Development, optimization and in vivo characterization of domperidone-controlled release hot-melt-extruded films for buccal delivery.

Objective: The aim of the present investigation was the development and in vivo characterization of domperidone (DOM) hot-melt extruded (HME) controlled release films by central composite design (CCD) for buccal delivery.

Methods: Concentration of PEO N750 (X1) and HPMC E5 LV (X2) as independent variables and tensile strength (Y1), percent drug release at 6 h (Q6, Y2) and percent drug permeated at 6 h (Y3, P6) as responses. In total, 13 formulations were prepared and studied.

Effect of rifampicin pretreatment on the oral bioavailability of domperidone in healthy human volunteers.

Background: Increased exsorption of domperidone was observed from different parts of the small intestine of the rat after pretreatment with rifampicin by the everted sac method. Based on the in vitro studies the effect of rifampicin pretreatment on the pharmacokinetics of domperidone was investigated in eight healthy male volunteers.

Methods: After an overnight fast, 20 mg domperidone was administered to the volunteers, either alone or after 6 days pretreatment with a once daily dose of 600 mg rifampicin.

Effect of silymarin pretreatment on the bioavailability of domperidone in healthy human volunteers.

Background: The aim of this study was to investigate the effect of silymarin pretreatment on domperidone oral bioavailability in humans.

Methods: The rats were pretreated with silymarin for 7 days. The transport of domperidone across the rat intestine (duodenum, jejunum, ileum, and colon) was studied by using in vitro everted and non-everted sac methods.

Effect of silibinin on the pharmacokinetics of nitrendipine in rabbits.

Silibinin, a major constituent of silymarin, is widely used for its hepatoprotective effects. This study investigated the effect of silibinin on the pharmacokinetics of oral nitrendipine in rabbits. In first set of experiment, male New Zealand rabbits were pretreated with silibinin (50 mg/kg, PO) for 7 days and on last day nitrendipine (10 mg/kg, PO) was administered.

Oral transmucosal delivery of domperidone from immediate release films produced via hot-melt extrusion technology.

The objective of the study was to prepare and characterize the domperidone (DOM) hot-melt extruded (HME) buccal films by both in vitro and in vivo techniques. The HME film formulations contained PEO N10 and/or its combination with HPMC E5 LV or Eudragit RL100 as polymeric carriers, and PEG3350 as a plasticizer. The blends were co-processed at a screw speed of 50 rpm with the barrel temperatures ranging from 120-160°C utilizing a bench top co-rotating twin-screw hot-melt extruder using a transverse-slit die.

Design and Characterization of Atenolol Transdermal Therapeutic Systems: Enhancement of Permeability via Iontophoresis.

The aim of the present investigation was to improve the permeation of Atenolol by preparing a transdermal patch and using the method of iontophoresis. Influence of chemical penetration enhancers was also studied. Combination of iontophoresis and chemical penetration enhancer d-limonene and oleic acid produced satisfactory permeation and flux.

Effect of pomegranate juice on intestinal transport and pharmacokinetics of nitrendipine in rats.

Pomegranate juice (PJ) is known to be a potent inhibitor of human cytochromes (CYP), particularly CYP2C9 and CYP3A4. The purpose of this study was to investigate the effect of oral PJ on the pharmacokinetics of nitrendipine (10 mg/kg) in rats. The effect of PJ was also investigated on the absorption kinetics of nitrendipine in rats using a single-pass intestinal perfusion model.

Effect of pomegranate juice on the pharmacokinetics of nitrendipine in rabbits.

Pomegranate juice (PJ) is known to be a potent inhibitor of human cytochrome enzymes. The purpose of this study was to investigate the effect of acute and chronic PJ on the pharmacokinetics of oral nitrendipine (10 mg/kg) in rabbits. Male New Zealand rabbits were pretreated with PJ for 1 week and on the last day, a single dose of nitrendipine was given orally.

Transmucosal delivery of domperidone from bilayered buccal patches: in vitro, ex vivo and in vivo characterization.

Bilayered mucoadhesive buccal patches for systemic administration of domperidone (DOM), a dopamine-receptor (D(2)) antagonist, were developed using hydroxy propyl methyl cellulose and PVPK30 as a primary layer and Eudragit RLPO and PEO as a secondary layer. Ex vivo drug permeation through porcine buccal membrane was performed. Bilayered buccal patches were developed by solvent casting technique and evaluated for in vitro drug release, moisture absorption, mechanical properties, surface pH, in vitro bioadhesion, in vivo residence time and ex vivo permeation of DOM through porcine buccal membrane from a bilayered buccal patch.

Stereoselective binding of chiral anti-diabetic drug nateglinide to plasma proteins.

The binding of nateglinide (NA) enantiomers with human plasma (HP), human serum albumin (HSA) and bovine serum albumin (BSA) was investigated. The protein binding was studied over a drug concentration range of 5-100 μM at a protein concentration of 600 μM. Unbound drug concentrations were determined by direct chiral liquid chromatography using chiralcel OJ-RH column.

Development of bioadhesive buccal tablets for felodipine and pioglitazone in combined dosage form: in vitro, ex vivo, and in vivo characterization.

The purpose of the present research was to develop bioadhesive buccal tablets for Felodipine (FDP) and Pioglitazone (PIO), low bioavailability drugs, in a combined dosage form for the management of diabetes and hypertension. Buccal tablets were prepared by direct compression method using bioadhesive polymers hydroxypropyl methyl cellulose, sodium carboxymethyl cellulose, and carbopol, alone or in combination of two polymers, and were evaluated for physicochemical properties, swelling index, in vitro bioadhesion, in vivo residence time, in vitro drug release, and ex vivo permeation through porcine buccal membrane. Formulation (PF6) showed peak detachment force (3.

Role of cyclodextrin complexation in felodipine-sustained release matrix tablets intended for oral transmucosal delivery: in vitro and ex vivo characterization.

The objective of the present research was two-fold: To characterize the produced inclusion complex of felodipine (FDP)-hydroxypropyl-β-cyclodextrin (HPβCD) utilizing lyophilization, and to develop and characterize a complexed sustained-release polymeric matrix tablets intended for buccal delivery. The phase-solubility diagram suggested an A(L) type system with 1:1 stoichiometry. Solid complexes prepared by physical mixing and lyophilization were characterized by thermal and non-thermal analytical techniques to corroborate the fact of complex formation.

Development of a high-performance liquid chromatography method for simultaneous determination of pioglitazone and felodipine in pig serum: application to pharmacokinetic study.

A simple and sensitive high-performance liquid chromatographic method was developed and validated for simultaneous estimation of pioglitazone and felodipine in pig serum. The present method consists of protein precipitation, extraction of analytes from pig serum into dichloromethane and separation using reversed-phase C(18) column. Nitrendipine was used as an internal standard and the eluent was monitored by UV detector at 240 nm.

Enhanced bioavailability of buspirone from reservoir-based transdermal therapeutic system, optimization of formulation employing Box-Behnken statistical design.

The purpose of the present study was to develop and optimize reservoir-based transdermal therapeutic system (TTS) for buspirone (BUSP), a low bioavailable drug. A three-factor, three-level Box-Behnken design was employed to optimize the TTS. Hydroxypropyl methylcellulose, D: -limonene and propylene glycol were varied as independent variables; cumulative amount permeated across rat abdominal skin in 24 h, flux and lag time were selected as dependent variables.

Formulation and evaluation of multiple tablets as a biphasic gastroretentive floating drug delivery system for fenoverine.

A biphasic gastroretentive drug delivery system of fenoverine was developed to maintain constant plasma concentration. The delivery system consisted of a loading-dose tablet and a floating multiple matrix tablet prepared by the direct compression process. The drug release from biphasic GRDDS in 0.

Enhanced bioavailability of lacidipine via microemulsion based transdermal gels: formulation optimization, ex vivo and in vivo characterization.

The purpose of the present study was to develop and optimize the microemulsion based transdermal therapeutic system for lacidipine (LCDP), a poorly water soluble and low bioavailable drug. The pseudo-ternary phase diagrams were developed for various microemulsion formulations composed of isopropyl myristate, Tween 80 and Labrasol. The microemulsion was optimized using a three-factor, three-level Box-Behnken design, the independent variables selected were isopropyl myristate, surfactant mixture (Tween 80 and Labrasol) and water; dependent variables (responses) were cumulative amount permeated across rat abdominal skin in 24h (Q(24); Y(1)), flux (Y(2)), and lag time (Y(3)).

Development of ultra fast liquid chromatographic method for simultaneous determination of nitrendipine and carvone in skin diffusate samples.

A simple and sensitive reverse phase ultra fast liquid chromatographic (UFLC) method for simultaneous determination of nitrendipine and carvone in skin diffusate samples and microemulsions was developed and validated. The separation was achieved using a gradient mobile phase, on an Onyx column. The eluents were monitored by photodiode array detection.

Development of high performance liquid chromatography method for buspirone in rabbit serum: Application to pharmacokinetic study.

A simple and sensitive high performance liquid chromatographic (HPLC) method for quantification of buspirone (BUSP) in rabbit serum was developed and validated. BUSP and internal standard (IS), diltiazem hydrochloride were extracted into dichloromethane and separated using an isocratic mobile phase, on a Kromasil C(8) column. The eluent was monitored by UV detector at 235 nm and at a flow rate of 1.

Iontophoretic delivery of lisinopril: Optimization of process variables by Box-Behnken statistical design.

The objective of the investigation was to optimize the iontophoresis process parameters of lisinopril (LSP) by 3 x 3 factorial design, Box-Behnken statistical design. LSP is an ideal candidate for iontophoretic delivery to avoid the incomplete absorption problem associated after its oral administration. Independent variables selected were current (X(1)), salt (sodium chloride) concentration (X(2)) and medium/pH (X(3)).

Development and evaluation of gastroretentive norfloxacin floating tablets.

Floating matrix tablets of norfloxacin were developed to prolong gastric residence time, leading to an increase in drug bioavailability. Tablets were prepared by the wet granulation technique, using polymers such as hydroxypropyl methylcellulose (HPMC K4M, HPMC K100M) and xanthan gum. Tablets were evaluated for their physical characteristics, viz.

Stereoselective plasma protein binding of amlodipine.

The binding of the (R)- and (S)-enantiomers of amlodipine to bovine serum albumin (BSA), human serum albumin (HSA), alpha(1)-acid glycoprotein (AGP), and human plasma (HP) was studied by equilibrium dialysis over the concentration range of 75-200 microM at a protein concentration of 150 microM. Unbound drug concentrations were determined by enantioselective capillary electrophoresis using 50 mM phosphate buffer, pH 2.5, containing 18 mM alpha-cyclodextrin as background electrolyte.

Optimization of hydrogels for transdermal delivery of lisinopril by Box-Behnken statistical design.

The aim of this study was to investigate the combined influence of three independent variables on the permeation kinetics of lisinopril from hydrogels for transdermal delivery. A three-factor, three-level Box-Behnken design was used to optimize the independent variables, Carbopol 971 P (X(1)), menthol (X(2)), and propylene glycol (X(3)). Fifteen batches were prepared and evaluated for responses as dependent variables.

Design and evaluation of a novel matrix type multiple units as biphasic gastroretentive drug delivery systems.

A biphasic gastroretentive floating drug delivery system with multiple-unit mini-tablets based on gas formation technique was developed to maintain constant plasma level of a drug concentration within the therapeutic window. The system consists of loading dose as uncoated core units, and prolonged-release core units are prepared by direct compression process; the latter were coated with three successive layers, one of which is seal coat, an effervescent (sodium bicarbonate) layer, and an outer polymeric layer of polymethacrylates. The formulations were evaluated for quality control tests, and all the parameters evaluated were within the acceptable limits.

Development of high performance liquid chromatography method for lacidipine in rabbit serum: application to pharmacokinetic study.

A simple and sensitive high performance liquid chromatographic (HPLC) method for quantification of lacidipine (LCDP) in rabbit serum was developed and validated. LCDP and internal standard (IS), felodipine were extracted into n-hexane and dichloromethane (70:30) solvent system and separated using an isocratic mobile phase, on an Inertsil C18 column. The effluent was monitored by UV detector at 240 nm and at a flow rate of 1.

Design and evaluation of polymeric coated minitablets as multiple unit gastroretentive floating drug delivery systems for furosemide.

A gastro retentive floating drug delivery system with multiple-unit minitablets based on gas formation technique was developed for furosemide. The system consists of core units (solid dispersion of furosemide:povidone and other excipients), prepared by direct compression process, which are coated with two successive layers, one of which is an effervescent (sodium bicarbonate) layer and other one an outer polymeric layer of polymethacrylates. The formulations were evaluated for pharmacopoeial quality control tests and all the physical parameters evaluated were within the acceptable limits.