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Simultaneous preclinical pharmacokinetics of VCZ, MOXI, and PIR using LC-MS/MS.

Bacterial and fungal co-infection leads to polymicrobial keratitis (PMK). The current study produced swellable mucoadhesive biopolymeric films composed of chitosan, HPMC, and glycerol using cast drying method. The film was dual-loaded with fluconazole (FCZ) and ofloxacin (OFX) to treat PMK. The prepared film exhibited excellent thickness, folding endurance, surface pH, tensile strength, and stability characteristics. In addition, it also exhibited good in vitro antimicrobial activity, ex-vivo mucoadhesion, and corneal permeation. AUC

Quantitative determination of biomarkers homocysteine (Hcy) and methylmalonic acid (MMA), the regulators of cobalamin (Cbl) and folate levels, together used as a biomarkers to diagnose chemical insufficiency/deficiency of Cbl and folate. We report simultaneous clinical estimation of total Hcy and MMA with efficient clean-up, sensitive and selective LC-MS/MS method. Efficient sample clean-up was achieved by a two-step extraction protocol with 100 μL serum. The validated method was applied to 893 clinical samples from 2 cohorts including pediatrics and mothers, respectively, for identifying their Cbl and folate status. The method shows excellent order of linearity for Hcy (22.2nM-3.7 μM) and MMA (42.34 nM - 5.92 μM), respectively. Complete method validation was performed where intraday-interday accuracy-precision and mean stability recovery data were found within ±15%. The validated method was extended for the quantification of serum total Hcy-MMA levels in clinical samples. The efficient extraction with negligible matrix-effect (ME) has reduced LC-MS/MS chocking and clean-up downtime. The rapid, sensitive and robust LC-MS/MS method has been successfully validated for simultaneous estimation of total Hcy and MMA using only 100 μL serum. The method was applicable to large number of clinical samples and was found to be good throughput with low contamination of mass detector, high sensitivity and selectivity.

A simple reverse-phase UHPLC (RP-UHPLC) analytical method was developed and validated according to International Council on Harmonization (ICH) guidelines for simultaneous estimation of ofloxacin (OFX) and fluconazole (FCZ) using a Response surface aided central composite design (CCD, Design-Expert®, Version 11.1.2.0). The method was validated for linearity, selectivity, sensitivity, accuracy, precision, limits of detection and quantification, solution stability and robustness. OFX and FCZ separation were achieved using Agilent 1290 Infinity II UHPLC system encompassed with Waters Atlantis® T3 (150 × 4.6 mm2 i.d., 3 µm particle size) column, water containing 0.1% v/v formic acid and methanol as isocratic mobile phase. OFX and FCZ eluted at 4.1 and 10.5 min with no interference of the excipients used in formulation at λmax 260 nm. The developed method was envisaged to determine total drug content, in vitro drug release study and ex-vivo corneal permeation study of conventional as well as novel drug delivery formulations. The proposed method is simple, cost-effective, dependable and reproducible and could be used for the regular analysis of OFX and FCZ in bulk and quality controls in the research and pharmaceutical industries.

S-011-1559 is a tyrosine-derived novel benzoxazine CDRI molecule targeted to the oestrogen-related receptor (ER-α/β) modulator in breast cancer. To explore the pharmacokinetics of S-011-1559, a selective and sensitive bioanalytical method using LC-MS/MS was established and validated in different biological matrices of female rats.Blood-to-plasma ratio and plasma protein binding (PPB) of S-011-1559 were found to be 97% in both rats and humans, respectively. The human serum albumin (HSA) and alpha-1-acid glycoprotein (AAG) binding was found in the range of > 68 to 45% and >14% respectively. Half-life and intrinsic clearance by microsomal stability study were found to be 28.83 min and 0.05 mL/min/mg in rats, 78.35 min and 0.036 mL/min/mg in humans, respectively. The IC50 value of S-011-1559 against CYP isoforms was revealed to moderately inhibit CYP2D6 by a reversible non-competitive mechanism.Tissue distribution of S-011-1559 on single intravenous injection at 2 mg/kg was found in the order of C lungs > C mammary gland > C spleen > C heart > C kidney > C liver > C brain.The data from the present study provides crucial information about S-011-1559 for further development as a novel potential drug candidate in modulating ER-α/β receptors of lung and breast neoplasia. S-011-1559 is a tyrosine-derived novel benzoxazine CDRI molecule targeted to the oestrogen-related receptor (ER-α/β) modulator in breast cancer. To explore the pharmacokinetics of S-011-1559, a selective and sensitive bioanalytical method using LC-MS/MS was established and validated in different biological matrices of female rats. Blood-to-plasma ratio and plasma protein binding (PPB) of S-011-1559 were found to be 97% in both rats and humans, respectively. The human serum albumin (HSA) and alpha-1-acid glycoprotein (AAG) binding was found in the range of > 68 to 45% and >14% respectively. Half-life and intrinsic clearance by microsomal stability study were found to be 28.83 min and 0.05 mL/min/mg in rats, 78.35 min and 0.036 mL/min/mg in humans, respectively. The IC50 value of S-011-1559 against CYP isoforms was revealed to moderately inhibit CYP2D6 by a reversible non-competitive mechanism. Tissue distribution of S-011-1559 on single intravenous injection at 2 mg/kg was found in the order of C lungs > C mammary gland > C spleen > C heart > C kidney > C liver > C brain. The data from the present study provides crucial information about S-011-1559 for further development as a novel potential drug candidate in modulating ER-α/β receptors of lung and breast neoplasia.

A novel Isoxazole (ISO) analog of curcumin is synthesized from curcumin and described as having a better pharmacological activity than curcumin, such as anti-cancer, anti-malarial, anti-mycobacterial, and many more. The present research aims to develop a bio-analytical method with a simple, rapid, selective, sensitive, accurate, and precise quantification of ISO by liquid chromatography coupled with tandem mass spectroscopy (LC-MS/MS) in rat plasma matrix. The simple plasma protein precipitation method was used for ISO extraction. The ISO was eluted in isocratic mode on a Water symmetry C

The expansion of polymicrobial keratomycosis (PMK) requires dynamic pharmacotherapy of antimycotics along with antibacterial agents such as fluconazole (FCZ) and ofloxacin (OFX). To effective clinical cure, different microbes require different dosage regimens. A responsive, selective, and fast method for estimation of FCZ and OFX in rabbit tears using high-performance liquid chromatography together with tandem mass spectrometry (LC-MS/MS) was established and validated using ketoconazole as an internal standard (IS). An isocratic separation was achieved using a C18 column with methanol and aqueous 0.2% formic acid (80:20, v/v) as a mobile phase with a total run time and flow rate of 4 min and 400 µL/ min, respectively. The FCZ and OFX were detected utilizing positive ion electrospray ionization (ESI) in multiple reactions monitoring mode. The tear sample extraction was carried out using simple deproteination using methanol. The systematic method validation was carried out according to USFDA regulatory guidelines for selectivity, linearity (r2>0.99), intra-day and inter-day precision and accuracy, matrix effect, dilution integrity, and stability. The validated bioanalytical method was successfully pertained to determine the pharmacokinetics profile of FCZ and OFX marketed formulation in preclinical rabbit tears.

The present study reports topical ocular prolong residence amphotericin B (AB) liposomal formulation. The AB was entrapped within phospholipon-90H-stearylamine-complex (AB-liposome) to form a stable liposome with a size range of 142 ± 0.11 nm. The AB-liposomes powder was prepared by an optimized freeze-drying process with cryoprotectant for reconstitution before use. Liposomes showed biphasic release, initial fast release followed by sustained release. AB-loaded liposomes significantly increase in t1/2 (half-life), MRT (mean residence time) and AUC (area under the curve) in comparison to the current clinically available formulation. PK-PD indices and pharmacokinetic simulation show six ocular instillations/24 h as compared to 24 instillations/24 h by marketed formulations for equivalent efficacy. Thus, phospholipon-90H-stearylamine could be a beneficial strategy for prolong ocular drug delivery and reduce dosing frequency.