Table 2.

Summary of the Number of Clinical Trials Listed on ClinicalTrials.gov Organized as the 3 Major Drug Delivery categories (Updated on August 2, 2016)

Category	All	Intervention	Phase I	Phase II	Phase III	Phase IV
I. Drug delivery technology and system
Device	9740	9459	2010	3002	2478	2946
Dosage form	16,655	16,542	5049	5824	4604	2295
Drug delivery system	7591	7520	1567	2562	2105	1901
Formulation	4338	4316	2205	1118	842	408
Liposome	1696	1693	407	921	430	115
Transdermal	614	607	134	158	182	152
Formulation comparison	1830	1820	983	363	384	180
Route	1564	1550	550	527	362	243
Sustained release	440	436	82	120	169	84
Lipid formulation	149	148	80	41	18	25
Nanoparticles	199	198	88	125	16	3
Aerosol and inhalation	188	187	48	53	72	25
Prodrugs	179	178	89	73	20	14
Colloid	129	126	12	43	31	46
Drug delivery technology and system	Subtotal	44,780
II. Biological molecule platform/technologies
Antibody	9596	9521	3298	4359	2149	728
Biologics and vaccines	4931	4900	1943	1836	1127	552
Peptide	2249	2222	843	950	368	329
Recombinant proteins	760	755	332	310	165	43
Antibody conjugates	609	605	147	203	220	75
Antisense	132	131	77	70	13	0
Oligonucleotide	114	112	65	58	10	2
siRNA	36	36	25	18	1	0
Aptamer	29	29	12	13	8	1
Biological molecule platform	Subtotal	18,456
III. PK-PD interactions
Metabolic inhibitor	2919	2890	610	710	879	829
Drug transport modulator	6378	6321	1114	1682	1905	1961
Drug interactions	2246	2220	1368	478	197	287
Metabolic induction	641	629	139	229	140	169
Active metabolite	839	837	498	230	69	81
PK/PD interactions	Subtotal	12,897