title: In vitro evaluation of the quality of essential drugs on the Tanzanian market.
abstract: We evaluated the in vitro availability and its stability under simulated tropical conditions of various formulations of four essential drugs marketed in Tanzania. We obtained 22 formulations (containing paracetamol, acetylsalicylic acid, chloroquine or sulphadoxine/pyrimethamine) from wholesale pharmacies in Dar es Salaam and the Medical Stores Department (Tanzania). The drug content, in vitro availability (dissolution) and its stability under simulated tropical conditions were determined using methods specified in the United States Pharmacopoeia (USP) 24 monograph of the respective drugs. All formulations passed the pharmacopoeia requirements for the drug content. However, seven formulations (three acetylsalicylic acid, two sulphadoxine/pyrimethamine and two paracetamol) failed to meet the USP 24 tolerance limits for dissolution. Another five formulations (three paracetamol and two chloroquine) failed to meet the dissolution tolerance limits after being subjected to an accelerated stability test under simulated tropical conditions (75% RH/40 degrees C) for 6 months. The study has demonstrated the presence on the Tanzanian market of essential drug formulations that met potency requirements and yet had unsatisfactory in vitro availability as they were not robust enough to withstand storage under simulated tropical conditions.
authors.affiliation: Department of Pharmaceutics, Faculty of Pharmacy, Muhimbili University College of Health Sciences, Dar es Salaam, Tanzania.
authors.forename: Peter G
authors.initials: PG
authors.lastname: Risha
authors.forename: Danstan
authors.initials: D
authors.lastname: Shewiyo
authors.forename: Amani
authors.initials: A
authors.lastname: Msami
authors.forename: Gerald
authors.initials: G
authors.lastname: Masuki
authors.forename: Geert
authors.initials: G
authors.lastname: Vergote
authors.forename: Chris
authors.initials: C
authors.lastname: Vervaet
authors.forename: Jean Paul
authors.initials: JP
authors.lastname: Remon
mesh_terms: D004355:Drug Stability; D004356:Drug Storage; D018954:Drugs, Essential / Q000737:chemistry / Q000592:standards*; D066298:In Vitro Techniques; D010602:Pharmacopoeias as Topic / Q000592:standards*; D011786:Quality Control; D012995:Solubility; D013636:Tanzania; D014329:Tropical Climate; D014481:United States
chemical_list: D018954:Drugs, Essential