUSION: The advantages of our method are a small sample volume (200 µl), short analysis time (13.5 min) and a simple sample extraction and clean-up compared with multiple extraction and washing steps and a longer analysis time in previously published methods.