Sherryl Robertson

Clozapine repackaged into dose administration aids: a common practice in Australian hospitals

Objectives  Clozapine is an atypical antipsychotic used in the treatment of schizophrenia. Due to the patient profile there is a high rate of repackaging of clozapine into dose administration aids (DAAs). Because of reports from hospital pharmacists about discoloration of returned clozapine tablets that have been repackaged into DAAs, the aim of this study was to evaluate the chemical, physical and photostability of these tablets repackaged into a DAA.

Dose administration aids: Pharmacists’ role in improving patient care

Dose administration aid (DAA) usage has become increasingly prevalent among populations worldwide and as such has become an important part of pharmacy practice. The evidence for the use of these aids has been favourable in Australia resulting in 2006 in a community based DAA program being considered by the Australian Government Department of Health and Ageing PPSAC (Professional Programs and Services Advisory Committee) and the first phase of this program implemented in October 2007. The program was established under the Better Community Health Initiative of the 4th Community Pharmacy Agreement between the Pharmacy Guild of Australia and the Commonwealth Government. The aim of this program is to reduce medication-related hospitalisations and adverse events through improved medication management and adherence by people in the community. The most common patient groups that access this service include the elderly, who are often on several different medications, and patients with cognitive disabilities who may have trouble understanding or remembering their dosage regimes. Repackaging of a medication, involving removal from its primary packaging invalidates the stability guarantee of the manufacturer. It is in fact the role of the healthcare team to ensure optimal patient care by making an informed judgment as to the effect on the quality and safety of this repackaging process. Drug manufacturers, on the whole, tend to discourage repackaging of medications and there is little quality data available to support this process. Indeed, only a small number of medications have been investigated for their stability following repackaging into DAAs, namely atenolol, paracetamol, frusemide, prochlorperazine, sodium valproate, aspirin (dosette boxes) and clozapine. This paper will review the repackaging of medications into DAAs and the role that the pharmacist plays in this process to improve patient care, in addition to presenting the Australian research that has contributed substantially to the body of information available internationally on the quality implications, relating to the stability of medicines repackaged into DAAs.

Stability of Dispersible Aspirin Tablets Repacked into Dosette Boxes

Although guidelines indicate that dispersible aspirin tablets should not be repacked into dose administration aids, it is common practice especially among older people.

Butyl methoxy dibenzoylmethane.

A comprehensive profile on Butyl methoxy dibenzoylmethane, one of the most commonly used ultraviolet (UV) filters in topical sunscreen products, is prepared. This UV filter, often referred to as Avobenzone, has its main absorbance in the UVA I region of the spectrum and is susceptible to photodegradation. The profile contains the following sections: general information, use and mechanism of action, method of preparation, physical characteristics, methods of analysis, stability, and toxicity. The physical characteristics section includes the melting range, differential scanning calorimetry, partition coefficient, ionization constant, solubility, and UV, infrared, nuclear magnetic resonance ((1)H NMR and (13)C NMR) and mass spectrometry and X-ray powder diffractometry. The method of analysis section in addition to compendial identification and purity and assay methods includes thin-layer gas and high-performance liquid chromatography. The photostability and photostabilization of Butyl methoxy dibenzoylmethane, in addition to its toxicity, are also documented.

Repackaged sodium valproate tablets – Meeting quality and adherence to ensure seizure control

PURPOSE Sodium valproate, which is commonly repacked to assist with adherence to ensure seizure control, is hygroscopic and therefore sensitive to moisture. The aim of this study was thus to determine the stability implications of removing the enteric coated tablets from their original packaging and repackaging into a Dose Administration Aid (DAA) with storage under various environmental conditions. METHODS Physicochemical stability of enteric coated sodium valproate tablets repackaged into a DAA and stored at controlled room temperature, accelerated and refrigerated conditions was evaluated for 28 days. A validated high performance liquid chromatography method was used for the quantitation of the drug content. RESULTS Although the chemical stability (sodium valproate between 95 and 105% of labelled content) was maintained for 28 days for all storage conditions, for those tablets stored under accelerated conditions the integrity of the enteric coat was compromised after only 8 days. CONCLUSIONS Repackaging of enteric coated sodium valproate should be undertaken with caution and be informed by storage climate. This is particularly relevant for those patients living in hot, humid environments where they should be advised to store their DAA in a refrigerator.

HPLC Method for the Simultaneous Determination of the UV-Filters Butyl Methoxy Dibenzoylmethane and Octocrylene in the Presence of Their Photodegradants

Butyl methoxy dibenzoylmethane (BMDM) and octocrylene (OC), common UV-filters in sunscreen products are often used in combination. Together they provide broad spectrum photoprotection from exposure to both UVA- and UVB-light. These UV-filters may, however, undergo photodegradation and generate photodegradants, resulting in a potential loss of photoprotection. It is thus a concern that the photostability testing as described by the ICH Guideline Q1B is not a requirement for sunscreen products in Australia, Europe or the USA. UV-filter photodegradants have in addition been shown to be toxic, highlighting the importance of their separation from the parent UV-filters. An HPLC method was developed and validated to quantitatively determine a combination of these UV-filters in the presence of their photodegradants. Reverse-phase chromatography was employed, using a C18 column and an isocratic mobile phase consisting of methanol/water/acetic acid (89/10/1 v/v). Validation according to the ICH guidelines for linearity, accuracy, precision, sensitivity, specificity and robustness was confirmed. The developed and validated method was then successfully applied to the determination of BMDM and OC in an aqueous cream base, typically used in sunscreens, after photostability testing, according to the ICH Guideline Q1B. In addition, the diketo-enol ratio of BMDM in methanol-d4 was determined by NMR and the two major photodegradants were identified by FTMS and LC–MS.

The efficacy and pharmacokinetics of terbinafine against the frog-killing fungus (Batrachochytrium dendrobatidis)

Captive and wild amphibians are under threat of extinction from the deadly fungal pathogen Batrachochytrium dendrobatidis (Bd). The antifungal drug terbinafine (TBF) is used by pet owners to treat Bd-infected frogs; however, it is not widely used in academic or zoological institutions due to limited veterinary clinical trials. To assess TBFs efficacy, we undertook treatment trials and pharmacokinetic studies to investigate drug absorption and persistence in frog skin; and then we correlated these data to the minimal lethal concentrations (MLC) against Bd. Despite an initial reduction in zoospore load, the recommended treatment (five daily 5 min 0.01% TBF baths) was unable to cure experimentally infected alpine tree frogs and naturally infected common eastern froglets. In vitro and in vivo pharmacokinetics showed that absorbed TBF accumulates in frog skin with increased exposure, indicating its suitability for treating cutaneous pathogens via direct application. The MLC of TBF for zoosporangia was 100 μg/ml for 2 h, while the minimal inhibitory concentration was 2 μg/ml, suggesting that the drug concentration absorbed during 5 min treatments is not sufficient to cure high Bd burdens. With longer treatments of five daily 30 min baths, Bd clearance improved from 12.5% to 50%. A higher dose of 0.02% TBF resulted in 78% of animals cured; however, clearance was not achieved in all individuals due to low TBF skin persistence, as the half-life was less than 2 h. Therefore, the current TBF regime is not recommended as a universal treatment against Bd until protocols are optimized, such as with increased exposure frequency.

Addressing varenicline adherence through repackaging in a dose administration aid

Background Ensuring adherence to prescribed smoking cessation medications, such as Champix® (varenicline), is essential during a quit attempt as non-adherence can significantly reduce the likelihood of achieving prolonged smoking abstinence. The use of dose administration aids may improve adherence, though medication stability on repackaging is not guaranteed, due to a lack of available data from manufacturers supporting this practice. Objective To determine the suitability for repackaging varenicline tartrate tablets into a dose administration aid, by assessing its physical and chemical stability after being repackaged and stored at ambient conditions for 6 weeks. Methods Varenicline tartrate (1.0 mg) tablets were repackaged into commercially available Webster-pak® blister compartments and stored for 42 days at ambient conditions characteristic of a Zone IVB climate (30 ± 2°C and 75 ± 5% relative humidity) according to the World Health Organization (WHO) guidelines on pharmaceutical stability testing. Physical and chemical tests were performed on the repackaged and control tablets, including an assessment of: tablet thickness, hardness, weight uniformity, friability, dissolution, disintegration, and content uniformity after exposure to ambient conditions and light according to International Council on Harmonisation of Technical Requirements of Pharmaceuticals for Human Use guideline Q1B. Results Weight, friability, and thickness of the tablets complied with compendial standards. A validated high performance liquid chromatography method was used to confirm that after exposure to light, and repackaging at 30°C/75% relative humidity, the tablets remained within the required 95%–105% of the stated drug content. However, tablet hardness and disintegration decreased over time, with tablets becoming softer and undergoing more rapid disintegration in water. Conclusion Repackaging 1.0 mg varenicline tartrate tablets into a dose administration aid can be undertaken to improve adherence rates and therefore smoking abstinence rates. This can be performed without compromising either the physical or chemical stability of the tablets.

Stability of repackaged dabigatran etexilate capsules in dose administration aids

Objective This study is aimed at assessing the stability of dabigatran etexilate (Pradaxa) capsules repackaged into a dose administration aid (DAA), in order to inform appropriate storage conditions that ensure quality. Although Pradaxa is used chronically by patients, and DAAs are known to improve adherence, removal of the capsules from their original packaging is not recommended by the manufacturer due to sensitivity to moisture. Methods Pradaxa capsules containing dabigatran etexilate 110 mg were repackaged into a commercially available DAA and stored under ambient conditions (30°C±2°C and 75%±5% relative humidity) for periods of 14 and 28 days and in a domestic refrigerator for 28 days. The capsules were evaluated for changes in their physical appearance and weight. Content uniformity and the drug concentration during dissolution were determined using a validated high-performance liquid chromatography method. Results Storage at ambient conditions for 14 and 28 days resulted in a percentage drug remaining of 92.5% and 71.6%, respectively, indicating a lack of compendial compliance (88.4%–111.8%) for the 28-day ambient sample. There was a statistically significant difference (p=0.015) in the dissolution behaviour of the 14-day samples, when compared with control capsules. In contrast, repackaged capsules stored in the refrigerator for 28 days had a drug content of 98.2% and dissolution was not significantly affected (p=0.132). Conclusion This study has clearly demonstrated that if repackaging of Pradaxa capsules is required, storage under refrigerated conditions ensures quality for 28 days.