A New, Rapid and Simple RP-HPLC Method for Stability Quantification of a Protease Inhibitor in Tablets.

Fosamprenavir calcium is a protease inhibitor widely used in the treatment and prevention of human immunodeficiency virus and acquired immunodeficiency syndrome. This protease inhibitor serves as a prodrug of amprenavir, offering better oral bioavailability. Although this drug was approved by the FDA in 2003, there are few methods established for quantifying the stability for quality control analysis of fosamprenavir-coated tablets. The purpose of the study was to develop and validate a method for determining the stability of fosamprenavir-coated tablets (Telzir®) that may be applied by any quality control laboratory. Chromatographic separation was performed using a Vertical RP-18 column programmed to run a gradient elution with sodium acetate buffer and acetonitrile. Flow rate was 1.2 mL min-1 for a total run time of 15 min. Ultraviolet detection was set at 264 nm and the use of a photodiode array detector in scan mode allowed selectivity confirmation by peak purity evaluation. The analyte peak was found to be adequately separated from degradation products generated during forced degradation studies. Thus, the proposed method was found to accurately indicate stability and was sufficient for routine quantitative analysis of fosamprenavir in coated tablets without interference from major degradation products and excipients.

A short overview on mycophenolic acid pharmacology and pharmacokinetics.

Immunosuppressive therapy is used in solid organ transplant treatment, and mycophenolic acid (MPA) is one of the immunosuppressive drugs most used worldwide. It is a potent, selective, non-competitive, and reversible inosine monophosphate dehydrogenase (IMPDH) inhibitor that acts to inhibit guanine synthesis. To improve solubility, MPA is used as the prodrug mycophenolate mofetil (MMF) or as an enteric-coated mycophenolate sodium salt (EC-MPS). It is metabolized into mycophenolic acid phenyl glucuronide (MPAG), the inactive and major metabolite, and into acyl glucuronide (AcMPAG), pharmacologically active. In kidney transplantation, combined immunosuppressive therapy with cyclosporine (CsA) and tacrolimus (Tac) is widely used, showing beneficial effects. This paper aimed to review papers published in the last two decades and discuss factors that can interfere with the pharmacokinetics of MPA. Data collected confirm that MPA plasma levels should be monitored to evaluate immunosuppressive therapy since pharmacokinetics can be influenced by factors such as interpatient variability, coadministration of other immunosuppressive agents, post-transplant period, renal function, and dose. However, to perform drug monitoring, costs and facility may be limitations. Monitoring MPAG together with MPA would be a great improvement in therapy as it represents a big part of MPA levels and can be related to the increase of adverse effects.

Canine metabolomics advances.

INTRODUCTION: Canis lupus familiaris is a domestic dog and many owners consider their pets as a family member. Medical bills with dogs are overcame only by the health care received by humans. Medical care is constantly progressing, and so is veterinary care. Metabolomics is the ''omic" technique aimed to the study of metabolome, low-molecular weight molecules, through biofluids or tissue samples. And it also allows to evaluate disease diagnosis and prognosis, therapeutic evaluation and toxicological studies. OBJECTIVES: The goal of this paper is to review the current and potential applications of metabolomics in domestic dogs. METHOD: ScienceDirect, Scopus, Reaxys and PubMed were searched for papers that performed canine metabolomics in any research area. RESULTS: We analysed 38 papers, published until April 2019 in canine metabolomics approach. Metabolomic research in dogs so far can be divided into three areas: (a) Metabolomics studies in veterinary science, such as improving pet dogs health and welfare. (b) Diet, breeds and species discrimination. (c) Use of dogs as animal model in different diseases and drug development (evaluation toxicity and effect). CONCLUSIONS: The results of this review showed that interest in metabolomics is growing in veterinary research. Several canine diseases have been evaluated with some promise for potential biomarker and/or disease mechanism discovery. Because canine metabolomics is a relatively new area, the researches spread across different research areas and with few studies in each area.

Comparison of plasma and oral fluid concentrations of mycophenolic acid and its glucuronide metabolite by LC-MS in kidney transplant patients.

PURPOSE: Mycophenolic acid is one of the most used immunosuppressive drugs in solid organ transplant treatments in the world. Developing a highly sensitive analytical method to analyse the drug and its metabolites in oral fluid and plasma is important to evaluate the possibility of using oral fluid as a biological matrix in therapeutic drug monitoring, instead of plasma. METHOD: The liquid chromatography coupled to mass spectrometry (LC-MS) method was developed and validated for determining mycophenolic acid (MPA) and its glucuronide metabolite (MPAG) in oral fluid and plasma, with both matrices presenting a detection limit of 1 ng/mL for MPA and 5 ng/mL for MPAG. Both analytes were analysed after a simple protein precipitation procedure. Transplanted-kidney samples of oral fluid and blood were collected from 13 patients that were hospitalised and kept at - 80 °C until analyses. RESULTS: The proposed method was linear in the concentration range of 5-500 ng/mL for MPA and 10-500 ng/mL for MPAG, with correlation coefficients (r) between 0.9925 and 0.9973. It was then applied to samples collected from kidney-transplanted patients and used for calculation of pharmacokinetics parameters. CONCLUSION: After comparing plasma and oral fluid concentrations as well as performing a non-compartmental pharmacokinetic analysis of the average curves, it is possible to suggest that oral fluid concentration may be used as an alternative for MPA and MPAG monitoring in kidney transplant patients.

Assessment of lisdexamfetamine dimesylate stability and identification of its degradation product by NMR spectroscopy.

Lisdexamfetamine dimesylate (LDX), a long-acting prodrug stimulant indicated for the treatment of the attention-deficit/hyperactivity disorder (ADHD), was subjected to forced degradation studies by acid and alkaline hydrolysis and the degradation profile was studied. To obtain between 10-30% of degraded product, acid and alkaline conditions were assessed with solutions of 0.01 M, 0.1 M, 0.5 M, and 1 M of DCl and NaOD. These solutions were analyzed through 1 H NMR spectra. Acid hydrolysis produced no degradation in 0.01 M and 0.1 M DCl and 4.38%, 9.69%, and 17.75% of degradation LDX, respectively, in 0.5 M, 1 M (4h) and 1 M (4 + 12 h) DCl. And alkaline hydrolysis produced no degradation in 0.01 M and 0.1 M DCl and a degradation LDX extension of 8.5%, 14.30%, and 22.91%, respectively, in 0.5 M, 1 M (4h) and 1 M (4 + 12 h) NaOD. LDX solutions subjected to 1 M (4 + 12 h) acid and alkaline hydrolysis were evaluated by NMR spectra (1 H NMR, 13 C NMR, HSQC and HMBC). LDX degradation product (DP) was identified and its structure elucidated as a diastereoisomer of LDX: (2R)-2,6-diamino-N-[(2S)-1-phenylpropan-2-yl] hexanamide without their physical separation.

Simultaneous determination of cocaine/crack and its metabolites in oral fluid, urine and plasma by liquid chromatography-mass spectrometry and its application in drug users.

INTRODUCTION: A single LC-MS equipment was used to validate three methods for simultaneously analyzing cocaine (COC), benzoylecgonine (BZE), cocaethylene (CE), anhydroecgonine methyl ester (AEME) and anhydroecgonine (AEC) in oral fluid (OF), urine and plasma. METHODS: The methods were carried out using a Kinetex HILIC column for polar compounds at 30°C. Mobile phase with isocratic condition of acetonitrile: 13mM ammonium acetate pH 6.0: methanol (55:35:10 v/v/v) at 0.8mL/min flow rate was used. RESULTS: After buffer dilution (OF) and protein precipitation (urine and plasma), calibration curve ranges were 4.25-544ng/mL for oral fluid and 5-320ng/mL for urine and plasma with correlation coefficients (r) between 0.9947 and 0.9992. The lowest concentration of the calibration curves were the lower limit of quantification. No major matrix effect could be noted, demonstrating the efficiency of the cleaning procedure. DISCUSSION: The methods were fully validated and proved to be suitable for analysis of 124 cocaine and/or crack cocaine users. Among the subjects, 56.5% reported daily use of cocaine in the previous three months. Results show a high prevalence of the analytes, with BZE as the most prevalent (94 cases), followed by COC (93 cases), AEC (70 cases), CE (33 cases) and AEME (13 cases). In addition, the concentration of BZE in urine was higher compared to OF and plasma found in the real samples, showing the facility of accumulation in chronic users in matrices with a large detection window.

Analytical Stability-Indicating Methods for Alogliptin in Tablets by LC-CAD and LC-UV.

Stability-indicating LC methods using a UV detector and a charged aerosol detector (CAD) simultaneously were validated for the assessment of alogliptin (ALG) in tablets. The analysis was performed on a C8 column (250 × 4.6 mm, 5 µm) at a flow of 0.8 mL/min, using acetonitrile-10 mM ammonium acetate buffer (pH 3.5; 90 + 10, v/v) as mobile phase and UV detection at 275 nm. Validation followed the International Conference on Harmonization guidelines. The method was linear over the range of 25-200 µg/mL. Normality of the residuals showed a normal distribution, no autocorrelation, and homoscedasticity. LODs were 6.25 and 2.65 µg/mL and LOQs were 20.85 and 8.84 µg/mL for the CAD and the UV detector, respectively. The methods were precise and accurate. Excipients and degradation products did not interfere in the methods in studies of specificity. None of the factors studied in the analysis of robustness had a significant effect on the quantification of the ALG by the Pareto chart. The results of the assay obtained with LC-CAD and LC-UV were similar. The methods could be considered interchangeable and stability-indicating, and can be applied as an appropriate QC tool for analysis of ALG in tablets.

Lisdexamfetamine: A pharmacokinetic review.

Lisdexamfetamine (LDX) is a d-amphetamine (d-AMPH) pro-drug used to treat Attention Deficit and Hyperactivity Disorder (ADHD) and Binge Eating Disorder (BED) symptoms. The in vivo pharmacodynamics of LDX is the same as that of its active product d-AMPH, although there are a few qualitative and quantitative differences due to pharmacokinetics. Due to the specific pharmacokinetics of the long-acting stimulants, this article revises the pharmacokinetic studies on LDX, the newest amphetamine pro-drug. The Medline/Pubmed, Science Direct and Biblioteca Virtual em Saúde (Lilacs and Ibecs) (2007-2016) databases were searched for articles and their list of references. As for basic pharmacokinetics studies, since LDX is a newly developed medication, there are few results concerning biotransformation, distribution and the use of different biological matrices for analysis. This is the first robust review on this topic, gathering data from all clinical pharmacokinetics studies available in the literature. The particular pharmacokinetics of LDX plays a major role in studying this pro-drug, since this knowledge was essential to understand some reports on clinical effects in literature, e.g. the small likelihood of reducing the effect by interactions, the effect of long duration use and the still questionable reduction of the potential for abuse. In general the already well-known pharmacokinetic properties of amphetamine make LDX relatively predictable, simplifying the use of LDX in clinical practice.

Pharmacokinetics study of mazindol in plasma, oral fluid, and urine of volunteers.

PURPOSE: There are no pharmacokinetics studies in oral fluid reported in the literature, as well as there are no data on correlation of drug levels in plasma, urine, and oral fluid in order to propose alternative matrices to monitor the use of mazindol by drivers. The present work aimed to study, preliminarily, mazindol's pharmacokinetics in plasma and oral fluid, as well as investigate the correlation of drug levels in urine, plasma, and oral fluid. METHOD: Blood, urine, and oral fluid samples from seven healthy male volunteers were collected at 0, 1, 2, 4, 5, 6, 8, 10, and 24 h after administration of tablets of 2 mg mazindol and analyzed by a previously validated method by LC-MS with liquid-liquid extraction. Levels of the drug found were higher in plasma when compared with oral fluid and higher in urine in relation to plasma. The study of the mazindol's pharmacokinetics showed that the most suitable model to describe the variation of the concentration over time is the compartment open model with absorption and elimination following the first-order kinetics, and confirming literature data, drug is metabolized, being the major metabolite detected, but not quantified. CONCLUSION: It was not found a good correlation between the concentrations of mazindol in urine and plasma, but between plasma and oral fluid, there was a good correlation, suggesting this as an alternative matrix to plasma. However, studies involving more subjects are needed.

Cocaine and crack cocaine abuse by pregnant or lactating mothers and analysis of its biomarkers in meconium and breast milk by LC-MS-A review.

Abusive use of drugs is a public health problem worldwide. The use of these substances by pregnant or lactating women can have many serious side effects in newborns. Among the commonest causes of addiction in drug users is cocaine in powdered form, inhaled, intravenously injected or smoked form (crack). Fast screening and a confirmation test using high specificity and sensitivity instruments such as LC-MS or GC/MS, can provide data to qualify and quantify chemical substances present in biological samples such as breast milk or meconium. Cocaine and/or crack can be detected through biomarkers or the unchanged molecule, enabling the form of cocaine use to be distinguished through the analytes. These methods must be carefully developed and validated according to internationally recognized guidelines. Thus, the study of biological matrices in which it can be detected through the development of simple and quick analytical methods can help prevent intoxication and diagnose the symptoms of dependency such as seizures, especially in babies, providing appropriate medical care.

Analysis of cocaine/crack biomarkers in meconium by LC-MS.

Fetal exposure to illicit drugs is a worldwide problem, since many addicted women do not stop using it during pregnancy. Cocaine consumed in powdered (snorted or injected) or smoked (crack cocaine) form are harmful for the baby and its side effects are not completely known. Meconium, the first stool of a newborn, is a precious matrix usually discarded, that may contain amounts of substances consumed in the last two trimesters of pregnancy. Analyzing this biological matrix it is possible to detect the unaltered molecule of cocaine (COC) or its metabolite benzoylecgonine (BZE) and pyrolytic products anhydroecgonine methyl ester (AEME) and anhydroecgonine (AEC). A liquid chromatography mass spectrometry (LC-MS) method was validated for meconium samples after solvent extraction, followed by direct injection of 10µL. Linearity covered a concentration range of 15 to 500ng/mg with a lower limit of quantification (LLOQ) of 15ng/mg for all analytes. Matrix effect was evaluated and showed adequate results. Detection of illicit substances usage can be crucial for the baby, since knowing that can help provide medical care as fast as possible. The method proved to be simple and fast, and was applied to 17 real meconium samples.

Validation and application of a liquid chromatography-electrospray ionization mass spectrometric method for determination of mazindol in human plasma and urine.

INTRODUCTION: Even after removal of some stimulants, like fenproporex, amfepramone and mazindol, from Brazilian market, the use of these substances is still high, especially by drivers. Mazindol is the second most used anorectic agent in the world acting as an indirect sympathomimetic agonist, having stimulatory action on central nervous system. Plasma is a good matrix to monitor since it reflects the psychomotor effects of these drugs, but unlike urine has an invasive collection; drug levels and detection time are quite low. METHOD: The method involved a liquid-liquid extraction of the samples and a LC-MS analysis was fully validated. Method was used to analyze samples of urine and plasma collected from health volunteers in a period of 24h. Metabolite of mazindol was synthesized using alkaline conditions. RESULTS: After validation the method proved to be adequate to analyze samples collected from health volunteers. Method was linear in the concentration range of 0.1-10ng/mL (r=0.9982) for plasma and 5-50ng/mL (r=0.9973) for urine. DISCUSSION: Analysis of the samples showed that mazindol can be detected after 1h of administration and that concentration levels in urine were always higher than in plasma. Mazindol metabolite was detected only in urine.

Determination of cocaine/crack biomarkers in colostrum by LC-MS following protein precipitation.

Drug abuse by nursing mothers is an ongoing concern because it may cause many adverse effects to the newborns. The development of analytical methods to analyze drugs of abuse in colostrum (first milk produced after birth) has a huge importance, because it enables the monitoring and the correct follow-up to users and newborns. A liquid chromatography mass spectrometry (LC-MS) method was developed and validated for the determination of cocaine and smoked cocaine (crack) biomarkers in colostrum. Cocaine (COC) and its major metabolite benzoylecgonine (BZE), the pyrolytic products anhydroecgonine methyl ester (AEME) and anhydroecgonine (AEC) were analyzed after a simple protein precipitation procedure using atropine (ATP) as internal standard (IS). Applying a chemometric approach study, all peaks were chromatographically separated at isocratic condition with a Kinetex HILIC column for polar compounds, at 30°C in 12min. One ion was detected for the quantification and three ions for confirmation of each analyte. The method was linear for all analytes in the concentration range of 5-300ng/mL with correlation coefficients (r) between 0.9983 and 0.9996. The lower limit of quantification (LLOQ) was 5ng/mL with acceptable validation parameters. Matrix effect was assessed by post-extraction addition approach and showed good results, demonstrating that protein precipitation cleaning procedure is fast, reliable and demand small quantities of organic solvent. The LC-MS method is fast and cheap compared to other equipments and was also successfully applied to assess real samples of colostrum from nursing mothers who were suspect of cocaine/crack abuse.

Determination of mazindol in human oral fluid by high performance liquid chromatography-electrospray ionization mass spectrometry.

Brazil is one of the countries most affected by abuse of stimulant medications by professional drivers, especially fenproporex, amfepramone and mazindol. Even though their sale is banned, they can be found in illegal markets, such as those located on the country's borders. The use of oral fluid to monitor drug levels has many advantages over plasma and urine because it is noninvasive, easier to collect and more difficult to adulterate. The aim of this study was to develop and validate a sensitive and specific method to quantify mazindol in human oral fluid by liquid chromatography-mass spectrometry (LC-MS). The LC system consisted of an LC-MS system operated in selected ion monitoring mode. The mobile phase was composed of water at pH 4.0, acetonitrile and methanol (60:15:25 v/v/v) at a flow rate of 1.0 mL/min and propranolol was used as internal standard. Total running time was 10 min. The lower limit of quantification was 0.2 ng/mL and the method exhibited good linearity within the 0.2-20 ng/mL range (r = 0.9987). A rapid, specific, sensitive, linear, precise and accurate method was developed for determination of mazindol in human oral fluid according to European Medicines Agency guidelines, and is suitable for monitoring mazindol levels in oral fluid of professional drivers.

Development and validation of a dissolution test for lodenafil carbonate based on in vivo data.

INTRODUCTION: Lodenafil carbonate is a phosphodiesterase type 5 inhibitor used for the treatment of erectile dysfunction. Currently, there is no dissolution test reported for lodenafil carbonate and this drug is not listed in any pharmacopoeia. OBJECTIVE: The present study focused on the development and validation of a dissolution test for lodenafil carbonate tablets, using a simulated absorption profile based on in vivo data. METHODS: The appropriate conditions were determined after testing sink conditions. Different conditions as medium, surfactant concentration and rotation speed were evaluated. The percentage of dose absorbed was calculated by deconvolution, using the Wagner-Nelson method. RESULTS: According to the obtained results, the use of 0.1 M HCl + 1.5% SLS (900 mL, at 37 + 0.5 °C) as the dissolution medium, paddles at 25 rpm were considered adequate. The samples were quantified by UV spectroscopy at 295 nm and the validation was performed according to international guidelines. The method showed specificity, linearity, accuracy and precision, within the acceptable range. Kinetics of drug release was better described by the first-order model. CONCLUSION: The proposed dissolution test can be used for the routine quality control of lodenafil carbonate in tablets.

From bacteria to antineoplastic: epothilones a successful history.

Malignancies are a major cause of morbidity and mortality worldwide. Cancer is a cell disease, characterized by a deviation of the control mechanisms of proliferation and differentiation of cells. Among the treatments available, chemotherapy is often the first choice. Epothilones are a new class of anticancer drugs that act by interacting with cellular microtubules interrupting the proliferation of cancer cells. Many synthetic and semi-synthetic analogues of epothilones have been prepared aiming improvement in effectiveness and tolerability, based on QSAR studies. These analogues have been effective for treatment of tumors resistant to first-line treatments. Six new epothilones are being subjected to clinical trials. Ixabepilone (Ixempra®) was approved by FDA in 2007, patupilone is in phase III clinical trial for ovarian and peritoneum cancer. Sagopilone, desoxiepothilone and KOS-1584 are in phase II clinical trials, for the treatment of recurrent glioblastoma and advanced metastatic breast cancer, metastasic breast cancer and metastatic pulmonary cancer, respectively. Desoxiepothilone reached only phase II trials and BMS-310705 reached phase III/IV trials, but were not approved for clinical use due to adverse effects such as neurotoxicity and severe diarrhea, which were dose-limiting. Furthermore, the low t1/2 (40h) in comparison with other class analogues, does not recommend the clinical use of this derivative. Some other synthetized epothilones presented antineoplastic activity in vitro, but are not yet submitted to clinical studies. Neuropathies and diarrhea are adverse effects presented by some substances of this class of anticancer drugs.

Fenproporex and amphetamine pharmacokinetics in oral fluid after controlled oral administration of fenproporex.

BACKGROUND: Fenproporex hydrochloride (FEN) is an anorectic drug used in the treatment of obesity, and its major metabolite is amphetamine (AMP), another central nervous system stimulant. The concentration versus time profile of FEN and its metabolite AMP has been described in classic biological matrices such as plasma and urine; however, there are no reports of such data in oral fluid. OBJECTIVE: The aim of this study is to describe the pharmacokinetics of FEN and AMP in oral fluid after intake of FEN. METHODS: Twenty-five milligrams of FEN (1 capsule of Desobesi-m) was orally administered to 6 male volunteers, and oral fluid samples were collected with a Quantisal device during 24.00 hours after drug ingestion. These samples were submitted to solid-phase microextraction before analysis by gas chromatography-mass spectrometry in the selected-ion-monitoring mode, using deuterium-labeled AMP as internal standard. RESULTS: After FEN administration, both analytes could be detected in oral fluid of all volunteers with an initial detection time varying from 0.50 to 1.00 hour. FEN peak concentrations occurred between 1.00 and 1.50 hours after administration and were between 70.7 and 227.5 µg/L. For AMP, peak concentration occurred between 1.50 and 4.00 hours, reaching 33.0-150.9 µg/L. CONCLUSION: The authors observed that oral administration of FEN resulted in significant amounts of FEN and AMP in oral fluid, showing that oral fluid could be a biological matrix suitable for pharmacokinetic studies for both analytes. Using a compartmental approach, FEN data were best fitted by 1-compartment model with first-order input and output, whereas AMP followed a 2-compartment model with first-order input and output.

Pharmacokinetic evaluation of doxorubicin plasma levels in normal and overweight patients with breast cancer and simulation of dose adjustment by different indexes of body mass.

Although being used for decades in the treatment of several types of cancer, either alone or in association, only a few data about the pharmacokinetics of doxorubicin (DOX) in humans are available. DOX is frequently used in association with other anticancer drugs in the management of breast cancer. Pharmacokinetic data available in the literature show that after i.v. administration DOX follows a two-compartment open model, with a fast distribution phase followed by a very slow elimination phase. The objective of this work is to perform a pilot study in order to verify if the usual dose adjustment based on body surface area (BSA) would be producing the same plasma concentration-time profiles in patients with normal (<25) and above normal (>25) body mass index (BMI). In order to assess the pharmacokinetics of DOX after a short-term i.v. infusion of 60mg/m(2) of BSA, an experimental design using only five plasma samples of each patient was applied. Samples were collected at 0.00, 0.66 (right after the end of infusion), 1.66, 8.66, and 24.66h. DOX pharmacokinetic profiles were evaluated after quantification of DOX using a new HPLC method developed and validated. Pharmacokinetic parameters (AUC(0-24.66) and C(max)) were analyzed by non-compartmental and compartmental approaches. Significant differences (α=0.05) between overweight and normal weight groups were found with respect to AUC and C(max). After adjustment of dose by weight and by BMI, the compartmental model was used to simulate plasma concentrations and new values for C(max) and AUC(0-24.66) were calculated. The new values obtained using both body weight (BW) and BMI were closer to the normal group than those obtained with BSA. According to the simulation, the differences of AUC and C(max) between the overweight group and the group of patients with normal weight were lower when the dose was adjusted by BW and BMI. These results suggest that more studies must be conducted, with more patients, in order to evaluate the best dose adjustment for DOX in women with breast cancer and overweight.

Development and validation of a discriminating in vitro dissolution method for a poorly soluble drug, olmesartan medoxomil: comparison between commercial tablets.

A dissolution test for tablets containing 40 mg of olmesartan medoxomil (OLM) was developed and validated using both LC-UV and UV methods. After evaluation of the sink condition, dissolution medium, and stability of the drug, the method was validated using USP apparatus 2, 50 rpm rotation speed, and 900 ml of deaerated H(2)O + 0.5% sodium lauryl sulfate (w/v) at pH 6.8 (adjusted with 18% phosphoric acid) as the dissolution medium. The model-independent method using difference factor (f(1)) and similarity factor (f(2)), model-dependent method, and dissolution efficiency were employed to compare dissolution profiles. The kinetic parameters of drug release were also investigated. The obtained results provided adequate dissolution profiles. The developed dissolution test was validated according to international guidelines. Since there is no monograph for this drug in tablets, the dissolution method presented here can be used as a quality control test for OLM in this dosage form, especially in a batch to batch evaluation.

Development and validation of dissolution test for lopinavir, a poorly water-soluble drug, in soft gel capsules, based on in vivo data.

The objective of the present study was to develop and validate a dissolution test for lopinavir soft gel capsules (Kaletra), using a simulated absorption profile based on in vivo data. Different conditions such as surfactant concentration, apparatus and rotation speed were evaluated. In vivo release profiles were obtained from the literature. The fraction (and percentage) of dose absorbed (FA) was calculated by using Wagner-Nelson method. The best in vitro dissolution profile was obtained using Apparatus 2 (paddle) at 25 rpm, 1000 ml of medium with 2.3% of sodium lauryl sulfate and pH 6.0. Under these conditions a level-A in vitro-in vivo correlation (IVIVC) was obtained (r = 0.997). The in vitro dissolution samples were analyzed using a HPLC method and the validation was performed according to USP protocol. The method showed accuracy, precision, linearity and specificity within the acceptable range. Both the HPLC method and the in vitro dissolution method were validated and could be used to evaluate the release profile of lopinavir soft gel capsules.