Propylene glycol and Kolliphor as solvents for systemic delivery of cannabinoids via intraperitoneal and subcutaneous routes in preclinical studies: a comparative technical note

Table 1 Studies performed

Study	Route	Mechanism of delivery	Solvent/vehicle	Groups (dosage 5 mg/kg)	Frequency of delivery	Euthanasia endpoint	Sample size (per group)
Study 1: ALZET osmotic pump subcutaneous delivery (original study identification of issue)	SC	Osmotic pump	Propylene glycol	THC, CBD, CBD + THC, vehicle	Continuous/daily	Early euthanasia	N = 4^a
Study 2: ALZET osmotic pump subcutaneous delivery with provisions to reduce risk of contamination	SC	Osmotic pump	Propylene glycol	THC, CBD, CBD + THC, vehicle	Continuous/daily	Early euthanasia	N = 2^a
Study 3: Isolated THC, CBD direct subcutaneous injection	SC	25-GA needle, 0.1 ml	THC dissolved in ethanol CBD dissolved in saline	THC (20 mg/day) CBD (20 mg/day)	Daily	7 days	N = 2^a
Study 4: Direct injection subcutaneous delivery, histopathology	SC	25-GA needle, 0.1 ml	Propylene glycol	THC, CBD, CBD + THC, vehicle, saline	Daily	10 days	N = 2^a
Study 5: Intraperitoneal delivery	IP	22-GA needle, 0.1 ml	Propylene glycol	THC, CBD, CBD + THC, vehicle	Weekly	8 weeks	N = 12
Study 6: ALZET osmotic pump subcutaneous delivery with change in solvent	SC	Osmotic pump	1:1:18 parts ethanol:Kolliphor:saline	THC, CBD, CBD + THC, vehicle	Continuous/daily	8 weeks	N = 4

ISSN: 2522-5782