Development of an Immediate-Release Prototype Tablet Formulation of Hydroxychloroquine Sulfate with an Interwoven Taste-Masking System.

Hydroxychloroquine sulfate (HCQS) was granted US-FDA approval in 1955 for the prevention and treatment of malaria. Since then, its uses have expanded to treat systemic lupus erythematosus and rheumatoid arthritis.  For each indication, HCQS is a crucial option for the treatment of pediatric, juvenile, adult, and elderly populations. Existing currently on the market are only 200-mg strength tablets exclusively for adult administration. To facilitate weight-based administration for pediatric and juvenile patients, an HCQS suspension is made by compounding a 200-mg HCQS tablet and suspending the crushed granules into water and Ora-Plus®. The Ora-Plus® suspension does not alter the extreme bitterness of HCQS such that it facilitates oral administration. Additional research has been executed to affirm that a slightly buffered, ion-pairing system, reduces the bitterness of HCQS. The buffered, ion-pairing system can be interwoven into an immediate-release tablet formulation likely without compromising tablet performance. With the taste-masking system embedded, the tablet could be more easily be compounded and suspended in water to generate a palatable oral suspension. Such a novel HCQS 200-mg tablet would be tailored for adult usages wherein the interwoven task-masking system could be utilized to facilitate weight-based administration for pediatric and juvenile patients. The dual quality target product profile of the tablet and the tablet compounded for suspension in water would make the tablet formulation applicable to a wide patient population ranging from pediatric to elder adults to facilitate in improving compliance and overall health outcomes.

Evaluation of an Immediate-Release Formulation of Hydroxychloroquine Sulfate With an Interwoven Pediatric Taste-Masking System.

Hydroxychloroquine sulfate (HCQ) is a quinoline used for the prevention and treatment of uncomplicated malaria, lupus erythematosus, and rheumatoid arthritis. For each indication, HCQ is an option for treatment of pediatric and juvenile patients on a weight basis; however, no tailored pediatric product is available on the market. Preliminary research confirmed that a slightly buffered, ion-pairing system significantly reduces the bitterness of HCQ, suggesting a high likelihood that a pediatric taste-masking system could be interwoven into an adult immediate-release formulation allowing the creation of a palatable suspension with water using common excipients. Because HCQ is a Biopharmaceutics Classification System Class 1 drug, the pharmacokinetics for an adult immediate-release formulation would not be altered by embeding a taste-masking system. Embedding the taste-masking and suspension agents within the adult tablet formulation would remove the need for aqueous-based vehicles and simplify the creation of a water-based suspension formulation to support improved compliance, dosing accuracy, and health outcomes in pediatric patients who are weight-base dosed with HCQ.

Evaluation of the pharmacokinetic interaction between repeated doses of rifapentine or rifampin and a single dose of bedaquiline in healthy adult subjects.

This study assessed the effects of rifapentine or rifampin on the pharmacokinetics of a single dose of bedaquiline and its M2 metabolite in healthy subjects using a two-period single-sequence design. In period 1, subjects received a single dose of bedaquiline (400 mg), followed by a 28-day washout. In period 2, subjects received either rifapentine (600 mg) or rifampin (600 mg) from day 20 to day 41, as well as a single bedaquiline dose (400 mg) on day 29. The pharmacokinetic profiles of bedaquiline and M2 were compared over 336 h after the administration of bedaquiline alone and in combination with steady-state rifapentine or rifampin. Coadministration of bedaquiline with rifapentine or rifampin resulted in lower bedaquiline exposures. The geometric mean ratios (GMRs) and 90% confidence intervals (CIs) for the maximum observed concentration (Cmax), area under the concentration-time curve to the last available concentration time point (AUC0-t), and AUC extrapolated to infinity (AUC0-inf) of bedaquiline were 62.19% (53.37 to 72.47), 42.79% (37.77 to 48.49), and 44.52% (40.12 to 49.39), respectively, when coadministered with rifapentine. Similarly, the GMRs and 90% CIs for the Cmax, AUC0-t, and AUC0-inf of bedaquiline were 60.24% (51.96 to 69.84), 41.36% (37.70 to 45.36), and 47.32% (41.49 to 53.97), respectively, when coadministered with rifampin. The Cmax, AUC0-t, and AUC0-inf of M2 were also altered when bedaquiline was coadministered with rifapentine or rifampin. Single doses of bedaquiline, administered alone or with multiple doses of rifapentine or rifampin, were well tolerated, with no safety concerns related to coadministration. Daily administration of rifapentine to patients with tuberculosis presents the same drug interaction challenges as rifampin and other rifamycins. Strong inducers of the cytochrome P450 isoenzyme CYP3A4 should be avoided when considering the use of bedaquiline. (This study is registered at clinicaltrials.gov under identifier NCT02216331.).

Effect of a high-calorie, high-fat meal on the bioavailability and pharmacokinetics of PA-824 in healthy adult subjects.

PA-824 is a novel nitroimidazo-oxazine being developed as an antituberculosis agent. Two randomized studies evaluated the pharmacokinetics and safety of a single oral dose of PA-824 administered to healthy adult subjects 30 min after a high-calorie, high-fat meal (fed state) versus after a minimum 10-h fast (fasted state). A total of 48 subjects were dosed in the two studies in a randomized crossover design with PA-824 at dose levels of 50, 200, or 1,000 mg in the fed state or fasted state. After the administration of PA-824, the geometric mean ratios of Cmax and AUC0-∞ revealed an increase in exposure with the addition of a high-calorie, high-fat meal compared to the fasted state by 140 and 145% at 50 mg, 176 and 188% at 200 mg, and 450 and 473% at 50, 200, and 1,000 mg, respectively. The median Tmax in the fed state was 4 h for the 50-mg dose and 5 h for the 200- and 1,000-mg doses. In the fasted state, the median Tmax was 4 h for the 50- and 200-mg doses and 6.5 h for the 1,000-mg dose. All doses were well tolerated, and no serious adverse events occurred in either study. (This study has been registered at ClinicalTrials.gov under registration numbers NCT01828827 and NCT01830439.).

Evaluation of pharmacokinetic interaction between PA-824 and midazolam in healthy adult subjects.

This study assessed the safety, tolerability, and pharmacokinetic interaction between PA-824, a novel antitubercular nitroimidazo-oxazine, and midazolam, a CYP3A4 substrate, in 14 healthy adult male and female subjects. The study followed up on observations in vitro that PA-824 caused weak and time-dependent inhibition of CYP3A4. Subjects received a single oral dose of midazolam (2 mg), followed by a 2-day washout. After the washout, all subjects received PA-824 (400 mg) once daily for 14 consecutive days. On day 14, all subjects received the final PA-824 dose coadministered with a 2-mg oral dose of midazolam. The pharmacokinetic endpoints AUC0-t, AUC(0-∞), and C(max) for midazolam and 1-hydroxy midazolam were compared between midazolam administered alone versus midazolam coadministered with PA-824. Statistical analysis demonstrated that the mean midazolam values of C(max), AUC(0-t), and AUC(0-∞) parameters were reduced by ca. 16, 15, and 15%, respectively, when PA-824 was coadministered with midazolam. The total exposure (AUC) of 1-hydroxy midazolam was 13 to 14% greater when coadministered with PA-824 compared to midazolam administered alone. The Cmax of 1-hydroxy midazolam was similar between treatments. Based on these results, PA-824 does not inhibit or induce CYP3A4 to a clinically meaningful extent and is not likely to markedly affect the pharmacokinetics of CYP3A4 metabolized drugs.