Generic Tablets Research Articles

Thai HIV-1-infected women do not require a dose increase of lopinavir/ritonavir during the third trimester of pregnancy

To investigate whether Thai HIV-1-infected pregnant women require a dose increase of lopinavir/ritonavir (LPV/r) and to assess the safety and efficacy of the generic tablets during pregnancy. Prospective, single-center pharmacokinetic study. HIV-infected pregnant, antiretroviral therapy-naive or experienced women started HAART containing generic LPV/r 400/100 mg tablets twice daily. The 12-h pharmacokinetic curves were recorded at gestational age 20 weeks (GA20, optional), 33 weeks (GA33) and 12 weeks postpartum (12PP, optional). Twenty women were included. Median [interquartile range (IQR)] age was 28 (25-33) years and mean (SD) weight at GA33 was 59.9 (4.2) kg. Mean (SD) values for LPV area under the curve(0-12 h), C(max), C(min), and T(half) were 72.9 (19.2) mg/l h, 9.3 (2.2) mg/l, 3.2 (1.3) mg/l and 4.8 (2.4) h, respectively, on GA33 and 98.0 (24.1) mg/l h, 11.7 (2.2) mg/l, 4.7 (2.2) mg/l and 5.9 (2.7) h, respectively on 12PP. Twelve women recorded both GA33 and 12PP curves; mean LPV AUC(0-12) was significantly lower at GA33 [-24.1 (95% confidence interval -44.4 to -3.7) mg/l h]. At GA33, 19 of 20 women had sufficient LPV trough concentrations (>1.0 mg/l) and at 12PP, all had sufficient LPV trough concentrations. None of the women stopped LPV/r before planned discontinuation due to side-effects. At delivery, 19 of 20 women had a viral load below 50 copies/ml. One woman had a viral load of 60 copies/ml, but was undetectable at 12PP. Standard dose generic LPV/r (400/100 mg twice daily) in Thai HIV-1-infected pregnant women leads to adequate plasma concentrations during the third trimester. The generic LPV/r tablet is well tolerated and effective for use during pregnancy.

A bioequivalence study of two tamsulosin sustained-release tablets in Indonesian healthy volunteers

The bioavailability of two 0.4 mg tamsulosin sustained-release film-coated tablet formulations was compared; using generic tablets (Prostam(®)) as test formulation and the originator product as reference formulation. Twenty-four subjects were included in this single-dose, open-label, randomized two-way crossover design following an overnight fasting. A one-week wash-out period was applied. Blood samples were drawn up to 72 h following drug administration. Plasma concentration of tamsulosin was determined by liquid chromatography-tandem mass spectrometry method with TurboIonSpray mode. Pharmacokinetic parameters AUC(0-t,) AUC(0-∞), C (max) and t (½) were determined and used for bioequivalence evaluation after log-transformation, whereas t (max) ratios were evaluated non-parametrically. The estimated point and 90% confidence intervals (CI) for AUC(0-t,) AUC(0-∞), C (max) and t (½) were 109.55% (96.41-124.49%), 109.94% (96.85-124.81%), 105.87% (92.88-120.67%) and 100.00% (90.56-110.43%), respectively. These results indicated that the two formulations of tamsulosin were bioequivalent; therefore they may be prescribed interchangeably.

Relative Bioavailability and Tolerability of Two Formulations of Bicalutamide 50-mg Tablets: A Randomized-Sequence, Open-Label, Two-Period Crossover Study in Healthy Korean Male Subjects

Background Bicalutamide is an oral nonsteroidal antiandrogenic drug used in the treatment of prostate cancer. A new generic 50-mg tablet formulation of bicalutamide has recently been developed. Objective This study evaluated the relative bioavailability and tolerability of the new generic formulation of bicalutamide 50-mg tablets (test) and the currently marketed formulation (reference) in healthy Korean male subjects. The study was conducted to meet Korean regulatory requirements for authorization to market the generic formulation. Methods This was a randomized-sequence, open-label study in which healthy Korean male subjects (aged 20–55 years) received single doses of the test and reference formulations in a 2-period crossover fashion, with a 6-week washout period between doses. Blood samples for the determination of plasma bicalutamide concentrations were obtained at regular intervals over 672 hours after dose administration. Pharmacokinetic parameters were determined using noncompartmental methods. Relative bioavailability was evaluated by comparing the log-transformed C max and AUC 0–672 of the 2 formulations; Korean regulatory requirements for the assumption of bioequivalence were met if the 90% CIs fell within the range of 0.80 to 1.25. Tolerability was assessed based on physical examinations, vital signs, clinical laboratory tests, electrocardiograms (ECGs), and adverse events (AEs) (spontaneously reported or observed by investigators). Results Of 47 volunteers screened for inclusion, 38 were enrolled and 32 completed the study (mean [SD] age, 24.9 [3.7] years; mean height, 173.8 [6.2] cm; mean weight, 66.1 [7.1] kg). Median T max was 24 hours for both formulations. The C max of the test and reference formulations was 1176.2 (191.6) and 1118.9 (209.5) μg/L, respectively. The corresponding values for AUC 0–672 were 277,503 (66,865) and 271,961 (75,597) μg · h/L. The 90% CIs for the geometric mean ratios of log-transformed C max and AUC 0–672 were 1.00 to 1.11 and 0.99 to 1.07, respectively. Thirty-three AEs were reported, including 17 events in 9 subjects who received the test formulation and 16 events in 12 subjects who received the reference formulation. All AEs were mild, and no subjects discontinued the study because of AEs. Conclusions In this single-dose study in healthy Korean male subjects, the pharmacokinetic parameters of the new generic formulation of bicalutamide 50-mg tablets did not differ significantly from those of the reference formulation. The new generic formulation met Korean regulatory criteria for the assumption of bioequivalence to the currently marketed formulation. Both formulations were well tolerated. Korea Food and Drug Administration registration number: PSPD 3057.

Relative bioavailability of generic and branded acetylcysteine effervescent tablets: A single-dose, open-label, randomized-sequence, two-period crossover study in fasting healthy chinese male volunteers

Background: Acetylcysteine may be used as a muco- lytic agent for the treatment of chronic bronchitis, chronic obstructive pulmonary disease, and other pul- monary diseases complicated by the production of viscous mucus. However, little is known of its pharma- cokinetic properties when given orally in healthy vol- unteers, particularly in a Chinese Han population. This study was conducted to provide support for the market- ing of a generic product in China. Objective: The purpose of this study was to compare the pharmacokinetics and relative bioavailability of a generic test formulation and a branded reference formulation of acetylcysteine in fasting healthy Chinese male volunteers. Methods: A single-dose, open-label, randomizedsequence, 2-period crossover design with a 7-day washout period between doses was used in this study. Healthy Chinese male nonsmokers aged 18 to 40 years with a body mass index (BMI) of 19 to 25 kg/m 2 were selected. Eligible volunteers were randomly assigned to receive acetylcysteine 600 mg PO as either the test formulation (3 tablets of 200 mg each) or reference formulation (1 tablet of 600 mg) under fasting conditions. A total of 15 serial blood samples were collected over a 24-hour interval, and total plasma acetylcysteine concentrations were analyzed by a validated liquid chromatographyisotopic dilution mass spectrometry method. Pharmacokinetic parameters (C max, T max, t ½ AUC 0-t, and AUC 0-∞ were calculated and analyzed statistically. The 2 formulations were considered bioequivalent if the 90% CIs of the log-transformed ratios (test/reference) of C max and AUC were within the predetermined bioequivalence ranges (70%–143% for C max; 80%–125% for AUC), as established by the State Food and Drug Administration of China. Tolerability was determined by vital signs, clinical laboratory tests, 12-lead ECGs, physical examinations, and interviews with the subjects about adverse events (AEs). Results: A total of 24 healthy Chinese Han male volunteers were enrolled in and completed the study (mean [SD] age, 25.0 [2.4] years; height, 173.0 [5.6] cm; weight, 65.9 [6.4] kg; BMI, 22.0 [1.7] kg/m 2). No formulation, period, or sequence effects were observed. The 90% CIs for the log-transformed C max, AUC 0-t, and AUC 0-∞ were 89.7% to 103.8%, 86.7% to 101.7%, and 87.7% to 102.4%, respectively, which met the predetermined criteria for assuming bioequivalence. Two subjects (8.3%) experienced 2 mild AEs (increase in total bile acid and prolongation of the QT interval), which were not considered to be related to study drug administration. Conclusions: This single-dose study of acetylcysteine 600 mg PO found that the 3 tablets of the generic test formulation and 1 tablet of the branded reference formulation met the regulatory criteria for assuming bioequivalence in these fasting healthy Chinese male volunteers. Both formulations were generally well tolerated

ORIGINAL ARTICLE: Quality of medicines stored together in multi-compartment compliance aids

Background and Objective: Dispensing medicines into compliance aids is a common practice in pharmacy contrary to manufacturers’ advice and studies have shown the appearance of light-sensitive tablets is compromised by such storage; we previously found evidence of reduced bioavailability at elevated temperature and humidity. Our objective was to examine the physicochemical stability of two generic atenolol tablets in different compliance aids and with aspirin co-storage at room temperature and at 40 °C/75% relative humidity. Methods: The physicochemical stability of atenolol tablets was evaluated after 28 days of storage and compared with controls by examining visual appearance, weight, disintegration, dissolution, friability and hardness to accepted standards and using a previously validated HPLC method for chemical assay. Results and Discussion: The response to storage was brand-dependent and not straightforward. With one make of atenolol (Alpharma), storage in compliance aids even at room temperature impacted on physical stability, reducing tablet hardness, with storage in Dosett® exerting a greater impact than storage in Medidos® (t-test P < 0·001). Co-storage at elevated temperature and humidity also impacted on the appearance of non-coated aspirin tablets (Angette™). The chemical stability of atenolol was not affected and we did not find evidence of changes to bioavailability with either make. Certainly data for one atenolol make (CP Pharmaceuticals) co-stored with aspirin (Angette™ and Nu-Seals) in both compliance aids at room temperature provided evidence of short-term stability. But medicines are dispensed into compliance aids in multi-factorial ways so our study highlights not only the lack of evidence but also a realization that evidence to support real practice may not be accomplished through research. Conclusion: Reassuring practitioners of the continued stability of medicines in compliance aids under the countless condition in which they are dispensed in practice may requires a different approach involving medical device regulators and more definitive professional guidance.

Relative bioavailability and pharmacokinetic comparison of two 2-mg risperidone tablet formulations: A single dose, randomized-sequence, double-blind, 2-way crossover study in healthy male volunteers in thailand

Background: Data regarding the pharmacokinetic properties of risperidone in the Thai population are limited. A new generic tablet formulation was recently developed, but bioequivalence research is necessary to obtain marketing authorization for it in Thailand. Objective: The aim of this study was to evaluate and compare the pharmacokinetic properties of risperidone and its active metabolite, 9-hydroxyrisperidone (which reportedly contributes to the drug's pharmacodynamic effects), in a newly developed generic tablet formulation (test) and a branded formulation (reference) in healthy, fasting, male Thai volunteers. Methods: A single-dose, randomized-sequence, doubleblind, 2-way crossover design was used in this study. The study took place from October 21 through November 28, 2007. After a ≥10-hour overnight fast, volunteers were orally administered one 2-mg risperidone tablet, either the test formulation (Condrug International Company, Ltd.) or the reference formulation—according to the randomization schedule—followed by a 14-day washout period and administration of the alternate formulation. Blood samples were collected over a period of 96 hours. Risperidone and 9-hydroxyrisperidone plasma concentrations were simultaneously determined using a validated HPLC/ion trap mass spectrometry method. The plasma concentration-time curves of the active moiety, risperidone, and 9-hydroxyrisperidone were generated for each volunteer, from which the C max, T max, AUC 0-last, AUC 0-∞, and t ½ were determined using noncompart-mental analysis. The effects of formulation, period, sequence, and subject (within sequence) on pharmacokinetic parameters were analyzed using ANOVA. According to regulatory requirements set forth by Thailand, the Association of Southeast Asian Nations, and the US Food and Drug Administration, products meet the criteria for bioequivalence if the 90% CIs of the treatment ratios for C max and AUC are within the range of 0.80 to 1.25. Tolerability was assessed by patient interview, monitoring vital signs (ie, resting blood pressure, heart rate, body temperature), physical examination, and laboratory tests (ie, urinalysis, hematology, blood chemistry) before and after the study. Results: A total of 22 Thai male volunteers (mean [SD] age, 28.18 [8.27] years [range, 20.62–44.19 years]; weight, 62.43 [4.76] kg [range, 55.03–76.02 kg]; and body mass index, 21.76 [2.07] kg/m 2 [range, 18.9924.91 kg/m 2]) completed the study. The mean (SD) relative bioavailabilities of test to reference formulations determined from AUC of the active moiety, risperidone, and 9-hydroxyrisperidone were 1.06 (0.18), 1.07 (0.29), and 1.04 (0.17), respectively. The ANOVA suggested no statistically significant effect of formulation, period, or sequence on the studied pharmacokinetic parameters of the active moiety, risperidone, or 9-hydroxyrisperidone. The 90% CIs for the natural logarithm-transformed ratios of C max, AUC 0-last, and AUC 0-∞ were as follows: for active moiety, 0.94 to 1.03, 0.98 to 1.11, and 0.98 to 1.10, respectively; for risperidone, 0.90 to 1.10, 0.96 to 1.13, and 0.96 to 1.14, respectively; and for 9-hydroxyrisperidone, 0.91 to 1.03, 0.97 to 1.10, and 0.96 to 1.09, respectively. All met the criteria for bioequivalence. The most commonly reported adverse events (AEs) were somnolence (100.0%), orthostatic hypotension (13.6%), headache (4.5%), and syncope (2.3%). AEs were mild and disappeared within 1 day. No volunteers withdrew from the study because of AEs. Conclusions: The single-dose pharmacokinetic data in this small, all-male, selected sample of fasting, healthy volunteers met Thailand's regulatory criteria for assuming bioequivalence of the tested generic and reference 2-mg risperidone tablets. Both formulations were well tolerated.

Pharmacokinetics and bioequivalence evaluation of two losartan potassium 50-mg tablets: A single-dose, randomized-sequence, open-label, two-way crossover study in healthy Chinese male volunteers

Background: Losartan is a nonpeptide angiotensin II receptor antagonist used as an antihypertensive agent. The relative bioavailability of a newly developed tablet compared with an established branded formulation has not been reported in a Chinese population. Objective: To meet the requirements for marketing a new generic product, the study was designed to compare the pharmacokinetic parameters and relative bioavailability of a new generic losartan potassium 50-mg tablet (test formulation) with a branded 50-mg tablet (reference formulation) in healthy Chinese male volunteers. Methods: A single-dose, randomized-sequence, openlabel, 2-way crossover study was conducted in healthy Chinese male volunteers. Eligible participants were randomly assigned in a 1:1 ratio to receive a single 50-mg tablet of the test or reference formulation, followed by a 1-week washout period and then administration of the alternate formulation. The study drugs were administered after a 10-hour overnight fast. Plasma samples were collected over 36 hours. Tolerability was evaluated by recording adverse events (AEs) and monitoring vital signs, ECGs, and laboratory tests at baseline and at completion of the study. Plasma concentrations of losartan and its active metabolite (EXP3174) were analyzed by LC-MS/MS. Pharmacokinetic parameters, including C max, AUC 0–36, and AUC 0−∞, were calculated. If the 90% CIs for the log-transformed values of AUC were within 80% to 125%, and that of C max was within 70% to 143%, the 2 products would be considered bioequivalent according to the guidelines of the US Food and Drug Administration and the State Food and Drug Administration of China. Results: Twenty–seven healthy Chinese male volunteers participated in this study (mean [SD] age, 24.5 [2.3] years [range, 20–29 years]; weight, 64.6 [4.0] kg [range, 60.0-75.0 kg]; height, 172.2 [4.8] cm [range, 165.0183.0 cm]; and body mass index, 21.8 [1.2] kg/m 2 [range, 20.0–25.0 kg/m 2]). One volunteer (3.7%) experienced an AE (microscopic hematuria) after administration of the test formulation. This resolved spontaneously after 10 days and was considered by the investigator as mild; the relationship with the study drug was uncertain. No serious AEs were reported. Both formulations were associated with significant reductions in systolic and diastolic blood pressure and significant increases in heart rate compared with baseline values (all, P < 0.05). No period, formulation, or sequence effects were observed for any pharmacokinetic parameter, except for a significant subject effect. For parent losartan, the 90% CIs for the ratios (test/reference) of C max, AUC 0–36, and AUCAUC 0−∞ were 83.65% to 113.36%, 89.79% to 98.25%, and 90.95% to 99.55%, respectively. For the metabolite EXP3174, the 90% CIs for the ratios of C max, AUC 0–36, and AUCAUC 0−∞ were 93.49% to 103.61%, 96.79% to 104.09%, and 97.06% to 105.83%. Both C max and AUC met the predetermined criteria for assuming bioequivalence. The relative bioavailability of the test formulation to the reference formulation was 93.92% for losartan and 100.40% for EXP3174. Conclusions: In this small study in healthy Chinese male volunteers, a single 50-mg oral dose of a losartan potassium tablet (test formulation) met the regulatory criteria for assuming bioequivalence to the established reference formulation. Both formulations were well tolerated.

Drug-resistant mutation patterns in CRF01_AE cases that failed d4T + 3TC + nevirapine fixed-dosed, combination treatment: Follow-up study from the Lampang cohort

HIV/AIDS patients are treated in Thailand's national antiretroviral treatment (ART) program with a generic combination tablet of stavudine, lamivudine, and nevirapine (GPOvir). To determine GPOvir-resistant mutations, HIV-1 sequences of 59 GPOvir-failure cases from the Lampang cohort were compared with sequences from 76 randomly selected ART-naïve cases. The GPOvir-failure cases had not only known stavudine-, lamivudine- and nevirapine-resistant mutations, but also V118I, G196E, and H221Y. Among the 59 GPOvir-failure cases, 29 were ART-naïve prior to GPOvir (naïve group), and 30 had previous ART (exposed group). To clarify the effect of previous ART in drug-resistant acquisition pathways, naïve and exposed groups were compared. The exposed group had predominantly thymidine analogue-related mutations, whereas the naïve group had a higher prevalence of Q151M and K103N mutations. M184V lamivudine resistance was most frequent in both naïve and exposed groups. To identify which mutations in CRF01_AE pol were polymorphisms, the connection and RNase domains were also analyzed. CRF01_AE-specific polymorphisms were found in 19 residues, and GPOvir-failure cases had significantly higher frequency of N348I, E399D, P537S, and I542M. Our results expand identification of mutations in CRF01_AE pol that are polymorphisms by also analyzing the connection and RNase H domains.

JPAG Session: Short Papers in Pharmaceutical Analysis

Objectives To develop near-infrared spectroscopic (NIRS) quantitative models for the assay of ciprofloxacin in proprietary and generic ciprofloxacin 500 mg intact and powdered tablets. Methods Ciprofloxacin 500 mg tablets were pruchased from the UK and the Tanzanianmarkets. Tablets in both intact and powdered forms were utilized to construct calibration models. Tablets of a single proprietary brand (Bayer, 500 mg)were powdered and diluted with excipient(s) to give mixtures of different concentrations of ciprofloxacin. In addition, standard additions of ciprofloxacin FOSS NIRSystem 6500 NIR spectrometer using a rapid content analyser. Each spectrum was the sum of 32 scans over the wavelength range 1100-2500 nm at 2 nm interval. Four spectra were also recorded from each tablet, two on each side at 90 degrees to each other. Four spectra were also recorded from the powdered samples in Waters (4 mm) vials shaking between measurements. The average of the spectra was taken in both cases in standard normal variate second derivative (SNV-D2) form. Results The ciprofloxacin tablets had a range of activity between 55 and 77% m/m estimated as the ratio of the label claim (in milligrams) to the weight of the tablet. These data were used to construct the Intact Tablet Model. The powdered models used various ranges of ciprofloxacin between 0 and 100%. In all cases, a partial least squares regression (PLSR) algorithm (Unscrambler 7.5) was utilized. The spectra were split into calibration and validation sets based on PCA data to give the greatest variability in the calibration set. The ratio of the calibration to validation sets was 75%:25%. Specific partial least squares components were chosen for each model to give the lowest root mean standard error of prediction as a percentage of the label claim (RSEP %). The PLSR loadings showed good correlation with the ciprofloxacin tablet spectrum. The predictive ability of the model was validated against known proprietary and generic intact and powdered tablets. The tablets contained ciprofloxacin or other antibiotics of different classes. A good prediction gave the label claim within +-10% of the ciprofloxacin tablets and 0% for the other tablets. In this respect, the best model that fulfilled the stated criteria was the one which utilized the standard addition of the ciprofloxacin to the crushed Bayer tablets. It gave an r2 value of 0.9989 and RSEP% of 0.96%. In addition, it was able to prdict both ciprofloxacin and blank tablets. Conclusions The NIRS method with PLSR regression is a simple, rapid, non-destructive technique for the determination of cirofloxacin in jkproprietary and generic tablets. It can be used without the need for a reference analytical technique and with an RSEP% as low a 0.96%.

Bioavailability of generic ritonavir and lopinavir/ritonavir tablet products in a dog model

In this study, we explored the bioavailability in dogs and chemical potency of generic ritonavir and lopinavir/ritonavir tablet products manufactured by various pharmaceutical companies. Chemical potency of the products was examined by HPLC quantitation of ritonavir and lopinavir. Using a dog model, we determined point estimates for Cmax and AUC of ritonavir and lopinavir/ritonavir for eight generic products compared to Abbott's Norvir 1 capsule and Kaletra 1 tablet. Chemical potencies ranged from 79.0% to 104.6%. Point estimates for AUC in the generic tablet products ranged from 0.01 to 1.11, indicating that the relative bioavailability of these formula- tions was in the range of 1-111% compared to the branded products. This study showed significant variability in bioavailability in a dog model amongst generic tablet products containing the protease inhibitors ritonavir or lopinavir/ritonavir. The chemical potency of the generic products was not indicative of the plasma levels of ritonavir or lopinavir that were achieved. These results reinforce the need for human bioequivalence testing of generic products containing ritonavir or lopinavir/ritonavir to assure that efficacy in patients is not compromised prior to these products being made available to patients. Procurement policies of funding agencies should require such quality assurance processes. 2009 Wiley-Liss, Inc. and the American Pharmacists Association J Pharm Sci 99:626-631, 2010

Pharmacokinetics of generic and trade formulations of lamivudine, stavudine and nevirapine in HIV-infected Malawian children

The aim of this study was to evaluate the pharmacokinetics of lamivudine (3TC), stavudine (d4T) and nevirapine (NVP) in HIV-infected Malawian children receiving quartered tablet multiples of Triomune 40 (generic tablet [GT]) compared with individual generic liquid (GL) and trade liquid (TL). This was a prospective randomized three-way crossover study. Patients (8-<12 kg, 18-<22 kg or 28-<32 kg body weight) taking Triomune 40 were recruited and randomized to receive GT twice daily (one-quarter, one-half or three-quarter tablets using Malawi treatment guidelines), GL twice daily (in the equivalent dose of GT) or TL twice daily (dosed using weight and age from US Department of Health and Human Services paediatric treatment guidelines). After 10 days of one formulation, 6-h pharmacokinetic sampling was performed, and patients were crossed over to subsequent formulations. Baseline concentration (C(0 h)), area under the curve (AUC)(0-6 h), maximum plasma concentration (C(max)) and time to C(max) were generated for each antiretroviral treatment. A total of 7 males and 11 females (6 in each GT dosing group) with a median (range) age of 7.2 years (1.3-13.6), weight of 19 kg (9.0-30.5) and height of 109 cm (75-132) were recruited. Combining all patients, no difference in pharmacokinetics was noted among the formulations for all drugs. However, patients in the one-quarter GT dosing group (8-<12 kg) had lower 3TC exposures than with the GL or TL (3TC AUC(0-6 h) 1,102, 1,720 and 2,060 h*ng/ml, respectively; P<0.005) and had more subtherapeutic NVP C(0 h) (10 of 13 occasions versus the one-half and three-quarter tablet groups). Compared with Western paediatric cohorts, Malawians had concentrations 30-40% lower for 3TC and d4T and 50% higher for NVP. Quartered multiples of Triomune 40 are appropriate for children 18-<22 kg and 28-<32 kg in weight; however, alternative formulations are suggested in children weighing 8-<12 kg.

Interchangeability of two 500 mg amoxicillin capsules with one 1000 mg amoxicillin tablet after a single oral administration

The aim of the study was to evaluate if two capsules (Amoxil® capsules, 500 mg/capsule) and one tablet (Amoxicare® tablets, 1000 mg/tablet) of amoxicillin have similar bioequivalence parameters. For this purpose a randomized, two-way, crossover, bioequivalence study was performed in 24 healthy, male volunteers, divided into two groups of 12 subjects each. One group was treated with the reference standard (Amoxil®) and the other one with the generic tablet Amoxicare®, with a crossover after a wash-out period of 7 days. Blood samples were collected at fixed time intervals and amoxicillin was determined by a validated HPLC method. The pharmacokinetic parameters AUC0-8, AUC0-∞, Cmax, Tmax, Ke and T1/2 were determined for both formulations and statistically compared to evaluate the bioequivalence between the two brands of amoxicillin, using the statistical model recommended by the FDA. Cmax and AUC0-∞ were statistically analyzed using analysis of variance (ANOVA); no statistically significant difference was observed between the two formulations. The 90% confidence intervals between the mean values of Cmax and AUC0-∞ fall within the FDA specified bioequivalent limits (80-125%) suggesting that the two products are bioequivalent and the two formulations are interchangeable. Based on these findings it was concluded that the practice of interchangeability between the above formulations to achieve better patient compliance could be followed without compromising the extent of amoxicillin absorption.

Comparative pharmacokinetic evaluation of two formulations of bicalutamide 50-mg tablets: An open-label, randomized-sequence, single-dose, two-period crossover study in healthy Korean male volunteers

Background: Bicalutamide is an oral nonsteroidal antiandrogen drug used during hormone ablation therapy for prostate cancer. A new generic formulation of bicalutamide has been developed. Objectives: This study was conducted to meet Korean and US regulatory requirements for the marketing of the generic 50-mg tablet formulation of bicalutamide. To this end, the pharmacokinetic properties of the new (test) formulation were compared with those of the currently marketed (reference) formulation. Tolerability was also evaluated. Methods: An open-label, randomized-sequence, single-dose, 2-period crossover study was conducted in healthy Korean male volunteers. Subjects received either the test or reference formulation of bicalutamide 50-mg tablets in the first period and crossed over to the alternative formulation in the second period. Serial blood samples for pharmacokinetic analysis were taken over 672 hours after dosing. Plasma concentrations of bicalutamide were measured by HPLC-MS/MS. Pharmacokinetic parameters, including AUC 0–672h, were determined by noncompartmental analysis. Log-transformed C max and AUC 0–672h for the 2 formulations were compared. Tolerability was monitored based on laboratory tests, ECGs, vital signs, and physical examinations. Results: Of the 34 subjects initially enrolled, 33 completed the study. The mean (SD) age, height, and weight of participants were 25.8 (4.1) years, 173.6 (5.7) cm, and 68.9 (7.8) kg, respectively. The median T max was 36.0 hours for both formulations. The mean (SD) t ½, C max, and AUC 0–672h for the reference formulation were 135.4 (28.6) hours, 933.2 (169.2) μg/L, and 215,680.1 (48,753.4) μg · h/L, respectively. Corresponding values for the test formulation were 134.3 (30.7) hours, 946.7 (179.9) μg/L, and 221,708.8 (54,935.1) μg · h/L. The 90% CIs for the mean ratios (test/reference) of log-transformed C max and AUC 0–672h were 0.97 to 1.06 and 0.98 to 1.07, respectively. Twelve adverse events were reported for each formulation, none of which were considered drug related in the test-formulation group and 4 of which were considered drug related in the reference-formulation group (3 cases of headache, 1 case of erythematous rash). Conclusions: In this single-dose study in healthy Korean male subjects, the new formulation of bicalutamide 50-mg tablets met Korean and US regulatory criteria for assumption of bioequivalence with the currently marketed formulation. Both formulations were generally well tolerated, with no clinically relevant safety concerns.

Relative bioavailability of generic and branded 250-mg and 500-mg oral chlorphenesin carbamate tablets in healthy Korean volunteers: A single-dose, randomized-sequence, open-label, two-period crossover trial

Background: Chlorphenesin carbamate is a skeletal muscle relaxant approved in Korea for use in the treatment of pain and discomfort related to skeletal muscle trauma and inflammation. Objective: The aim of this study was to assess the bioequivalence of a generic formulation of chlorphenesin carbamate at doses of 250 and 500 mg and 2 branded formulations of the same doses in healthy Korean adults. Methods: This single-dose, randomized-sequence, open-label, 2-period crossover study was conducted in healthy Korean male and female volunteers. Subjects were assigned to receive, in a randomized sequence, a single dose of the generic (test) and branded (reference) formulations of chlorphenesin carbamate at a dose of 250 or 500 mg. Blood samples were drawn at 0, 0.33, 0.67, 1, 1.5, 2, 3, 4, 6, 9, 12, and 15 hours after administration. Pharmacokinetic properties (C max, T max, AUC 0−t AUC 0-∞, t 1/2, and ke) were determined using HPLC. The formulations were to be considered bioequivalent if the 90% CIs of the treatment ratios of the geometric means of C max and AUC 0−t were within a predetermined range of log 0.80 to log 1.25 based on regulatory criteria. Tolerability was assessed by monitoring for adverse events (AEs) on physical examination and/or e-mail and personal interview at the beginning and end of each study period. Results: Twenty-eight subjects (22 men, 6 women) received chlorphenesin carbamate at the 250-mg dose, and 24 male subjects received the 500-mg dose. The mean (SD) ages of the subjects were 24.0 (2.6) and 24.0 (1.9) years in the 250- and 500-mg groups, respectively. No significant differences were found between the test and reference formulations (90% CIs: C max, 1.0048–1.1153 with the 250-mg dose and 0.9630–1.1189 with the 500-mg dose; AUC 0−t, 0.9882–1.0546 and 0.9842–1.0578, respectively). No clinically significant AEs (upper gastric pain, abdominal bloating, pyrexia, edema, nausea, heartburn, constipation, headache, dizziness, drowsiness, or fatigue) were reported throughout the study. Conclusion: In this single-dose study in these healthy Korean subjects, the generic and branded formulations of chlorphenesin carbamate 250 and 500 mg met the regulatory criteria for bioequivalence. All formulations were well tolerated.

Equivalence of ranitidine generic tablets studied using the in vitro dissolution test

The pharmaceutical equivalence of Zantac (reference drug) and 10 domestic and foreign generics of ranitidine hydrochloride as 150-mg coated tablets has been studied using the pharmacopoeic (USP 29) dissolution test. Analyses showed insignificant differences in the excipients entering into the compositions of ranitidine generic tablets registered in Russia. It is established that Zantac and generics of two manufacturers are rapidly soluble (according to the WHO classification). Analysis of the similarity coefficients determined for the dissolution profiles measured in media with different pH values showed the biological nonequivalence of some generics and the reference drug. It is demonstrated that the in vitro dissolution test recommended by WHO can be used for determining the bioequivalence of ranitidine generics.

Bioequivalence of two film-coated tablets of imatinib mesylate 400 mg: A randomized, open-label, single-dose, fasting, two-period, two-sequence crossover comparison in healthy male South American volunteers

Background: Imatinib is a tyrosine kinase inhibitor that has been established as a highly effective therapy for chronic myelogenous leukemia and gastrointestinal stromal tumors. A new generic, once-daily 400-mg tablet of imatinib has been developed by a pharmaceutical company in Argentina, where the regulatory standard for marketing authorization of an imatinib generic is in vitro dissolution testing.Objective: The aim of this study was to assess the bioequivalence of a new generic film-coated test tablet formulation versus a film-coated reference tablet formulation of imatinib 400 mg. The local manufacturer seeks to validate the in vitro performance of this new formulation with a bioequivalence study.Methods: A randomized, open-label, single-dose, fasting, 2-period, 2-sequence crossover design with a 2-week washout period was used in this study. The study population consisted of healthy male South American (Uruguayan) volunteers, who were assigned in a 1:1 ratio to a randomized sequence (test-reference or reference-test). In each period, the test or reference formulation was administered after an overnight fast. During the 72-hour follow-up period, participants were monitored for vital signs and symptoms. Blood samples were collected at 15 time points, including baseline, until 72 hours. Physical examination and laboratory tests (blood, urine) were repeated 1 week after study completion. A noncompartmental model was used to determine the pharmacokinetic parameters of imatinib. The 90% CIs of the test/reference ratios for AUC0-∞ and Cmax were determined; the test and reference formulations were considered bioequivalent if the 90% CIs were between 0.80 and 1.25. Adverse events were assessed by a nurse who administered a questionnaire while the healthy volunteers were admitted in the unit.Results: The bioequivalence study was conducted in 30 Uruguayan male volunteers. Demographic characteristics (mean [SD]) included age, 27.8 (6.5) years; weight, 71.2 (9.8) kg; height, 1.71 (0.09) m; and body mass index, 24.3 (3.0) kg/m2. The mean (SD) of AUC0-∞ was 38,179 (15,504) ng/mL · h−1 for the test formulation and 40,554 (17,027) ng/mL · h−1 for the reference formulation. The mean of Cmax for the test formulation was 2472 (933) ng/mL, and the mean Tmax was 3.28 (0.93) hours. The mean of Cmax for the reference formulation was 2566 (963) ng/mL, and the mean Tmax was 3.63 (1.20) hours. The point estimates (90% CIs) for the test/reference ratios of the log-transformed AUC- and Cmax mean values were 0.95 (0.87–1.03) and 0.97 (0.89–1.05), respectively, which met the regulatory criteria for bioequiv-alence. Thirty-four mild to moderate adverse events were reported (13 with the test formulation and 21 with the reference formulation), and no serious or unexpected adverse events were observed during the study. The adverse events included 16 cases of headache, 13 cases of nausea, 4 cases of vomiting, and 1 episode of diarrhea.Conclusions: The results of this study suggest that the test formulation of imatinib met the regulatory criteria for bioequivalence to the reference formulation in these healthy fasting male volunteers. Both formulations were generally well tolerated and appeared to have a similar adverse-event profile.

Lower-Dose vs High-Dose Oral Estradiol Therapy of Hormone Receptor–Positive, Aromatase Inhibitor–Resistant Advanced Breast Cancer

Estrogen deprivation therapy with aromatase inhibitors has been hypothesized to paradoxically sensitize hormone-receptor-positive breast cancer tumor cells to low-dose estradiol therapy. To determine whether 6 mg of estradiol (daily) is a viable therapy for postmenopausal women with advanced aromatase inhibitor-resistant hormone receptor-positive breast cancer. A phase 2 randomized trial of 6 mg vs 30 mg of oral estradiol used daily (April 2004-February 2008 [enrollment closed]). Eligible patients (66 randomized) had metastatic breast cancer treated with an aromatase inhibitor with progression-free survival (> or = 24 wk) or relapse (after > or = 2 y) of adjuvant aromatase inhibitor use. Patients at high risk of estradiol-related adverse events were excluded. Patients were examined after 1 and 2 weeks for clinical and laboratory toxicities and flare reactions and thereafter every 4 weeks. Tumor radiological assessment occurred every 12 weeks. At least 1 measurable lesion or 4 measurable lesions (bone-only disease) were evaluated for tumor response. Randomization to receive 1 oral 2-mg generic estradiol tablet 3 times daily or five 2-mg tablets 3 times daily. Primary end point: clinical benefit rate (response plus stable disease at 24 weeks). toxicity, progression-free survival, time to treatment failure, quality of life, and the predictive properties of the metabolic flare reaction detected by positron emission tomography/computed tomography with fluorodeoxyglucose F 18. The adverse event rate (> or = grade 3) in the 30-mg group (11/32 [34%]; 95% confidence interval [CI], 23%-47%) was higher than in the 6-mg group (4/34 [18%]; 95% CI, 5%-22%; P = .03). Clinical benefit rates were 9 of 32 (28%; 95% CI, 18%-41%) in the 30-mg group and 10 of 34 (29%; 95% CI, 19%-42%) in the 6-mg group. An estradiol-stimulated increase in fluorodeoxyglucose F 18 uptake (> or = 12% prospectively defined) was predictive of response (positive predictive value, 80%; 95% CI, 61%-92%). Seven patients with estradiol-sensitive disease were re-treated with aromatase inhibitors at estradiol progression, among which 2 had partial response and 1 had stable disease, suggesting resensitization to estrogen deprivation. In women with advanced breast cancer and acquired resistance to aromatase inhibitors, a daily dose of 6 mg of estradiol provided a similar clinical benefit rate as 30 mg, with fewer serious adverse events. The efficacy of treatment with the lower dose should be further examined in phase 3 clinical trials. clinicaltrials.gov Identifier: NCT00324259.

UJI DISINTEGRASI DAN DISOLUSI TERBANDING TABLET ALOPURINOL GENERIK BERMEREK DAN GENERIK BERLOGO YANG BEREDAR DI PASARAN

ABSTRACT Allopurinol is a pyrimidine derivative that effective to normalize levels of uric acid in blood and urine. Allopurinol is very slightly soluble in water, but it has high permeability (BCS class II) so that the dissolution is an important determine to express the drug bioavailability. Additional material differences and the production process of each plant can cause differences in the quality of the resulting allopurinol tablets. This study aimed to compare the quality of branded generic and generic products allopurinol tablets in the quality of disintegration and dissolution. This study used 5 kinds branded generic (A, B, C, D, E) and 5 kinds of generic products (F, G, H, I, J). Disintegration test carried out according to USP-NF 32 nd edition by the medium of water at 37 ± 2°C. Dissolution tests conducted according to USP-NF 32 nd edition using apparatus 2 (paddle methode), the speed of rotation 75 rpm, in 0.01 N HCl medium at 37 ± 0.5°C. The data obtained compared with the requirements listed in the Indonesia Pharmacopoeia 4 th edition and USP-NF 32 nd edition, and then statistically analyzed by T test at 95% confidence interval. Results of disintegration and dissolution tests met the requirements in the literature. Statistical test results showed that products had different disintegration and dissolution profile. Keywords: allopurinol, disintegration, dissolution, tablets

Pharmacokinetic properties and bioequivalence of two formulations of arbidol: An open-label, single-dose, randomized-sequence, two-period crossover study in healthy chinese male volunteers

Background: Arbidol is an antiviral drug indicated for the prevention and treatment of all types of influenza infection and some other kinds of acute respiratory infections, specifically against influenza groups A and B, and severe acute respiratory syndrome. It is used to help prevent influenza infection as long as necessary with little risk for influenza mutation rendering it less effective.Objective: The aim of this study was to compare the pharmacokinetic properties and tolerability, and to determine bioequivalence, of a newly developed generic dispersible tablet formulation (test) and a branded capsule formulation (reference) of arbidol 200 mg in healthy Chinese fasted male volunteers.Methods: This open-label, single-dose, randomized-sequence, 2-period crossover study was conducted in healthy native Chinese male volunteers. Eligible subjects were randomly assigned in a 1:1 ratio to receive a single 200-mg dose of the test or reference formulation, followed by a 1-week washout period and administration of the alternate formulation. The study drugs were administered after a 12-hour overnight fast. After the study drug administration, serial blood samples were collected for 72 hours after administration. Plasma drug concentrations were determined using high-performance liquid chromatography coupled with tandem mass spectrometry. Several pharmacokinetic pararameters, including Cmax, Tmax, t½, AUC0-t, and AUC0-∞, were determined from the plasma concentrations of the 2 formulations of arbidol using noncom-partmental analysis. The formulations were to be considered bioequivalent if the log-transformed ratios of Cmax and AUC were within the predetermined bioequivalence range of 80% to 125% established by the State Food and Drug Administration (SFDA) of the People's Republic of China. Tolerability was assessed by monitoring vital signs (blood pressure, heart rate, temperature, and electrocardiography), laboratory analysis (hematology, blood biochemistry, hepatic function, and urinalysis), and subject interview on adverse events.Results: Twenty subjects were enrolled and completed the study (mean [SD] age, 21.1 [1.1] years; weight, 64.7 [5.1] kg; and height, 172.3 [3.1] cm). Neither period nor sequence effect was observed. The main pharmacokinetic properties with the test and reference formulations were as follows: Cmax, 417.4 (107.6) and 414.8 (95.1) ng/mL, respectively (P = NS); median (range) Tmax, 0.63 (0.25–1.0) and 0.75 (0.5–1.5) hours (P = 0.035); AUC0-t, 2033.6 (564.9) and 1992.0 (483.3) ng/mL/h (P = NS); AUC0-∞, 2285.4 (597.7) and 2215.2 (604.0) ng/mL/h (P = NS); and t1/2, 6.9 (4.2) and 6.1 (5.2) hours (P = NS). The 90% CIs for the log-transformed ratios of Cmax, AUC0-t, and AUC0-∞ were 91.7% to 109.7%, 91.0% to 112.8%, and 92.0% to 116.3%, respectively (all, P < 0.05), which were within the predetermined range for bioequivalence. No adverse events were found on analysis of vital signs or laboratory tests or reported by subjects in this study.Conclusion: In this study in healthy Chinese male volunteers, the dispersible tablet formulation and the 200-mg capsule formulation of arbidol met the SFDA's regulatory definition of bioequivalence based on the rate and extent of absorption.

Bioequivalence studies and sugar-based excipients effects on the properties of new generic ketoconazole tablets formulations and stability evaluation by using direct compression method

In this work we described the development of a new solid oral formulation of ketoconazole, a broad-spectrum antifungal agent that belongs to the class II of Biopharmaceutics Classification System (BCS). The ketoconazole raw material supplier was selected to present a best flow and compactation. In addition we used direct compression and superdisintegrants associated to polyols to enhance the dissolution of the ketoconazole tablets. The dissolution was evaluated based in level C in vivo/in vitro correlation established. The best formulation was obtained with croscarmellose/maltose association that in the accelerated stability assays presented no differences on quality specifications and no drug-excipients interaction by DSC analyses. In this work it was possible to confirm the use of sugar-based excipients as suitable dissolution enhancers in pharmaceutical technology and real processes conditions.