Ritalinic acid in urine: Impact of age and dose.

OBJECTIVES: The objective of this work was to study the results of urine drug testing for ritalinic acid (RA), the major urinary metabolite of methylphenidate (MP) (e.g., Ritalin®). The impact of age from 4 to 65 years old and older on median levels of RA was investigated as well as potential variations in pH, specific gravity and creatinine content of the patient urine samples. DESIGN AND METHODS: Samples from patients who were 1) prescribed MP and found to be positive for RA, 2) prescribed MP but found to be negative for RA and 3) not prescribed MP but tested positive for RA were examined by liquid chromatography - mass spectrometry/mass spectrometry (LC-MS/MS) for RA concentration. The levels of RA were examined for median and average levels and further normalized and transformed to reveal a near gaussian distribution. RESULTS: Over 20,000 samples from patients who were prescribed MP were examined for this work. Analysis of these data for a subset of patients prescribed MP and testing positive for RA revealed statistically different median values of RA for school age patients of 6 years old through 17 years old from adult patients 18 through 64 years old. Another 6751 samples were positive for RA without a prescription but were not included in the overall assessment of these data. CONCLUSIONS: While not clear as to the reason, these data indicate that school age children under the age of 18 have much higher levels of RA than adult patients. These results can be used to estimate "normal" levels of RA in these chronically dosed populations.

Food effect on pharmacokinetics of cannabidiol oral capsules in adult patients with refractory epilepsy.

OBJECTIVE: To evaluate the pharmacokinetics of a purified oral cannabidiol (CBD) capsule administered with and without food in adults with refractory epilepsy. METHODS: Adult patients who were prescribed CBD for seizures, had localization-related intractable epilepsy with ≥4 seizures per month, and qualified for Minnesota cannabis were enrolled. A single dose of 99% pure CBD capsules was taken under both fasting (no breakfast) and fed (high fat 840-860 calorie) conditions. Blood sampling for CBD plasma concentrations was performed under each condition between 0 and 72 hours post-dose and measured by a validated liquid chormatography-mass spectometry assay. CBD pharmacokinetic profiles including maximum concentration (Cmax ), area-under-the-curve from zero to infinity (AUC0-∞ ), and time-to-maximum concentration (Tmax ) were calculated. The confidence intervals (CIs) for log-transformed Cmax and AUC0-∞ ratios between fed and fasting states were calculated. Seizure and adverse events information was collected. RESULTS: Eight patients completed the study. On average Cmax was 14 times and AUC0-∞ 4 times higher in the fed state. The 90% CI for the ratio of fed versus fast conditions for Cmax and AUC0-∞ were 7.47-31.86 and 3.42-7.82, respectively. No sequence or period effect for Cmax and AUC0-∞ was observed. No adverse events were reported. SIGNIFICANCE: Administering CBD as a capsule rather than a liquid allows for more precise determination of pharmacokinetics parameters and is more representative of CBD swallowed products. The fat content of a meal can lead to significant increases in Cmax and AUC0-∞ and can account for variability in bioavailability and overall drug exposure within patients with oral products.

Simultaneous Quantification of 13 Cannabinoids and Metabolites in Human Plasma by Liquid Chromatography Tandem Mass Spectrometry in Adult Epilepsy Patients.

BACKGROUND: A sensitive, robust method was developed and validated to quantitate 13 major natural cannabinoid parent and metabolite compounds in human plasma at or below 0.5 ng/mL. METHODS: A liquid chromatography tandem mass spectrometry method was developed and validated to measure 13 cannabinoid compounds: cannabidiol (CBD), cannabidiolic acid, cannabidivarin, cannabinol, cannabigerol, cannabigerolic acid, cannabichromene, Δ-tetrahydocannabinol (THC), Δ-tetrahydrocannabinolic acid A (THCA), Δ-tetrahydrocannabivarin (THCV), 11-hydroxy-Δ-tetrahydrocannbinol (11-OH-THC), 11-nor-9-carboxy-Δ-tetrahydrocannbinol (THC-COOH), and 11-nor-9-carboxy-Δ-tetrahydrocannabinol glucuronide (THC-COOH-glu). Samples (200 µL) were extracted through protein precipitation and separated with a Kinetex EVO C18 column and a 65%-95% gradient of methanol and 0.2% ammonium hydroxide/H2O at a flow rate of 0.4 mL/min. Samples were obtained from patients with epilepsy receiving cannabis for the treatment of seizures. RESULTS: The extracted lower limit of quantification was 0.05 ng/mL for CBD, cannabidivarin, cannabinol, and 11-OH-THC; 0.10 ng/mL for cannabidiolic acid, cannabigerol, cannabichromene, cannabigerolic acid, THC, THCA, and THCV; and 0.50 ng/mL for THC-COOH and THC-COOH-glu. Mean quality control intraday accuracy and precision for all analytes ranged 96.5%-104% and 2.7%-4.9%, respectively, whereas interday accuracy and precision ranged 98%-103.3% and 0.2%-3.6%, respectively. An absolute matrix effect was observed for some analytes, however, with minimal relative matrix effect. Lack of nonspecific drug binding to extraction glass and plasticware was verified. Patient CBD levels ranged from 0.135 to 11.13 ng/mL. CONCLUSIONS: The validated method met FDA guidelines for bioanalytical assays precision and accuracy criteria. The assay reliably confirmed the use of particular medical cannabis formulations in patient samples as well as reliably measured low CBD concentrations from single-dose CBD exposure.

Preclinical Efficacy and Characterization of Candidate Vaccines for Treatment of Opioid Use Disorders Using Clinically Viable Carrier Proteins.

Vaccines may offer a new treatment strategy for opioid use disorders and opioid-related overdoses. To speed translation, this study evaluates opioid conjugate vaccines containing components suitable for pharmaceutical manufacturing and compares analytical assays for conjugate characterization. Three oxycodone-based haptens (OXY) containing either PEGylated or tetraglycine [(Gly)4] linkers were conjugated to a keyhole limpet hemocyanin (KLH) carrier protein via carbodiimide (EDAC) or maleimide chemistry. The EDAC-conjugated OXY(Gly)4-KLH was most effective in reducing oxycodone distribution to the brain in mice. Vaccine efficacy was T cell-dependent. The lead OXY hapten was conjugated to the KLH, tetanus toxoid, diphtheria cross-reactive material (CRM), as well as the E. coli-expressed CRM (EcoCRM) and nontoxic tetanus toxin heavy chain fragment C (rTTHc) carrier proteins. All vaccines induced early hapten-specific B cell expansion and showed equivalent efficacy against oxycodone in mice. However, some hapten-protein conjugates were easier to characterize for molecular weight and size. Finally, heroin vaccines formulated with either EcoCRM or KLH were equally effective in reducing heroin-induced antinociception and distribution to the brain of heroin and its metabolites in mice. This study identifies vaccine candidates and vaccine components for further development.

Opioid Dose- and Route-Dependent Efficacy of Oxycodone and Heroin Vaccines in Rats.

Heroin and oxycodone abuse occurs over a wide range of drug doses and by various routes of administration characterized by differing rates of drug absorption. The current study addressed the efficacy of a heroin vaccine [morphine hapten conjugated to keyhole limpet hemocyanin (M-KLH)] or oxycodone vaccine [oxycodone hapten conjugated to keyhole limpet hemocyanin (OXY-KLH)] for reducing drug distribution to brain after intravenous heroin or oxycodone, or subcutaneous oxycodone. Rats immunized with M-KLH or keyhole limpet hemocyanin (KLH) control received an intravenous bolus dose of 0.26 or 2.6 mg/kg heroin. Vaccination with M-KLH increased retention of heroin and its active metabolites 6-acetylmorphine (6-AM) and morphine in plasma compared with KLH controls, and reduced total opioid (heroin + 6-AM + morphine) distribution to brain but only at the lower heroin dose. Immunization also protected against respiratory depression at the lower heroin dose. Rats immunized with OXY-KLH or KLH control received 0.22 or 2.2 mg/kg oxycodone intravenously, the molar equivalent of the heroin doses. Immunization with OXY-KLH significantly reduced oxycodone distribution to brain after either oxycodone dose, although the magnitude of effect of immunization at the higher oxycodone dose was small (12%). By contrast, vaccination with OXY-KLH was more effective when oxycodone was administered subcutaneously rather than intravenously, reducing oxycodone distribution to brain by 44% after an oxycodone dose of 2.3 mg/kg. Vaccination also reduced oxycodone-induced antinociception. These data suggest that the efficacy of OXY-KLH and M-KLH opioid vaccines is highly dependent upon opioid dose and route of administration.