Development and evaluation of a composite dosage form containing desmopressin acetate for buccal administration.

Desmopressin acetate (DDAVP) is an oligopeptide indicated for the treatment of primary nocturnal enuresis, for example. The poor oral bioavailability of DDAVP accelerated a shift to alternative routes of administration like nasal and oromucosal, whereby nasal administration results in high fluctuations increasing the risk of undesirable side effects. Aim of the study was to use a new composite dosage form (solid matrix attached to a bilayer mucoadhesive film) to make DDAVP available via oromucosal route, reducing the risk of undesirable side effects through precise dosing. DDAVP was incorporated into a solid matrix in the form of a minitablet, and both direct tableting (AV > 30) and granulation followed by tableting (AV = 17.86) were compared. Minitablets with content uniformity could only be obtained by granulation and loss supplementation (AV = 11.27) with immediate drug release (>80% after 7-8 min) and rapid disintegration (<49 s). Permeation studies were performed with a clinically relevant dose (200 µg) in a time interval of up to one hour, resulting in apparent permeation coefficients of 4.90 × 10-6 cm/s (minitablet) and 2.04 × 10-6 cm/s (composite). Comparable fluctuations showed no inferiority of composite and minitablet regarding dosing accuracy. Thus, a step towards controlled and dose-accurate transmucosal delivery of systemically active DDAVP could be achieved.

Application and validation of a coaxial liquid core waveguide fluorescence detector for the permeation analysis of desmopressin acetate.

In recent years, the development of peptide drugs and alternative routes of administration, such as buccal and sublingual routes, has become increasingly important to the pharmaceutical industry. Performing experiments under physiologically relevant conditions is still a challenge that has not yet been fully mastered. The requirements associated with these alternative administration routes (e.g. permeation testing for buccal administration) push common analytical detection systems in pharmaceutical technology to their limits, especially with regard to large molecules and peptides. An HPLC-coupled coaxial liquid-core waveguide fluorescence detector has been developed and evaluated within this study to overcome these limits by achieving a more sensitive detection. Desmopressin acetate was selected as the peptide drug with the aim of investigating its permeation behavior during the clinically relevant application period of one hour. Based on the detector system, a complete validation according to the requirements of international guidelines was successfully performed. The results of the validation showed an increase in sensitivity resulting in a limit of detection of 4.7 ng/mL and a lower limit of quantification of 9.5 ng/mL. Moreover, it has been demonstrated that the permeation of desmopressin can be observed in clinically relevant dosages and time periods of up to one hour using this innovative detector system.

Manufacturing and characterisation of a novel composite dosage form for buccal drug administration.

The potential of alternative routes of application compared to the traditional oral route is constantly growing. Especially in transmucosal applications for the oral cavity, easy accessibility is an attractive feature with many new opportunities. The combination of a minitablet and a buccal mucoadhesive carrier film has been shown to enable safe and accurate drug administration compared to semi-solid formulations currently available on the market. In order to investigate these so-called composite dosage forms in more detail, two different manufacturing methods were compared within this study to investigate the resulting properties. The formulation development of the minitablets containing lidocaine, complying with the compendial requirements, resulted in immediate release using both manufacturing methods (more than 80% lidocaine release after 3-4 min using direct incorporation, 7-8 min by the gluing method). Differences in morphology and drug migration behaviour could be observed. The directly incorporated minitablets revealed a twofold higher drug migration (1.5 mm) into the mucoadhesive shielding film within two weeks compared to the glued minitablets (0.8 mm). These findings enable a further optimization of the formulation depending on the duration of the application and the feasibility for the addressed patient population.

Development and evaluation of mucoadhesive buccal dosage forms of lidocaine hydrochloride by ex-vivo permeation studies.

Intraoral lidocaine formulations are applied in children and adults for pain relief. The potential risks associated with orally administered lidocaine due to accidental ingestions were highlighted in a warning letter by the US Food and Drug Administration (FDA). This increases the urgency for a need of a child-appropriate dosage forms. For risk minimization, a novel buccal composite dosage form was developed consisting of a lidocaine containing minitablet centered on top of a bilayered mucoadhesive buccal film, so called composite. The preparation included direct tableting of minitablets as well as film-casting technique. Within a comparability study, the permeation of this composite was classified against marketed lidocaine gel, a single-layer film, and a minitablet. These ex-vivo permeation studies under physiologically related conditions in combination with LC-MS/MS quantification enabled the evaluation of permeation in clinically relevant short-term application. The composite showed comparable permeation to marketed gel (104.26 ± 30.15 µg/cm2 vs 128.17 ± 12.49 µg/cm2 cumulative amount of drug) and a higher permeation compared to film (25.84 ± 6.01 µg/cm2). Therefore, a controlled drug application can be assumed by the composite, whereby the risk of inadvertent swallowing as well as uncontrolled absorbed amount of drug substance may be substantially minimized.

Oromucosal films: from patient centricity to production by printing techniques.

Introduction: Oromucosal films, comprising mucoadhesive buccal films (MBFs) and orodispersible films (ODFs), are considered patient-centric dosage forms. Target groups are patients with special needs. Various active pharmaceutical ingredients have been shown to be suitable for oromucosal film production. A shift is seen in the production techniques, from conventional solvent casting to printing techniques. Areas covered: In this review, the patient acceptability of oromucosal films is discussed. An overview is given of the small molecule drugs, biopharmaceuticals and herbal extracts that have been incorporated so far. Finally, the current state of 2D and 3D printing techniques for production purposes is discussed. Expert opinion: The patient-centric features are important for the further development and acceptance of this oral solid dosage form. Oromucosal films perfectly fit in the current attention for personalized medicine. Both MBFs and ODFs are intended for either a local or a systemic effect. For buccal absorption, sufficient mucoadhesion is one of the most important criteria an oromucosal film must comply with. For the preparation, the solvent casting technique is still predominately used. Some limitations of this production method can be tackled by printing techniques. However, these novel techniques introduce new requirements, yet to be set, for oromucosal film preparation.