Quantitative analysis of drug losses administered via nasogastric tube – In vitro study

PurposeDrug administration through nasogastric tube (NGT) is a standard practice but the real amount of the delivered drug is unknown. Therefore, we designed a study to determine the losses of various dosage forms administered by different methods through NGT.MethodsIn vitro model was used. Five different administration methods (A–E) and six dosage forms (simple compressed tablets – T/S; film coated tablets – T/FC; enteric coated tablets – T/EC; capsules with powder filling – C/P; capsules containing extended release pellets – C/ER; capsules containing gastro-resistant pellets – C/GR) were investigated. Measurement was repeated six times for each drug-method combination. The overall losses were determined by gravimetry. In method A partial losses associated with each step of drug administration were also determined.ResultsSignificant drug losses were measured (4–38%). Only methods A (crushing–beaker–syringe–water–NGT) and B (crushing–water–syringe–NGT) were suitable for administration of all tested dosage forms. Method B proved the most effective for all kinds of tablets and C/GR (p < 0.05) and tended to be more effective also for C/ER (p = 0.052) compared to method A. C/P showed minimal losses for both tested methods (B and E). Flushing of the drug through NGT causes major losses during drug administration compared to crushing and transfer (p < 0.05). All methods for intact pellets (C–E) were found inappropriate for clinical practice due to NGT clogging.ConclusionsChoosing a suitable administration method can significantly affect the amount of drugs delivered through NGT.

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