The Effect Of Food On The Pharmacokinetic Properties And Bioequivalence Of Two Formulations Of Levocetirizine Dihydrochloride In Healthy Chinese Volunteers

Biowaiver Monograph for Immediate-Release Solid Oral Dosage Forms: Levocetirizine Dihydrochloride

Levocetirizine, a histamine H1-receptor antagonist, is prescribed to treat uncomplicated skin rashes associated with chronic idiopathic urticaria as well as the symptoms of both seasonal and continual allergic rhinitis. In this monograph, the practicality of using Biopharmaceutics Classification System (BCS) based methodologies as a substitute for pharmacokinetic studies in human volunteers to appraise the bioequivalence of immediate-release (IR) oral, solid dosage forms containing levocetirizine dihydrochloride was investigated, using data from the literature and in-house testing. Levocetirizine's solubility and permeability properties, as well as its dissolution from commercial products, its therapeutic uses, therapeutic index, pharmacokinetics and pharmacodynamic traits, were reviewed in accordance with the BCS, along with any reports in the literature about failure to meet bioequivalence (BE) requirements, bioavailability issues, drug-excipient interactions as well as other relevant information. The data presented in this monograph unequivocally point to classification of levocetirizine in BCS Class 1. For products that are somewhat supra-equivalent or somewhat sub-equivalent, clinical risks are expected to be insignificant in light of levocetirizine's wide therapeutic index and unlikelihood of severe adverse effects. After careful consideration of all the information available, it was concluded that the BCS-based biowaiver can be implemented for products which contain levocetirizine dihydrochloride, provided (a) the test product comprises excipients that are typically found in IR oral, solid drug products that have been approved by a country belonging to or associated with ICH and are used in quantities that are typical for such products, (b) data supporting the BCS-based biowaiver are gathered using ICH-recommended methods, and (c) all in vitro dissolution requirements specified in the ICH guidance are met by both the test and comparator products (in this case, the comparator is the innovator product).

Interactions between selected over-the-counter drugs and food: clinical relevance and prevention

The use of medicines is associated with both therapeutic and adverse effects and interactions. In particular, interactions between drugs and food are common, and can either enhance the action of drugs or diminish their effect. Health professionals have a responsibility to screen for and educate patients about food-drug interactions, as well as to assist in decreasing their occurrence. The aim of this study was to identify any interactions present between food and selected over-the-counter (OTC) drugs. Sixty-five publications out of a potential 1112 found in the search were included in the study and among them 28 concerned painkillers, 6 - antihistamines, 4 - nasal decongestants, 10 were for proton pump inhibitors and for iron and 8 for sildenafil. Interactions between food and OTC drugs do exist. These drugs should not be taken regardless of the meal. Providing relevant information to the patient will increase drug safety and efficacy.

A new nanosuspension prepared with wet milling method for oral delivery of highly variable drug Cyclosporine A: Development, optimization and in vivo evaluation

Cyclosporine A (CsA) is a cyclic polypeptide, that has been widely used for immunosuppression. This study aims to develop nanosuspension for oral administration of CsA using the wet milling (WM) method one of the top-down technologies. The WM method was optimized by studying the effects of critical process parameters for WM on the particle size (PS), particle size distribution (PDI), and zeta potential (ZP) of nanosuspensions using the Design of Experiment (DoE) approach. Nanosuspension was developed using hydroxypropyl methylcellulose (HPMC) and sodium dodecyl sulfate (SDS) and in vitro characterization studies were performed. In vitro dissolution and in vivo pharmacokinetic studies were conducted with biorelevant media (fasted and fed state simulated fluids) and fasted and fed states in rats, respectively. In vivo immunological studies were also performed. PS, PDI, and ZP values for nanosuspension were approximately 600 nm, 0.4, -25 mV, respectively. The solubility of CsA was increased by 4.5-folds by nanosuspensions. Dissolution studies showed that nanosuspension had higher dissolution than the commercial product in the FeSSIF medium. The pharmacokinetic study indicated that AUC_0-24 values of CsA nanosuspension were to be 2.09 and 5.51-fold higher than coarse powder in fasted and fed conditions, respectively. Immunological studies were carried out after oral administration of nanosuspension for 21 days, the ratio of CD4+/CD8+ was found to be more acceptable than the commercial product. These results demonstrated that nanosuspension is a promising approach for increasing the bioavailability and avoiding the food effect on absorption of CsA which one of the highly variable drugs.

Biliary Excretion-Mediated Food Effects and Prediction

Many orally administered drugs with negative food effects (i.e., lower exposure under fed conditions) are often primarily or partially eliminated by biliary excretion. The aim of this study is to assess the potential correlation between a negative food effect and biliary excretion. Correlation analysis was conducted using a training dataset containing 27 drugs which met the following criteria: (1) immediate-release formulations, (2) shows a negative food effect, (3) > 10% biliary clearance, and (4) does not undergo extensive metabolism. A correlation between fed-state biliary clearance (CL_b,fed) and fasted-state biliary clearance (CL_b,fast) (y = 1.81*x, R² = 0.68) was observed. The 1.8-fold increase in biliary clearance was then used as a correction factor to improve physiologically based pharmacokinetic (PBPK) prediction of food effects for 12 test drugs. The mean deviations of predicted fed/fasting AUC ratio and C_max ratio from clinically observed values were reduced from 32.4 to 17.2% and from 63.3 to 54.3%, respectively. In contrast to the positive food effects on most biopharmaceutics classification system (BCS) class II drugs for which food-stimulated bile flow increases drug solubility and absorption, our results suggest that the elimination of biliary excreted drugs is increased by food-stimulated bile flow, resulting in negative food effects.